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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) 1990, 1991, 1992, 1993, 1994, 1998 Free Software Foundation, Inc.
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4 @c See the file lispref.texi for copying conditions.
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5 @setfilename ../../info/display.info
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6 @node Display, Hash Tables, Annotations, Top
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7 @chapter Emacs Display
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8
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9 This chapter describes a number of other features related to the display
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10 that XEmacs presents to the user.
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11
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12 @menu
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13 * Refresh Screen:: Clearing the screen and redrawing everything on it.
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14 * Truncation:: Folding or wrapping long text lines.
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15 * The Echo Area:: Where messages are displayed.
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16 * Warnings:: Display of Warnings.
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17 * Invisible Text:: Hiding part of the buffer text.
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18 * Selective Display:: Hiding part of the buffer text (the old way).
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19 * Overlay Arrow:: Display of an arrow to indicate position.
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20 * Temporary Displays:: Displays that go away automatically.
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21 * Blinking:: How XEmacs shows the matching open parenthesis.
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22 * Usual Display:: The usual conventions for displaying nonprinting chars.
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23 * Display Tables:: How to specify other conventions.
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24 * Beeping:: Audible signal to the user.
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25 @end menu
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26
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27 @node Refresh Screen
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28 @section Refreshing the Screen
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29
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30 The function @code{redraw-frame} redisplays the entire contents of a
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31 given frame. @xref{Frames}.
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32
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33 @c Emacs 19 feature
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34 @defun redraw-frame frame
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35 This function clears and redisplays frame @var{frame}.
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36 @end defun
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37
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38 Even more powerful is @code{redraw-display}:
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39
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40 @deffn Command redraw-display &optional device
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41 This function redraws all frames on @var{device} marked as having their
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42 image garbled. @var{device} defaults to the selected device. If
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43 @var{device} is @code{t}, all devices will have their frames checked.
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44 @end deffn
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45
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46 Processing user input takes absolute priority over redisplay. If you
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47 call these functions when input is available, they do nothing
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48 immediately, but a full redisplay does happen eventually---after all the
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49 input has been processed.
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50
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51 Normally, suspending and resuming XEmacs also refreshes the screen.
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52 Some terminal emulators record separate contents for display-oriented
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53 programs such as XEmacs and for ordinary sequential display. If you are
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54 using such a terminal, you might want to inhibit the redisplay on
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55 resumption. @xref{Suspending XEmacs}.
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56
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57 @defvar no-redraw-on-reenter
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58 @cindex suspend (cf. @code{no-redraw-on-reenter})
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59 @cindex resume (cf. @code{no-redraw-on-reenter})
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60 This variable controls whether XEmacs redraws the entire screen after it
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61 has been suspended and resumed. Non-@code{nil} means yes, @code{nil}
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62 means no.
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63 @end defvar
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64
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65 @cindex display update
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66 @cindex update display
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67 @cindex refresh display
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68 The above functions do not actually cause the display to be updated;
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69 rather, they clear out the internal display records that XEmacs
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70 maintains, so that the next time the display is updated it will be
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71 redrawn from scratch. Normally this occurs the next time that
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72 @code{next-event} or @code{sit-for} is called; however, a display update
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73 will not occur if there is input pending. @xref{Command Loop}.
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74
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75 @defun force-cursor-redisplay
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76 This function causes an immediate update of the cursor on the selected
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77 frame. (This function does not exist in FSF Emacs.)
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78 @end defun
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79
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80 @node Truncation
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81 @section Truncation
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82 @cindex line wrapping
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83 @cindex continuation lines
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84 @cindex @samp{$} in display
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85 @cindex @samp{\} in display
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86
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87 When a line of text extends beyond the right edge of a window, the
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88 line can either be truncated or continued on the next line. When a line
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89 is truncated, this is normally shown with a @samp{\} in the rightmost
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90 column of the window on X displays, and with a @samp{$} on TTY devices.
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91 When a line is continued or ``wrapped'' onto the next line, this is
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92 shown with a curved arrow in the rightmost column of the window (or with
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93 a @samp{\} on TTY devices). The additional screen lines used to display
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94 a long text line are called @dfn{continuation} lines.
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95
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96 Normally, whenever line truncation is in effect for a particular
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97 window, a horizontal scrollbar is displayed in that window if the
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98 device supports scrollbars. @xref{Scrollbars}.
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99
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100 Note that continuation is different from filling; continuation happens
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101 on the screen only, not in the buffer contents, and it breaks a line
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102 precisely at the right margin, not at a word boundary. @xref{Filling}.
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103
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104 @defopt truncate-lines
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105 This buffer-local variable controls how XEmacs displays lines that
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106 extend beyond the right edge of the window. If it is non-@code{nil},
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107 then XEmacs does not display continuation lines; rather each line of
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108 text occupies exactly one screen line, and a backslash appears at the
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109 edge of any line that extends to or beyond the edge of the window. The
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110 default is @code{nil}.
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111
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112 If the variable @code{truncate-partial-width-windows} is non-@code{nil},
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113 then truncation is always used for side-by-side windows (within one
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114 frame) regardless of the value of @code{truncate-lines}.
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115 @end defopt
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116
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117 @defopt default-truncate-lines
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118 This variable is the default value for @code{truncate-lines}, for
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119 buffers that do not have local values for it.
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120 @end defopt
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121
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122 @defopt truncate-partial-width-windows
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123 This variable controls display of lines that extend beyond the right
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124 edge of the window, in side-by-side windows (@pxref{Splitting Windows}).
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125 If it is non-@code{nil}, these lines are truncated; otherwise,
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126 @code{truncate-lines} says what to do with them.
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127 @end defopt
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128
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129 The backslash and curved arrow used to indicate truncated or continued
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130 lines are only defaults, and can be changed. These images are actually
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131 glyphs (@pxref{Glyphs}). XEmacs provides a great deal of flexibility
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132 in how glyphs can be controlled. (This differs from FSF Emacs, which
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133 uses display tables to control these images.)
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134
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135 For details, @ref{Redisplay Glyphs}.
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136
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137 @ignore Not yet in XEmacs
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138 If your buffer contains @strong{very} long lines, and you use
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139 continuation to display them, just thinking about them can make Emacs
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140 redisplay slow. The column computation and indentation functions also
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141 become slow. Then you might find it advisable to set
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142 @code{cache-long-line-scans} to @code{t}.
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143
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144 @defvar cache-long-line-scans
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145 If this variable is non-@code{nil}, various indentation and motion
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146 functions, and Emacs redisplay, cache the results of scanning the
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147 buffer, and consult the cache to avoid rescanning regions of the buffer
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148 unless they are modified.
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149
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150 Turning on the cache slows down processing of short lines somewhat.
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151
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152 This variable is automatically local in every buffer.
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153 @end defvar
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154 @end ignore
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155
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156 @node The Echo Area
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157 @section The Echo Area
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158 @cindex error display
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159 @cindex echo area
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160
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161 The @dfn{echo area} is used for displaying messages made with the
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162 @code{message} primitive, and for echoing keystrokes. It is not the
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163 same as the minibuffer, despite the fact that the minibuffer appears
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164 (when active) in the same place on the screen as the echo area. The
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165 @cite{XEmacs Reference Manual} specifies the rules for resolving conflicts
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166 between the echo area and the minibuffer for use of that screen space
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167 (@pxref{Minibuffer,, The Minibuffer, emacs, The XEmacs Reference Manual}).
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168 Error messages appear in the echo area; see @ref{Errors}.
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169
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170 You can write output in the echo area by using the Lisp printing
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171 functions with @code{t} as the stream (@pxref{Output Functions}), or as
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172 follows:
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173
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174 @defun message string &rest arguments
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175 This function displays a one-line message in the echo area. The
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176 argument @var{string} is similar to a C language @code{printf} control
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177 string. See @code{format} in @ref{String Conversion}, for the details
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178 on the conversion specifications. @code{message} returns the
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179 constructed string.
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180
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181 In batch mode, @code{message} prints the message text on the standard
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182 error stream, followed by a newline.
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183
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184 @c Emacs 19 feature
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185 If @var{string} is @code{nil}, @code{message} clears the echo area. If
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186 the minibuffer is active, this brings the minibuffer contents back onto
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187 the screen immediately.
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188
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189 @example
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190 @group
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191 (message "Minibuffer depth is %d."
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192 (minibuffer-depth))
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193 @print{} Minibuffer depth is 0.
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194 @result{} "Minibuffer depth is 0."
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195 @end group
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196
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197 @group
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198 ---------- Echo Area ----------
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199 Minibuffer depth is 0.
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200 ---------- Echo Area ----------
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201 @end group
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202 @end example
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203 @end defun
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204
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205 In addition to only displaying a message, XEmacs allows you to
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206 @dfn{label} your messages, giving you fine-grained control of their
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207 display. Message label is a symbol denoting the message type. Some
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208 standard labels are:
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209
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210 @itemize @bullet
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211 @item @code{message}---default label used by the @code{message}
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212 function;
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213
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214 @item @code{error}---default label used for reporting errors;
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215
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216 @item @code{progress}---progress indicators like
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217 @samp{Converting... 45%} (not logged by default);
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218
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219 @item @code{prompt}---prompt-like messages like @samp{Isearch: foo} (not
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220 logged by default);
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221
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222 @item @code{command}---helper command messages like @samp{Mark set} (not
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223 logged by default);
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224
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225 @item @code{no-log}---messages that should never be logged
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226 @end itemize
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227
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228 Several messages may be stacked in the echo area at once. Lisp programs
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229 may access these messages, or remove them as appropriate, via the
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230 message stack.
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231
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232 @defun display-message label message &optional frame stdout-p
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233 This function displays @var{message} (a string) labeled as @var{label},
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234 as described above.
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235
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236 The @var{frame} argument specifies the frame to whose minibuffer the
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237 message should be printed. This is currently unimplemented. The
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238 @var{stdout-p} argument is used internally.
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239
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240 @example
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241 (display-message 'command "Mark set")
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242 @end example
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243 @end defun
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244
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245 @defun lmessage label string &rest arguments
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246 This function displays a message @var{string} with label @var{label}.
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247 It is similar to @code{message} in that it accepts a @code{printf}-like
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248 strings and any number of arguments.
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249
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250 @example
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251 @group
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252 ;; @r{Display a command message.}
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253 (lmessage 'command "Comment column set to %d" comment-column)
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254 @end group
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255
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256 @group
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257 ;; @r{Display a progress message.}
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258 (lmessage 'progress "Fontifying %s... (%d)" buffer percentage)
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259 @end group
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260
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261 @group
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262 ;; @r{Display a message that should not be logged.}
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263 (lmessage 'no-log "Done")
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264 @end group
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265 @end example
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266 @end defun
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267
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268 @defun clear-message &optional label frame stdout-p no-restore
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269 This function remove any message with the given @var{label}
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270 from the message-stack, erasing it from the echo area if it's currently
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271 displayed there.
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272
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273 If a message remains at the head of the message-stack and
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274 @var{no-restore} is @code{nil}, it will be displayed. The string which
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275 remains in the echo area will be returned, or @code{nil} if the
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276 message-stack is now empty. If @var{label} is nil, the entire
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277 message-stack is cleared.
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278
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279 @example
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280 ;; @r{Show a message, wait for 2 seconds, and restore old minibuffer}
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281 ;; @r{contents.}
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282 (message "A message")
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283 @print{} A message
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284 @result{} "A Message"
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285 (lmessage 'my-label "Newsflash! Newsflash!")
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286 @print{} Newsflash! Newsflash!
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287 @result{} "Newsflash! Newsflash!"
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288 (sit-for 2)
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289 (clear-message 'my-label)
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290 @print{} A message
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291 @result{} "A message"
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292 @end example
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293
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294 Unless you need the return value or you need to specify a label,
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295 you should just use @code{(message nil)}.
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296 @end defun
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297
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298 @defun current-message &optional frame
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299 This function returns the current message in the echo area, or
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300 @code{nil}. The @var{frame} argument is currently unused.
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301 @end defun
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302
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303 Some of the messages displayed in the echo area are also recorded in the
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304 @samp{ *Message-Log*} buffer. Exactly which messages will be recorded
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305 can be tuned using the following variables.
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306
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307 @defopt log-message-max-size
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308 This variable specifies the maximum size of the @samp{ *Message-log*}
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309 buffer.
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310 @end defopt
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311
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312 @defvar log-message-ignore-labels
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313 This variable specifies the labels whose messages will not be logged.
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314 It should be a list of symbols.
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315 @end defvar
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316
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317 @defvar log-message-ignore-regexps
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318 This variable specifies the regular expressions matching messages that
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319 will not be logged. It should be a list of regular expressions.
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320
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321 Normally, packages that generate messages that might need to be ignored
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322 should label them with @code{progress}, @code{prompt}, or @code{no-log},
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323 so they can be filtered by @code{log-message-ignore-labels}.
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324 @end defvar
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325
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326 @defvar echo-keystrokes
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327 This variable determines how much time should elapse before command
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328 characters echo. Its value must be a number, which specifies the number
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329 of seconds to wait before echoing. If the user types a prefix key (such
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330 as @kbd{C-x}) and then delays this many seconds before continuing, the
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331 prefix key is echoed in the echo area. Any subsequent characters in the
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332 same command will be echoed as well.
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333
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334 If the value is zero, then command input is not echoed.
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335 @end defvar
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336
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337 @defvar cursor-in-echo-area
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338 This variable controls where the cursor appears when a message is
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339 displayed in the echo area. If it is non-@code{nil}, then the cursor
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340 appears at the end of the message. Otherwise, the cursor appears at
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341 point---not in the echo area at all.
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342
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343 The value is normally @code{nil}; Lisp programs bind it to @code{t}
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344 for brief periods of time.
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345 @end defvar
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346
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347 @node Warnings
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348 @section Warnings
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349
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350 XEmacs contains a facility for unified display of various warnings.
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351 Unlike errors, warnings are displayed in the situations when XEmacs
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352 encounters a problem that is recoverable, but which should be fixed for
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353 safe future operation.
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354
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355 For example, warnings are printed by the startup code when it encounters
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356 problems with X keysyms, when there is an error in @file{.emacs}, and in
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357 other problematic situations. Unlike messages, warnings are displayed
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358 in a separate buffer, and include an explanatory message that may span
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359 across several lines. Here is an example of how a warning is displayed:
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360
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361 @example
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362 (1) (initialization/error) An error has occurred while loading ~/.emacs:
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363
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364 Symbol's value as variable is void: bogus-variable
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365
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366 To ensure normal operation, you should investigate the cause of the error
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367 in your initialization file and remove it. Use the `-debug-init' option
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368 to XEmacs to view a complete error backtrace.
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369 @end example
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370
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371 Each warning has a @dfn{class} and a @dfn{priority level}. The class is
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372 a symbol describing what sort of warning this is, such as
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373 @code{initialization}, @code{resource} or @code{key-mapping}.
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374
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375 The warning priority level specifies how important the warning is. The
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376 recognized warning levels, in increased order of priority, are:
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377 @code{debug}, @code{info}, @code{notice}, @code{warning}, @code{error},
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378 @code{critical}, @code{alert} and @code{emergency}.
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379
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380 @defun display-warning class message &optional level
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381 This function displays a warning message @var{message} (a string).
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382 @var{class} should be a warning class symbol, as described above, or a
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383 list of such symbols. @var{level} describes the warning priority level.
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384 If unspecified, it default to @code{warning}.
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385
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386 @example
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387 @group
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388 (display-warning 'resource
|
|
|
389 "Bad resource specification encountered:
|
|
|
390 something like
|
|
|
391
|
|
|
392 Emacs*foo: bar
|
|
|
393
|
|
|
394 You should replace the * with a . in order to get proper behavior when
|
|
|
395 you use the specifier and/or `set-face-*' functions.")
|
|
|
396 @end group
|
|
|
397
|
|
|
398 @group
|
|
|
399 ---------- Warning buffer ----------
|
|
|
400 (1) (resource/warning) Bad resource specification encountered:
|
|
|
401 something like
|
|
|
402
|
|
|
403 Emacs*foo: bar
|
|
|
404
|
|
|
405 You should replace the * with a . in order to get proper behavior when
|
|
|
406 you use the specifier and/or `set-face-*' functions.
|
|
|
407 ---------- Warning buffer ----------
|
|
|
408 @end group
|
|
|
409 @end example
|
|
|
410 @end defun
|
|
|
411
|
|
|
412 @defun lwarn class level message &rest args
|
|
|
413 This function displays a formatted labeled warning message. As above,
|
|
|
414 @var{class} should be the warning class symbol, or a list of such
|
|
|
415 symbols, and @var{level} should specify the warning priority level
|
|
|
416 (@code{warning} by default).
|
|
|
417
|
|
|
418 Unlike in @code{display-warning}, @var{message} may be a formatted
|
|
|
419 message, which will be, together with the rest of the arguments, passed
|
|
|
420 to @code{format}.
|
|
|
421
|
|
|
422 @example
|
|
|
423 (lwarn 'message-log 'warning
|
|
|
424 "Error caught in `remove-message-hook': %s"
|
|
|
425 (error-message-string e))
|
|
|
426 @end example
|
|
|
427 @end defun
|
|
|
428
|
|
|
429 @defvar log-warning-minimum-level
|
|
|
430 This variable specifies the minimum level of warnings that should be
|
|
|
431 generated. Warnings with level lower than defined by this variable are
|
|
|
432 completely ignored, as if they never happened.
|
|
|
433 @end defvar
|
|
|
434
|
|
|
435 @defvar display-warning-minimum-level
|
|
|
436 This variable specifies the minimum level of warnings that should be
|
|
|
437 displayed. Unlike @code{log-warning-minimum-level}, setting this
|
|
|
438 function does not suppress warnings entirely---they are still generated
|
|
|
439 in the @samp{*Warnings*} buffer, only they are not displayed by default.
|
|
|
440 @end defvar
|
|
|
441
|
|
|
442 @defvar log-warning-suppressed-classes
|
|
|
443 This variable specifies a list of classes that should not be logged or
|
|
|
444 displayed. If any of the class symbols associated with a warning is the
|
|
|
445 same as any of the symbols listed here, the warning will be completely
|
|
|
446 ignored, as it they never happened.
|
|
|
447 @end defvar
|
|
|
448
|
|
|
449 @defvar display-warning-suppressed-classes
|
|
|
450 This variable specifies a list of classes that should not be logged or
|
|
|
451 displayed. If any of the class symbols associated with a warning is the
|
|
|
452 same as any of the symbols listed here, the warning will not be
|
|
|
453 displayed. The warning will still logged in the *Warnings* buffer
|
|
|
454 (unless also contained in `log-warning-suppressed-classes'), but the
|
|
|
455 buffer will not be automatically popped up.
|
|
|
456 @end defvar
|
|
|
457
|
|
|
458 @node Invisible Text
|
|
|
459 @section Invisible Text
|
|
|
460
|
|
|
461 @cindex invisible text
|
|
|
462 You can make characters @dfn{invisible}, so that they do not appear on
|
|
|
463 the screen, with the @code{invisible} property. This can be either a
|
|
|
464 text property or a property of an overlay.
|
|
|
465
|
|
|
466 In the simplest case, any non-@code{nil} @code{invisible} property makes
|
|
|
467 a character invisible. This is the default case---if you don't alter
|
|
|
468 the default value of @code{buffer-invisibility-spec}, this is how the
|
|
|
469 @code{invisibility} property works. This feature is much like selective
|
|
|
470 display (@pxref{Selective Display}), but more general and cleaner.
|
|
|
471
|
|
|
472 More generally, you can use the variable @code{buffer-invisibility-spec}
|
|
|
473 to control which values of the @code{invisible} property make text
|
|
|
474 invisible. This permits you to classify the text into different subsets
|
|
|
475 in advance, by giving them different @code{invisible} values, and
|
|
|
476 subsequently make various subsets visible or invisible by changing the
|
|
|
477 value of @code{buffer-invisibility-spec}.
|
|
|
478
|
|
|
479 Controlling visibility with @code{buffer-invisibility-spec} is
|
|
|
480 especially useful in a program to display the list of entries in a data
|
|
|
481 base. It permits the implementation of convenient filtering commands to
|
|
|
482 view just a part of the entries in the data base. Setting this variable
|
|
|
483 is very fast, much faster than scanning all the text in the buffer
|
|
|
484 looking for properties to change.
|
|
|
485
|
|
|
486 @defvar buffer-invisibility-spec
|
|
|
487 This variable specifies which kinds of @code{invisible} properties
|
|
|
488 actually make a character invisible.
|
|
|
489
|
|
|
490 @table @asis
|
|
|
491 @item @code{t}
|
|
|
492 A character is invisible if its @code{invisible} property is
|
|
|
493 non-@code{nil}. This is the default.
|
|
|
494
|
|
|
495 @item a list
|
|
|
496 Each element of the list makes certain characters invisible.
|
|
|
497 Ultimately, a character is invisible if any of the elements of this list
|
|
|
498 applies to it. The list can have two kinds of elements:
|
|
|
499
|
|
|
500 @table @code
|
|
|
501 @item @var{atom}
|
|
|
502 A character is invisible if its @code{invisible} property value
|
|
|
503 is @var{atom} or if it is a list with @var{atom} as a member.
|
|
|
504
|
|
|
505 @item (@var{atom} . t)
|
|
|
506 A character is invisible if its @code{invisible} property value
|
|
|
507 is @var{atom} or if it is a list with @var{atom} as a member.
|
|
|
508 Moreover, if this character is at the end of a line and is followed
|
|
|
509 by a visible newline, it displays an ellipsis.
|
|
|
510 @end table
|
|
|
511 @end table
|
|
|
512 @end defvar
|
|
|
513
|
|
|
514 Ordinarily, commands that operate on text or move point do not care
|
|
|
515 whether the text is invisible. However, the user-level line motion
|
|
|
516 commands explicitly ignore invisible newlines.
|
|
|
517
|
|
|
518 @node Selective Display
|
|
|
519 @section Selective Display
|
|
|
520 @cindex selective display
|
|
|
521
|
|
|
522 @dfn{Selective display} is a pair of features that hide certain
|
|
|
523 lines on the screen.
|
|
|
524
|
|
|
525 The first variant, explicit selective display, is designed for use in
|
|
|
526 a Lisp program. The program controls which lines are hidden by altering
|
|
|
527 the text. Outline mode has traditionally used this variant. It has
|
|
|
528 been partially replaced by the invisible text feature (@pxref{Invisible
|
|
|
529 Text}); there is a new version of Outline mode which uses that instead.
|
|
|
530
|
|
|
531 In the second variant, the choice of lines to hide is made
|
|
|
532 automatically based on indentation. This variant is designed to be a
|
|
|
533 user-level feature.
|
|
|
534
|
|
|
535 The way you control explicit selective display is by replacing a
|
|
|
536 newline (control-j) with a carriage return (control-m). The text that
|
|
|
537 was formerly a line following that newline is now invisible. Strictly
|
|
|
538 speaking, it is temporarily no longer a line at all, since only newlines
|
|
|
539 can separate lines; it is now part of the previous line.
|
|
|
540
|
|
|
541 Selective display does not directly affect editing commands. For
|
|
|
542 example, @kbd{C-f} (@code{forward-char}) moves point unhesitatingly into
|
|
|
543 invisible text. However, the replacement of newline characters with
|
|
|
544 carriage return characters affects some editing commands. For example,
|
|
|
545 @code{next-line} skips invisible lines, since it searches only for
|
|
|
546 newlines. Modes that use selective display can also define commands
|
|
|
547 that take account of the newlines, or that make parts of the text
|
|
|
548 visible or invisible.
|
|
|
549
|
|
|
550 When you write a selectively displayed buffer into a file, all the
|
|
|
551 control-m's are output as newlines. This means that when you next read
|
|
|
552 in the file, it looks OK, with nothing invisible. The selective display
|
|
|
553 effect is seen only within XEmacs.
|
|
|
554
|
|
|
555 @defvar selective-display
|
|
|
556 This buffer-local variable enables selective display. This means that
|
|
|
557 lines, or portions of lines, may be made invisible.
|
|
|
558
|
|
|
559 @itemize @bullet
|
|
|
560 @item
|
|
|
561 If the value of @code{selective-display} is @code{t}, then any portion
|
|
|
562 of a line that follows a control-m is not displayed.
|
|
|
563
|
|
|
564 @item
|
|
|
565 If the value of @code{selective-display} is a positive integer, then
|
|
|
566 lines that start with more than that many columns of indentation are not
|
|
|
567 displayed.
|
|
|
568 @end itemize
|
|
|
569
|
|
|
570 When some portion of a buffer is invisible, the vertical movement
|
|
|
571 commands operate as if that portion did not exist, allowing a single
|
|
|
572 @code{next-line} command to skip any number of invisible lines.
|
|
|
573 However, character movement commands (such as @code{forward-char}) do
|
|
|
574 not skip the invisible portion, and it is possible (if tricky) to insert
|
|
|
575 or delete text in an invisible portion.
|
|
|
576
|
|
|
577 In the examples below, we show the @emph{display appearance} of the
|
|
|
578 buffer @code{foo}, which changes with the value of
|
|
|
579 @code{selective-display}. The @emph{contents} of the buffer do not
|
|
|
580 change.
|
|
|
581
|
|
|
582 @example
|
|
|
583 @group
|
|
|
584 (setq selective-display nil)
|
|
|
585 @result{} nil
|
|
|
586
|
|
|
587 ---------- Buffer: foo ----------
|
|
|
588 1 on this column
|
|
|
589 2on this column
|
|
|
590 3n this column
|
|
|
591 3n this column
|
|
|
592 2on this column
|
|
|
593 1 on this column
|
|
|
594 ---------- Buffer: foo ----------
|
|
|
595 @end group
|
|
|
596
|
|
|
597 @group
|
|
|
598 (setq selective-display 2)
|
|
|
599 @result{} 2
|
|
|
600
|
|
|
601 ---------- Buffer: foo ----------
|
|
|
602 1 on this column
|
|
|
603 2on this column
|
|
|
604 2on this column
|
|
|
605 1 on this column
|
|
|
606 ---------- Buffer: foo ----------
|
|
|
607 @end group
|
|
|
608 @end example
|
|
|
609 @end defvar
|
|
|
610
|
|
|
611 @defvar selective-display-ellipses
|
|
|
612 If this buffer-local variable is non-@code{nil}, then XEmacs displays
|
|
|
613 @samp{@dots{}} at the end of a line that is followed by invisible text.
|
|
|
614 This example is a continuation of the previous one.
|
|
|
615
|
|
|
616 @example
|
|
|
617 @group
|
|
|
618 (setq selective-display-ellipses t)
|
|
|
619 @result{} t
|
|
|
620
|
|
|
621 ---------- Buffer: foo ----------
|
|
|
622 1 on this column
|
|
|
623 2on this column ...
|
|
|
624 2on this column
|
|
|
625 1 on this column
|
|
|
626 ---------- Buffer: foo ----------
|
|
|
627 @end group
|
|
|
628 @end example
|
|
|
629
|
|
|
630 You can use a display table to substitute other text for the ellipsis
|
|
|
631 (@samp{@dots{}}). @xref{Display Tables}.
|
|
|
632 @end defvar
|
|
|
633
|
|
|
634 @node Overlay Arrow
|
|
|
635 @section The Overlay Arrow
|
|
|
636 @cindex overlay arrow
|
|
|
637
|
|
|
638 The @dfn{overlay arrow} is useful for directing the user's attention
|
|
|
639 to a particular line in a buffer. For example, in the modes used for
|
|
|
640 interface to debuggers, the overlay arrow indicates the line of code
|
|
|
641 about to be executed.
|
|
|
642
|
|
|
643 @defvar overlay-arrow-string
|
|
|
644 This variable holds the string to display to call attention to a
|
|
|
645 particular line, or @code{nil} if the arrow feature is not in use.
|
|
|
646 Despite its name, the value of this variable can be either a string
|
|
|
647 or a glyph (@pxref{Glyphs}).
|
|
|
648 @end defvar
|
|
|
649
|
|
|
650 @defvar overlay-arrow-position
|
|
|
651 This variable holds a marker that indicates where to display the overlay
|
|
|
652 arrow. It should point at the beginning of a line. The arrow text
|
|
|
653 appears at the beginning of that line, overlaying any text that would
|
|
|
654 otherwise appear. Since the arrow is usually short, and the line
|
|
|
655 usually begins with indentation, normally nothing significant is
|
|
|
656 overwritten.
|
|
|
657
|
|
|
658 The overlay string is displayed only in the buffer that this marker
|
|
|
659 points into. Thus, only one buffer can have an overlay arrow at any
|
|
|
660 given time.
|
|
|
661 @c !!! overlay-arrow-position: but the overlay string may remain in the display
|
|
|
662 @c of some other buffer until an update is required. This should be fixed
|
|
|
663 @c now. Is it?
|
|
|
664 @end defvar
|
|
|
665
|
|
|
666 You can do the same job by creating an extent with a
|
|
|
667 @code{begin-glyph} property. @xref{Extent Properties}.
|
|
|
668
|
|
|
669 @node Temporary Displays
|
|
|
670 @section Temporary Displays
|
|
|
671
|
|
|
672 Temporary displays are used by commands to put output into a buffer
|
|
|
673 and then present it to the user for perusal rather than for editing.
|
|
|
674 Many of the help commands use this feature.
|
|
|
675
|
|
|
676 @defspec with-output-to-temp-buffer buffer-name forms@dots{}
|
|
|
677 This function executes @var{forms} while arranging to insert any
|
|
|
678 output they print into the buffer named @var{buffer-name}. The buffer
|
|
|
679 is then shown in some window for viewing, displayed but not selected.
|
|
|
680
|
|
|
681 The string @var{buffer-name} specifies the temporary buffer, which
|
|
|
682 need not already exist. The argument must be a string, not a buffer.
|
|
|
683 The buffer is erased initially (with no questions asked), and it is
|
|
|
684 marked as unmodified after @code{with-output-to-temp-buffer} exits.
|
|
|
685
|
|
|
686 @code{with-output-to-temp-buffer} binds @code{standard-output} to the
|
|
|
687 temporary buffer, then it evaluates the forms in @var{forms}. Output
|
|
|
688 using the Lisp output functions within @var{forms} goes by default to
|
|
|
689 that buffer (but screen display and messages in the echo area, although
|
|
|
690 they are ``output'' in the general sense of the word, are not affected).
|
|
|
691 @xref{Output Functions}.
|
|
|
692
|
|
|
693 The value of the last form in @var{forms} is returned.
|
|
|
694
|
|
|
695 @example
|
|
|
696 @group
|
|
|
697 ---------- Buffer: foo ----------
|
|
|
698 This is the contents of foo.
|
|
|
699 ---------- Buffer: foo ----------
|
|
|
700 @end group
|
|
|
701
|
|
|
702 @group
|
|
|
703 (with-output-to-temp-buffer "foo"
|
|
|
704 (print 20)
|
|
|
705 (print standard-output))
|
|
|
706 @result{} #<buffer foo>
|
|
|
707
|
|
|
708 ---------- Buffer: foo ----------
|
|
|
709 20
|
|
|
710
|
|
|
711 #<buffer foo>
|
|
|
712
|
|
|
713 ---------- Buffer: foo ----------
|
|
|
714 @end group
|
|
|
715 @end example
|
|
|
716 @end defspec
|
|
|
717
|
|
|
718 @defvar temp-buffer-show-function
|
|
|
719 If this variable is non-@code{nil}, @code{with-output-to-temp-buffer}
|
|
|
720 calls it as a function to do the job of displaying a help buffer. The
|
|
|
721 function gets one argument, which is the buffer it should display.
|
|
|
722
|
|
|
723 In Emacs versions 18 and earlier, this variable was called
|
|
|
724 @code{temp-buffer-show-hook}.
|
|
|
725 @end defvar
|
|
|
726
|
|
|
727 @defun momentary-string-display string position &optional char message
|
|
|
728 This function momentarily displays @var{string} in the current buffer at
|
|
|
729 @var{position}. It has no effect on the undo list or on the buffer's
|
|
|
730 modification status.
|
|
|
731
|
|
|
732 The momentary display remains until the next input event. If the next
|
|
|
733 input event is @var{char}, @code{momentary-string-display} ignores it
|
|
|
734 and returns. Otherwise, that event remains buffered for subsequent use
|
|
|
735 as input. Thus, typing @var{char} will simply remove the string from
|
|
|
736 the display, while typing (say) @kbd{C-f} will remove the string from
|
|
|
737 the display and later (presumably) move point forward. The argument
|
|
|
738 @var{char} is a space by default.
|
|
|
739
|
|
|
740 The return value of @code{momentary-string-display} is not meaningful.
|
|
|
741
|
|
|
742 You can do the same job in a more general way by creating an extent
|
|
|
743 with a begin-glyph property. @xref{Extent Properties}.
|
|
|
744
|
|
|
745 If @var{message} is non-@code{nil}, it is displayed in the echo area
|
|
|
746 while @var{string} is displayed in the buffer. If it is @code{nil}, a
|
|
|
747 default message says to type @var{char} to continue.
|
|
|
748
|
|
|
749 In this example, point is initially located at the beginning of the
|
|
|
750 second line:
|
|
|
751
|
|
|
752 @example
|
|
|
753 @group
|
|
|
754 ---------- Buffer: foo ----------
|
|
|
755 This is the contents of foo.
|
|
|
756 @point{}Second line.
|
|
|
757 ---------- Buffer: foo ----------
|
|
|
758 @end group
|
|
|
759
|
|
|
760 @group
|
|
|
761 (momentary-string-display
|
|
|
762 "**** Important Message! ****"
|
|
|
763 (point) ?\r
|
|
|
764 "Type RET when done reading")
|
|
|
765 @result{} t
|
|
|
766 @end group
|
|
|
767
|
|
|
768 @group
|
|
|
769 ---------- Buffer: foo ----------
|
|
|
770 This is the contents of foo.
|
|
|
771 **** Important Message! ****Second line.
|
|
|
772 ---------- Buffer: foo ----------
|
|
|
773
|
|
|
774 ---------- Echo Area ----------
|
|
|
775 Type RET when done reading
|
|
|
776 ---------- Echo Area ----------
|
|
|
777 @end group
|
|
|
778 @end example
|
|
|
779
|
|
|
780 This function works by actually changing the text in the buffer. As a
|
|
|
781 result, if you later undo in this buffer, you will see the message come
|
|
|
782 and go.
|
|
|
783 @end defun
|
|
|
784
|
|
|
785 @node Blinking
|
|
|
786 @section Blinking Parentheses
|
|
|
787 @cindex parenthesis matching
|
|
|
788 @cindex blinking
|
|
|
789 @cindex balancing parentheses
|
|
|
790 @cindex close parenthesis
|
|
|
791
|
|
|
792 This section describes the mechanism by which XEmacs shows a matching
|
|
|
793 open parenthesis when the user inserts a close parenthesis.
|
|
|
794
|
|
|
795 @vindex blink-paren-hook
|
|
|
796 @defvar blink-paren-function
|
|
|
797 The value of this variable should be a function (of no arguments) to
|
|
|
798 be called whenever a character with close parenthesis syntax is inserted.
|
|
|
799 The value of @code{blink-paren-function} may be @code{nil}, in which
|
|
|
800 case nothing is done.
|
|
|
801
|
|
|
802 @quotation
|
|
|
803 @strong{Please note:} This variable was named @code{blink-paren-hook} in
|
|
|
804 older Emacs versions, but since it is not called with the standard
|
|
|
805 convention for hooks, it was renamed to @code{blink-paren-function} in
|
|
|
806 version 19.
|
|
|
807 @end quotation
|
|
|
808 @end defvar
|
|
|
809
|
|
|
810 @defvar blink-matching-paren
|
|
|
811 If this variable is @code{nil}, then @code{blink-matching-open} does
|
|
|
812 nothing.
|
|
|
813 @end defvar
|
|
|
814
|
|
|
815 @defvar blink-matching-paren-distance
|
|
|
816 This variable specifies the maximum distance to scan for a matching
|
|
|
817 parenthesis before giving up.
|
|
|
818 @end defvar
|
|
|
819
|
|
|
820 @defvar blink-matching-paren-delay
|
|
|
821 This variable specifies the number of seconds for the cursor to remain
|
|
|
822 at the matching parenthesis. A fraction of a second often gives
|
|
|
823 good results, but the default is 1, which works on all systems.
|
|
|
824 @end defvar
|
|
|
825
|
|
|
826 @defun blink-matching-open
|
|
|
827 This function is the default value of @code{blink-paren-function}. It
|
|
|
828 assumes that point follows a character with close parenthesis syntax and
|
|
|
829 moves the cursor momentarily to the matching opening character. If that
|
|
|
830 character is not already on the screen, it displays the character's
|
|
|
831 context in the echo area. To avoid long delays, this function does not
|
|
|
832 search farther than @code{blink-matching-paren-distance} characters.
|
|
|
833
|
|
|
834 Here is an example of calling this function explicitly.
|
|
|
835
|
|
|
836 @smallexample
|
|
|
837 @group
|
|
|
838 (defun interactive-blink-matching-open ()
|
|
|
839 @c Do not break this line! -- rms.
|
|
|
840 @c The first line of a doc string
|
|
|
841 @c must stand alone.
|
|
|
842 "Indicate momentarily the start of sexp before point."
|
|
|
843 (interactive)
|
|
|
844 @end group
|
|
|
845 @group
|
|
|
846 (let ((blink-matching-paren-distance
|
|
|
847 (buffer-size))
|
|
|
848 (blink-matching-paren t))
|
|
|
849 (blink-matching-open)))
|
|
|
850 @end group
|
|
|
851 @end smallexample
|
|
|
852 @end defun
|
|
|
853
|
|
|
854 @node Usual Display
|
|
|
855 @section Usual Display Conventions
|
|
|
856
|
|
|
857 The usual display conventions define how to display each character
|
|
|
858 code. You can override these conventions by setting up a display table
|
|
|
859 (@pxref{Display Tables}). Here are the usual display conventions:
|
|
|
860
|
|
|
861 @itemize @bullet
|
|
|
862 @item
|
|
|
863 Character codes 32 through 126 map to glyph codes 32 through 126.
|
|
|
864 Normally this means they display as themselves.
|
|
|
865
|
|
|
866 @item
|
|
|
867 Character code 9 is a horizontal tab. It displays as whitespace
|
|
|
868 up to a position determined by @code{tab-width}.
|
|
|
869
|
|
|
870 @item
|
|
|
871 Character code 10 is a newline.
|
|
|
872
|
|
|
873 @item
|
|
|
874 All other codes in the range 0 through 31, and code 127, display in one
|
|
|
875 of two ways according to the value of @code{ctl-arrow}. If it is
|
|
|
876 non-@code{nil}, these codes map to sequences of two glyphs, where the
|
|
|
877 first glyph is the @sc{ascii} code for @samp{^}. (A display table can
|
|
|
878 specify a glyph to use instead of @samp{^}.) Otherwise, these codes map
|
|
|
879 just like the codes in the range 128 to 255.
|
|
|
880
|
|
|
881 @item
|
|
|
882 Character codes 128 through 255 map to sequences of four glyphs, where
|
|
|
883 the first glyph is the @sc{ascii} code for @samp{\}, and the others are
|
|
|
884 digit characters representing the code in octal. (A display table can
|
|
|
885 specify a glyph to use instead of @samp{\}.)
|
|
|
886 @end itemize
|
|
|
887
|
|
|
888 The usual display conventions apply even when there is a display
|
|
|
889 table, for any character whose entry in the active display table is
|
|
|
890 @code{nil}. Thus, when you set up a display table, you need only
|
|
|
891 specify the characters for which you want unusual behavior.
|
|
|
892
|
|
|
893 These variables affect the way certain characters are displayed on the
|
|
|
894 screen. Since they change the number of columns the characters occupy,
|
|
|
895 they also affect the indentation functions.
|
|
|
896
|
|
|
897 @defopt ctl-arrow
|
|
|
898 @cindex control characters in display
|
|
|
899 This buffer-local variable controls how control characters are
|
|
|
900 displayed. If it is non-@code{nil}, they are displayed as a caret
|
|
|
901 followed by the character: @samp{^A}. If it is @code{nil}, they are
|
|
|
902 displayed as a backslash followed by three octal digits: @samp{\001}.
|
|
|
903 @end defopt
|
|
|
904
|
|
|
905 @c Following may have overfull hbox.
|
|
|
906 @defvar default-ctl-arrow
|
|
|
907 The value of this variable is the default value for @code{ctl-arrow} in
|
|
|
908 buffers that do not override it. @xref{Default Value}.
|
|
|
909 @end defvar
|
|
|
910
|
|
|
911 @defopt tab-width
|
|
|
912 The value of this variable is the spacing between tab stops used for
|
|
|
913 displaying tab characters in Emacs buffers. The default is 8. Note
|
|
|
914 that this feature is completely independent from the user-settable tab
|
|
|
915 stops used by the command @code{tab-to-tab-stop}. @xref{Indent Tabs}.
|
|
|
916 @end defopt
|
|
|
917
|
|
|
918 @node Display Tables
|
|
|
919 @section Display Tables
|
|
|
920
|
|
|
921 @cindex display table
|
|
|
922 You can use the @dfn{display table} feature to control how all 256
|
|
|
923 possible character codes display on the screen. This is useful for
|
|
|
924 displaying European languages that have letters not in the @sc{ascii}
|
|
|
925 character set.
|
|
|
926
|
|
|
927 The display table maps each character code into a sequence of
|
|
|
928 @dfn{runes}, each rune being an image that takes up one character
|
|
|
929 position on the screen. You can also define how to display each rune
|
|
|
930 on your terminal, using the @dfn{rune table}.
|
|
|
931
|
|
|
932 @menu
|
|
|
933 * Display Table Format:: What a display table consists of.
|
|
|
934 * Active Display Table:: How XEmacs selects a display table to use.
|
|
|
935 * Character Descriptors:: Format of an individual element of a
|
|
|
936 display table.
|
|
|
937 @end menu
|
|
|
938
|
|
|
939 @ignore Not yet working in XEmacs?
|
|
|
940 * ISO Latin 1:: How to use display tables
|
|
|
941 to support the ISO Latin 1 character set.
|
|
|
942 @end ignore
|
|
|
943
|
|
|
944 @node Display Table Format
|
|
|
945 @subsection Display Table Format
|
|
|
946
|
|
|
947 A display table is an array of 256 elements. (In FSF Emacs, a display
|
|
|
948 table is 262 elements. The six extra elements specify the truncation
|
|
|
949 and continuation glyphs, etc. This method is very kludgey, and in
|
|
|
950 XEmacs the variables @code{truncation-glyph}, @code{continuation-glyph},
|
|
|
951 etc. are used. @xref{Truncation}.)
|
|
|
952
|
|
|
953 @defun make-display-table
|
|
|
954 This creates and returns a display table. The table initially has
|
|
|
955 @code{nil} in all elements.
|
|
|
956 @end defun
|
|
|
957
|
|
|
958 The 256 elements correspond to character codes; the @var{n}th
|
|
|
959 element says how to display the character code @var{n}. The value
|
|
|
960 should be @code{nil}, a string, a glyph, or a vector of strings and
|
|
|
961 glyphs (@pxref{Character Descriptors}). If an element is @code{nil},
|
|
|
962 it says to display that character according to the usual display
|
|
|
963 conventions (@pxref{Usual Display}).
|
|
|
964
|
|
|
965 If you use the display table to change the display of newline
|
|
|
966 characters, the whole buffer will be displayed as one long ``line.''
|
|
|
967
|
|
|
968 For example, here is how to construct a display table that mimics the
|
|
|
969 effect of setting @code{ctl-arrow} to a non-@code{nil} value:
|
|
|
970
|
|
|
971 @example
|
|
|
972 (setq disptab (make-display-table))
|
|
|
973 (let ((i 0))
|
|
|
974 (while (< i 32)
|
|
|
975 (or (= i ?\t) (= i ?\n)
|
|
|
976 (aset disptab i (concat "^" (char-to-string (+ i 64)))))
|
|
|
977 (setq i (1+ i)))
|
|
|
978 (aset disptab 127 "^?"))
|
|
|
979 @end example
|
|
|
980
|
|
|
981 @node Active Display Table
|
|
|
982 @subsection Active Display Table
|
|
|
983 @cindex active display table
|
|
|
984
|
|
|
985 The active display table is controlled by the variable
|
|
|
986 @code{current-display-table}. This is a specifier, which means
|
|
|
987 that you can specify separate values for it in individual buffers,
|
|
|
988 windows, frames, and devices, as well as a global value. It also
|
|
|
989 means that you cannot set this variable using @code{setq}; use
|
|
|
990 @code{set-specifier} instead. @xref{Specifiers}. (FSF Emacs
|
|
|
991 uses @code{window-display-table}, @code{buffer-display-table},
|
|
|
992 @code{standard-display-table}, etc. to control the display table.
|
|
|
993 However, specifiers are a cleaner and more powerful way of doing
|
|
|
994 the same thing. FSF Emacs also uses a different format for
|
|
|
995 the contents of a display table, using additional indirection
|
|
|
996 to a ``glyph table'' and such. Note that ``glyph'' has a different
|
|
|
997 meaning in XEmacs.)
|
|
|
998
|
|
442
|
999 @defvar current-display-table
|
|
|
1000
|
|
|
1001 The display table currently in use. This is a specifier.
|
|
|
1002
|
|
|
1003 Display tables are used to control how characters are displayed. Each
|
|
|
1004 time that redisplay processes a character, it is looked up in all the
|
|
|
1005 display tables that apply (obtained by calling @code{specifier-instance}
|
|
|
1006 on @code{current-display-table} and any overriding display tables
|
|
|
1007 specified in currently active faces). The first entry found that
|
|
|
1008 matches the character determines how the character is displayed. If
|
|
|
1009 there is no matching entry, the default display method is
|
|
|
1010 used. (Non-control characters are displayed as themselves and control
|
|
|
1011 characters are displayed according to the buffer-local variable
|
|
|
1012 @code{ctl-arrow}. Control characters are further affected by
|
|
|
1013 @code{control-arrow-glyph} and @code{octal-escape-glyph}.)
|
|
|
1014
|
|
|
1015 Each instantiator in this specifier and the display-table specifiers
|
|
|
1016 in faces is a display table or a list of such tables. If a list, each
|
|
|
1017 table will be searched in turn for an entry matching a particular
|
|
|
1018 character. Each display table is one of
|
|
|
1019
|
|
|
1020 @itemize @bullet
|
|
|
1021 @item
|
|
|
1022 A vector, specifying values for characters starting at 0.
|
|
|
1023 @item
|
|
|
1024 A char table, either of type @code{char} or @code{generic}.
|
|
|
1025 @item
|
|
|
1026 A range table.
|
|
|
1027 @end itemize
|
|
|
1028
|
|
|
1029 Each entry in a display table should be one of
|
|
|
1030
|
|
|
1031 @itemize @bullet
|
|
|
1032 @item
|
|
|
1033 nil (this entry is ignored and the search continues).
|
|
|
1034 @item
|
|
|
1035 A character (use this character; if it happens to be the same as
|
|
|
1036 the original character, default processing happens, otherwise
|
|
|
1037 redisplay attempts to display this character directly;
|
|
|
1038 #### At some point recursive display-table lookup will be
|
|
|
1039 implemented).
|
|
|
1040 @item
|
|
|
1041 A string (display each character in the string directly;
|
|
|
1042 #### At some point recursive display-table lookup will be
|
|
|
1043 implemented).
|
|
|
1044 @item
|
|
|
1045 A glyph (display the glyph;
|
|
|
1046 #### At some point recursive display-table lookup will be
|
|
|
1047 implemented when a string glyph is being processed).
|
|
|
1048 @item
|
|
|
1049 A cons of the form (format "@var{string}") where @var{string} is a
|
|
|
1050 printf-like spec used to process the character. #### Unfortunately no
|
|
|
1051 formatting directives other than %% are implemented.
|
|
|
1052 @item
|
|
|
1053 A vector (each element of the vector is processed recursively;
|
|
|
1054 in such a case, nil elements in the vector are simply ignored).
|
|
|
1055
|
|
|
1056 #### At some point in the near future, display tables are likely to
|
|
|
1057 be expanded to include other features, such as referencing characters
|
|
|
1058 in particular fonts and allowing the character search to continue
|
|
|
1059 all the way up the chain of specifier instantiators. These features
|
|
|
1060 are necessary to properly display Unicode characters.
|
|
|
1061 @end itemize
|
|
|
1062 @end defvar
|
|
|
1063
|
|
428
|
1064 Individual faces can also specify an overriding display table;
|
|
|
1065 this is set using @code{set-face-display-table}. @xref{Faces}.
|
|
|
1066
|
|
|
1067 If no display table can be determined for a particular window,
|
|
|
1068 then XEmacs uses the usual display conventions. @xref{Usual Display}.
|
|
|
1069
|
|
|
1070 @node Character Descriptors
|
|
|
1071 @subsection Character Descriptors
|
|
|
1072
|
|
|
1073 @cindex character descriptor
|
|
|
1074 Each element of the display-table vector describes how to display
|
|
|
1075 a particular character and is called a @dfn{character descriptor}.
|
|
|
1076 A character descriptor can be:
|
|
|
1077
|
|
|
1078 @table @asis
|
|
|
1079 @item a string
|
|
|
1080 Display this particular string wherever the character is to be displayed.
|
|
|
1081
|
|
|
1082 @item a glyph
|
|
|
1083 Display this particular glyph wherever the character is to be displayed.
|
|
|
1084
|
|
|
1085 @item a vector
|
|
|
1086 The vector may contain strings and/or glyphs. Display the elements of
|
|
|
1087 the vector one after another wherever the character is to be displayed.
|
|
|
1088
|
|
|
1089 @item @code{nil}
|
|
|
1090 Display according to the standard interpretation (@pxref{Usual Display}).
|
|
|
1091 @end table
|
|
|
1092
|
|
|
1093 @ignore Not yet working in XEmacs?
|
|
|
1094 @node ISO Latin 1
|
|
|
1095 @subsection ISO Latin 1
|
|
|
1096
|
|
|
1097 If you have a terminal that can handle the entire ISO Latin 1 character
|
|
|
1098 set, you can arrange to use that character set as follows:
|
|
|
1099
|
|
|
1100 @example
|
|
|
1101 (require 'disp-table)
|
|
|
1102 ;; @r{Set char codes 160--255 to display as themselves.}
|
|
|
1103 ;; @r{(Codes 128--159 are the additional control characters.)}
|
|
|
1104 (standard-display-8bit 160 255)
|
|
|
1105 @end example
|
|
|
1106
|
|
|
1107 If you are editing buffers written in the ISO Latin 1 character set and
|
|
|
1108 your terminal doesn't handle anything but @sc{ascii}, you can load the
|
|
|
1109 file @file{iso-ascii} to set up a display table that displays the other
|
|
|
1110 ISO characters as explanatory sequences of @sc{ascii} characters. For
|
|
|
1111 example, the character ``o with umlaut'' displays as @samp{@{"o@}}.
|
|
|
1112
|
|
|
1113 Some European countries have terminals that don't support ISO Latin 1
|
|
|
1114 but do support the special characters for that country's language. You
|
|
|
1115 can define a display table to work one language using such terminals.
|
|
|
1116 For an example, see @file{lisp/iso-swed.el}, which handles certain
|
|
|
1117 Swedish terminals.
|
|
|
1118
|
|
|
1119 You can load the appropriate display table for your terminal
|
|
|
1120 automatically by writing a terminal-specific Lisp file for the terminal
|
|
|
1121 type.
|
|
|
1122 @end ignore
|
|
|
1123
|
|
|
1124 @node Beeping
|
|
|
1125 @section Beeping
|
|
|
1126 @cindex beeping
|
|
|
1127 @cindex bell
|
|
|
1128 @cindex sound
|
|
|
1129
|
|
|
1130 You can make XEmacs ring a bell, play a sound, or blink the screen to
|
|
|
1131 attract the user's attention. Be conservative about how often you do
|
|
|
1132 this; frequent bells can become irritating. Also be careful not to use
|
|
|
1133 beeping alone when signaling an error is appropriate. (@xref{Errors}.)
|
|
|
1134
|
|
|
1135 @defun ding &optional dont-terminate sound device
|
|
|
1136 @cindex keyboard macro termination
|
|
|
1137 This function beeps, or flashes the screen (see @code{visible-bell}
|
|
|
1138 below). It also terminates any keyboard macro currently executing
|
|
|
1139 unless @var{dont-terminate} is non-@code{nil}. If @var{sound} is
|
|
|
1140 specified, it should be a symbol specifying which sound to make. This
|
|
|
1141 sound will be played if @code{visible-bell} is @code{nil}. (This only
|
|
|
1142 works if sound support was compiled into the executable and you are
|
|
|
1143 running on the console of a Sun SparcStation, SGI, HP9000s700, or Linux
|
|
|
1144 PC. Otherwise you just get a beep.) The optional third argument
|
|
|
1145 specifies what device to make the sound on, and defaults to the selected
|
|
|
1146 device.
|
|
|
1147 @end defun
|
|
|
1148
|
|
|
1149 @defun beep &optional dont-terminate sound device
|
|
|
1150 This is a synonym for @code{ding}.
|
|
|
1151 @end defun
|
|
|
1152
|
|
|
1153 @defopt visible-bell
|
|
|
1154 This variable determines whether XEmacs should flash the screen to
|
|
|
1155 represent a bell. Non-@code{nil} means yes, @code{nil} means no. On
|
|
|
1156 TTY devices, this is effective only if the Termcap entry for the
|
|
|
1157 terminal type has the visible bell flag (@samp{vb}) set.
|
|
|
1158 @end defopt
|
|
|
1159
|
|
|
1160 @defvar sound-alist
|
|
|
1161 This variable holds an alist associating names with sounds. When
|
|
|
1162 @code{beep} or @code{ding} is called with one of the name symbols, the
|
|
|
1163 associated sound will be generated instead of the standard beep.
|
|
|
1164
|
|
|
1165 Each element of @code{sound-alist} is a list describing a sound. The
|
|
|
1166 first element of the list is the name of the sound being defined.
|
|
|
1167 Subsequent elements of the list are alternating keyword/value pairs:
|
|
|
1168
|
|
|
1169 @table @code
|
|
|
1170 @item sound
|
|
|
1171 A string of raw sound data, or the name of another sound to play. The
|
|
|
1172 symbol @code{t} here means use the default X beep.
|
|
|
1173 @item volume
|
|
|
1174 An integer from 0-100, defaulting to @code{bell-volume}.
|
|
|
1175 @item pitch
|
|
|
1176 If using the default X beep, the pitch (Hz) to generate.
|
|
|
1177 @item duration
|
|
|
1178 If using the default X beep, the duration (milliseconds).
|
|
|
1179 @end table
|
|
|
1180
|
|
|
1181 For compatibility, elements of `sound-alist' may also be:
|
|
|
1182
|
|
|
1183 @itemize @bullet
|
|
|
1184 @item
|
|
|
1185 @code{( sound-name . <sound> )}
|
|
|
1186 @item
|
|
|
1187 @code{( sound-name <volume> <sound> )}
|
|
|
1188 @end itemize
|
|
|
1189
|
|
|
1190 You should probably add things to this list by calling the function
|
|
|
1191 @code{load-sound-file}.
|
|
|
1192
|
|
|
1193 Caveats:
|
|
|
1194
|
|
|
1195 @itemize @minus
|
|
|
1196 @item
|
|
|
1197 You can only play audio data if running on the console screen of a Sun
|
|
|
1198 SparcStation, SGI, or HP9000s700.
|
|
|
1199
|
|
|
1200 @item
|
|
|
1201 The pitch, duration, and volume options are available everywhere, but
|
|
|
1202 many X servers ignore the `pitch' option.
|
|
|
1203 @end itemize
|
|
|
1204
|
|
|
1205 The following beep-types are used by XEmacs itself:
|
|
|
1206
|
|
|
1207 @table @code
|
|
|
1208 @item auto-save-error
|
|
|
1209 when an auto-save does not succeed
|
|
|
1210 @item command-error
|
|
|
1211 when the XEmacs command loop catches an error
|
|
|
1212 @item undefined-key
|
|
|
1213 when you type a key that is undefined
|
|
|
1214 @item undefined-click
|
|
|
1215 when you use an undefined mouse-click combination
|
|
|
1216 @item no-completion
|
|
|
1217 during completing-read
|
|
|
1218 @item y-or-n-p
|
|
|
1219 when you type something other than 'y' or 'n'
|
|
|
1220 @item yes-or-no-p
|
|
|
1221 when you type something other than 'yes' or 'no'
|
|
|
1222 @item default
|
|
|
1223 used when nothing else is appropriate.
|
|
|
1224 @end table
|
|
|
1225
|
|
|
1226 Other lisp packages may use other beep types, but these are the ones that
|
|
|
1227 the C kernel of XEmacs uses.
|
|
|
1228 @end defvar
|
|
|
1229
|
|
|
1230 @defopt bell-volume
|
|
|
1231 This variable specifies the default volume for sounds, from 0 to 100.
|
|
|
1232 @end defopt
|
|
|
1233
|
|
|
1234 @deffn Command load-default-sounds
|
|
|
1235 This function loads and installs some sound files as beep-types.
|
|
|
1236 @end deffn
|
|
|
1237
|
|
|
1238 @deffn Command load-sound-file filename sound-name &optional volume
|
|
|
1239 This function reads in an audio file and adds it to @code{sound-alist}.
|
|
|
1240 The sound file must be in the Sun/NeXT U-LAW format. @var{sound-name}
|
|
|
1241 should be a symbol, specifying the name of the sound. If @var{volume}
|
|
|
1242 is specified, the sound will be played at that volume; otherwise, the
|
|
|
1243 value of @var{bell-volume} will be used.
|
|
|
1244 @end deffn
|
|
|
1245
|
|
|
1246 @defun play-sound sound &optional volume device
|
|
|
1247 This function plays sound @var{sound}, which should be a symbol
|
|
|
1248 mentioned in @code{sound-alist}. If @var{volume} is specified, it
|
|
|
1249 overrides the value (if any) specified in @code{sound-alist}.
|
|
|
1250 @var{device} specifies the device to play the sound on, and defaults
|
|
|
1251 to the selected device.
|
|
|
1252 @end defun
|
|
|
1253
|
|
|
1254 @deffn Command play-sound-file file &optional volume device
|
|
|
1255 This function plays the named sound file at volume @var{volume}, which
|
|
|
1256 defaults to @code{bell-volume}. @var{device} specifies the device to
|
|
|
1257 play the sound on, and defaults to the selected device.
|
|
|
1258 @end deffn
|
