```
error: casting references to a bigger memory layout than the backing allocation is undefined behavior, even if the reference is unused
--> internal/core/item_tree.rs:1035:32
|
1035 | Pin::new_unchecked(&*(&**component as *const Dyn as *const u8)),
| ^^^^-----------^^^^^^^^^^^^^^^^^^^^^^^^^^^^
| |
| backing allocation comes from here
|
= note: casting from `vtable::Dyn` (0 bytes) to `u8` (1 bytes)
= note: `#[deny(invalid_reference_casting)]` on by default
```
In `ItemRc::find_sibling` we currently do:
1. get the range
2. check that the next index is within the range
3. call `get_subtree`
The problem is that get_subtree itselg will call 'ensure_updated' which
will do the relayout of the ListView and may get a different range of
element.
So don't query the range before and just have get_subtree to return an
empty ItemWeak if we are out of the actual range.
Couldn't really find a way to make a test since this is called from
the accessibility code which is hard to test as is
For #3700
and their related name.
Also move the component module in the item_Tree module
register_component -> register_item_tree
ComponentItemTree -> ItemTreeNodeArray
For #3323
Rationale from that issue:
Right now, we use the term `component` in the Slint language and in the compiler to be a a tree of elements that can be used as an element in a .slint file.
The term is also currently used in the runtime as a tree of runtime Items that are allocated together. (declared in ComponentVTable)
But there are no 1 to 1 mapping between a `component` in the slint language, and a runtime Component.
(for example, the items behind a `if` or `for` or `PopupMenu` are in a different runtime component. And `component` declared in Slint are often inlined)
So we should rename the internal runtime `Component` to `ItemTree`
The currently public `slint::ComponentHandle` wraps the "root" of the ItemTree, but that's ok because it is generated from a .slint `component`, so it doesn't change name
Known caveats:
- winit doesn't forward mouse events to the IME, so clicking
with the mouse while composing results in funny effects such
as the pre-edit text following the cursor.
- With FemtoVG there's no text decoration support, thus no underlining
of the preedit area.
Just make a single recursive function, it is easier to read than using
the visitor helper with a post and pre visit.
Also remove that function that visits with a post and pre visit as it is
no longer used
Implement basic accessibility (a11y) support, using the Qt backend.
_This should get us started, but accessibility support is an additional way to interact with UIs that is very different from the "graphical way" most users will interact with the UI. No single PR will "make a toolkit accessibility", this needs to be an ongoing effort!_
Parts of this PR:
* Add functions to access a11y-related properties to Component
* Add helper functions to Item struct
* Handle accessible- properties in the compiler
* Add documentation, add description, enforce some basic rules
* Make the Text element accessible by default
* Don't optimize away accessibility property in the LLR
* Ensure that accessibility property are marked as used
* Add some accessibility properties to the native style widgets
* Support for bool and integer `accessible` properties
* Implement basic support for accessibility
* Make basic widgets accessible by default
* Make slider focus-able and interactable with keyboard
* Tell a11y layer about value changes
* Generate QAccessible constants using bindgen
* Don't expose the `accessible` properties when using the MCU backend: There is no backend to make use of them
* Handle focus change based on keyboard focus of the window
* Report accessible widgets at correct positions
* Allow for (virtual) focus delegation at the a11y level
* Calculate value step size dynamically
* Make sure to not send notifications to a11y backend about dead objects
Remove the `parent_item` function. After the recent changes that did not
return an item anymore and since the item tree is exposed, this function
was only used to find the repeater a component was created by.
So replace the old function with a new one that only returns the parent
node in the parent component.
This saves a few lines of generated code that is not used anymore.
Co-authored-by: Simon Hausmann <hausmann@gmail.com>
