Module zng::widget::info

Widget info tree and info builder.

Examples

The example declares a new info state for widgets and a property that sets the new state. The new state is then used in a widget.

mod custom {
    use zng::prelude_wgt::*;

    static_id! {
        static ref STATE_ID: StateId<bool>;
    }

    #[property(CONTEXT)]
    pub fn flag_state(child: impl UiNode, state: impl IntoVar<bool>) -> impl UiNode {
        let state = state.into_var();
        match_node(child, move |_, op| match op {
            UiNodeOp::Init => {
                WIDGET.sub_var_info(&state);
            }
            UiNodeOp::Info { info } => {
                info.set_meta(*STATE_ID, state.get());
            }
            _ => {}
        })
    }

    pub trait StateExt {
        fn state(&self) -> Option<bool>;
    }
    impl StateExt for WidgetInfo {
        fn state(&self) -> Option<bool> {
            self.meta().get_clone(*STATE_ID)
        }
    }
}

Wgt! {
    custom::flag_state = true;
    widget::on_info_init = hn!(|_| {
        use custom::StateExt as _;
        let info = WIDGET.info();
        println!("state: {:?}", info.state());
    });
}

Modules

• access
  Accessibility metadata types.
• inspector
  Helper types for inspecting an UI tree.
• iter
  Widget info tree iterators.

Structs

• HitInfo
  A hit-test hit.
• HitTestInfo
  A hit-test result.
• InlineSegmentInfo
  Info about a segment in the first or last row of an inlined widget.
• InteractionPath
  Represents a WidgetPath annotated with each widget’s Interactivity.
• Interactivity
  Represents the level of interaction allowed for a widget.
• InteractivityChangedArgs
  INTERACTIVITY_CHANGED_EVENT args.
• InteractivityFilterArgs
  Argument for a interactivity filter function.
• ParallelBuilder
  Represents a builder split from the main builder that can be used in parallel and then folded back onto the main builder.
• TransformChangedArgs
  TRANSFORM_CHANGED_EVENT args.
• VisibilityChangedArgs
  VISIBILITY_CHANGED_EVENT args.
• WidgetBorderInfo
  Shared reference to the combined border and corner radius of a WidgetInfo.
• WidgetBoundsInfo
  Shared reference to layout size, offsets, rendered transforms and bounds of a widget.
• WidgetDescendantsRange
  Represents the descendants of a widget, allows checking if widgets are descendant with O(1) time.
• WidgetInfo
  Reference to a widget info in a WidgetInfoTree.
• WidgetInfoBuilder
  Widget info tree builder.
• WidgetInfoChangedArgs
  WIDGET_INFO_CHANGED_EVENT args.
• WidgetInfoTree
  A tree of WidgetInfo.
• WidgetInfoTreeStats
  Stats over the lifetime of a widget info tree.
• WidgetInlineInfo
  Info about the inlined rows of the widget.
• WidgetInlineMeasure
  Info about the input inline connecting rows of the widget.
• WidgetPath
  Full address of a widget.

Enums

• RelativeHitZ
  Hit-test result on a widget relative to it’s descendants.
• TreeFilter
  Widget tree filter selected for a widget in the tree.
• WidgetInfoMeta
  Tag for the WidgetInfo::meta state-map.

Statics

• INTERACTIVITY_CHANGED_EVENT
  Widget interactivity has changed after an info update.
• TRANSFORM_CHANGED_EVENT
  A widget global inner transform has changed after render.
• VISIBILITY_CHANGED_EVENT
  Widget visibility has changed after render.
• WIDGET_INFO_CHANGED_EVENT
  A window widget tree was rebuild.