wlr_scene_*_create() functions all allocate memory via calloc() and
return NULL if the allocation fails. Previously, the failures were
handled in any of 3 different ways:
- sending a wayland protocol error
- exiting labwc with an error
- segfault (no NULL check at all)
Since labwc does not attempt to survive heap exhaustion in other
allocation paths (such as `znew`), it seems more consistent to use the
same die_if_null() check used in those paths to exit with an error.
For the three most common create() functions (tree, rect, buffer),
add small lab_wlr_ wrappers to common/scene-helpers.
- check for valid scene_output in output_is_usable()
- change many "output != NULL" checks to use output_is_usable()
- remove one now-redundant separate check for valid scene_output
Fixes a crash at startup (with autoEnableOutputs=no) due to
dereferencing null scene_output in create_output_config() since:
7d7ece21d9
("output: suppress error when output position is unavailable")
Fixes: #3357
Our codebase for ssd scenes has grown with a lot of technical debts:
- We needed to call `ssd_get_part()` everywhere to get the scene node of a
ssd part. We then needed to cast it to `wlr_scene_rect` and
`wlr_scene_buffer`. This bloated our codebase and even blocked
duplicated button types in `<titlebar><layout>`.
- `ssd_get_part_type()` was a dirty hack. It compared parent, grandparent
and grandgrandparent of a node with each subtree in the ssd to get the
part type of the node.
To resolve this issues, this commit changes how ssd scenes are managed:
- Access scene rects and scene buffers just as a member of `struct ssd`.
- `ssd_part` is now a attachment to a scene node that can be accessed via
node_descriptor->data, with a new node-descriptor type
`LAB_NODE_DESC_SSD_PART`. `LAB_NODE_DESC_SSD_BUTTON` is unified into it.
Now the scene graph under ssd->tree looks like below. The parentheses
indicate the type of ssd_part attached to the node:
ssd->tree (LAB_SSD_NONE)
+--titlebar (LAB_SSD_PART_TITLEBAR)
| +--inactive
| | +--background bar
| | +--left corner
| | +--right corner
| | +--title (LAB_SSD_PART_TITLE)
| | +--iconify button (LAB_SSD_BUTTON_ICONIFY)
| | | +--normal close icon image
| | | +--hovered close icon image
| | | +--...
| | +--window icon (LAB_SSD_BUTTON_WINDOW_ICON)
| | | +--window icon image
| | +--...
| +--active
| +--...
+--border
| +--inactive
| | +--top
| | +--...
| +--active
| +--top
| +--...
+--shadow
| +--inactive
| | +--top
| | +--...
| +--active
| +--top
| +--...
+--extents
+--top
+--...
When hovering on SSD, `get_cursor_context()` traverses this scene node
from the leaf. If it finds a `ssd_part` attached to the node, it returns
`ssd_part_type` that represents the resizing direction, button types or
`Title`/`Titlebar`.
Eliminate corner extents and instead use cursor position to map SSD
borders and extents to corner contexts, with a size configurable by the
<resize><cornerRange> parameter. This simplifies extent handling,
eliminates bugs in the detection of corner context, and allows users to
expand corner targets if they wish.
Co-authored-by: Andrew J. Hesford <ajh@sideband.org>
This fixes the ugly look of SSD for tiny windows (e.g. "xterm -geometry
1x1") due to the early return in `ssd_update_geometry()`. Now SSDs are
rendered correctly for those windows by hiding some buttons when the
window width is smaller than the total width of buttons. Additionally for
windows smaller than (button width)*2, the corners are un-rounded so a
small titlebar can be rendered with a scene-rect.
