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1 @c -*-texinfo-*-
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2 @c This is part of the XEmacs Lisp Reference Manual.
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3 @c Copyright (C) 1995, 1996 Ben Wing.
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4 @c Copyright (C) 2002, 2004 Free Software Foundation, Inc.
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5 @c See the file lispref.texi for copying conditions.
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6 @setfilename ../../info/specifiers.info
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7 @node Specifiers, Faces and Window-System Objects, Extents, top
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8 @chapter Specifiers
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9 @cindex specifier
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10
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11 A specifier is an object used to keep track of a property whose value
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12 should vary according to @emph{display context}, a window, a frame, or
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13 device. The value of many built-in properties, such as the font,
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14 foreground, background, and such properties of a face and variables
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15 such as @code{modeline-shadow-thickness} and
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16 @code{top-toolbar-height}, is actually a specifier object. The
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17 specifier object, in turn, is ``instanced'' in a particular situation
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18 to yield the real value of the property in the current context.
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19
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20 @defun specifierp object
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21 This function returns non-@code{nil} if @var{object} is a specifier.
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22 @end defun
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23
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24 @menu
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25 * Introduction to Specifiers:: Specifiers provide a clean way for
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26 display and other properties to vary
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27 (under user control) in a wide variety
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28 of contexts.
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29 * Simple Specifier Usage:: Getting started with specifiers.
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30 * Specifiers In-Depth:: Gory details about specifier innards.
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31 * Specifier Instancing:: Instancing means obtaining the ``value'' of
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32 a specifier in a particular context.
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33 * Specifier Types:: Specifiers come in different flavors.
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34 * Adding Specifications:: Specifications control a specifier's ``value''
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35 by giving conditions under which a
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36 particular value is valid.
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37 * Retrieving Specifications:: Querying a specifier's specifications.
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38 * Specifier Tag Functions:: Working with specifier tags.
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39 * Specifier Instancing Functions::
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40 Functions to instance a specifier.
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41 * Specifier Examples:: Making all this stuff clearer.
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42 * Creating Specifiers:: Creating specifiers for your own use.
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43 * Specifier Validation Functions::
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44 Validating the components of a specifier.
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45 * Other Specification Functions::
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46 Other ways of working with specifications.
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47 @end menu
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48
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49 @node Introduction to Specifiers
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50 @section Introduction to Specifiers
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51
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52 Perhaps the most useful way to explain specifiers is via an analogy.
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53 Emacs Lisp programmers are used to @emph{buffer-local variables}
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54 @ref{Buffer-Local Variables}. For example, the variable
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55 @code{modeline-format}, which controls the format of the modeline, can
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56 have different values depending on the particular buffer being edited.
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57 The variable has a default value which most modes will use, but a
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58 specialized package such as Calendar might change the variable so as to
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59 tailor the modeline to its own purposes. Other variables are perhaps
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60 best thought of as ``mode local,'' such as font-lock keywords, but they
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61 are implemented as buffer locals.
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62
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63 Other properties (such as those that can be changed by the
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64 @code{modify-frame-parameters} function, for example the color of the
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65 text cursor) can have frame-local values, although it might also make
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66 sense for them to have buffer-local values. In other cases, you might
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67 want the property to vary depending on the particular window within the
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68 frame that applies (e.g. the top or bottom window in a split frame), the
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69 device type that that frame appears on (X or tty), etc. Perhaps you can
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70 envision some more complicated scenario where you want a particular
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71 value in a specified buffer, another value in all other buffers
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72 displayed on a particular frame, another value in all other buffers
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73 displayed in all other frames on any mono (two-color, e.g. black and
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74 white only) displays, and a default value in all other circumstances.
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75
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76 Specifiers generalize both buffer- and frame-local properties.
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77 Specifiers vary according to the @emph{display} context. Font-lock
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78 keywords in a buffer will be the same no matter which window the
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79 buffer is displayed in, but windows on TTY devices will simply not be
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80 capable of the flexibility that windows on modern GUI devices are.
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81 Specifiers provide a way for the programmer to @emph{declare} that an
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82 emphasized text should be italic on GUI devices and inverse video on
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83 TTYs. They also provide a way for the programmer to declare
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84 fallbacks, so that a color specified as ``chartreuse'' where possible
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85 can fall back to ``yellow'' on devices where only ANSI (4-bit) color
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86 is available. The complex calculations and device querying are
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87 transparent to both user and programmer. You ask for what you want;
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88 it's up to XEmacs to provide it, or a reasonable approximation.
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89
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90 We call such a declaration a @dfn{specification}. A @dfn{specification}
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91 applies in a particular @dfn{locale}, which is a window, buffer, frame,
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92 device, or the global locale. The value part of the specification is
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93 called an @dfn{instantiator}. The process of determining the value in a
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94 particular context, or @dfn{domain}, is called @dfn{instantiation} or
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95 @dfn{instancing}. A domain is a window, frame, or device.
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96
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97 The difference between @dfn{locale} and @dfn{domain} is somewhat subtle.
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98 You may think of a locale as a class of domains, which may span
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99 different devices. Since the specification is abstract (a Lisp form),
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100 you can state it without reference to a device. On the other hand, when
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101 you instantiate a specification, you must know the type of the device.
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102 It is useless to specify that ``blue means emphasis'' on a monochrome
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103 device. Thus instantiation requires specification of the device on
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104 which it will be rendered.
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105
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106 Thus a @dfn{specifier} allows a great deal of flexibility in
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107 controlling exactly what value a property has in which circumstances.
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108 Specifiers are most commonly used for display properties, such as an image or
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109 the foreground color of a face. As a simple example, you can specify
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110 that the foreground of the default face be
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111
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112 @itemize @bullet
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113 @item
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114 blue for a particular buffer
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115 @item
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116 green for all other buffers
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117 @end itemize
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118
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119 As a more complicated example, you could specify that the foreground of
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120 the default face be
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121
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122 @itemize @bullet
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123 @item
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124 forest green for all buffers displayed in a particular Emacs window, or
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125 green if the X server doesn't recognize the color @samp{forest green}
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126 @item
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127 blue for all buffers displayed in a particular frame
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128 @item
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129 red for all other buffers displayed on a color device
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130 @item
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131 white for all other buffers
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132 @end itemize
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133
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134 @node Simple Specifier Usage
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135 @section Simple Specifier Usage
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136 @cindex specifier examples
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137 @cindex examples, specifier
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138 @cindex adding a button to a toolbar
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139 @cindex toolbar button, adding
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140
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141 A useful specifier application is adding a button to a toolbar. XEmacs
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142 provides several toolbars, one along each edge of the frame. Normally
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143 only one is used at a time, the default. The default toolbar is
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144 actually a specifier object which is the value of
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145 @code{default-toolbar}. @xref{Toolbar Intro}.
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146
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147 The specification of a toolbar is simple: it is a list of buttons.
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148 Each button is a vector with four elements: an icon, a command, the
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149 enabled flag, and a help string. Let's retrieve the instance of the
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150 toolbar you see in the selected frame.
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151
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152 @example
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153 (specifier-instance default-toolbar)
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154 @end example
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155
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156 The value returned is, as promised, a list of vectors. Now let's build
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157 up a button, and add it to the toolbar. Our button will invoke the last
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158 defined keyboard macro. This is an alternative to
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159 @code{name-last-kbd-macro} for creating a persistent macro, rather than
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160 an alias for @kbd{C-x e}.
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161
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162 A toolbar button icon can be quite sophisticated, with different images
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163 for button up, button down, and disabled states, and a similar set with
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164 captions. We'll use a very simple icon, but we have to jump through a
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165 few non-obvious hoops designed to support the sophisticated applications.
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166 The rest of the button descriptor is straightforward.
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167
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168 @example
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169 (setq toolbar-my-kbd-macro-button
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170 `[ (list (make-glyph "MyKbdMac"))
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171 (lambda () (interactive) (execute-kbd-macro ,last-kbd-macro))
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172 t
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173 "Execute a previously defined keyboard macro." ])
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174
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175 (set-specifier default-toolbar
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176 (cons toolbar-my-kbd-macro-button
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177 (specifier-specs default-toolbar 'global))
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178 'global)
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179 @end example
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180
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181 To remove the button, just substitute the function @code{delete} for the
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182 @code{cons} above.
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183
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184 What is the difference between @code{specifier-instance}, which we used
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185 in the example of retrieving the toolbar descriptor, and
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186 @code{specifier-specs}, which was used in the toolbar manipulating code?
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187 @code{specifier-specs} retrieves a copy of the instantiator, which is
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188 abstract and does not depend on context. @code{specifier-instance}, on
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189 the other hand, actually instantiates the specification, and returns the
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190 result for the given context. Another way to express this is:
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191 @code{specifier-specs} takes a @emph{locale} as an argument, while
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192 @code{specifier-instance} takes a @emph{domain}. The reason for
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193 providing @code{specifier-instance} is that sometimes you wish to see
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194 the object that XEmacs will actually use. @code{specifier-specs}, on
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195 the other hand, shows you what the programmer (or user) requested. When
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196 a program manipulates specifications, clearly it's the latter that is
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197 desirable.
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198
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199 In the case of the toolbar descriptor, it turns out that these are the
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200 same: the instancing process is trivial. However, many specifications
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201 have non-trivial instancing. Compare the results of the following forms
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202 on my system. (The @samp{(cdr (first ...))} form is due to my use of
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203 Mule. On non-Mule XEmacsen, just use @code{specifier-specs}.)
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204
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205 @example
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206 (cdr (first (specifier-specs (face-font 'default) 'global)))
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207 => "-*--14-*jisx0208*-0"
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208
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209 (specifier-instance (face-font 'default))
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210 #<font-instance "-*--14-*jisx0208*-0" on #<x-device on ":0.0" 0x970> 0xe0028b 0x176b>
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211 @end example
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212
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213 In this case, @code{specifier-instance} returns an opaque object;
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214 programs can't work on it, they can only pass it around. Worse, in some
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215 environments the instantiation will fail, resulting in a different value
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216 (when another instantiation succeeds), or worse yet, an error, if all
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217 attempts to instance the specifier fail. @code{specifier-instance} is
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218 context-dependent, even for the exact same specification.
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219 @code{specifier-specs} is deterministic, and only depends on the
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220 specifications.
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221
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222 Note that in the toolbar-changing code we operate in the global locale.
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223 This means that narrower locales, if they have specifications, will
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224 shadow our changes. (Specifier instancing does not merge
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225 specifications. It selects the "highest-priority successful
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226 specification" and instances that.)
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227
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228 In fact, in our example, it seems pretty likely that different buffers
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229 @emph{should} have different buttons. (The icon can be the same, but
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230 the keyboard macro you create in a Dired buffer is highly unlikely to be
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231 useful in a LaTeX buffer!) Here's one way to implement this:
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232
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233 @example
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234 (setq toolbar-my-kbd-macro-button
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235 `[ (list (make-glyph "MyKbdMac"))
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236 (lambda () (interactive) (execute-kbd-macro ,last-kbd-macro))
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237 t
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238 "Execute a previously defined keyboard macro." ])
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239
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240 (set-specifier default-toolbar
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241 (cons toolbar-my-kbd-macro-button
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242 (cond ((specifier-specs default-toolbar
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243 (current-buffer)))
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244 ((specifier-specs default-toolbar
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245 'global)))
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246 (current-buffer))
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247 @end example
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248
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249 Finally, a cautionary note: the use of @code{specifier-specs} in the
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250 code above is for expository purposes. Don't use it in production code.
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251 In fact, the @code{set-specifier} form above is likely to fail
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252 occasionally, because you can add many specifications for the same
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253 locale.
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254
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255 In these cases, @code{specifier-specs} will return a list. A further
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256 refinement is that a specification may be associated with a set of
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257 @dfn{specifier tags}. If the list of specifier tags is non-nil, then
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258 @code{specifier-specs} will return a cons of the tag set and the
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259 instantiator. Evidently @code{specifier-specs} is a bit unreliable.
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260 (For toolbars, the code above should work 99% of the time, because
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261 toolbars are rarely changed. Since instantiation is trivial, multiple
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262 specs are not useful---the first one always succeeds.)
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263
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264 In fact, @code{specifier-specs} is intended to be used to display specs
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265 to humans with a minimum of clutter. The robust way to access
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266 specifications is via @code{specifier-spec-list}. @xref{Adding
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267 Specifications}, for the definition of @dfn{spec-list}. @xref{Retrieving
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268 Specifications}, for documentation of @code{specifier-specs} and
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269 @code{specifier-spec-list}. To get the desired effect, replace the form
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270 @code{(specifier-spec default-toolbar 'global)} with
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271
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272 @example
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273 (cdr (second (first (specifier-spec-list default-toolbar 'global))))
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274 @end example
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275
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276 (It should be obvious why the example uses the lazy unreliable method!)
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277
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278 @node Specifiers In-Depth
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279 @section In-Depth Overview of a Specifier
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280 @cindex specification (in a specifier)
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281 @cindex domain (in a specifier)
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282 @cindex locale (in a specifier)
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283 @cindex instantiator (in a specifier)
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284 @cindex instancing (in a specifier)
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285 @cindex instance (in a specifier)
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286 @cindex inst-list (in a specifier)
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287 @cindex inst-pair (in a specifier)
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288 @cindex tag (in a specifier)
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289 @cindex tag set (in a specifier)
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290 @cindex specifier, specification
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291 @cindex specifier, domain
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292 @cindex specifier, locale
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293 @cindex specifier, instantiator
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294 @cindex specifier, instancing
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295 @cindex specifier, instance
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296 @cindex specifier, inst-list
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297 @cindex specifier, inst-pair
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298 @cindex specifier, tag
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299 @cindex specifier, tag set
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300
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301 Having variables vary according the editing context is very useful, and
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302 the buffer is the natural ``atomic'' unit of editing context. In a GUI
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303 environment, it can be similarly useful to have variables whose values
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304 vary according to display context. The atomic unit of display context
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305 is the Emacs window. Buffers are cleanly grouped by modes, but windows
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306 are not so easily pigeonholed. On the one hand, a window displays a
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307 buffer, and thus one possible hierarchy is window, buffer, mode. On the
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308 other, a window is a component of a frame. This generates the window,
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309 frame, device hierarchy. Finally, there are objects such as toolbars
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310 whose properties are described by specifiers. These do not fit
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311 naturally into either hierarchy. This problem is as yet not cleanly
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312 solved.
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313
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314 Another potential source of conceptual confusion is the instantiation
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315 process. Instantiating a buffer-local variable is simple: at any given
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316 point in time there is a current buffer, and its local values are used
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317 and set whenever the variable is accessed, unless the programmer goes to
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318 some special effort (uses @code{default-value} and @code{set-default}.
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319 However, a specifier object encapsulates a set of @dfn{specifications},
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320 each of which says what its value should be if a particular condition
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321 applies. Several such conditions might apply simultaneously in a given
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322 window.
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323
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324 For example, one specification might be ``The value should be
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325 darkseagreen2 on X devices'' another might be ``The value should be blue
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326 in the *Help* buffer''. So what do we do for "the *Help* buffer on an X
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327 device"? The answer is simple: give each type of locale a priority and
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328 check them in priority order, returning the first instantiator that
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329 successfully instantiates a value.
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330
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331 Given a specifier, a logical question is ``What is its value in a
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332 particular situation?'' This involves looking through the specifications
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333 to see which ones apply to this particular situation, and perhaps
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334 preferring one over another if more than one applies. In specifier
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335 terminology, a ``particular situation'' is called a @dfn{domain}, and
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336 determining its value in a particular domain is called @dfn{instancing}.
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337 Most of the time, a domain is identified by a particular window. For
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338 example, if the redisplay engine is drawing text in the default face in
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339 a particular window, it retrieves the specifier for the foreground color
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340 of the default face and @dfn{instances} it in the domain given by that
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341 window; in other words, it asks the specifier, ``What is your value in
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342 this window?''.
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343
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344 Note that the redisplay example is in a sense canonical. That is,
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345 specifiers are designed to present a uniform and @emph{efficient} API
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346 to redisplay. It is the efficiency constraint that motivates the
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347 introduction of specifier tags, and many restrictions on access (for
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348 example, a buffer is not a domain, and you cannot instantiate a
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349 specifier over a buffer).
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350
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428
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351 More specifically, a specifier contains a set of @dfn{specifications},
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352 each of which associates a @dfn{locale} (a window object, a buffer
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353 object, a frame object, a device object, or the symbol @code{global})
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|
354 with an @dfn{inst-list}, which is a list of one or more
|
|
|
355 @dfn{inst-pairs}. (For each possible locale, there can be at most one
|
|
|
356 specification containing that locale.) Each inst-pair is a cons of a
|
|
|
357 @dfn{tag set} (an unordered list of zero or more symbols, or @dfn{tags})
|
|
|
358 and an @dfn{instantiator} (the allowed form of this varies depending on
|
|
|
359 the type of specifier). In a given specification, there may be more
|
|
|
360 than one inst-pair with the same tag set; this is unlike for locales.
|
|
|
361
|
|
|
362 The tag set is used to restrict the sorts of devices over which the
|
|
|
363 instantiator is valid and to uniquely identify instantiators added by a
|
|
|
364 particular application, so that different applications can work on the
|
|
|
365 same specifier and not interfere with each other. Each tag can have a
|
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366 @dfn{predicate} associated with it, which is a function of one argument
|
|
|
367 (a device) that specifies whether the tag matches that particular
|
|
|
368 device. (If a tag does not have a predicate, it matches all devices.)
|
|
|
369 All tags in a tag set must match a device for the associated inst-pair
|
|
|
370 to be instantiable over that device. (A null tag set is perfectly
|
|
1135
|
371 valid, and trivially matches all devices.)
|
|
428
|
372
|
|
1135
|
373 @c #### don't we have more device types now, gtk, ms-windows, mac-carbon?
|
|
428
|
374 The valid device types (normally @code{x}, @code{tty}, and
|
|
|
375 @code{stream}) and device classes (normally @code{color},
|
|
|
376 @code{grayscale}, and @code{mono}) can always be used as tags, and match
|
|
|
377 devices of the associated type or class (@pxref{Consoles and Devices}).
|
|
|
378 User-defined tags may be defined, with an optional predicate specified.
|
|
|
379 An application can create its own tag, use it to mark all its
|
|
|
380 instantiators, and be fairly confident that it will not interfere with
|
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440
|
381 other applications that modify the same specifier---Functions that add
|
|
428
|
382 a specification to a specifier usually only overwrite existing
|
|
|
383 inst-pairs with the same tag set as was given, and a particular tag or
|
|
|
384 tag set can be specified when removing instantiators.
|
|
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385
|
|
|
386 When a specifier is instanced in a domain, both the locale and the tag
|
|
|
387 set can be viewed as specifying necessary conditions that must apply in
|
|
|
388 that domain for an instantiator to be considered as a possible result of
|
|
|
389 the instancing. More specific locales always override more general
|
|
|
390 locales (thus, there is no particular ordering of the specifications in
|
|
|
391 a specifier); however, the tag sets are simply considered in the order
|
|
|
392 that the inst-pairs occur in the specification's inst-list.
|
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|
393
|
|
|
394 Note also that the actual object that results from the instancing
|
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395 (called an @dfn{instance object}) may not be the same as the instantiator
|
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|
396 from which it was derived. For some specifier types (such as integer
|
|
|
397 specifiers and boolean specifiers), the instantiator will be returned
|
|
|
398 directly as the instance object. For other types, however, this
|
|
|
399 is not the case. For example, for font specifiers, the instantiator
|
|
|
400 is a font-description string and the instance object is a font-instance
|
|
|
401 object, which describes how the font is displayed on a particular device.
|
|
|
402 A font-instance object encapsulates such things as the actual font name
|
|
|
403 used to display the font on that device (a font-description string
|
|
|
404 under X is usually a wildcard specification that may resolve to
|
|
|
405 different font names, with possibly different foundries, widths, etc.,
|
|
|
406 on different devices), the extra properties of that font on that
|
|
|
407 device, etc. Furthermore, this conversion (called @dfn{instantiation})
|
|
440
|
408 might fail---a font or color might not exist on a particular device,
|
|
428
|
409 for example.
|
|
|
410
|
|
|
411 @node Specifier Instancing
|
|
|
412 @section How a Specifier Is Instanced
|
|
|
413 @cindex fallback (in a specifier)
|
|
|
414 @cindex specifier, fallback
|
|
|
415
|
|
|
416 Instancing of a specifier in a particular window domain proceeds as
|
|
|
417 follows:
|
|
|
418
|
|
|
419 @itemize @bullet
|
|
|
420 @item
|
|
|
421 First, XEmacs searches for a specification whose locale is the same as
|
|
|
422 the window. If that fails, the search is repeated, looking for a locale
|
|
|
423 that is the same as the window's buffer. If that fails, the search is
|
|
|
424 repeated using the window's frame, then using the device that frame is
|
|
|
425 on. Finally, the specification whose locale is the symbol @code{global}
|
|
|
426 (if there is such a specification) is considered.
|
|
|
427 @item
|
|
|
428 The inst-pairs contained in the specification that was found are
|
|
|
429 considered in their order in the inst-list, looking for one whose tag
|
|
|
430 set matches the device that is derived from the window domain. (The
|
|
|
431 tag set is an unordered list of zero or more tag symbols. For all
|
|
|
432 tags that have predicates associated with them, the predicate must
|
|
|
433 match the device.)
|
|
|
434 @item
|
|
|
435 If a matching tag set is found, the corresponding instantiator is passed
|
|
|
436 to the specifier's instantiation method, which is specific to the type
|
|
|
437 of the specifier. If it succeeds, the resulting instance object is
|
|
|
438 returned as the result of the instancing and the instancing is done.
|
|
|
439 Otherwise, the operation continues, looking for another matching
|
|
|
440 inst-pair in the current specification.
|
|
|
441 @item
|
|
|
442 When there are no more inst-pairs to be considered in the current
|
|
|
443 specification, the search starts over, looking for another specification
|
|
|
444 as in the first step above.
|
|
|
445 @item
|
|
|
446 If all specifications are exhausted and no instance object can be
|
|
|
447 derived, the instancing fails. (Actually, this is not completely true.
|
|
|
448 Some specifier objects for built-in properties have a @dfn{fallback}
|
|
|
449 value, which is either an inst-list or another specifier object, that is
|
|
|
450 consulted if the instancing is about to fail. If it is an inst-list,
|
|
|
451 the searching proceeds using the inst-pairs in that list. If it is a
|
|
|
452 specifier, the entire instancing starts over using that specifier
|
|
|
453 instead of the given one. Fallback values are set by the C code and
|
|
|
454 cannot be modified, except perhaps indirectly, using any Lisp functions.
|
|
|
455 The purpose of them is to supply some values to make sure that
|
|
|
456 instancing of built-in properties can't fail and to implement some basic
|
|
|
457 specifier inheritance, such as the fact that faces inherit their
|
|
|
458 properties from the @code{default} face.)
|
|
|
459 @end itemize
|
|
|
460
|
|
|
461 It is also possible to instance a specifier over a frame domain or
|
|
|
462 device domain instead of over a window domain. The C code, for example,
|
|
|
463 instances the @code{top-toolbar-height} variable over a frame domain in
|
|
|
464 order to determine the height of a frame's top toolbar. Instancing over
|
|
|
465 a frame or device is similar to instancing over a window except that
|
|
|
466 specifications for locales that cannot be derived from the domain are
|
|
|
467 ignored. Specifically, instancing over a frame looks first for frame
|
|
|
468 locales, then device locales, then the @code{global} locale. Instancing
|
|
|
469 over a device domain looks only for device locales and the @code{global}
|
|
|
470 locale.
|
|
|
471
|
|
|
472 @node Specifier Types
|
|
|
473 @section Specifier Types
|
|
|
474
|
|
|
475 There are various different types of specifiers. The type of a
|
|
|
476 specifier controls what sorts of instantiators are valid, how an
|
|
|
477 instantiator is instantiated, etc. Here is a list of built-in specifier
|
|
|
478 types:
|
|
|
479
|
|
|
480 @table @code
|
|
|
481 @item boolean
|
|
|
482 The valid instantiators are the symbols @code{t} and @code{nil}.
|
|
|
483 Instance objects are the same as instantiators so no special
|
|
|
484 instantiation function is needed.
|
|
|
485
|
|
|
486 @item integer
|
|
|
487 The valid instantiators are integers. Instance objects are the same as
|
|
|
488 instantiators so no special instantiation function is needed.
|
|
|
489 @code{modeline-shadow-thickness} is an example of an integer specifier
|
|
|
490 (negative thicknesses indicate that the shadow is drawn recessed instead
|
|
|
491 of raised).
|
|
|
492
|
|
|
493 @item natnum
|
|
|
494 The valid instantiators are natnums (non-negative integers). Instance
|
|
|
495 objects are the same as instantiators so no special instantiation
|
|
|
496 function is needed. Natnum specifiers are used for dimension variables
|
|
|
497 such as @code{top-toolbar-height}.
|
|
|
498
|
|
|
499 @item generic
|
|
|
500 All Lisp objects are valid instantiators. Instance objects are the same
|
|
|
501 as instantiators so no special instantiation function is needed.
|
|
|
502
|
|
|
503 @item font
|
|
|
504 The valid instantiators are strings describing fonts or vectors
|
|
|
505 indicating inheritance from the font of some face. Instance objects are
|
|
|
506 font-instance objects, which are specific to a particular device. The
|
|
|
507 instantiation method for font specifiers can fail, unlike for integer,
|
|
|
508 natnum, boolean, and generic specifiers.
|
|
|
509
|
|
|
510 @item color
|
|
|
511 The valid instantiators are strings describing colors or vectors
|
|
|
512 indicating inheritance from the foreground or background of some face.
|
|
|
513 Instance objects are color-instance objects, which are specific to a
|
|
|
514 particular device. The instantiation method for color specifiers can fail,
|
|
|
515 as for font specifiers.
|
|
|
516
|
|
|
517 @item image
|
|
|
518 Images are perhaps the most complicated type of built-in specifier. The
|
|
|
519 valid instantiators are strings (a filename, inline data for a pixmap,
|
|
|
520 or text to be displayed in a text glyph) or vectors describing inline
|
|
|
521 data of various sorts or indicating inheritance from the
|
|
|
522 background-pixmap property of some face. Instance objects are either
|
|
|
523 strings (for text images), image-instance objects (for pixmap images),
|
|
|
524 or subwindow objects (for subwindow images). The instantiation method
|
|
|
525 for image specifiers can fail, as for font and color specifiers.
|
|
|
526
|
|
|
527 @item face-boolean
|
|
|
528 The valid instantiators are the symbols @code{t} and @code{nil} and
|
|
|
529 vectors indicating inheritance from a boolean property of some face.
|
|
|
530 Specifiers of this sort are used for all of the built-in boolean
|
|
|
531 properties of faces. Instance objects are either the symbol @code{t}
|
|
|
532 or the symbol @code{nil}.
|
|
|
533
|
|
|
534 @item toolbar
|
|
|
535 The valid instantiators are toolbar descriptors, which are lists
|
|
|
536 of toolbar-button descriptors (each of which is a vector of two
|
|
|
537 or four elements). @xref{Toolbar}, for more information.
|
|
|
538 @end table
|
|
|
539
|
|
|
540 Color and font instance objects can also be used in turn as
|
|
|
541 instantiators for a new color or font instance object. Since these
|
|
|
542 instance objects are device-specific, the instantiator can be used
|
|
|
543 directly as the new instance object, but only if they are of the same
|
|
|
544 device. If the devices differ, the base color or font of the
|
|
|
545 instantiating object is effectively used instead as the instantiator.
|
|
|
546
|
|
|
547 @xref{Faces and Window-System Objects}, for more information on fonts,
|
|
|
548 colors, and face-boolean specifiers. @xref{Glyphs}, for more information
|
|
|
549 about image specifiers. @xref{Toolbar}, for more information on toolbar
|
|
|
550 specifiers.
|
|
|
551
|
|
|
552 @defun specifier-type specifier
|
|
|
553 This function returns the type of @var{specifier}. The returned value
|
|
|
554 will be a symbol: one of @code{integer}, @code{boolean}, etc., as
|
|
|
555 listed in the above table.
|
|
|
556 @end defun
|
|
|
557
|
|
|
558 Functions are also provided to query whether an object is a particular
|
|
|
559 kind of specifier:
|
|
|
560
|
|
|
561 @defun boolean-specifier-p object
|
|
|
562 This function returns non-@code{nil} if @var{object} is a boolean
|
|
|
563 specifier.
|
|
|
564 @end defun
|
|
|
565
|
|
|
566 @defun integer-specifier-p object
|
|
|
567 This function returns non-@code{nil} if @var{object} is an integer
|
|
|
568 specifier.
|
|
|
569 @end defun
|
|
|
570
|
|
|
571 @defun natnum-specifier-p object
|
|
|
572 This function returns non-@code{nil} if @var{object} is a natnum
|
|
|
573 specifier.
|
|
|
574 @end defun
|
|
|
575
|
|
|
576 @defun generic-specifier-p object
|
|
|
577 This function returns non-@code{nil} if @var{object} is a generic
|
|
|
578 specifier.
|
|
|
579 @end defun
|
|
|
580
|
|
|
581 @defun face-boolean-specifier-p object
|
|
|
582 This function returns non-@code{nil} if @var{object} is a face-boolean
|
|
|
583 specifier.
|
|
|
584 @end defun
|
|
|
585
|
|
|
586 @defun toolbar-specifier-p object
|
|
|
587 This function returns non-@code{nil} if @var{object} is a toolbar
|
|
|
588 specifier.
|
|
|
589 @end defun
|
|
|
590
|
|
|
591 @defun font-specifier-p object
|
|
|
592 This function returns non-@code{nil} if @var{object} is a font
|
|
|
593 specifier.
|
|
|
594 @end defun
|
|
|
595
|
|
|
596 @defun color-specifier-p object
|
|
|
597 This function returns non-@code{nil} if @var{object} is a color
|
|
|
598 specifier.
|
|
|
599 @end defun
|
|
|
600
|
|
|
601 @defun image-specifier-p object
|
|
|
602 This function returns non-@code{nil} if @var{object} is an image
|
|
|
603 specifier.
|
|
|
604 @end defun
|
|
|
605
|
|
|
606 @node Adding Specifications
|
|
|
607 @section Adding specifications to a Specifier
|
|
|
608
|
|
|
609 @defun add-spec-to-specifier specifier instantiator &optional locale tag-set how-to-add
|
|
|
610 This function adds a specification to @var{specifier}. The
|
|
|
611 specification maps from @var{locale} (which should be a window, buffer,
|
|
|
612 frame, device, or the symbol @code{global}, and defaults to
|
|
|
613 @code{global}) to @var{instantiator}, whose allowed values depend on the
|
|
|
614 type of the specifier. Optional argument @var{tag-set} limits the
|
|
|
615 instantiator to apply only to the specified tag set, which should be a
|
|
|
616 list of tags all of which must match the device being instantiated over
|
|
|
617 (tags are a device type, a device class, or tags defined with
|
|
|
618 @code{define-specifier-tag}). Specifying a single symbol for
|
|
|
619 @var{tag-set} is equivalent to specifying a one-element list containing
|
|
|
620 that symbol. Optional argument @var{how-to-add} specifies what to do if
|
|
|
621 there are already specifications in the specifier. It should be one of
|
|
|
622
|
|
|
623 @table @code
|
|
|
624 @item prepend
|
|
|
625 Put at the beginning of the current list of instantiators for @var{locale}.
|
|
|
626 @item append
|
|
|
627 Add to the end of the current list of instantiators for @var{locale}.
|
|
|
628 @item remove-tag-set-prepend
|
|
|
629 This is the default. Remove any existing instantiators whose tag set is
|
|
|
630 the same as @var{tag-set}; then put the new instantiator at the
|
|
|
631 beginning of the current list.
|
|
|
632 @item remove-tag-set-append
|
|
|
633 Remove any existing instantiators whose tag set is the same as
|
|
|
634 @var{tag-set}; then put the new instantiator at the end of the current
|
|
|
635 list.
|
|
|
636 @item remove-locale
|
|
|
637 Remove all previous instantiators for this locale before adding the new
|
|
|
638 spec.
|
|
|
639 @item remove-locale-type
|
|
|
640 Remove all specifications for all locales of the same type as
|
|
|
641 @var{locale} (this includes @var{locale} itself) before adding the new
|
|
|
642 spec.
|
|
|
643 @item remove-all
|
|
|
644 Remove all specifications from the specifier before adding the new spec.
|
|
|
645 @end table
|
|
|
646
|
|
|
647 @code{remove-tag-set-prepend} is the default.
|
|
|
648
|
|
|
649 You can retrieve the specifications for a particular locale or locale type
|
|
|
650 with the function @code{specifier-spec-list} or @code{specifier-specs}.
|
|
|
651 @end defun
|
|
|
652
|
|
|
653 @defun add-spec-list-to-specifier specifier spec-list &optional how-to-add
|
|
|
654 This function adds a @dfn{spec-list} (a list of specifications) to
|
|
|
655 @var{specifier}. The format of a spec-list is
|
|
|
656
|
|
|
657 @example
|
|
|
658 @code{((@var{locale} (@var{tag-set} . @var{instantiator}) ...) ...)}
|
|
|
659 @end example
|
|
|
660
|
|
|
661 where
|
|
|
662
|
|
|
663 @itemize @bullet
|
|
|
664 @item
|
|
|
665 @var{locale} := a window, a buffer, a frame, a device, or @code{global}
|
|
|
666 @item
|
|
|
667 @var{tag-set} := an unordered list of zero or more @var{tags}, each of
|
|
|
668 which is a symbol
|
|
|
669 @item
|
|
|
670 @var{tag} := a device class (@pxref{Consoles and Devices}), a device type,
|
|
|
671 or a tag defined with @code{define-specifier-tag}
|
|
|
672 @item
|
|
|
673 @var{instantiator} := format determined by the type of specifier
|
|
|
674 @end itemize
|
|
|
675
|
|
|
676 The pair @code{(@var{tag-set} . @var{instantiator})} is called an
|
|
|
677 @dfn{inst-pair}. A list of inst-pairs is called an @dfn{inst-list}.
|
|
|
678 The pair @code{(@var{locale} . @var{inst-list})} is called a
|
|
|
679 @dfn{specification}. A spec-list, then, can be viewed as a list of
|
|
|
680 specifications.
|
|
|
681
|
|
|
682 @var{how-to-add} specifies how to combine the new specifications with
|
|
|
683 the existing ones, and has the same semantics as for
|
|
|
684 @code{add-spec-to-specifier}.
|
|
|
685
|
|
1875
|
686 The higher-level function @code{set-specifier} is often
|
|
|
687 more convenient because it allows abbreviations of spec-lists to be used
|
|
|
688 instead of the heavily nested canonical syntax. However, one should
|
|
|
689 take great care in using them with specifiers types which can have lists
|
|
|
690 as instantiators, such as toolbar specifiers and generic specifiers. In
|
|
|
691 those cases it's probably best to use @code{add-spec-to-specifier} or
|
|
|
692 @code{add-spec-list-to-specifier}.
|
|
428
|
693 @end defun
|
|
|
694
|
|
444
|
695 @defspec let-specifier specifier-list &rest body
|
|
428
|
696 This special form temporarily adds specifications to specifiers,
|
|
|
697 evaluates forms in @var{body} and restores the specifiers to their
|
|
|
698 previous states. The specifiers and their temporary specifications are
|
|
|
699 listed in @var{specifier-list}.
|
|
|
700
|
|
|
701 The format of @var{specifier-list} is
|
|
|
702
|
|
|
703 @example
|
|
|
704 ((@var{specifier} @var{value} &optional @var{locale} @var{tag-set} @var{how-to-add}) ...)
|
|
|
705 @end example
|
|
|
706
|
|
|
707 @var{specifier} is the specifier to be temporarily modified.
|
|
|
708 @var{value} is the instantiator to be temporarily added to specifier in
|
|
|
709 @var{locale}. @var{locale}, @var{tag-set} and @var{how-to-add} have the
|
|
|
710 same meaning as in @code{add-spec-to-specifier}.
|
|
|
711
|
|
|
712 This special form is implemented as a macro; the code resulting from
|
|
|
713 macro expansion will add specifications to specifiers using
|
|
|
714 @code{add-spec-to-specifier}. After forms in @var{body} are evaluated,
|
|
|
715 the temporary specifications are removed and old specifier spec-lists
|
|
|
716 are restored.
|
|
|
717
|
|
|
718 @var{locale}, @var{tag-set} and @var{how-to-add} may be omitted, and
|
|
|
719 default to @code{nil}. The value of the last form in @var{body} is
|
|
|
720 returned.
|
|
|
721
|
|
|
722 NOTE: If you want the specifier's instance to change in all
|
|
|
723 circumstances, use @code{(selected-window)} as the @var{locale}. If
|
|
|
724 @var{locale} is @code{nil} or omitted, it defaults to @code{global}.
|
|
|
725
|
|
|
726 The following example removes the 3D modeline effect in the currently
|
|
|
727 selected window for the duration of a second:
|
|
|
728
|
|
|
729 @example
|
|
|
730 (let-specifier ((modeline-shadow-thickness 0 (selected-window)))
|
|
|
731 (sit-for 1))
|
|
|
732 @end example
|
|
444
|
733 @end defspec
|
|
428
|
734
|
|
444
|
735 @defun set-specifier specifier value &optional locale tag-set how-to-add
|
|
428
|
736 This function adds some specifications to @var{specifier}. @var{value}
|
|
|
737 can be a single instantiator or tagged instantiator (added as a global
|
|
|
738 specification), a list of tagged and/or untagged instantiators (added as
|
|
|
739 a global specification), a cons of a locale and instantiator or locale
|
|
|
740 and instantiator list, a list of such conses, or nearly any other
|
|
|
741 reasonable form. More specifically, @var{value} can be anything
|
|
1875
|
742 accepted by @code{canonicalize-spec-list} (described below).
|
|
428
|
743
|
|
444
|
744 @var{locale}, @var{tag-set}, and @var{how-to-add} are the same as in
|
|
|
745 @code{add-spec-to-specifier}.
|
|
428
|
746
|
|
|
747 Note that @code{set-specifier} is exactly complementary to
|
|
|
748 @code{specifier-specs} except in the case where @var{specifier} has no
|
|
|
749 specs at all in it but @code{nil} is a valid instantiator (in that case,
|
|
|
750 @code{specifier-specs} will return @code{nil} (meaning no specs) and
|
|
|
751 @code{set-specifier} will interpret the @code{nil} as meaning ``I'm
|
|
|
752 adding a global instantiator and its value is @code{nil}''), or in
|
|
|
753 strange cases where there is an ambiguity between a spec-list and an
|
|
|
754 inst-list, etc. (The built-in specifier types are designed in such a way
|
|
1875
|
755 as to avoid any such ambiguities.) For robust code,
|
|
|
756 @code{set-specifier} should probably be avoided for specifier types
|
|
|
757 which accept lists as instantiators (currently toolbar specifiers and
|
|
|
758 generic specifiers).
|
|
428
|
759
|
|
|
760 If you want to work with spec-lists, you should probably not use these
|
|
|
761 functions, but should use the lower-level functions
|
|
|
762 @code{specifier-spec-list} and @code{add-spec-list-to-specifier}. These
|
|
|
763 functions always work with fully-qualified spec-lists; thus, there is no
|
|
|
764 ambiguity.
|
|
|
765 @end defun
|
|
|
766
|
|
|
767 @defun canonicalize-inst-pair inst-pair specifier-type &optional noerror
|
|
|
768 This function canonicalizes the given @var{inst-pair}.
|
|
|
769
|
|
|
770 @var{specifier-type} specifies the type of specifier that this
|
|
|
771 @var{spec-list} will be used for.
|
|
|
772
|
|
|
773 Canonicalizing means converting to the full form for an inst-pair, i.e.
|
|
|
774 @code{(@var{tag-set} . @var{instantiator})}. A single, untagged
|
|
|
775 instantiator is given a tag set of @code{nil} (the empty set), and a
|
|
|
776 single tag is converted into a tag set consisting only of that tag.
|
|
|
777
|
|
|
778 If @var{noerror} is non-@code{nil}, signal an error if the inst-pair is
|
|
|
779 invalid; otherwise return @code{t}.
|
|
|
780 @end defun
|
|
|
781
|
|
|
782 @defun canonicalize-inst-list inst-list specifier-type &optional noerror
|
|
|
783 This function canonicalizes the given @var{inst-list} (a list of
|
|
|
784 inst-pairs).
|
|
|
785
|
|
|
786 @var{specifier-type} specifies the type of specifier that this @var{inst-list}
|
|
|
787 will be used for.
|
|
|
788
|
|
|
789 Canonicalizing means converting to the full form for an inst-list, i.e.
|
|
|
790 @code{((@var{tag-set} . @var{instantiator}) ...)}. This function
|
|
|
791 accepts a single inst-pair or any abbreviation thereof or a list of
|
|
|
792 (possibly abbreviated) inst-pairs. (See @code{canonicalize-inst-pair}.)
|
|
|
793
|
|
|
794 If @var{noerror} is non-@code{nil}, signal an error if the inst-list is
|
|
|
795 invalid; otherwise return @code{t}.
|
|
|
796 @end defun
|
|
|
797
|
|
|
798 @defun canonicalize-spec spec specifier-type &optional noerror
|
|
|
799 This function canonicalizes the given @var{spec} (a specification).
|
|
|
800
|
|
|
801 @var{specifier-type} specifies the type of specifier that this
|
|
|
802 @var{spec-list} will be used for.
|
|
|
803
|
|
|
804 Canonicalizing means converting to the full form for a spec, i.e.
|
|
|
805 @code{(@var{locale} (@var{tag-set} . @var{instantiator}) ...)}. This
|
|
|
806 function accepts a possibly abbreviated inst-list or a cons of a locale
|
|
|
807 and a possibly abbreviated inst-list. (See
|
|
|
808 @code{canonicalize-inst-list}.)
|
|
|
809
|
|
|
810 If @var{noerror} is @code{nil}, signal an error if the specification is
|
|
|
811 invalid; otherwise return @code{t}.
|
|
|
812 @end defun
|
|
|
813
|
|
|
814 @defun canonicalize-spec-list spec-list specifier-type &optional noerror
|
|
|
815 This function canonicalizes the given @var{spec-list} (a list of
|
|
|
816 specifications).
|
|
|
817
|
|
|
818 @var{specifier-type} specifies the type of specifier that this
|
|
|
819 @var{spec-list} will be used for.
|
|
|
820
|
|
1875
|
821 If @var{noerror} is @code{nil}, signal an error if the spec-list is
|
|
|
822 invalid; otherwise return @code{t} for an invalid spec-list. (Note that
|
|
|
823 this cannot be confused with a canonical spec-list.)
|
|
|
824
|
|
428
|
825 Canonicalizing means converting to the full form for a spec-list, i.e.
|
|
|
826 @code{((@var{locale} (@var{tag-set} . @var{instantiator}) ...) ...)}.
|
|
|
827 This function accepts a possibly abbreviated specification or a list of
|
|
|
828 such things. (See @code{canonicalize-spec}.) This is the function used
|
|
|
829 to convert spec-lists accepted by @code{set-specifier} and such into a
|
|
|
830 form suitable for @code{add-spec-list-to-specifier}.
|
|
|
831
|
|
|
832 This function tries extremely hard to resolve any ambiguities,
|
|
|
833 and the built-in specifier types (font, image, toolbar, etc.) are
|
|
|
834 designed so that there won't be any ambiguities.
|
|
|
835
|
|
1875
|
836 The canonicalization algorithm is as follows:
|
|
|
837
|
|
|
838 @enumerate
|
|
|
839 @item
|
|
|
840 Attempt to parse @var{spec-list} as a single, possibly abbreviated,
|
|
|
841 specification.
|
|
|
842 @item
|
|
|
843 If that fails, attempt to parse @var{spec-list} as a list of (abbreviated)
|
|
|
844 specifications.
|
|
|
845 @item
|
|
|
846 If that fails, @var{spec-list} is invalid.
|
|
|
847 @end enumerate
|
|
|
848
|
|
|
849 A possibly abbreviated specification @var{spec} is parsed by
|
|
|
850
|
|
|
851 @enumerate
|
|
|
852 @item
|
|
|
853 Attempt to parse @var{spec} as a possibly abbreviated inst-list.
|
|
|
854 @item
|
|
|
855 If that fails, attempt to parse @var{spec} as a cons of a locale and an
|
|
|
856 (abbreviated) inst-list.
|
|
|
857 @item
|
|
|
858 If that fails, @var{spec} is invalid.
|
|
|
859 @end enumerate
|
|
|
860
|
|
|
861 A possibly abbreviated inst-list @var{inst-list} is parsed by
|
|
|
862
|
|
|
863 @enumerate
|
|
|
864 @item
|
|
|
865 Attempt to parse @var{inst-list} as a possibly abbreviated inst-pair.
|
|
|
866 @item
|
|
|
867 If that fails, attempt to parse @var{inst-list} as a list of (abbreviated)
|
|
|
868 inst-pairs.
|
|
|
869 @item
|
|
|
870 If that fails, @var{inst-list} is invalid.
|
|
|
871 @end enumerate
|
|
|
872
|
|
|
873 A possibly abbreviated inst-pair @var{inst-pair} is parsed by
|
|
|
874
|
|
|
875 @enumerate
|
|
|
876 @item
|
|
|
877 Check if @var{inst-pair} is @code{valid-instantiator-p}.
|
|
|
878 @item
|
|
|
879 If not, check if @var{inst-pair} is a cons of something that is a tag, ie,
|
|
|
880 @code{valid-specifier-tag-p}, and something that is @code{valid-instantiator-p}.
|
|
|
881 @item
|
|
|
882 If not, check if @var{inst-pair} is a cons of a list of tags and something that
|
|
|
883 is @code{valid-instantiator-p}.
|
|
|
884 @item
|
|
|
885 Otherwise, @var{inst-pair} is invalid.
|
|
|
886 @end enumerate
|
|
|
887
|
|
|
888 In summary, this function generally prefers more abbreviated forms.
|
|
428
|
889 @end defun
|
|
|
890
|
|
|
891 @node Retrieving Specifications
|
|
|
892 @section Retrieving the Specifications from a Specifier
|
|
|
893
|
|
|
894 @defun specifier-spec-list specifier &optional locale tag-set exact-p
|
|
|
895 This function returns the spec-list of specifications for
|
|
|
896 @var{specifier} in @var{locale}.
|
|
|
897
|
|
|
898 If @var{locale} is a particular locale (a window, buffer, frame, device,
|
|
|
899 or the symbol @code{global}), a spec-list consisting of the
|
|
|
900 specification for that locale will be returned.
|
|
|
901
|
|
444
|
902 If @var{locale} is a locale type (i.e. one of the symbols @code{window},
|
|
428
|
903 @code{buffer}, @code{frame}, or @code{device}), a spec-list of the
|
|
|
904 specifications for all locales of that type will be returned.
|
|
|
905
|
|
|
906 If @var{locale} is @code{nil} or the symbol @code{all}, a spec-list of
|
|
|
907 all specifications in @var{specifier} will be returned.
|
|
|
908
|
|
|
909 @var{locale} can also be a list of locales, locale types, and/or
|
|
|
910 @code{all}; the result is as if @code{specifier-spec-list} were called
|
|
|
911 on each element of the list and the results concatenated together.
|
|
|
912
|
|
|
913 Only instantiators where @var{tag-set} (a list of zero or more tags) is
|
|
|
914 a subset of (or possibly equal to) the instantiator's tag set are
|
|
444
|
915 returned. (The default value of @code{nil} is a subset of all tag sets,
|
|
428
|
916 so in this case no instantiators will be screened out.) If @var{exact-p}
|
|
|
917 is non-@code{nil}, however, @var{tag-set} must be equal to an
|
|
|
918 instantiator's tag set for the instantiator to be returned.
|
|
|
919 @end defun
|
|
|
920
|
|
|
921 @defun specifier-specs specifier &optional locale tag-set exact-p
|
|
|
922 This function returns the specification(s) for @var{specifier} in
|
|
|
923 @var{locale}.
|
|
|
924
|
|
|
925 If @var{locale} is a single locale or is a list of one element
|
|
|
926 containing a single locale, then a ``short form'' of the instantiators
|
|
|
927 for that locale will be returned. Otherwise, this function is identical
|
|
|
928 to @code{specifier-spec-list}.
|
|
|
929
|
|
|
930 The ``short form'' is designed for readability and not for ease of use
|
|
|
931 in Lisp programs, and is as follows:
|
|
|
932
|
|
|
933 @enumerate
|
|
|
934 @item
|
|
|
935 If there is only one instantiator, then an inst-pair (i.e. cons of tag
|
|
|
936 and instantiator) will be returned; otherwise a list of inst-pairs will
|
|
|
937 be returned.
|
|
|
938 @item
|
|
|
939 For each inst-pair returned, if the instantiator's tag is @code{any},
|
|
|
940 the tag will be removed and the instantiator itself will be returned
|
|
|
941 instead of the inst-pair.
|
|
|
942 @item
|
|
|
943 If there is only one instantiator, its value is @code{nil}, and its tag
|
|
|
944 is @code{any}, a one-element list containing @code{nil} will be returned
|
|
|
945 rather than just @code{nil}, to distinguish this case from there being
|
|
|
946 no instantiators at all.
|
|
|
947 @end enumerate
|
|
|
948
|
|
|
949 @end defun
|
|
|
950
|
|
|
951 @defun specifier-fallback specifier
|
|
|
952 This function returns the fallback value for @var{specifier}. Fallback
|
|
|
953 values are provided by the C code for certain built-in specifiers to
|
|
|
954 make sure that instancing won't fail even if all specs are removed from
|
|
|
955 the specifier, or to implement simple inheritance behavior (e.g. this
|
|
|
956 method is used to ensure that faces other than @code{default} inherit
|
|
|
957 their attributes from @code{default}). By design, you cannot change the
|
|
|
958 fallback value, and specifiers created with @code{make-specifier} will
|
|
|
959 never have a fallback (although a similar, Lisp-accessible capability
|
|
|
960 may be provided in the future to allow for inheritance).
|
|
|
961
|
|
|
962 The fallback value will be an inst-list that is instanced like
|
|
|
963 any other inst-list, a specifier of the same type as @var{specifier}
|
|
|
964 (results in inheritance), or @code{nil} for no fallback.
|
|
|
965
|
|
|
966 When you instance a specifier, you can explicitly request that the
|
|
|
967 fallback not be consulted. (The C code does this, for example, when
|
|
|
968 merging faces.) See @code{specifier-instance}.
|
|
|
969 @end defun
|
|
|
970
|
|
|
971 @node Specifier Tag Functions
|
|
|
972 @section Working With Specifier Tags
|
|
|
973
|
|
|
974 A specifier tag set is an entity that is attached to an instantiator
|
|
|
975 and can be used to restrict the scope of that instantiator to a
|
|
|
976 particular device class or device type and/or to mark instantiators
|
|
|
977 added by a particular package so that they can be later removed.
|
|
|
978
|
|
442
|
979 A specifier tag set consists of a list of zero or more specifier tags,
|
|
428
|
980 each of which is a symbol that is recognized by XEmacs as a tag. (The
|
|
|
981 valid device types and device classes are always tags, as are any tags
|
|
|
982 defined by @code{define-specifier-tag}.) It is called a ``tag set'' (as
|
|
|
983 opposed to a list) because the order of the tags or the number of times
|
|
|
984 a particular tag occurs does not matter.
|
|
|
985
|
|
|
986 Each tag has a predicate associated with it, which specifies whether
|
|
|
987 that tag applies to a particular device. The tags which are device
|
|
|
988 types and classes match devices of that type or class. User-defined
|
|
|
989 tags can have any predicate, or none (meaning that all devices match).
|
|
|
990 When attempting to instance a specifier, a particular instantiator is
|
|
|
991 only considered if the device of the domain being instanced over matches
|
|
|
992 all tags in the tag set attached to that instantiator.
|
|
|
993
|
|
|
994 Most of the time, a tag set is not specified, and the instantiator gets
|
|
|
995 a null tag set, which matches all devices.
|
|
|
996
|
|
|
997 @defun valid-specifier-tag-p tag
|
|
|
998 This function returns non-@code{nil} if @var{tag} is a valid specifier
|
|
|
999 tag.
|
|
|
1000 @end defun
|
|
|
1001
|
|
|
1002 @defun valid-specifier-tag-set-p tag-set
|
|
|
1003 This function returns non-@code{nil} if @var{tag-set} is a valid
|
|
|
1004 specifier tag set.
|
|
|
1005 @end defun
|
|
|
1006
|
|
|
1007 @defun canonicalize-tag-set tag-set
|
|
|
1008 This function canonicalizes the given tag set. Two canonicalized tag
|
|
|
1009 sets can be compared with @code{equal} to see if they represent the same
|
|
|
1010 tag set. (Specifically, canonicalizing involves sorting by symbol name
|
|
|
1011 and removing duplicates.)
|
|
|
1012 @end defun
|
|
|
1013
|
|
|
1014 @defun device-matches-specifier-tag-set-p device tag-set
|
|
|
1015 This function returns non-@code{nil} if @var{device} matches specifier
|
|
|
1016 tag set @var{tag-set}. This means that @var{device} matches each tag in
|
|
|
1017 the tag set.
|
|
|
1018 @end defun
|
|
|
1019
|
|
|
1020 @defun define-specifier-tag tag &optional predicate
|
|
|
1021 This function defines a new specifier tag. If @var{predicate} is
|
|
|
1022 specified, it should be a function of one argument (a device) that
|
|
|
1023 specifies whether the tag matches that particular device. If
|
|
|
1024 @var{predicate} is omitted, the tag matches all devices.
|
|
|
1025
|
|
|
1026 You can redefine an existing user-defined specifier tag. However, you
|
|
|
1027 cannot redefine the built-in specifier tags (the device types and
|
|
|
1028 classes) or the symbols @code{nil}, @code{t}, @code{all}, or
|
|
|
1029 @code{global}.
|
|
|
1030 @end defun
|
|
|
1031
|
|
|
1032 @defun device-matching-specifier-tag-list &optional device
|
|
|
1033 This function returns a list of all specifier tags matching
|
|
|
1034 @var{device}. @var{device} defaults to the selected device if omitted.
|
|
|
1035 @end defun
|
|
|
1036
|
|
|
1037 @defun specifier-tag-list
|
|
|
1038 This function returns a list of all currently-defined specifier tags.
|
|
|
1039 This includes the built-in ones (the device types and classes).
|
|
|
1040 @end defun
|
|
|
1041
|
|
|
1042 @defun specifier-tag-predicate tag
|
|
|
1043 This function returns the predicate for the given specifier tag.
|
|
|
1044 @end defun
|
|
|
1045
|
|
|
1046 @node Specifier Instancing Functions
|
|
|
1047 @section Functions for Instancing a Specifier
|
|
|
1048
|
|
|
1049 @defun specifier-instance specifier &optional domain default no-fallback
|
|
1882
|
1050 This function instantiates @var{specifier} (returns its value) in
|
|
428
|
1051 @var{domain}. If no instance can be generated for this domain, return
|
|
|
1052 @var{default}.
|
|
|
1053
|
|
|
1054 @var{domain} should be a window, frame, or device. Other values that
|
|
|
1055 are legal as a locale (e.g. a buffer) are not valid as a domain because
|
|
|
1056 they do not provide enough information to identify a particular device
|
|
|
1057 (see @code{valid-specifier-domain-p}). @var{domain} defaults to the
|
|
|
1058 selected window if omitted.
|
|
|
1059
|
|
|
1060 @dfn{Instantiating} a specifier in a particular domain means determining
|
|
|
1061 the specifier's ``value'' in that domain. This is accomplished by
|
|
|
1062 searching through the specifications in the specifier that correspond to
|
|
|
1063 all locales that can be derived from the given domain, from specific to
|
|
|
1064 general. In most cases, the domain is an Emacs window. In that case
|
|
|
1065 specifications are searched for as follows:
|
|
|
1066
|
|
|
1067 @enumerate
|
|
|
1068 @item
|
|
|
1069 A specification whose locale is the window itself;
|
|
|
1070 @item
|
|
|
1071 A specification whose locale is the window's buffer;
|
|
|
1072 @item
|
|
|
1073 A specification whose locale is the window's frame;
|
|
|
1074 @item
|
|
|
1075 A specification whose locale is the window's frame's device;
|
|
|
1076 @item
|
|
|
1077 A specification whose locale is the symbol @code{global}.
|
|
|
1078 @end enumerate
|
|
|
1079
|
|
|
1080 If all of those fail, then the C-code-provided fallback value for this
|
|
|
1081 specifier is consulted (see @code{specifier-fallback}). If it is an
|
|
|
1082 inst-list, then this function attempts to instantiate that list just as
|
|
|
1083 when a specification is located in the first five steps above. If the
|
|
|
1084 fallback is a specifier, @code{specifier-instance} is called recursively
|
|
|
1085 on this specifier and the return value used. Note, however, that if the
|
|
|
1086 optional argument @var{no-fallback} is non-@code{nil}, the fallback
|
|
|
1087 value will not be consulted.
|
|
|
1088
|
|
|
1089 Note that there may be more than one specification matching a particular
|
|
|
1090 locale; all such specifications are considered before looking for any
|
|
|
1091 specifications for more general locales. Any particular specification
|
|
|
1092 that is found may be rejected because it is tagged to a particular
|
|
|
1093 device class (e.g. @code{color}) or device type (e.g. @code{x}) or both
|
|
|
1094 and the device for the given domain does not match this, or because the
|
|
|
1095 specification is not valid for the device of the given domain (e.g. the
|
|
|
1096 font or color name does not exist for this particular X server).
|
|
|
1097
|
|
|
1098 The returned value is dependent on the type of specifier. For example,
|
|
|
1099 for a font specifier (as returned by the @code{face-font} function), the
|
|
|
1100 returned value will be a font-instance object. For images, the returned
|
|
|
1101 value will be a string, pixmap, or subwindow.
|
|
|
1102 @end defun
|
|
|
1103
|
|
1875
|
1104 @defun specifier-matching-instance specifier matchspec &optional domain default no-fallback
|
|
1882
|
1105 This function returns an instance for @var{specifier} in @var{domain}
|
|
1875
|
1106 that matches @var{matchspec}. If no instance can be generated for
|
|
|
1107 @var{domain}, return @var{default}.
|
|
|
1108
|
|
|
1109 This function is identical to @code{specifier-instance} except that a
|
|
|
1110 specification will only be considered if it matches @var{matchspec}.
|
|
|
1111 The definition of ``match,'' and allowed values for @var{matchspec}, are
|
|
|
1112 dependent on the particular type of specifier. Here are some examples:
|
|
|
1113
|
|
|
1114 @itemize
|
|
|
1115 @item
|
|
|
1116 For chartable (e.g. display table) specifiers, @var{matchspec} should be a
|
|
|
1117 character, and the specification (a chartable) must give a value for
|
|
|
1118 that character in order to be considered. This allows you to specify,
|
|
1877
|
1119 @emph{e.g.}, a buffer-local display table that only gives values for particular
|
|
1875
|
1120 characters. All other characters are handled as if the buffer-local
|
|
|
1121 display table is not there. (Chartable specifiers are not yet
|
|
|
1122 implemented.)
|
|
1877
|
1123 @item
|
|
1875
|
1124 For font specifiers, @var{matchspec} should be a list (@var{charset}
|
|
|
1125 . @var{second-stage-p}), and the specification (a font string) must have
|
|
|
1126 a registry that matches the charset's registry. (This only makes sense
|
|
|
1127 with Mule support.) This makes it easy to choose a font that can
|
|
|
1128 display a particular character. (This is what redisplay does, in fact.)
|
|
|
1129 @var{second-stage-p} means to ignore the font's registry and instead
|
|
|
1130 look at the characters in the font to see if the font can support the
|
|
|
1131 charset. This currently only makes sense under MS Windows.
|
|
1878
|
1132 @end itemize
|
|
1875
|
1133 @end defun
|
|
|
1134
|
|
428
|
1135 @defun specifier-instance-from-inst-list specifier domain inst-list &optional default
|
|
|
1136 This function attempts to convert a particular inst-list into an
|
|
|
1137 instance. This attempts to instantiate @var{inst-list} in the given
|
|
|
1138 @var{domain}, as if @var{inst-list} existed in a specification in
|
|
|
1139 @var{specifier}. If the instantiation fails, @var{default} is returned.
|
|
|
1140 In most circumstances, you should not use this function; use
|
|
|
1141 @code{specifier-instance} instead.
|
|
|
1142 @end defun
|
|
|
1143
|
|
1869
|
1144 @node Specifier Examples
|
|
|
1145 @section Examples of Specifier Usage
|
|
428
|
1146
|
|
|
1147 Now let us present an example to clarify the theoretical discussions we
|
|
|
1148 have been through. In this example, we will use the general specifier
|
|
|
1149 functions for clarity. Keep in mind that many types of specifiers, and
|
|
|
1150 some other types of objects that are associated with specifiers
|
|
|
1151 (e.g. faces), provide convenience functions making it easier to work
|
|
|
1152 with objects of that type.
|
|
|
1153
|
|
|
1154 Let us consider the background color of the default face. A specifier
|
|
|
1155 is used to specify how that color will appear in different domains.
|
|
|
1156 First, let's retrieve the specifier:
|
|
|
1157
|
|
|
1158 @example
|
|
|
1159 (setq sp (face-property 'default 'background))
|
|
|
1160 @result{} #<color-specifier 0x3da>
|
|
|
1161 @end example
|
|
|
1162
|
|
|
1163 @example
|
|
|
1164 (specifier-specs sp)
|
|
|
1165 @result{} ((#<buffer "device.c"> (nil . "forest green"))
|
|
|
1166 (#<window on "Makefile" 0x8a2b> (nil . "hot pink"))
|
|
|
1167 (#<x-frame "emacs" 0x4ac> (nil . "puke orange")
|
|
440
|
1168 (nil . "moccasin"))
|
|
428
|
1169 (#<x-frame "VM" 0x4ac> (nil . "magenta"))
|
|
440
|
1170 (global ((tty) . "cyan") (nil . "white"))
|
|
428
|
1171 )
|
|
|
1172 @end example
|
|
|
1173
|
|
|
1174 Then, say we want to determine what the background color of the default
|
|
|
1175 face is for the window currently displaying the buffer @samp{*scratch*}.
|
|
|
1176 We call
|
|
|
1177
|
|
|
1178 @example
|
|
|
1179 (get-buffer-window "*scratch*")
|
|
|
1180 @result{} #<window on "*scratch*" 0x4ad>
|
|
|
1181 (window-frame (get-buffer-window "*scratch*"))
|
|
|
1182 @result{} #<x-frame "emacs" 0x4ac>
|
|
|
1183 (specifier-instance sp (get-buffer-window "*scratch*"))
|
|
|
1184 @result{} #<color-instance moccasin 47=(FFFF,E4E4,B5B5) 0x6309>
|
|
|
1185 @end example
|
|
|
1186
|
|
|
1187 Note that we passed a window to @code{specifier-instance}, not a buffer.
|
|
|
1188 We cannot pass a buffer because a buffer by itself does not provide enough
|
|
|
1189 information. The buffer might not be displayed anywhere at all, or
|
|
|
1190 could be displayed in many different frames on different devices.
|
|
|
1191
|
|
|
1192 The result is arrived at like this:
|
|
|
1193
|
|
|
1194 @enumerate
|
|
|
1195 @item
|
|
|
1196 First, we look for a specification matching the buffer displayed in the
|
|
440
|
1197 window, i.e. @samp{*scratch*}. There are none, so we proceed.
|
|
428
|
1198 @item
|
|
|
1199 Then, we look for a specification matching the window itself. Again, there
|
|
|
1200 are none.
|
|
|
1201 @item
|
|
|
1202 Then, we look for a specification matching the window's frame. The
|
|
|
1203 specification @code{(#<x-frame "emacs" 0x4ac> . "puke orange")} is
|
|
|
1204 found. We call the instantiation method for colors, passing it the
|
|
|
1205 locale we were searching over (i.e. the window, in this case) and the
|
|
|
1206 instantiator (@samp{"puke orange"}). However, the particular device
|
|
|
1207 which this window is on (let's say it's an X connection) doesn't
|
|
|
1208 recognize the color @samp{"puke orange"}, so the specification is
|
|
|
1209 rejected.
|
|
|
1210 @item
|
|
|
1211 So we continue looking for a specification matching the window's frame.
|
|
|
1212 We find @samp{(#<x-frame "emacs" 0x4ac> . "moccasin")}. Again, we
|
|
|
1213 call the instantiation method for colors. This time, the X server
|
|
|
1214 our window is on recognizes the color @samp{moccasin}, and so the
|
|
|
1215 instantiation method succeeds and returns a color instance.
|
|
|
1216 @end enumerate
|
|
|
1217
|
|
1869
|
1218 Here's another example, which implements something like GNU Emacs's
|
|
|
1219 ``frame-local'' variables.
|
|
|
1220
|
|
|
1221 @example
|
|
|
1222 ;; Implementation
|
|
|
1223
|
|
|
1224 ;; There are probably better ways to write this macro
|
|
|
1225 ;; Heaven help you if VAR is a buffer-local; you will become very
|
|
|
1226 ;; confused. Probably should error on that.
|
|
|
1227 (defmacro define-frame-local-variable (var)
|
|
|
1228 "Make the unbound symbol VAR become a frame-local variable."
|
|
|
1229 (let ((val (if (boundp var) (symbol-value var) nil)))
|
|
|
1230 `(progn
|
|
|
1231 (setq ,var (make-specifier 'generic))
|
|
|
1232 (add-spec-to-specifier ,var ',val 'global))))
|
|
|
1233
|
|
|
1234 ;; I'm not real happy about this terminology, how can `setq' be a defun?
|
|
|
1235 ;; But `frame-set' would have people writing "(frame-set 'foo value)".
|
|
|
1236 (defun frame-setq (var value &optional frame)
|
|
|
1237 "Set the local value of VAR to VALUE in FRAME.
|
|
|
1238
|
|
|
1239 FRAME defaults to the selected frame."
|
|
|
1240 (and frame (not (framep frame))
|
|
|
1241 (error 'invalid-argument "FRAME must be a frame", frame))
|
|
|
1242 (add-spec-to-specifier var value (or frame (selected-frame))))
|
|
|
1243
|
|
|
1244 (defun frame-value (var &optional frame)
|
|
|
1245 "Get the local value of VAR in FRAME.
|
|
|
1246
|
|
|
1247 FRAME defaults to the selected frame."
|
|
|
1248 (and frame (not (framep frame))
|
|
|
1249 (error 'invalid-argument "FRAME must be a frame", frame))
|
|
|
1250 ;; this is not just a map from frames to values; it also falls back
|
|
|
1251 ;; to the global value
|
|
|
1252 (specifier-instance var (or frame (selected-frame))))
|
|
|
1253
|
|
|
1254 ;; for completeness
|
|
|
1255 (defun frame-set-default (var value)
|
|
|
1256 "Set the default value of frame-local variable VAR to VALUE."
|
|
|
1257 (add-spec-to-specifier var value 'global))
|
|
|
1258
|
|
|
1259 (defun frame-get-default (var)
|
|
|
1260 "Get the default value of frame-local variable VAR."
|
|
|
1261 (car (specifier-specs var 'global)))
|
|
|
1262 @end example
|
|
|
1263
|
|
|
1264 Now you can execute the above definitions (eg, with @code{eval-last-sexp})
|
|
|
1265 and switch to @file{*scratch*} to play. Things will work differently if
|
|
|
1266 you already have a variable named @code{foo}.
|
|
|
1267
|
|
|
1268 @example
|
|
|
1269 ;; Usage
|
|
|
1270
|
|
|
1271 foo
|
|
|
1272 @error{} Symbol's value as variable is void: foo
|
|
|
1273
|
|
|
1274 (define-frame-local-variable foo)
|
|
|
1275 @result{} nil
|
|
|
1276
|
|
|
1277 ;; the value of foo is a specifier, which is an opaque object;
|
|
|
1278 ;; you must use accessor functions to get values
|
|
|
1279
|
|
|
1280 foo
|
|
|
1281 @result{} #<generic-specifier global=(nil) 0x4f5cb>
|
|
|
1282
|
|
|
1283 ;; since no frame-local value is set, the global value (which is the
|
|
|
1284 ;; constant `nil') is returned
|
|
|
1285 (frame-value foo)
|
|
|
1286 @result{} nil
|
|
|
1287
|
|
|
1288 ;; get the default explicitly
|
|
|
1289 (frame-get-default foo)
|
|
|
1290 @result{} nil
|
|
|
1291
|
|
|
1292 ;; get the whole specification list
|
|
|
1293 (specifier-specs foo 'global)
|
|
|
1294 @result{} (nil)
|
|
|
1295
|
|
|
1296 ;; give foo a frame-local value
|
|
|
1297
|
|
|
1298 (frame-setq foo 'bar)
|
|
|
1299 @result{} nil
|
|
|
1300
|
|
|
1301 ;; access foo in several ways
|
|
|
1302
|
|
|
1303 ;; Note that the print function for this kind of specifier only
|
|
|
1304 ;; gives you the global setting. To get the full list of specs for
|
|
|
1305 ;; debugging or study purposes, you must use specifier-specs or
|
|
|
1306 ;; specifier-spec-list.
|
|
|
1307 foo
|
|
|
1308 @result{} #<generic-specifier global=(nil) 0x4f5cb>
|
|
|
1309
|
|
|
1310 ;; get the whole specification list
|
|
|
1311 (specifier-specs foo)
|
|
|
1312 @result{} ((#<x-frame "Message" 0x1bd66> (nil . bar)) (global (nil)))
|
|
|
1313
|
|
|
1314 ;; get the frame-local value
|
|
|
1315 (frame-value foo)
|
|
|
1316 @result{} bar
|
|
|
1317
|
|
|
1318 ;; get the default explicitly
|
|
|
1319 (frame-get-default foo)
|
|
|
1320 @result{} nil
|
|
|
1321
|
|
|
1322 ;; Switch to another frame and evaluate:
|
|
|
1323 ;; C-x 5 o M-: (frame-setq foo 'baz) RET M-: (frame-value foo) RET
|
|
|
1324 @result{} baz
|
|
|
1325
|
|
|
1326 ;; Switch back.
|
|
|
1327 ;; C-x 5 o
|
|
|
1328 (specifier-specs foo)
|
|
|
1329 @result{} ((#<x-frame "emacs" 0x28ec> (nil . baz))
|
|
|
1330 (#<x-frame "Message" 0x1bd66> (nil . bar))
|
|
|
1331 (global (nil)))
|
|
|
1332
|
|
|
1333 (frame-value foo)
|
|
|
1334 @result{} bar
|
|
|
1335
|
|
|
1336 (frame-get-default foo)
|
|
|
1337 @result{} nil
|
|
|
1338 @end example
|
|
|
1339
|
|
|
1340 Note that since specifiers generalize both frame-local and buffer-local
|
|
|
1341 variables in a sensible way, XEmacs is not likely to put a high priority
|
|
|
1342 on implementing frame-local variables.
|
|
|
1343 @c Thanks to Jerry James for the following explanation. He is not
|
|
|
1344 @c responsible for its use here, Stephen Turnbull is.
|
|
|
1345 In fact, some developers think that frame-local variables are evil for
|
|
|
1346 the same reason that buffer-local variables are evil: the declaration is
|
|
|
1347 both global and invisible. That is, you cannot tell whether a variable
|
|
|
1348 is ``normal,'' buffer-local, or frame-local just by looking at it. So
|
|
|
1349 if you have namespace management problems, and some other Lisp package
|
|
|
1350 happens to use a variable name that you already declared frame- or
|
|
|
1351 buffer-local, weird stuff happens, and it is extremely hard to track
|
|
|
1352 down.
|
|
|
1353
|
|
|
1354
|
|
428
|
1355 @node Creating Specifiers
|
|
|
1356 @section Creating New Specifier Objects
|
|
|
1357
|
|
|
1358 @defun make-specifier type
|
|
|
1359 This function creates a new specifier.
|
|
|
1360
|
|
|
1361 A specifier is an object that can be used to keep track of a property
|
|
|
1362 whose value can be per-buffer, per-window, per-frame, or per-device,
|
|
|
1363 and can further be restricted to a particular device-type or device-class.
|
|
|
1364 Specifiers are used, for example, for the various built-in properties of a
|
|
|
1365 face; this allows a face to have different values in different frames,
|
|
444
|
1366 buffers, etc. For more information, see @code{specifier-instance},
|
|
|
1367 @code{specifier-specs}, and @code{add-spec-to-specifier}; or, for a detailed
|
|
428
|
1368 description of specifiers, including how they are instantiated over a
|
|
|
1369 particular domain (i.e. how their value in that domain is determined),
|
|
|
1370 see the chapter on specifiers in the XEmacs Lisp Reference Manual.
|
|
|
1371
|
|
|
1372 @var{type} specifies the particular type of specifier, and should be one
|
|
|
1373 of the symbols @code{generic}, @code{integer}, @code{natnum},
|
|
|
1374 @code{boolean}, @code{color}, @code{font}, @code{image},
|
|
|
1375 @code{face-boolean}, or @code{toolbar}.
|
|
|
1376
|
|
|
1377 For more information on particular types of specifiers, see the
|
|
442
|
1378 functions @code{make-generic-specifier}, @code{make-integer-specifier},
|
|
|
1379 @code{make-natnum-specifier}, @code{make-boolean-specifier},
|
|
|
1380 @code{make-color-specifier}, @code{make-font-specifier},
|
|
|
1381 @code{make-image-specifier}, @code{make-face-boolean-specifier}, and
|
|
|
1382 @code{make-toolbar-specifier}.
|
|
428
|
1383 @end defun
|
|
|
1384
|
|
|
1385 @defun make-specifier-and-init type spec-list &optional dont-canonicalize
|
|
1875
|
1386 This function creates and initializes a new specifier.
|
|
428
|
1387
|
|
1875
|
1388 This is a convenience API combining @code{make-specifier} and
|
|
|
1389 @code{set-specifier} that allows you to create
|
|
428
|
1390 a specifier and add specs to it at the same time. @var{type} specifies
|
|
1875
|
1391 the specifier type. Allowed types are as for @code{make-specifier}.
|
|
|
1392
|
|
|
1393 @var{spec-list} supplies the specification(s) to be
|
|
|
1394 added to the specifier. Any abbreviation of
|
|
|
1395 the full spec-list form accepted by @code{canonicalize-spec-list} may
|
|
|
1396 be used.
|
|
|
1397 However, if the optional argument @var{dont-canonicalize} is non-@code{nil},
|
|
|
1398 canonicalization is not performed, and the @var{spec-list} must already
|
|
|
1399 be in full form.
|
|
428
|
1400 @end defun
|
|
|
1401
|
|
442
|
1402 @defun make-integer-specifier spec-list
|
|
|
1403
|
|
|
1404 Return a new @code{integer} specifier object with the given
|
|
|
1405 specification list. @var{spec-list} can be a list of specifications
|
|
|
1406 (each of which is a cons of a locale and a list of instantiators), a
|
|
|
1407 single instantiator, or a list of instantiators.
|
|
|
1408
|
|
|
1409 Valid instantiators for integer specifiers are integers.
|
|
|
1410 @end defun
|
|
|
1411
|
|
|
1412 @defun make-boolean-specifier spec-list
|
|
|
1413
|
|
|
1414 Return a new @code{boolean} specifier object with the given
|
|
|
1415 specification list. @var{spec-list} can be a list of specifications
|
|
|
1416 (each of which is a cons of a locale and a list of instantiators), a
|
|
|
1417 single instantiator, or a list of instantiators.
|
|
|
1418
|
|
|
1419 Valid instantiators for boolean specifiers are @code{t} and @code{nil}.
|
|
|
1420 @end defun
|
|
|
1421
|
|
|
1422 @defun make-natnum-specifier spec-list
|
|
|
1423
|
|
|
1424 Return a new @code{natnum} specifier object with the given specification
|
|
|
1425 list. @var{spec-list} can be a list of specifications (each of which is
|
|
|
1426 a cons of a locale and a list of instantiators), a single instantiator,
|
|
|
1427 or a list of instantiators.
|
|
|
1428
|
|
|
1429 Valid instantiators for natnum specifiers are non-negative integers.
|
|
|
1430 @end defun
|
|
|
1431
|
|
|
1432 @defun make-generic-specifier spec-list
|
|
|
1433
|
|
|
1434 Return a new @code{generic} specifier object with the given
|
|
|
1435 specification list. @var{spec-list} can be a list of specifications
|
|
|
1436 (each of which is a cons of a locale and a list of instantiators), a
|
|
|
1437 single instantiator, or a list of instantiators.
|
|
|
1438
|
|
|
1439 Valid instantiators for generic specifiers are all Lisp values. They
|
|
|
1440 are returned back unchanged when a specifier is instantiated.
|
|
|
1441 @end defun
|
|
|
1442
|
|
|
1443 @defun make-display-table-specifier spec-list
|
|
|
1444
|
|
|
1445 Return a new @code{display-table} specifier object with the given spec
|
|
|
1446 list. @var{spec-list} can be a list of specifications (each of which is
|
|
|
1447 a cons of a locale and a list of instantiators), a single instantiator,
|
|
|
1448 or a list of instantiators.
|
|
|
1449
|
|
|
1450 Valid instantiators for display-table specifiers are described in detail
|
|
|
1451 in the doc string for @code{current-display-table} (@pxref{Active
|
|
|
1452 Display Table}).
|
|
|
1453 @end defun
|
|
|
1454
|
|
428
|
1455 @node Specifier Validation Functions
|
|
|
1456 @section Functions for Checking the Validity of Specifier Components
|
|
|
1457
|
|
|
1458 @defun valid-specifier-domain-p domain
|
|
|
1459 This function returns non-@code{nil} if @var{domain} is a valid
|
|
|
1460 specifier domain. A domain is used to instance a specifier
|
|
|
1461 (i.e. determine the specifier's value in that domain). Valid domains
|
|
|
1462 are a window, frame, or device. (@code{nil} is not valid.)
|
|
|
1463 @end defun
|
|
|
1464
|
|
|
1465 @defun valid-specifier-locale-p locale
|
|
|
1466 This function returns non-@code{nil} if @var{locale} is a valid
|
|
|
1467 specifier locale. Valid locales are a device, a frame, a window, a
|
|
|
1468 buffer, and @code{global}. (@code{nil} is not valid.)
|
|
|
1469 @end defun
|
|
|
1470
|
|
|
1471 @defun valid-specifier-locale-type-p locale-type
|
|
444
|
1472 Given a specifier @var{locale-type}, this function returns non-@code{nil} if it
|
|
428
|
1473 is valid. Valid locale types are the symbols @code{global},
|
|
|
1474 @code{device}, @code{frame}, @code{window}, and @code{buffer}. (Note,
|
|
|
1475 however, that in functions that accept either a locale or a locale type,
|
|
|
1476 @code{global} is considered an individual locale.)
|
|
|
1477 @end defun
|
|
|
1478
|
|
|
1479 @defun valid-specifier-type-p specifier-type
|
|
|
1480 Given a @var{specifier-type}, this function returns non-@code{nil} if it
|
|
|
1481 is valid. Valid types are @code{generic}, @code{integer},
|
|
|
1482 @code{boolean}, @code{color}, @code{font}, @code{image},
|
|
|
1483 @code{face-boolean}, and @code{toolbar}.
|
|
|
1484 @end defun
|
|
|
1485
|
|
|
1486 @defun valid-specifier-tag-p tag
|
|
|
1487 This function returns non-@code{nil} if @var{tag} is a valid specifier
|
|
|
1488 tag.
|
|
|
1489 @end defun
|
|
|
1490
|
|
|
1491 @defun valid-instantiator-p instantiator specifier-type
|
|
|
1492 This function returns non-@code{nil} if @var{instantiator} is valid for
|
|
|
1493 @var{specifier-type}.
|
|
|
1494 @end defun
|
|
|
1495
|
|
|
1496 @defun valid-inst-list-p inst-list type
|
|
|
1497 This function returns non-@code{nil} if @var{inst-list} is valid for
|
|
|
1498 specifier type @var{type}.
|
|
|
1499 @end defun
|
|
|
1500
|
|
|
1501 @defun valid-spec-list-p spec-list type
|
|
|
1502 This function returns non-@code{nil} if @var{spec-list} is valid for
|
|
|
1503 specifier type @var{type}.
|
|
|
1504 @end defun
|
|
|
1505
|
|
|
1506 @defun check-valid-instantiator instantiator specifier-type
|
|
|
1507 This function signals an error if @var{instantiator} is invalid for
|
|
|
1508 @var{specifier-type}.
|
|
|
1509 @end defun
|
|
|
1510
|
|
|
1511 @defun check-valid-inst-list inst-list type
|
|
|
1512 This function signals an error if @var{inst-list} is invalid for
|
|
|
1513 specifier type @var{type}.
|
|
|
1514 @end defun
|
|
|
1515
|
|
|
1516 @defun check-valid-spec-list spec-list type
|
|
|
1517 This function signals an error if @var{spec-list} is invalid for
|
|
|
1518 specifier type @var{type}.
|
|
|
1519 @end defun
|
|
|
1520
|
|
|
1521 @node Other Specification Functions
|
|
|
1522 @section Other Functions for Working with Specifications in a Specifier
|
|
|
1523
|
|
|
1524 @defun copy-specifier specifier &optional dest locale tag-set exact-p how-to-add
|
|
|
1525 This function copies @var{specifier} to @var{dest}, or creates a new one
|
|
|
1526 if @var{dest} is @code{nil}.
|
|
|
1527
|
|
|
1528 If @var{dest} is @code{nil} or omitted, a new specifier will be created
|
|
|
1529 and the specifications copied into it. Otherwise, the specifications
|
|
|
1530 will be copied into the existing specifier in @var{dest}.
|
|
|
1531
|
|
|
1532 If @var{locale} is @code{nil} or the symbol @code{all}, all
|
|
|
1533 specifications will be copied. If @var{locale} is a particular locale,
|
|
|
1534 the specification for that particular locale will be copied. If
|
|
|
1535 @var{locale} is a locale type, the specifications for all locales of
|
|
|
1536 that type will be copied. @var{locale} can also be a list of locales,
|
|
|
1537 locale types, and/or @code{all}; this is equivalent to calling
|
|
|
1538 @code{copy-specifier} for each of the elements of the list. See
|
|
|
1539 @code{specifier-spec-list} for more information about @var{locale}.
|
|
|
1540
|
|
|
1541 Only instantiators where @var{tag-set} (a list of zero or more tags) is
|
|
|
1542 a subset of (or possibly equal to) the instantiator's tag set are
|
|
|
1543 copied. (The default value of @code{nil} is a subset of all tag sets,
|
|
|
1544 so in this case no instantiators will be screened out.) If @var{exact-p}
|
|
|
1545 is non-@code{nil}, however, @var{tag-set} must be equal to an
|
|
|
1546 instantiator's tag set for the instantiator to be copied.
|
|
|
1547
|
|
|
1548 Optional argument @var{how-to-add} specifies what to do with existing
|
|
444
|
1549 specifications in @var{dest}. If @code{nil}, then whichever locales or locale
|
|
428
|
1550 types are copied will first be completely erased in @var{dest}.
|
|
|
1551 Otherwise, it is the same as in @code{add-spec-to-specifier}.
|
|
|
1552 @end defun
|
|
|
1553
|
|
|
1554 @defun remove-specifier specifier &optional locale tag-set exact-p
|
|
|
1555 This function removes specification(s) for @var{specifier}.
|
|
|
1556
|
|
|
1557 If @var{locale} is a particular locale (a buffer, window, frame, device,
|
|
|
1558 or the symbol @code{global}), the specification for that locale will be
|
|
|
1559 removed.
|
|
|
1560
|
|
|
1561 If instead, @var{locale} is a locale type (i.e. a symbol @code{buffer},
|
|
|
1562 @code{window}, @code{frame}, or @code{device}), the specifications for
|
|
|
1563 all locales of that type will be removed.
|
|
|
1564
|
|
|
1565 If @var{locale} is @code{nil} or the symbol @code{all}, all
|
|
|
1566 specifications will be removed.
|
|
|
1567
|
|
|
1568 @var{locale} can also be a list of locales, locale types, and/or
|
|
|
1569 @code{all}; this is equivalent to calling @code{remove-specifier} for
|
|
|
1570 each of the elements in the list.
|
|
|
1571
|
|
|
1572 Only instantiators where @var{tag-set} (a list of zero or more tags) is
|
|
|
1573 a subset of (or possibly equal to) the instantiator's tag set are
|
|
|
1574 removed. (The default value of @code{nil} is a subset of all tag sets,
|
|
|
1575 so in this case no instantiators will be screened out.) If @var{exact-p}
|
|
|
1576 is non-@code{nil}, however, @var{tag-set} must be equal to an
|
|
|
1577 instantiator's tag set for the instantiator to be removed.
|
|
|
1578 @end defun
|
|
|
1579
|
|
|
1580 @defun map-specifier specifier func &optional locale maparg
|
|
|
1581 This function applies @var{func} to the specification(s) for
|
|
|
1582 @var{locale} in @var{specifier}.
|
|
|
1583
|
|
1875
|
1584 If optional @var{locale} is a locale, @var{func} will be called for that
|
|
|
1585 locale.
|
|
428
|
1586 If @var{locale} is a locale type, @var{func} will be mapped over all
|
|
|
1587 locales of that type. If @var{locale} is @code{nil} or the symbol
|
|
|
1588 @code{all}, @var{func} will be mapped over all locales in
|
|
|
1589 @var{specifier}.
|
|
|
1590
|
|
1875
|
1591 Optional @var{ms-tag-set} and @var{ms-exact-p} are as in
|
|
|
1592 @code{specifier-spec-list'}.
|
|
|
1593 Optional @var{ms-maparg} will be passed to @var{ms-func}.
|
|
|
1594
|
|
428
|
1595 @var{func} is called with four arguments: the @var{specifier}, the
|
|
|
1596 locale being mapped over, the inst-list for that locale, and the
|
|
|
1597 optional @var{maparg}. If any invocation of @var{func} returns
|
|
|
1598 non-@code{nil}, the mapping will stop and the returned value becomes the
|
|
|
1599 value returned from @code{map-specifier}. Otherwise,
|
|
|
1600 @code{map-specifier} returns @code{nil}.
|
|
|
1601 @end defun
|
|
|
1602
|
|
|
1603 @defun specifier-locale-type-from-locale locale
|
|
|
1604 Given a specifier @var{locale}, this function returns its type.
|
|
|
1605 @end defun
|
