Changing the displaying order of a graph's items (z-order)

To gain control over some details of the drawing of items as nodes and edges, like the drawing order, one can use the various methods of com.yworks.canvas.ICanvasObject:

• mark the item for repainting: set ICanvasObject.dirty:boolean to true
• show or hide the item: set ICanvasObject.visible
• to control the painting order (z-order) use:
  • ICanvasObject.lower():void
  • ICanvasObject.raise():void
  • ICanvasObject.toFront():void
  • ICanvasObject.toBack():void

See the API documentation for more.

To get the ICanvasObject for an item, use the com.yworks.graph.model.GraphModelManager's method getCanvasObjects(item:IModelItem):Array, which returns an Array of the canvas objects which are related to the item. The GraphModelManager can be obtained from the com.yworks.ui.GraphCanvasComponent's property graphModelManager. Thus, the complete code to get the item's canvas objects is (where gcc is the GraphCanvasComponent): var canvasObjects:Array = gcc.graphModelManager.getCanvasObjects( item );

Using canvas object groups

Canvas object groups, described by com.yworks.canvas.ICanvasObjectGroup offer the same functionality as com.yworks.canvas.ICanvasObjects, i.e. you can, for example, put whole groups into the back by calling toBack() on a ICanvasObjectGroup. Some important object groups are

• the content group which contains the whole content of the graph and which can be accessed by GraphCanvasComponent.contentGroup
• the selection group, which contains the canvas objects selected by the user and which can be accessed by GraphCanvasComponent.selectionGroup

Other important object groups can be acessed via the com.yworks.graph.model.GraphModelManager:

• The nodes: gmm.nodeGroup
• The edges: gmm.edgeGroup
• The node labels: gmm.nodeLabelGroup
• The edge labels: gmm.edgeLabelGroup
• The ports: gmm.portGroup

Where gmm is the instance of the GraphModelManager

Draw edges behind grouped nodes

When using a grouped graph, edges are drawn in front of nodes.Since yFiles FLEX 1.5 the GraphModelManager offers the property drawEdgesBehindGroupedNodes that can be set to true to render the edges behind the nodes.