Struct druid::widget::ClipBox

pub struct ClipBox<T, W> { /* fields omitted */ }

A widget exposing a rectangular view into its child, which can be used as a building block for widgets that scroll their child.

Implementations

impl<T, W: Widget<T>> ClipBox<T, W>

pub fn new(child: W) -> Self

Creates a new ClipBox wrapping child.

pub fn child(&self) -> &W

Returns a reference to the child widget.

pub fn child_mut(&mut self) -> &mut W

Returns a mutable reference to the child widget.

pub fn viewport(&self) -> Viewport

Returns a the viewport describing this ClipBox's position.

pub fn viewport_size(&self) -> Size

Returns the size of the rectangular viewport into the child widget. To get the position of the viewport, see viewport_origin.

pub fn content_size(&self) -> Size

Returns the size of the child widget.

pub fn constrain_horizontal(self, constrain: bool) -> Self

Builder-style method for deciding whether to constrain the child horizontally. The default is false. See constrain_vertical for more details.

pub fn set_constrain_horizontal(&mut self, constrain: bool)

Determine whether to constrain the child horizontally.

See constrain_vertical for more details.

pub fn constrain_vertical(self, constrain: bool) -> Self

Builder-style method for deciding whether to constrain the child vertically. The default is false.

This setting affects how a ClipBox lays out its child.

• When it is false (the default), the child does receive any upper bound on its height: the idea is that the child can be as tall as it wants, and the viewport will somehow get moved around to see all of it.
• When it is true, the viewport's maximum height will be passed down as an upper bound on the height of the child, and the viewport will set its own height to be the same as its child's height.

pub fn set_constrain_vertical(&mut self, constrain: bool)

Determine whether to constrain the child vertically.

See constrain_vertical for more details.

pub fn pan_by(&mut self, delta: Vec2) -> bool

Changes the viewport offset by delta.

Returns true if the offset actually changed. Even if delta is non-zero, the offset might not change. For example, if you try to move the viewport down but it is already at the bottom of the child widget, then the offset will not change and this function will return false.

pub fn pan_to(&mut self, origin: Point) -> bool

Sets the viewport origin to pos.

Returns true if the position changed. Note that the valid values for the viewport origin are constrained by the size of the child, and so the origin might not get set to exactly pos.

pub fn pan_to_visible(&mut self, region: Rect) -> bool

Adjust the viewport to display as much of the target region as is possible.

Returns true if the viewport changes.

This will move the viewport the smallest distance that fully shows the target region. If the target region is larger than the viewport, we will display the portion that fits, prioritizing the portion closest to the origin.

pub fn viewport_origin(&self) -> Point

Returns the origin of the viewport rectangle.

pub fn with_port<F: FnOnce(&mut Viewport)>(&mut self, f: F)

Allows this ClipBox's viewport rectangle to be modified. The provided callback function can modify its argument, and when it is done then this ClipBox will be modified to have the new viewport rectangle.

Trait Implementations

impl<T: Data, W: Widget<T>> Widget<T> for ClipBox<T, W>

pub fn event(
    &mut self,
    ctx: &mut EventCtx<'_, '_>,
    ev: &Event,
    data: &mut T,
    env: &Env
)

Handle an event.

pub fn lifecycle(
    &mut self,
    ctx: &mut LifeCycleCtx<'_, '_>,
    ev: &LifeCycle,
    data: &T,
    env: &Env
)

Handle a life cycle notification.

pub fn update(
    &mut self,
    ctx: &mut UpdateCtx<'_, '_>,
    _old_data: &T,
    data: &T,
    env: &Env
)

Update the widget's appearance in response to a change in the app's Data or Env.

pub fn layout(
    &mut self,
    ctx: &mut LayoutCtx<'_, '_>,
    bc: &BoxConstraints,
    data: &T,
    env: &Env
) -> Size

Compute layout.

pub fn paint(&mut self, ctx: &mut PaintCtx<'_, '_, '_>, data: &T, env: &Env)

Paint the widget appearance.