com.yworks.yfiles.view

Interface ICanvasObjectGroup

All Superinterfaces:

ICanvasObject, IEnumerable<ICanvasObject>, IListEnumerable<ICanvasObject>, Iterable<ICanvasObject>

public interface ICanvasObjectGroup
extends ICanvasObject, IListEnumerable<ICanvasObject>

This is the interface implemented by the composite building blocks of a scene graph in a CanvasControl.

It is meant to group multiple ICanvasObject instances as a logic unit. The interface is not meant to be implemented by application programmers. Instances implementing this interface can be retrieved from the factory methods in the canvas control. The interface extends the IListEnumerable interface to allow for easy iteration and determination of the size of the group.

Field Summary

Fields inherited from interface com.yworks.yfiles.utils.IListEnumerable

EMPTY

Method Summary

Modifier and Type	Method and Description
ICanvasObject	addChild(Object userObject, ICanvasObjectDescriptor descriptor) Adds a child element to the scene graph as a child of this group.
ICanvasObjectGroup	addGroup() Adds a new ICanvasObjectGroup to this group in the current scene graph.
ICanvasObject	getFirst() Returns the first item in the rendering list of this group or null.
ICanvasObject	getLast() Returns the last item in the rendering list of this group or null.

Methods inherited from interface com.yworks.yfiles.view.ICanvasObject

above, below, getDescriptor, getGroup, getNext, getPrevious, getUserObject, isDirty, isVisible, lower, raise, remove, setDescriptor, setDirty, setGroup, setUserObject, setVisible, toBack, toFront

Methods inherited from interface com.yworks.yfiles.utils.IListEnumerable

concat, create, create, first, getItem, last, size

Methods inherited from interface com.yworks.yfiles.utils.IEnumerable

concat, concat, enumerator, iterator, parallelStream, stream

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Method Detail

addChild

ICanvasObject addChild(Object userObject,
                       ICanvasObjectDescriptor descriptor)

Adds a child element to the scene graph as a child of this group.

The descriptor will be queried for the various rendering related implementations for the given userObject at rendering time.

Parameters:

userObject - The user object to associate with this child element. This object will be passed to the descriptor's methods.

descriptor - An implementation of the ICanvasObjectDescriptor interface that will be passed the userObject to provide the various implementations that are used during rendering.

Returns:

A handle that can be used to control the rendering order and to later remove the element from the scene graph, again.

See Also:

ICanvasObjectDescriptor, ICanvasObjectDescriptor.DYNAMIC_DIRTY_INSTANCE

addGroup

ICanvasObjectGroup addGroup()

Adds a new ICanvasObjectGroup to this group in the current scene graph.

This can be used to build groups of ICanvasObject instances that can be moved within the scene graph or whose visibility can be controlled easily. The group will have a null UserObject.

Returns:

A handle to the newly created group that can be used to control the rendering order and to later remove the group from the scene graph, again.

getFirst

ICanvasObject getFirst()

Returns the first item in the rendering list of this group or null.

This is the item that will be rendered first, i.e. behind all of the other items in the rendering list. In order to iterate over all immediate children, use the following idiom:

Returns:

The First.

See Also:

IListEnumerable, CollectionExtensions.getEnumerator(java.lang.Iterable)

getLast

ICanvasObject getLast()

Returns the last item in the rendering list of this group or null.

This is the item that will be on top of all other items in the list. In order to iterate over all immediate children in reverse order, use the following idiom:

Returns:

The Last.