Struct masonry::PaintCtx

pub struct PaintCtx<'a> { /* private fields */ }

A context passed to paint methods of widgets.

Implementations

impl PaintCtx<'_>

pub fn widget_id(&self) -> WidgetId

get the WidgetId of the current widget.

pub fn skip_child(&self, child: &mut WidgetPod<impl Widget>)

Skip iterating over the given child.

Normally, container widgets are supposed to iterate over each of their child widgets in their methods. By default, the framework treats not doing so as a mistake, and panics if debug assertions are on.

This tells the framework that a child was deliberately skipped.

impl PaintCtx<'_>

pub fn size(&self) -> Size

The layout size.

This is the layout size as ultimately determined by the parent container, on the previous layout pass.

Generally it will be the same as the size returned by the child widget’s layout method.

pub fn window_origin(&self) -> Point

The origin of the widget in window coordinates, relative to the top left corner of the content area.

pub fn to_window(&self, widget_point: Point) -> Point

Convert a point from the widget’s coordinate space to the window’s.

The returned point is relative to the content area; it excludes window chrome.

pub fn is_hot(&self) -> bool

The “hot” (aka hover) status of a widget.

A widget is “hot” when the mouse is hovered over it. Widgets will often change their appearance as a visual indication that they will respond to mouse interaction.

The hot status is computed from the widget’s layout rect. In a container hierarchy, all widgets with layout rects containing the mouse position have hot status.

Discussion: there is currently some confusion about whether a widget can be considered hot when some other widget is active (for example, when clicking to one widget and dragging to the next). The documentation should clearly state the resolution.

pub fn is_active(&self) -> bool

The active status of a widget.

Active status generally corresponds to a mouse button down. Widgets with behavior similar to a button will call set_active on mouse down and then up.

When a widget is active, it gets mouse events even when the mouse is dragged away.

pub fn is_focused(&self) -> bool

The focus status of a widget.

Returns true if this specific widget is focused. To check if any descendants are focused use has_focus.

Focus means that the widget receives keyboard events.

A widget can request focus using the request_focus method. It’s also possible to register for automatic focus via register_for_focus.

If a widget gains or loses focus it will get a LifeCycle::FocusChanged event.

Only one widget at a time is focused. However due to the way events are routed, all ancestors of that widget will also receive keyboard events.

pub fn has_focus(&self) -> bool

The (tree) focus status of a widget.

Returns true if either this specific widget or any one of its descendants is focused. To check if only this specific widget is focused use is_focused.

pub fn is_disabled(&self) -> bool

The disabled state of a widget.

Returns true if this widget or any of its ancestors is explicitly disabled. To make this widget explicitly disabled use set_disabled.

Disabled means that this widget should not change the state of the application. What that means is not entirely clear but in any it should not change its data. Therefore others can use this as a safety mechanism to prevent the application from entering an illegal state. For an example the decrease button of a counter of type usize should be disabled if the value is 0.

pub fn is_stashed(&self) -> bool

Check is widget is stashed.

Note: Stashed widgets are a WIP feature

impl PaintCtx<'_>

pub fn font_ctx(&mut self) -> &mut FontContext

impl PaintCtx<'_>

pub fn depth(&self) -> u32

The depth in the tree of the currently painting widget.

This may be used in combination with paint_with_z_index in order to correctly order painting operations.

The depth here may not be exact; it is only guaranteed that a child will have a greater depth than its parent.