That's what this class really is; in fact that's what the first line of
the comment says it is.
This commit does not rename the main files, since those will contain
other time-related classes in a little bit.
We have a new, improved string type coming up in AK (OOM aware, no null
state), and while it's going to use UTF-8, the name UTF8String is a
mouthful - so let's free up the String name by renaming the existing
class.
Making the old one have an annoying name will hopefully also help with
quick adoption :^)
Pior to this change when the user added text after having saved the file
the Text Editor wouldn't enable the modified flag, unless this new text
was a new line.
This happened because the UndoStack was merging the Command added by
the new text with the old text one, and when is_current_modified()
was called, the m_stack_index would not have been incremented, and
it would return false.
In this change was added a condition to verify if the modified tag is
active, and the merge is only done if the document is already modified.
UndoStack will now merge adjacent commands *if they want to be merged*
instead of bundling everything you push onto it until you tell it
to "finalize the combo."
This uses less memory and gives applications full control over how
their undo stacks end up. :^)
When pushing a new command on an undo stack, we will now attempt to
merge it into the stack's current command.
Merging is implemented by overriding the "merge_with(Command const&)"
virtual on GUI::Command. :^)
This was quite unreliable before. Changes to the undo stack's modified
state are now reflected in the document's modified state, and the
GUI::TextEditor widget has its undo/redo actions updated automatically.
UndoStack is still a bit hard to understand due to the lazy coalescing
of commands, and that's something we should improve upon (e.g with more
explicit, incremental command merging.) But for now, this is a nice
improvement and undo/redo finally behaves in a way that feels natural.
The undo stack was very difficult to understand as it grew by adding
new undo commands to the front of the internal vector. This meant we
had to keep updating indices as the stack grew and shrank.
This patch makes the internal vector grow by appending instead.
Since the `redo` action never goes back to `index: 0`,
we have to mark the clean index as being the current
non-empty index for the undo/redo navigation to work properly.
The problem is that if we never `undo`, the stack index stays at zero,
which is the empty container waiting for commands. In that situation,
if we save the document, it registers the clean index as being 1
(the non-empty index) but because the stack index has never left zero,
the document was being reported as modified, being out of sync with
the window modified state.
Since we keep a stack of command combos, let's call entries on the
stack "Combo" instead of "UndoCommandsContainer".
And since it has a vector of commands, let's call it "commands"
instead of "m_undo_vector".
SPDX License Identifiers are a more compact / standardized
way of representing file license information.
See: https://spdx.dev/resources/use/#identifiers
This was done with the `ambr` search and replace tool.
ambr --no-parent-ignore --key-from-file --rep-from-file key.txt rep.txt *
