Module builder 

Widget and property builder types.

Examples

The example declares a new widget type, ShowProperties!, that inherits from Text! and display what properties are set on itself by accessing the WidgetBuilder at two points. First call is directly in the widget_intrinsic that is called after inherited intrinsics, but before the instance properties are set. Second call is in a build action that is called when the widget starts building, after the instance properties are set.

mod widgets {
    use std::fmt::Write as _;
    use zng::prelude_wgt::*;

    #[widget($crate::widgets::ShowProperties)]
    pub struct ShowProperties(zng::text::Text);

    impl ShowProperties {
        fn widget_intrinsic(&mut self) {
            let txt = var(Txt::from(""));
            widget_set! {
                self;
                txt = txt.clone();
            }

            let builder = self.widget_builder();

            let mut t = Txt::from("Properties set by default:\n");
            for p in builder.properties() {
                writeln!(&mut t, "• {}", p.args.property().name).unwrap();
            }

            builder.push_build_action(move |builder| {
                writeln!(&mut t, "\nAll properties set:").unwrap();
                for p in builder.properties() {
                    writeln!(&mut t, "• {}", p.args.property().name).unwrap();
                }
                txt.set(t.clone());
            });
        }
    }
}

widgets::ShowProperties! {
    font_size = 20;
}

Full API

See zng_app::widget::builder for the full API.

Macros

property_args

New Box<PropertyArgs> box from a property and value.

property_id

New PropertyId that represents the type and name.

property_info

New PropertyInfo from property path.

property_input_types

Gets the strong input storage types from a property path.

source_location

New SourceLocation that represents the location you call this macro.

widget_type

Gets the WidgetType info of a widget.

Structs

AnyWhenArcHandlerBuilder

A when builder for AnyArcHandler values.

BuilderProperty

Represents a property removed from WidgetBuilding.

BuilderPropertyMut

Represents a mutable reference to property in WidgetBuilder or WidgetBuilding.

BuilderPropertyRef

Represents a property in WidgetBuilder or WidgetBuilding.

Importance

Value that indicates the override importance of a property instance, higher overrides lower.

NestGroup

Property nest position group.

NestPosition

Represents the sort index of a property or intrinsic node in a widget instance.

PropertyAttribute

Represents a custom build action targeting a property input that is applied after when is build.

PropertyAttributeArgs

Arguments for PropertyAttribute<I> build action.

PropertyAttributeWhen

Data for a property attribute associated with an WhenInfo.

PropertyId

Unique ID of a property implementation.

PropertyInfo

Property info.

PropertyInput

Property input info.

PropertyInputTypes

Represents the strong types of each input of a property.

PropertyNewArgs

Args for PropertyInfo::new closure.

SourceLocation

A location in source-code.

WhenInfo

Represents a when block in a widget.

WhenInput

Input var read in a when condition expression.

WhenInputVar

Represents a WhenInput variable that can be rebound.

WidgetBuilder

Widget instance builder.

WidgetBuilderProperties

Direct property access in WidgetBuilder and WidgetBuilding.

WidgetBuilding

Represents a finalizing WidgetBuilder.

WidgetType

Unique identifier of a widget type.

Enums

InputKind

Kind of property input.

WhenInputMember

Represents what member and how it was accessed in a WhenInput.

Traits

PropertyArgs

Represents a property instantiation request.

Type Aliases

PropertyAttributes

Property attribute build actions that must be applied to property args.

PropertyAttributesWhenData

Data for property build actions associated with when condition assigns.