ViewportApi<T> extension

Viewport operations for NodeFlowController.

This extension provides methods for:

• Viewport state management (get/set viewport, zoom, pan)
• Coordinate transformations (screen ↔ graph) using typed coordinates
• Navigation (center, fit to view, focus on nodes)
• Visibility queries (is point/rect visible)
• Screen and mouse position tracking

All coordinate methods use typed extension types (GraphPosition, ScreenPosition, GraphRect) to prevent accidentally mixing coordinate spaces.

on

• NodeFlowController<T>

Properties

currentPan → ScreenOffset

Available on NodeFlowController<T>, provided by the ViewportApi extension

Gets the current pan position of the viewport.

no setter

currentZoom → double

Available on NodeFlowController<T>, provided by the ViewportApi extension

Gets the current zoom level of the viewport.

no setter

mousePositionWorld → GraphPosition?

Available on NodeFlowController<T>, provided by the ViewportApi extension

Gets the current mouse position in graph coordinates.

no setter

selectedNodesBounds → GraphRect?

Available on NodeFlowController<T>, provided by the ViewportApi extension

Gets the bounding rectangle that encompasses all selected nodes in graph coordinates.

no setter

viewportExtent → GraphRect

Available on NodeFlowController<T>, provided by the ViewportApi extension

Gets the viewport extent as a GraphRect in graph coordinates.

no setter

viewportScreenBounds → ScreenRect

Available on NodeFlowController<T>, provided by the ViewportApi extension

Gets the viewport extent as a ScreenRect in screen coordinates.

no setter

Methods

centerOn(GraphOffset point) → void

Available on NodeFlowController<T>, provided by the ViewportApi extension

Centers the viewport on a specific point in graph coordinates without changing zoom.

centerOnNode(String nodeId) → void

Available on NodeFlowController<T>, provided by the ViewportApi extension

Centers the viewport on a specific node without changing the zoom level.

centerOnSelection() → void

Available on NodeFlowController<T>, provided by the ViewportApi extension

Centers the viewport on the center point of all selected nodes without changing zoom.

centerViewport() → void

Available on NodeFlowController<T>, provided by the ViewportApi extension

Centers the viewport on the geometric center of all nodes without changing zoom.

fitSelectedNodes() → void

Available on NodeFlowController<T>, provided by the ViewportApi extension

Adjusts the viewport to fit all selected nodes in the view with padding.

fitToView() → void

Available on NodeFlowController<T>, provided by the ViewportApi extension

Adjusts the viewport to fit all nodes in the view with padding.

getViewportCenter() → GraphPosition

Available on NodeFlowController<T>, provided by the ViewportApi extension

Gets the center point of the current viewport in graph coordinates.

globalToGraph(ScreenPosition globalPosition) → GraphPosition

Available on NodeFlowController<T>, provided by the ViewportApi extension

Converts a global screen position to graph coordinates.

graphToScreen(GraphPosition graphPoint) → ScreenPosition

Available on NodeFlowController<T>, provided by the ViewportApi extension

Converts a graph coordinate point to screen coordinates.

isPointVisible(GraphPosition graphPoint) → bool

Available on NodeFlowController<T>, provided by the ViewportApi extension

Checks if a graph coordinate point is visible in the current viewport.

isRectVisible(GraphRect graphRect) → bool

Available on NodeFlowController<T>, provided by the ViewportApi extension

Checks if a graph coordinate rectangle intersects with the viewport.

panBy(ScreenOffset delta) → void

Available on NodeFlowController<T>, provided by the ViewportApi extension

Pans the viewport by a delta offset.

resetViewport() → void

Available on NodeFlowController<T>, provided by the ViewportApi extension

Resets the viewport to zoom 1.0 and centers on all nodes in the graph.

screenToGraph(ScreenPosition screenPoint) → GraphPosition

Available on NodeFlowController<T>, provided by the ViewportApi extension

Converts a screen coordinate point to graph coordinates.

setMousePositionWorld(GraphPosition? position) → void

Available on NodeFlowController<T>, provided by the ViewportApi extension

Updates the mouse position in graph coordinates.

setScreenSize(Size size) → void

Available on NodeFlowController<T>, provided by the ViewportApi extension

Sets the screen size used for viewport calculations.

setViewport(GraphViewport viewport) → void

Available on NodeFlowController<T>, provided by the ViewportApi extension

Sets the viewport to a specific position and zoom level.

zoomBy(double delta) → void

Available on NodeFlowController<T>, provided by the ViewportApi extension

Zoom the viewport by a delta value while maintaining the viewport center as the focal point.

zoomTo(double zoom) → void

Available on NodeFlowController<T>, provided by the ViewportApi extension

Sets the viewport zoom to a specific value.