view man/lispref/dragndrop.texi @ 4967:0d4c9d0f6a8d

rewrite dynarr code -------------------- ChangeLog entries follow: -------------------- src/ChangeLog addition: 2010-02-03 Ben Wing <ben@xemacs.org> * device-x.c (x_get_resource_prefix): * device-x.c (Fx_get_resource): * device-x.c (Fx_get_resource_prefix): * device-x.c (Fx_put_resource): * dialog-msw.c: * dialog-msw.c (handle_question_dialog_box): * dired-msw.c (mswindows_sort_files): * dired-msw.c (mswindows_get_files): * extents.c (extent_fragment_sort_by_priority): * extents.c (Fset_extent_parent): * file-coding.c (coding_reader): * file-coding.c (coding_writer): * file-coding.c (gzip_convert): * frame.c (generate_title_string): * gutter.c (calculate_gutter_size_from_display_lines): * indent.c (vmotion_1): * lread.c (read_bit_vector): * mule-coding.c (iso2022_decode): * rangetab.c: * rangetab.c (Fcopy_range_table): * rangetab.c (Fget_range_table): * rangetab.c (unified_range_table_copy_data): * redisplay-msw.c (mswindows_output_string): * redisplay-output.c (output_display_line): * redisplay-output.c (redisplay_move_cursor): * redisplay-output.c (redisplay_clear_bottom_of_window): * redisplay-tty.c (tty_output_ichar_dynarr): * redisplay-tty.c (set_foreground_to): * redisplay-tty.c (set_background_to): * redisplay-xlike-inc.c (XLIKE_output_string): * redisplay.c (redisplay_window_text_width_string): * redisplay.c (redisplay_text_width_string): * redisplay.c (create_text_block): * redisplay.c (SET_CURRENT_MODE_CHARS_PIXSIZE): * redisplay.c (generate_fstring_runes): * redisplay.c (regenerate_modeline): * redisplay.c (ensure_modeline_generated): * redisplay.c (real_current_modeline_height): * redisplay.c (create_string_text_block): * redisplay.c (regenerate_window): * redisplay.c (REGEN_INC_FIND_START_END): * redisplay.c (point_visible): * redisplay.c (redisplay_window): * redisplay.c (mark_glyph_block_dynarr): * redisplay.c (line_start_cache_start): * redisplay.c (start_with_line_at_pixpos): * redisplay.c (update_line_start_cache): * redisplay.c (glyph_to_pixel_translation): * redisplay.c (pixel_to_glyph_translation): * sysdep.c (qxe_readdir): * text.c (dfc_convert_to_external_format): * text.c (dfc_convert_to_internal_format): * toolbar-common.c (common_output_toolbar_button): * window.c (window_modeline_height): * window.c (Fwindow_last_line_visible_height): * window.c (window_displayed_height): * window.c (window_scroll): * window.c (get_current_pixel_pos): Use Dynarr_begin() in place of Dynarr_atp (foo, 0). * dynarr.c (Dynarr_realloc): * dynarr.c (Dynarr_lisp_realloc): * dynarr.c (Dynarr_resize): * dynarr.c (Dynarr_insert_many): * dynarr.c (Dynarr_delete_many): * dynarr.c (Dynarr_memory_usage): * dynarr.c (stack_like_malloc): * dynarr.c (stack_like_free): * lisp.h: * lisp.h (DECLARE_DYNARR_LISP_IMP): * lisp.h (XD_DYNARR_DESC): * lisp.h (Dynarr_pop): * gutter.c (output_gutter): * redisplay-output.c (sync_rune_structs): * redisplay-output.c (redisplay_output_window): Redo the dynarr code, add greater checks. Rename the `len', `largest' and `max' members to `len_', `largest_' and `max_' to try and catch existing places that might directly modify these values. Make new accessors Dynarr_largest() and Dynarr_max() and make them and existing Dynarr_length() be non-lvalues by adding '+ 0' to them; fix a couple of places in the redisplay code that tried to modify the length directly by setting Dynarr_length(). Use the accessors whenever possible even in the dynarr code itself. The accessors also verify that 0 <= len <= largest <= max. Rename settor function Dynarr_set_size() to Dynarr_set_length() and use it more consistently; also create lower-level Dynarr_set_length_1(). This latter function should be the only function that directly modifies the `len_' member of a Dynarr, and in the process makes sure that the `largest' value is kept correct. Consistently use ERROR_CHECK_STRUCTURES instead of ERROR_CHECK_TYPES for error-checking code. Reintroduce the temporarily disabled verification code on the positions of Dynarr_at(), Dynarr_atp() and Dynarr_atp_past_end(). Also create Dynarr_resize_if() in place of a repeated code fragment. Clean up all the functions that modify Dynarrs to use the new macros and functions and verify the correctness of the Dynarr both before and after the change. Note that there are two kinds of verification -- one for accessing and one for modifying. The difference is that the modify verification additionally checks to make sure that the Dynarr isn't locked. (This is used in redisplay to check for problems with reentrancy.) * lrecord.h: Move XD_DYNARR_DESC to lisp.h, grouping with the dynarr code.
author Ben Wing <ben@xemacs.org>
date Wed, 03 Feb 2010 20:51:18 -0600
parents bc4f2511bbea
children
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@c -*-texinfo-*-
@c This is part of the XEmacs Lisp Reference Manual.
@c Copyright (C) 1998 Oliver Graf <ograf@fga.de>
@c Original reference is (c) 1990, 1991, 1992, 1993, 1994 Free Software Foundation, Inc.
@c See the file lispref.texi for copying conditions.
@setfilename ../../info/dragndrop.texi
@node Drag and Drop, Modes, Scrollbars, Top
@chapter Drag and Drop
@cindex drag and drop

@emph{WARNING}: the Drag'n'Drop API is still under development and the
interface may change! The current implementation is considered experimental.

  Drag'n'drop is a way to transfer information between multiple applications.
To do this several GUIs define their own protocols. Examples are CDE, Motif,
KDE, MSWindows, GNOME, and many more. To catch all these protocols, XEmacs
provides a generic API.

One prime idea behind the API is to use a data interface that is
transparent for all systems. The author thinks that this is best
archived by using URL and MIME data, cause any internet enabled system
must support these for email already. XEmacs also already provides
powerful interfaces to support these types of data (tm and w3).

@menu
* Supported Protocols:: Which low-level protocols are supported.
* Drop Interface::      How XEmacs handles a drop from another application.
* Drag Interface::      Calls to initiate a drag from XEmacs.
@end menu

@node Supported Protocols
@section Supported Protocols

The current release of XEmacs only support a small set of Drag'n'drop
protocols. Some of these only support limited options available in the API.

@menu
* CDE dt::              Common Desktop Environment used on suns.
* MSWindows OLE::       Mr. Gates way of live.
* Loose ends::          The other protocols.
@end menu

@node CDE dt
@subsection CDE dt
@cindex CDE dt

CDE stands for Common Desktop Environment. It is based on the Motif
widget library. It's drag'n'drop protocol is also an abstraction of the
Motif protocol (so it might be possible, that XEmacs will also support
the Motif protocol soon).

CDE has three different types: file, buffer, and text. XEmacs only uses
file and buffer drags. The API will disallow full URL drags, only file
method URLs are passed through.

Buffer drags are always converted to plain text.

@node MSWindows OLE
@subsection MSWindows OLE
@cindex MSWindows OLE

Only allows file drags and drops.

@node Loose ends
@subsection Loose ends

The following protocols will be supported soon: Xdnd, Motif, Xde (if I
get some specs).

In particular Xdnd will be one of the protocols that can benefit from
the XEmacs API, cause it also uses MIME types to encode dragged data.

@node Drop Interface
@section Drop Interface
@cindex drop
@cindex Drop API

For each activated low-level protocol, an internal routine will catch
incoming drops and convert them to a dragdrop-drop type
misc-user-event.

This misc-user-event has its function argument set to
@code{dragdrop-drop-dispatch} and the object contains the data of the drop
(converted to URL/MIME specific data). This function will search the variable
@code{experimental-dragdrop-drop-functions} for a function that can handle the
dropped data.

To modify the drop behavior, the user can modify the variable
@code{experimental-dragdrop-drop-functions}. Each element of this list
specifies a possible handler for dropped data. The first one that can handle
the data will return @code{t} and exit. Another possibility is to set a
extent-property with the same name. Extents are checked prior to the
variable.

The customization group @code{drag-n-drop} shows all variables of user
interest.

@node Drag Interface
@section Drag Interface
@cindex drag
@cindex Drag API

This describes the drag API (not implemented yet).