~~This is extracted from #10643.~~
~~It looks like the editor had a small optimization to drop events when
hovering the gutter. This also happens while dragging a tab over the
gutter, and causes some stuttering. Please correct me if this wasn't
just a small optimization, but I could not derive a different reason for
this code to exist.~~
The window was waiting for event propagation to update any drag. This
change makes sure the drag always gets updated, which makes sure it will
always be fluid, no matter if any element stops event propagation. Ty
@as-cii for pointing me to a better solution!
Release Notes:
- Fixed issue where dragging tab over any element that stops event
propagation would stutter
This introduces multiple improvements to the drop targets.
## Hitbox shape
Currently, hitboxes are rectangles, where the vertical ones reach all
the way to the ends, which reduces the space for the horizontal ones,
making the hitboxes a bit awkward in the corners. This new approach just
determines the closest side.
Visual representation:
## Hitbox size
The width of the hitbox was currently always 8 rem all around. In setups
with many columns or rows, or when the font size was very large, this
could potentially overlap the center hitbox, not allowing to drop a tab
without another split. Now the width of the hitboxes are a fraction of
the smaller size of its parents width and height. This makes sure the
hitboxes have the same width all around, but never fully block the
center hitbox.
I've also made this value configurable through the new
`drop_target_size` config which takes a `f32` fraction and is set to 0.2
by default.
Not sure if this is worth mentioning, but this technically allows to
remove the split hitboxes all together by setting it to `0.0`, or
removing the center hitbox by setting it to any value `>=0.5`. Not that
this is necessary, but it would be possible now.
## Larger visualization
The visual overlay when using one of the side hitboxes were also `8em`
wide. Since their logical size now changed, and it can't currently be
represented with GPUI (without abusing the `canvas` element), I made the
visual feedback take half of the width or height of the available space,
just like how other editors do this.
Also, the opacity/alpha value set by a theme is currently ignored. This
change now respects the themes opacity for it!
## Respect alpha value
Currently, the alpha value of `drop_target.background` is ignored. Even
the default themes set a value that is overwritten by a hard coded
value. I have removed this hard coded value and it now respects the
alpha value.
This change affects existing themes, see
https://github.com/zed-industries/zed/pull/10643#issuecomment-2059641528
## ~~No more lag while dragging over gutter~~ Extracted into #10737
~~It looks like the editor had a small optimization to drop events when
hovering the gutter. This also happens while dragging a tab over the
gutter, and causes some stuttering. Please correct me if this wasn't
just a small optimization, but I could not derive a different reason for
this code to exist.~~
Here is a video that tries to show all those changes with a before on
the left, and the after on the right:
https://github.com/zed-industries/zed/assets/1282767/f97f3420-513f-410f-a1c8-7966429ad348
Release Notes:
- Added `drop_target_size` setting. This should be a fractional percent
(e.g., `0.5`).
- Improved the hitboxes for drop targets.
- Updated drop targets to respect the alpha channel of the
`drop_target.background` color.
This small inconsistency was mentioned on the discord. This fixes it.
Release Notes:
- Themes: Renamed `scrollbar_thumb.background` to
`scrollbar.thumb.background` to be consistent with other style
properties.
---------
Co-authored-by: Marshall Bowers <elliott.codes@gmail.com>
Philipp Schaffrath
