Instead of hard-coding 22 in random places, just make the following
widgets have a fixed height of 22 by default: Button, CheckBox,
ColorInput, ComboBox, RadioButton, SpinBox, TextBox.
In the future we can make this relative to the current font size,
but for now at least this centralizes the setting a bit better.
Move the shadow 1 more pixel away from the unhovered icon location,
making a total 2 pixel distance between the icon and the shadow.
Also tweak the shadow color to be a darkened variant of the base color
underneath the icon.
If a hook triggers the deletion of the GUI::Button, we would be unable
to proceed in a well-defined manner here, so let's protect ourselves.
This probably needs to be done in a whole lot of places, since GUI
widgets are just ref-counted Core::Objects and running arbitrary code
can mean that they get deleted.
This makes most operations thread safe, especially so that they
can safely be used in the Kernel. This includes obtaining a strong
reference from a weak reference, which now requires an explicit
call to WeakPtr::strong_ref(). Another major change is that
Weakable::make_weak_ref() may require the explicit target type.
Previously we used reinterpret_cast in WeakPtr, assuming that it
can be properly converted. But WeakPtr does not necessarily have
the knowledge to be able to do this. Instead, we now ask the class
itself to deliver a WeakPtr to the type that we want.
Also, WeakLink is no longer specific to a target type. The reason
for this is that we want to be able to safely convert e.g. WeakPtr<T>
to WeakPtr<U>, and before this we just reinterpret_cast the internal
WeakLink<T> to WeakLink<U>, which is a bold assumption that it would
actually produce the correct code. Instead, WeakLink now operates
on just a raw pointer and we only make those constructors/operators
available if we can verify that it can be safely cast.
In order to guarantee thread safety, we now use the least significant
bit in the pointer for locking purposes. This also means that only
properly aligned pointers can be used.
Every widget now has a GUI::FocusPolicy that determines how it can
receive focus:
- NoFocus: The widget is not focusable (default)
- TabFocus: The widget can be focused using the tab key.
- ClickFocus: The widget can be focused by clicking on it.
- StrongFocus: Both of the above.
For widgets that have a focus proxy, getting/setting the focus policy
will affect the proxy instead.
This make buttons look extra clickable when hovered by lifting up their
icons (-1,-1) and painting a little icon-shaped shadow under them.
Partially inspired by the Office XP toolbars, although we don't go all
the way with the faux-hyperlink stuff that was all the rage back then.
