This adds support using the GtkTextHistory helper for undo/redo to the
GtkText widget. It is similar in use to GtkTextView, but with a simplified
interface.
You can disable undo support using the GtkText:enable-undo property. By
default, it is enabled.
This changes the semantics of ::deleted-text to perform the removal of
text in the default handler. This means, that if you want the old behavior
where your signal handler is called after the text has been deleted, you
should connect with G_CONNECT_AFTER in your signal handler (or use
g_signal_connect_after).
Without this change, there was never a way to get the deleted-text before
the operation had completed and this is necessary to provide undo support
to the text widgets.
This builds upon the GtkTextHistory helper to provide undo and redo support
for the GtkTextView widget and GtkTextBuffer object.
You can undo/redo using familiar shortcuts such as Primary+Z,
Primary+Shift+Z, ad Primary+Y.
Developers that wish to disable undo, should set the
GtkTextBuffer:enable-undo property to FALSE.
You can wrap irreversible actions
gtk_text_buffer_begin_irreversible_action() and
gtk_text_buffer_end_irreversible_action(). This will cause the undo stack
to drop all undo/redo actions and the changes made between them will be
the "initial state" of the buffer.
Calling gtk_text_buffer_set_text() will do this automatically for you.
The GtkTextHistory helper provides the fundamental undo/redo stack that
can be integrated with other text widgets. It allows coalescing related
actions to reduce both the number of undo actions to the user as well as
the memory overhead.
A new istring helper is used by GtkTextHistory to allow for "inline
strings" that gracefully grow to using allocations with g_realloc(). This
ensure that most undo operations require no additional allocations other
than the struct for the action itself.
A queue of undoable and redoable actions are maintained and the link for
the queue is embedded in the undo action union. This allows again, for
reducing the number of allocations involved for undo operations.
The msys2 runner has started failing for internal reasons:
- gtk-3-24 times out
- master fails with a ld.exe assertion:
BFD (GNU Binutils) 2.33.1 assertion fail
../../binutils-2.33.1/bfd/cofflink.c:2348
Both seem related to some MSYS2 issue. Until the runner is updated, we
should not block on it.
Using gsettings for this information does not work
in sandboxed scenarios, where settings are per-app.
Since the Wayland protocol provides this information
nowadays, just drop the old code for reading
the gsettings.
set_active() is meant to set the state of the property, which happens
during setup.
The clicked signal is emitting events from user actions.
It is impossible to use Togglebuttons for MVC applications as long as it
does that.
