Previously, TextEditor processed the Select all command directly on the
keydown event handler. For this reason, WindowManager would not process
it as an action for the focused control and an action with the same
keyboard shortcut from the parent could override the TextEditor's one
even when it is focused.
For instance, when pressing Ctrl+A on the FileManager's path bar, all
files were selected instead, which is not the expected behavior.
Now the Select all command is an actual action on TextEditor, so that
WindowManager can process it correctly before any other actions. I also
added an icon for it!
If you start selecting text and move the cursor outside the TextEditor
widget area without letting go of the mouse button, we will now keep
scrolling a little bit every 100ms.
This patch introduces the GUI::SyntaxHighlighter class, which can be
attached to a GUI::TextEditor to provide syntax highlighting.
The C++ syntax highlighting from HackStudio becomes a new class called
GUI::CppSyntaxHighlighter. This will make it possible to get C++ syntax
highlighting in any app that uses a GUI::TextEditor. :^)
Sidenote: It does feel a bit weird having a C++ lexer in a GUI toolkit
library, and we'll probably end up moving this out to a separate place
as this functionality grows larger.
