This adds geometric sort ordering back in for semantics nodes that don't have a sort order defined.
With this change, widgets that either have no sort order, or have an equivalent sort order, will be compared geometrically. The comparison is between the two starting corners, so it is TextDirection-aware: parent nodes that are set to have LTR text will compare upper left corners of their children, and upper right when set to RTL.
Also fixed a bug in the Transform widget that didn't mark modified nodes as needing a semantics update.
It seems that setTraversalBefore doesn't work as well as setTraversalAfter for some reason, although I'm using them the same way. Some apps would lock up TalkBack when traversing if setTraversalBefore was set, but not with the equivalent setTraversalAfter.
It's not entirely clear why this is, but I'm going with this to at least get it fixed for apps we know about.
Fixes#14600
This adds an API for defining the semantic node traversal order.
It adds a sortOrder argument to the Semantics widget, which is a class that can define a list of sort keys to sort on. The keys are sorted globally so that an order that doesn't have to do with the current widget hierarchy may be defined.
It also adds a shortcut sortKey argument to the Semantics widget that simply sets the sortOrder to just contain that key.
The platform side (flutter/engine#4540) gets an additional member in the SemanticsData object that is an integer describing where in the overall order each semantics node belongs. There is an associated engine-side change that takes this integer and uses it to order widgets for the platform's accessibility services.
`RenderSemanticsGestureHandler` is no longer a semantics boundary, which allows us to correctly mark disabled buttons as disabled without having their semantics size and semantics node id change unexpectedly.
Fixes https://github.com/flutter/flutter/issues/12589.
Fixes https://github.com/flutter/flutter/issues/11991.
See also https://github.com/flutter/flutter/issues/11993.
This change also required some refactoring to how we deal with `twoPaneSemantics` scrolling as it previously relied on `RenderSemanticsGestureHandler` being a semantics boundary. This should also make the underlying logic easier to understand.
In addition, the following minor changes are included in this PR:
* Removal of orphaned and unused `SemanticsConfiguration.isMergingDescendantsIntoOneNode`.
* Logic optimizations for `markNeedsSemanticsUpdate` .
* Fix for edge case where `MergeSemantics` failed to merge semantics.
* Use of emojis to better indicate leaf merging in the printed semantics tree.
* Better assert message for adding invisible child semantics nodes.
* Make some semantics tests robuster by not relying on creation order of SemanticsNode ids across test boundaries.
Fixes https://github.com/flutter/flutter/issues/13943.
**This PR contains a breaking API change:**
`SemanticsConfiguration.addAction()` has been removed and replaces by action-specific setters (`onTap`, `onLongPress`, etc.) to take care of the fact that some action handlers (those, who take arguments) have different signatures.
* make time picker accessible
* use new CustomPaint a11y API
* flutter_localizations tests; use bigger distance delta
* fix am/pm control; selected values
* fix translations; remove @mustCallSuper in describeSemanticsConfiguration
* exclude AM/PM announcement from iOS as on iOS the label is read back automatically
Summary:
- Add `key` field to `SemanticsNode`, while moving key into `foundation` library so it can be used by the render layer.
- Introduce `SemanticsProperties` and move many of the `Semantics` fields into it.
- Introduce `CustomPaintSemantics` - a `SemanticsNode` prototype created by `CustomPainter`.
- Introduce `semanticsBuilder` and `shouldRebuildSemantics` in `CustomerPainter`
**Breaking change**
The default `Semantics` constructor becomes non-const (due to https://github.com/dart-lang/sdk/issues/20962). However, a new `const Semantics.fromProperties` is added that still allowed creating constant `Semantics` widgets ([mailing list announcement](https://groups.google.com/forum/#!topic/flutter-dev/KQXBl2_1sws)).
Fixes https://github.com/flutter/flutter/issues/11791
Fixes https://github.com/flutter/flutter/issues/1666
I got tired of drive-by spelling fixes, so I figured I'd just take care of them all at once.
This only corrects errors in the dartdocs, not regular comments, and I skipped any sample code in the dartdocs. It doesn't touch any identifiers in the dartdocs either. No code changes, just comments.
UnconstrainedBox will allow its child to size itself as if it had no constraints, and then attempt to fit around that object, until its own constraints are exceeded, in which case it will clip and display an overflow warning.
I also factored out DebugOverflowIndicator, which will draw overflow indicators on containers which overflow but aren't expected to.
