This patch adds GUI::Action::create_checkable() helpers that work just
like the existing create() helpers, but the actions become checkable(!)
Clients are no longer required to manage the checked state of their
actions manually, but instead they will be checked/unchecked as needed
by GUI::Action itself before the activation hook is fired.
Put each tool's thickness altering actions into a GActionGroup and make
them mutually exclusive so we get that nice radio button appearance.
This all feel very clunky and we should move towards having something
like a "tool settings" pane that gets populated by the currently active
tool instead.
As suggested by Joshua, this commit adds the 2-clause BSD license as a
comment block to the top of every source file.
For the first pass, I've just added myself for simplicity. I encourage
everyone to add themselves as copyright holders of any file they've
added or modified in some significant way. If I've added myself in
error somewhere, feel free to replace it with the appropriate copyright
holder instead.
Going forward, all new source files should include a license header.
Painter gains the ability to draw lines with arbitrary thickness.
It's basically implemented by drawing filled rects for thickness>1.
In PaintBrush, Tool classes can now override on_contextmenu() to
provide a context menu for the toolbox button. :^)
