Fixes#1500
This overhauls how we do focus management for surfaces to make it more
robust. This DID somehow all work before but was always brittle and was
a sketchy play with SwiftUI/AppKit behavior across macOS versions.
The new approach uses our window controller and terminal delegate
system to disseminate focus information whenever any surface changes
focus. This ensures that only ONE surface ever has focus in libghostty
because the controller ensures it is widely distributed.
This enables the standard effect created by a sytem tab bar, which
ensures unselected tabs blend with the window's/titlebar's background
color. This also ensures the `windowButtonsBackdrop` view matches the
color of the adjacent tab (be it selected or not).
In a light appearance there was a shadow cast on top of the inactive
tabs that looked bad. In a dark appearance the shadow manifests as a
solid line that required a faux border to look right. This removes both
and improves the aesthetics of the tab bar in light themes.
FAR from a perfect fix, as the background seen through the tabs during window drags will be behind by a frame or so still, but definitely a vast improvement over not updating at all.
Noticed that windows glitch when cascading: they show up in center of
screen, then quickly move to the correct position at last-cascade point.
This fixes the issue, by moving the `showWindow` call to _after_ the
setting of the last cascade point.
Now if you look at the code and think: "shouldn't this work without the
async-dispatch, like this?"
```swift
if (!window.styleMask.contains(.fullScreen)) {
Self.lastCascadePoint = window.cascadeTopLeft(from: Self.lastCascadePoint)
}
c.showWindow(self)
```
Then, yes, I had the same thought, but it doesn't. And as discussed on
Discord, we probably don't know what's going on behind the scenes.
So this is the simplified code of the version we have to live with:
async dispatching the cascade and non-cascade versions both.
Fixes#1214
This introduces the `window-colorspace` configuration which allows
configuring the colorspace to use for windows on macOS. The default is
sRGB (same as before) but this can also be set to `display-p3`.
