[Tuxpaint-devel] Shortcut ([Del] key) for quick access to a small eraser

[Bill K. <nb...@so...>]

Tonight I thought that, since Tux Paint is now focused on SDL2, I
could finally look into adding drawing tablet (e.g., Wacom) support to
Tux Paint.

Right now, it works, but acts as a mouse: no pressure, no recognition
of which stylus tip (pen vs. eraser) is being usded, etc.

Unfortunately, even after so many years, SDL isn't quite ready! :-D
(See https://github.com/libsdl-org/SDL/issues/2217)

However, I realized the process would end up being very similar
to what I did for the color picker "pipette" shortcut ([Ctrl] key)
in 0.9.28, and decided I could add a similar feature that would
give users quick access to an eraser via a shortcut key.

Once SDL could actually tell us when a stylus' eraser tip is
being used, we could simply do the same thing as when the
shortcut key is being held!

So, I've added code in what will become Tux Paint 0.9.29 that lets you
hold the [Del] ("delete"; not to be confused with "backspace") key,
at _almost_ any time, to get quick access to a small, round eraser.


Without checking for the state of things, I discovered that this
feature would interfer with the rotation steps of both the Shapes
and Stamps tools.  So I specifically avoid invoking this new code
in those two situations.

Other parts of Tux Paint -- like the Fill tool's linear gradient and
brush modes, interactive Magic tools, etc. -- appear to inherently
avoid interference from this feature, since you're in the process of
click+dragging.  It's impossible to get another click in there;
pressing [Del] on its own doesn't invoke this code, it's the
combination of an otherwise-uncaught click, plus the [Del] key
already being held.

However, as usual, it's late at night, I should have gone to bed
2 hours ago, and mistakes happen.  So, if you notice any glitches,
please let me know ASAP so I can try to address them.


So far, I think I need to tackle:

 * interferrence with onscreen keyboard (Text & Label tools)

 * "--mouse-accessibility" mode
   (other features, like the [Ctrl] quick access color picker,
   probably need to better support this option!)

 * "--keyboard" mode
   (ditto)



-- 
-bill!
Sent from my computer