Interface IReadOnlyViewportState

Namespace

FlowGraph.Core.Rendering

Assembly

FlowGraph.Core.dll

Read-only viewport state for observing pan/zoom changes.

The viewport defines the visible area of the infinite canvas and provides coordinate transformation between canvas space (where elements live) and screen space (what the user sees).

Inspired by:

• react-diagrams: CanvasModel with offsetX, offsetY, zoom
• Konva.js: Stage with scale, position properties
• mxGraph: mxGraphView with scale and translate

public interface IReadOnlyViewportState : ICoordinateTransformer

Inherited Members

ICoordinateTransformer.Zoom

ICoordinateTransformer.OffsetX

ICoordinateTransformer.OffsetY

ICoordinateTransformer.ViewportToCanvas(double, double)

ICoordinateTransformer.CanvasToViewport(double, double)

ICoordinateTransformer.ViewportToCanvasDelta(double, double)

ICoordinateTransformer.CanvasToViewportDelta(double, double)

ICoordinateTransformer.ScreenToCanvas(double, double)

ICoordinateTransformer.CanvasToScreen(double, double)

ICoordinateTransformer.ScreenToCanvasDelta(double, double)

ICoordinateTransformer.CanvasToScreenDelta(double, double)

Extension Methods

CoordinateTransformerExtensions.CanvasToScreen(ICoordinateTransformer, Rect)

CoordinateTransformerExtensions.CanvasToScreen(ICoordinateTransformer, Point)

CoordinateTransformerExtensions.CanvasToViewport(ICoordinateTransformer, Rect)

CoordinateTransformerExtensions.CanvasToViewport(ICoordinateTransformer, Point)

CoordinateTransformerExtensions.ScreenToCanvas(ICoordinateTransformer, Rect)

CoordinateTransformerExtensions.ScreenToCanvas(ICoordinateTransformer, Point)

CoordinateTransformerExtensions.ViewportToCanvas(ICoordinateTransformer, Rect)

CoordinateTransformerExtensions.ViewportToCanvas(ICoordinateTransformer, Point)

Properties

ViewSize

The visible size of the viewport in screen coordinates (pixels).

Size ViewSize { get; }

Property Value

Size

Methods

GetVisibleCanvasRect()

Gets the currently visible area in canvas coordinates.

This is the inverse transform of the screen bounds. Use this to determine which graph elements are potentially visible for culling/virtualization.

Rect GetVisibleCanvasRect()

Returns

Rect

A rectangle in canvas coordinates representing the visible area. Returns Empty if ViewSize is not set.

Events

ViewportChanged

Event raised when any viewport property changes (zoom, offset, or view size).

Subscribers should invalidate their display or recalculate visibility when this event fires.

event EventHandler? ViewportChanged

Event Type

EventHandler