Struct ZoomPanView 

pub struct ZoomPanView { /* private fields */ }

Zoom and pan over content: pinch or Cmd/Ctrl with the wheel to zoom, a drag or the wheel to move, a double click between fit and 100%, and the keys +, -, 0, 1 and the arrows (with Shift, further). A thrown drag coasts to a stop, which asks for frames only meanwhile and never happens with reduced motion. The content cannot leave the view.

Content is an image or a closure that draws from where the view puts it, not a laid out view: the runtime has no transform for a subtree, and scaling one by Motion::effect would neither move what can be clicked nor paint children whose unscaled place is off screen. A closure can still reuse any drawing through Scene::apply_effect.

While a gesture runs it paints without a build. If nothing else in the UI reads the ZoomView, it costs no rebuilds at all, however big the screen around it.

use ravenrs_core::ImageData;
use ravenrs_reactive::State;
use ravenrs_widgets::{Minimap, ZoomControl, ZoomPanView, ZoomView};

let view = State::new(ZoomView::fit());
let stage = ZoomPanView::image(view.binding(), photo());
let controls = ZoomControl::new(view.binding());
let map = Minimap::image(view.binding(), photo());

Implementations

impl ZoomPanView

pub fn image(view: Binding<ZoomView>, image: ImageData) -> Self

Shows an image, with one unit of content per pixel of it.

pub fn custom( view: Binding<ZoomView>, content: Size, draw: impl Fn(ZoomPanPaint, &mut Scene) + 'static, ) -> Self

Shows what draw draws, for content of this size in units of the caller.

pub fn size(self, width: f32, height: f32) -> Self

Fixed size in logical pixels, instead of taking the free space.

pub fn grow(self, grow: f32) -> Self

How much of the free space along the parent stack it takes (1 by default).

pub fn range(self, least: f32, most: f32) -> Self

The least and the most scale, where 1 is 100%. By default, it goes down to what shows the whole content and up to 1600%. What shows the whole content is always in range.

pub fn inertia(self, inertia: bool) -> Self

Lets a thrown drag coast (on by default).

pub fn label(self, label: impl Into<String>) -> Self

The name screen readers announce, instead of the one in Labels.

Trait Implementations

impl Debug for ZoomPanView

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl View for ZoomPanView

fn build(&self, cx: &mut BuildCx<'_>) -> NodeId

Creates this view’s node for the current build.

fn type_name(&self) -> &'static str

The name the diagnostics panel shows this view’s cost under.