The main inspiration behind this was to have a correct ex CSS unit.
The mean line is based off what it shows in the CSS Values and Units
Level 4 specification, section 6.1.1.
https://www.w3.org/TR/css-values-4/#font-relative-lengths
Under the hood, a lambda is just a struct full of pointers/references/copies and whatever else
the compiler deems necessary. In the case of 'update_demo', the struct lives on the stack
frame of FontEditorWidget::FontEditorWidget(). Hence it is still alive when it's called
during the constructor.
However, when 'fixed_width_checkbox.on_checked' fires, that stack frame is no longer alive,
and thus the *reference* to the (struct of) the lambda is invalid\! This meant that
'update_demo' silently read invalid data, tried to call '.update()' on some innocent arbitrary
memory address, and it crashed somewhere unrelated.
Passing 'update_demo' by value (like with all the other event handlers) fixes this issue.
Note that this solution only works because 'update_demo' itself has no state; otherwise
the various copies of 'update_demo' might notice that they are, in fact, independent copies
of the original lambda. But that doesn't matter here.
Since the vast majority of message boxes should be modal, require
the parent window to be passed in, which can be nullptr for the
rare case that they don't. By it being the first argument, the
default arguments also don't need to be explicitly stated in most
cases, and it encourages passing in a parent window handle.
Fix up several message boxes that should have been modal.
I started adding things to a Draw namespace, but it somehow felt really
wrong seeing Draw::Rect and Draw::Bitmap, etc. So instead, let's rename
the library to LibGfx. :^)
As suggested by Joshua, this commit adds the 2-clause BSD license as a
comment block to the top of every source file.
For the first pass, I've just added myself for simplicity. I encourage
everyone to add themselves as copyright holders of any file they've
added or modified in some significant way. If I've added myself in
error somewhere, feel free to replace it with the appropriate copyright
holder instead.
Going forward, all new source files should include a license header.
Here goes the first attempt at using VisualBuilder to make an application.
There are many features missing that we are gonna have to implement,
noticeably custom widgets (for the glyph editor and glyph map widgets)
but this patch already moves most of the UI layout to a form file. :^)
This is essentially a combo widget containing a single-line GTextEditor
and two buttons for increment and decrement. The GTextEditor::on_change
callback is hooked to prevent non-numeric input but it's not entirely
perfect since that callback is asynchronous. This will work until we have
some more sophisticated input validation mechanism though.
I added focus rects to these widgets because I had just started working on
focus support and I was excited but it doesn't really make sense for these
things to have focus rects. :^)
While I was here I also optimized the repaint code to only update the edited
glyph in the glyph map when editing its pixels.
