The relevant `on-paint' call is one that is forced for a GL
canvas to try to draw a frame's content before the frame is
shown. Sometimes, thread scheduling would let the frame get
sufficiently initialized at the Cocoa level before the `on-paint'
call happened, but sometimes not.
The code to draw a border has to determine the widget's position
within the drawing window. Gtk 3.0 has a function to provide that
transformation, but Gtk 2.0 doesn't seem to have one, and it seems
that the transformation implemented in `racket/gui' wasn't right.
Closes PR 13453
There appears to be no way to make `on-demand' work right for the
Unity window manager's global menu bar, since there's no notificiation
when the menu bar is clicked. We approximate the correct behavior
by calling `on-demand' when a containing frame loses the keyboard
focus, which might be because the menu bar was clicked; that may be
too late (because the menu has already been shown), but it should
work most of the time.
Closes PR 13347.
Relevant to PR 13395, but DrRacket will have to change to work
around the remaining limitations of `on-demand'.
I started from tabs that are not on the beginning of lines, and in
several places I did further cleanings.
If you're worried about knowing who wrote some code, for example, if you
get to this commit in "git blame", then note that you can use the "-w"
flag in many git commands to ignore whitespaces. For example, to see
per-line authors, use "git blame -w <file>". Another example: to see
the (*much* smaller) non-whitespace changes in this (or any other)
commit, use "git log -p -w -1 <sha1>".
Also, use keywords for `make-pen' and `make-brush'.
Adding `make-pen' and `make-color' creates many conflicts among
teaching libraries, such as `2htdp/image'. These are easy to fix
up in the tree, but adding such obvious names to `racket/draw'
may create other compatibility problems, so we might have to reconsider
the names.
In consultation with Asumu.
Especially for gtk, where a client-resize notification was
getting mixed up with a frame-configure notification. On all
platforms, `on-size' and `on-move' for a frame% were queued
at too high a priority.
Since the number of monitors can change at any time, reliable
use of these functions requires handling failure in some way.
Handling #f results is easier (and less likely to mask other
problems) than catching exceptions.
