The `Bitmap` type was referring to to its internal pixel format by a
name that represents the order of the color components as they are layed
out in memory. Contrary, the `Color` type was using a naming that where
the name represents the order of the components from most to least
significant byte when viewed as a unsigned 32bit integer. This is
confusing as you have to keep remembering which mental model to use
depending on which code you work with.
To unify the two, the naming of RGBA-like colors in the `Color` type has
been adjusted to match the one from the Bitmap type. This seems to be
generally in line with how web APIs think about these types:
* `ImageData.pixelFormat` can be `rgba-8unorm` backed by a
`Uint8ClamedArray`, but there is no pixel format backed by a 32bit
unsigned type.
* WebGL can use format `RGBA` with type `UNSIGNED_BYTE`, but there is no
such format with type `UNSIGNED_INT`.
Additionally, it appears that other browsers and browser-adjacent
libraries also think similarly about these types:
* Firefox:
https://github.com/mozilla-firefox/firefox/blob/main/gfx/2d/Types.h
* WebKit:
https://github.com/WebKit/WebKit/blob/main/Source/WebCore/platform/graphics/PixelFormat.h
* Skia:
https://chromium.googlesource.com/skia/+/refs/heads/main/include/core/SkColorType.h
This has the not so nice side effect that APIs that interact with these
types through 32bit unsigned integers now have the component order
inverted due to little-endian byte order. E.g. specifying a color as hex
constant needs to be done as `0xAABBGGRR` if it is to be treated as
RGBA8888.
We could alleviate this by providing endian-independent APIs to callers.
But I suspect long-term we might want to think differently about bitmap
data anyway, e.g. to better support HDR in the future. However, such
changes would be more involved than just unifying the naming as done
here. So I considered that out of scope for now.
If we're sharing buffers, we only want to share trivial structures
as anything else could potentially share internal pointers, which
most likely is going to cause problems due to different address
spaces.
Fix the GUI::SystemTheme structure, which was not trivial, which
is now caught at compile time.
Fixes#3650
Change #2811 made window title stripes and window title shadow themable,
but it used the same stripe and shadow color for all window modes.
This is fine for the new 'basalt' theme which uses the same color
in all four window modes, but it changed the default theme so that
background windows had brown stripes and a brown shadow.
Instead, make the title stripe and title shadow themable per window mode,
and change the default theme to restore the colors it had before
change #2811: The title stripe color is the same as Border1 for all
window modes, and the title shadow is the same as the title stripe
darkened by 0.6.
The theming system can now control title bar height, title button
size, title stripe color and the title text shadow color.
The implemented theme metrics system could be later extended to LibGUI
to allow themes to change widget padding, border width, etc.
