Touch selections

[Carlos Garnacho <carlosg gnome org>]

Hello GTK+ list,

I went ahead at implementing the missing functionality from:
https://live.gnome.org/GnomeOS/Design/Whiteboards/Selections

On the GTK+ touch-selections branch [1] there is now:
      * Improved text handle dragging behavior, including a bigger input
        area, covering the line height, plus other smaller fixes.
      * A popup widget for bubble-like context menus, with separated
        show/grab semantics
      * An specific subclass for selection edition popups
      * Support in entry/textview

You don't need a touch device to see this working, the
GTK_TEST_TOUCHSCREEN envvar can be used to get this working on all input
devices

Some thoughts/notes:
      * Those 2 widgets have been made public, I can see other uses for
        bubbles, and apps like nautilus/file-roller could want the
        selection window too
      * The text handles helper object is still private though, there
        are little potential users, although funnily there's already a
        patch around with a copy of this code for Abiword.
      * Theming of the bubble shape is still quite poor, given the
        bubble tail can be irregular on edge cases, I can hardly think
        how to use CSS here, besides just taking the border color and
        stroking by hand and giving up on the rest.
      * As used by GtkEntry/TextView, there's no keyboard navigation nor
        interaction at all with the selection bubble, although being
        mostly designed as a touch interaction helper, it doesn't make
        much sense either. There are separate grab/ungrab methods for
        other usecases.
      * For interaction behavior I've mostly followed the whiteboard
        recipe, could be nice to get designers early in the loop now
        that there's and implementation they can play on.

Testing/Comments welcome,

  Carlos

[1] http://git.gnome.org/browse/gtk+/?h=touch-selections