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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 02:20:21 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 02:20:21 +0000
commit4f64827f3a395072f300b86ef17f730805b47048 (patch)
treec16297f7d68903dc80c86e3003b8e3ab5f030f7d /HACKING
parentInitial commit. (diff)
downloadscreen-4f64827f3a395072f300b86ef17f730805b47048.tar.xz
screen-4f64827f3a395072f300b86ef17f730805b47048.zip
Adding upstream version 4.6.2.upstream/4.6.2upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
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+WIP notes on hacking the Screen source.
+
+* Screen commands are handled by the DoAction function in process.c.
+ The local variable nr is set to an integer value representing the
+ command to be evaluated; for every command `foo', there is an
+ integer value RC_FOO for use as nr's value to represent it. Find
+ the matching case label to follow procesing of the command.
+
+ The RC_FOO values are defined in comm.h, which is automatically
+ generated by comm.sh, based on the names of the commands
+ themselves (found in comm.c).
+
+* The current display is held in the global variable "display".
+ Variable names like D_foo are shorthands for display->d_foo (where d_foo
+ is a member of "struct display").
+
+* Names like D_IS, D_TI, D_SG usually refer to the values of various
+ termcap features of the current display. These are found in term.h,
+ which is automatically generated from term.c by term.sh.
+
+* The main input-reading function for handling user input from a display,
+ is disp_readev_fn in display.c. This also handles automatic transformation
+ of mouse-tracking codes from display coordinates to screen-window
+ coordinates, and decodes characters from the display's encoding, passing
+ it on to the foreground input processor.
+
+ Input is passed through ProcessInput in process.c to handle
+ keybindings (specified by bindkey and such), and then processed by
+ layer-specific input-processing functions, which you'll find in
+ instances of struct LayFuncs. For instance, keystrokes are processed
+ by:
+
+ normal windows: WinPrGocess
+ window in copy-mode: MarkProcess
+ window list: WListProcess
+ command input line: InpProcess
+
+* Handling string escapes (in hardstatus and the like), such as %w or
+ %{= bw}, is done in screen.c, MakeWinMsgEv().