tree 0537c834fe6df7bb25b1b1cbc61f6839cd4ef916
parent e381036051eb9586b71bc244665d14ac46647345
author John Stiles <johnstiles@google.com> 1593616339 -0400
committer Skia Commit-Bot <skia-commit-bot@chromium.org> 1593619623 +0000

Fix modifier key handling in OS X to allow command-keys to work.

A variety of modifier key handling issues are addressed in this CL:
- Added a skui::Key for the Super key (this is ImGui's name for command)
- Added OS X event handling for `flagsChanged` (sent when modifier keys
  are pressed)
- OS X manually tracks modifier key state and sends key-up and key-down
  events to the ImGuiLayer as necessary
- OS X does not send key-up events when hotkeys are pressed, so these
  are manually synthesized and sent to ImGui (otherwise hotkeys are
  repeated forever)
- Replaced hardcoded Virtual Key valus in OS X code with named constants
- Our custom bitmask type was lacking the ability to XOR

This CL does NOT enable the OS X clipboard; this uses the ImGui internal
clipboard.

Change-Id: I76b55215858bfb6441dbef18ad638426fa8bc073
Bug: skia:10338
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/300182
Commit-Queue: Jim Van Verth <jvanverth@google.com>
Reviewed-by: Jim Van Verth <jvanverth@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>