com.yworks.yfiles.view.input

Class NodeDropInputMode

java.lang.Object

com.yworks.yfiles.view.input.DropInputMode

com.yworks.yfiles.view.input.ItemDropInputMode<INode>

com.yworks.yfiles.view.input.NodeDropInputMode

All Implemented Interfaces:

IInputMode

public class NodeDropInputMode
extends ItemDropInputMode<INode>

An ItemDropInputMode specialized to drag'n'drop INodes.

A dragged INode is visualized during the drag operation. The input mode does also support snapping of the dragged INode via the SnapContext. When the dragged node is dropped, This mode can can drag nodes onto group and optional folder nodes and automatically add the node to the corresponding group node in the hierarchy. In this case the IsValidParentPredicate will be queried if the dropped upon node is actually a valid parent.

Field Summary

Fields inherited from class com.yworks.yfiles.view.input.DropInputMode

DATA_FORMAT_DROP_ID

Constructor Summary

Constructors

Modifier	Constructor and Description
	NodeDropInputMode() Constructs a new instance of class NodeDropInputMode for the type INode.
protected	NodeDropInputMode(Class expectedType) Constructs a new instance of class DropInputMode for the expected data type.

Method Summary

Modifier and Type	Method and Description
protected void	collectSnapResults(Object source, CollectSnapResultsEventArgs args) Callback registered on the SnapContext that collects SnapResults for the dragged element.
protected INode	createNode(IInputModeContext context, IGraph graph, INode node, IModelItem dropTarget, RectD layout) Creates the node in the graph after it's been dropped.
protected IModelItem	getDropTarget(PointD dragLocation) Returns the drop target at the specified location.
Predicate<INode>	getIsGroupNodePredicate() Gets the callback for testing whether a dragged node should be created as a group node.
Predicate<INode>	getIsValidParentPredicate() Gets the callback for testing whether an existing node in the graph can be used as a valid parent node in the context of grouping.
protected RectD	getNodeLayout(PointD mouseLocation, SizeD size) Calculates the layout of the new node.
protected void	initializePreview() Initializes the item preview.
boolean	isFolderNodeAsParentAllowed() Gets a value indicating whether nodes can be dropped on collapsed folder nodes.
boolean	isNonGroupNodeAsParentAllowed() Gets a value indicating whether nodes can be dropped onto nodes that are no group nodes.
protected void	populatePreviewGraph(IGraph previewGraph) Subclasses shall fill the specified graph that is used to preview the dragged item.
void	setFolderNodeAsParentAllowed(boolean value) Sets a value indicating whether nodes can be dropped on collapsed folder nodes.
void	setIsGroupNodePredicate(Predicate<INode> value) Sets the callback for testing whether a dragged node should be created as a group node.
void	setIsValidParentPredicate(Predicate<INode> value) Sets the callback for testing whether an existing node in the graph can be used as a valid parent node in the context of grouping.
void	setNonGroupNodeAsParentAllowed(boolean value) Sets a value indicating whether nodes can be dropped onto nodes that are no group nodes.
protected void	updatePreview(IGraph previewGraph, PointD dragLocation) Subclasses shall update the preview graph so the dragged item is displayed at the specified dragLocation.

Methods inherited from class com.yworks.yfiles.view.input.ItemDropInputMode

addItemCreatedListener, cleanup, cleanupDropTarget, cleanupPreview, cleanupSnapContext, getDraggedItem, getDropTarget, getItemCreator, getPreviewGraph, getSnapContext, getSnappedMousePosition, initializeDropTarget, initializeSnapContext, isDropTargetHighlightEnabled, isPreviewEnabled, isSnappingEnabled, onConcurrencyControllerDeactivated, onDragDropped, onDragEntered, onDragExited, onDraggedOver, onItemCreated, removeItemCreatedListener, setDragLocation, setDropTarget, setDropTargetHighlightEnabled, setItemCreator, setPreviewEnabled, setSnapContext, setSnappingEnabled, updateDropTarget

Methods inherited from class com.yworks.yfiles.view.input.DropInputMode

addDragDroppedListener, addDragEnteredListener, addDragLeftListener, addDragOverListener, adjustTransferMode, cancel, createInputModeEventArgs, getController, getDropData, getDropData, getDropDataMap, getDropLocation, getExpectedType, getInputModeContext, getLastDragEvent, getMousePosition, getPriority, getTransferMode, getValidDropHitTestable, install, isCapturingMouseInputDuringDragEnabled, isEnabled, isExclusive, onCanceled, onConcurrencyControllerActivated, onStopped, removeDragDroppedListener, removeDragEnteredListener, removeDragLeftListener, removeDragOverListener, setCapturingMouseInputDuringDragEnabled, setDropDataMap, setEnabled, setExclusive, setPriority, setTransferMode, setValidDropHitTestable, stop, uninstall

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

NodeDropInputMode

public NodeDropInputMode()

Constructs a new instance of class NodeDropInputMode for the type INode.

NodeDropInputMode

protected NodeDropInputMode(Class expectedType)

Constructs a new instance of class DropInputMode for the expected data type. Not used in this class since data type is always INode. This constructor only exists for usage in child class.

Method Detail

collectSnapResults

protected void collectSnapResults(Object source,
                                  CollectSnapResultsEventArgs args)

Description copied from class: ItemDropInputMode

Callback registered on the SnapContext that collects SnapResults for the dragged element.

The default implementation doesn't collect any snap results.

Overrides:

collectSnapResults in class ItemDropInputMode<INode>

Parameters:

source - The SnapContext this callback is registered at.

args - The arguments describing the movement SnapResults shall be collected for.

createNode

protected INode createNode(IInputModeContext context,
                           IGraph graph,
                           INode node,
                           IModelItem dropTarget,
                           RectD layout)

Creates the node in the graph after it's been dropped.

This method is called by the ItemCreator that is set as default on this class.

Parameters:

context - The context for which the node should be created.

graph - The Graph in which to create the item.

node - The node that was dragged and should therefore be created.

dropTarget - The IModelItem on which the node is dropped.

layout - The bounds of the new node.

Returns:

a newly created node.

getDropTarget

protected IModelItem getDropTarget(PointD dragLocation)

Description copied from class: ItemDropInputMode

Returns the drop target at the specified location.

The drop target is highlighted, if DropTargetHighlightEnabled is enabled. Per default, null is returned.

Overrides:

getDropTarget in class ItemDropInputMode<INode>

Parameters:

dragLocation - The location to return the drop target for.

Returns:

The drop target at the specified location or null if no drop target can be found.

getIsGroupNodePredicate

public final Predicate<INode> getIsGroupNodePredicate()

Gets the callback for testing whether a dragged node should be created as a group node.

The default implementation returns false always. Can be set to a different value to implement custom group node detection.

Returns:

The IsGroupNodePredicate.

See Also:

setIsGroupNodePredicate(Predicate)

getIsValidParentPredicate

public final Predicate<INode> getIsValidParentPredicate()

Gets the callback for testing whether an existing node in the graph can be used as a valid parent node in the context of grouping.

The default implementation returns true always. Can be set to a different value to implement custom group node detection. Note that the node passed to the predicate may be null to indicate that the node will be placed at the root of the hierarchy.

Returns:

The IsValidParentPredicate.

See Also:

isNonGroupNodeAsParentAllowed(), isFolderNodeAsParentAllowed(), setIsValidParentPredicate(Predicate)

getNodeLayout

protected RectD getNodeLayout(PointD mouseLocation,
                              SizeD size)

Calculates the layout of the new node.

In this implementation the mouse location is used as center of the node. Can be overridden in child class to implement a different layout.

Parameters:

mouseLocation - Current mouse position

size - Size of the node

Returns:

a RectD with the given size and the mouse location as center.

initializePreview

protected void initializePreview()

Description copied from class: ItemDropInputMode

Initializes the item preview.

This method is called by ItemDropInputMode.onDragEntered(InputModeEventArgs). If a preview shall be displayed, the preview graph is initialized and ItemDropInputMode.populatePreviewGraph(IGraph) is called.

Overrides:

initializePreview in class ItemDropInputMode<INode>

isFolderNodeAsParentAllowed

public final boolean isFolderNodeAsParentAllowed()

Gets a value indicating whether nodes can be dropped on collapsed folder nodes.

If this property is set to true, dropping nodes on collapsed folder nodes will create the node inside the folder node in the master graph. In that case the ItemCreated event will yield the node in the master graph. The node will not be contained in the currently visible graph. By default this feature is disabled. In any case the IsValidParentPredicate will be queried additionally if the node is a valid parent.

Returns:

true if folder node parents are allowed; false otherwise.

See Also:

setFolderNodeAsParentAllowed(boolean)

isNonGroupNodeAsParentAllowed

public final boolean isNonGroupNodeAsParentAllowed()

Gets a value indicating whether nodes can be dropped onto nodes that are no group nodes.

If this property is enabled, dropping a node on a non-group node will effectively convert the non-group node to a real group node. By default this feature is disabled. In any case the IsValidParentPredicate will be queried additionally if the node is a valid parent.

Returns:

true if non-group node parents are allowed as valid drop targets; false otherwise.

See Also:

setNonGroupNodeAsParentAllowed(boolean)

populatePreviewGraph

protected void populatePreviewGraph(IGraph previewGraph)

Description copied from class: ItemDropInputMode

Subclasses shall fill the specified graph that is used to preview the dragged item.

Overrides:

populatePreviewGraph in class ItemDropInputMode<INode>

Parameters:

previewGraph - The preview graph to fill.

setFolderNodeAsParentAllowed

public final void setFolderNodeAsParentAllowed(boolean value)

Sets a value indicating whether nodes can be dropped on collapsed folder nodes.

If this property is set to true, dropping nodes on collapsed folder nodes will create the node inside the folder node in the master graph. In that case the ItemCreated event will yield the node in the master graph. The node will not be contained in the currently visible graph. By default this feature is disabled. In any case the IsValidParentPredicate will be queried additionally if the node is a valid parent.

Parameters:

value - true if folder node parents are allowed; false otherwise.

See Also:

isFolderNodeAsParentAllowed()

setIsGroupNodePredicate

public final void setIsGroupNodePredicate(Predicate<INode> value)

Sets the callback for testing whether a dragged node should be created as a group node.

The default implementation returns false always. Can be set to a different value to implement custom group node detection.

Parameters:

value - The IsGroupNodePredicate to set.

See Also:

getIsGroupNodePredicate()

setIsValidParentPredicate

public final void setIsValidParentPredicate(Predicate<INode> value)

Sets the callback for testing whether an existing node in the graph can be used as a valid parent node in the context of grouping.

The default implementation returns true always. Can be set to a different value to implement custom group node detection. Note that the node passed to the predicate may be null to indicate that the node will be placed at the root of the hierarchy.

Parameters:

value - The IsValidParentPredicate to set.

See Also:

isNonGroupNodeAsParentAllowed(), isFolderNodeAsParentAllowed(), getIsValidParentPredicate()

setNonGroupNodeAsParentAllowed

public final void setNonGroupNodeAsParentAllowed(boolean value)

Sets a value indicating whether nodes can be dropped onto nodes that are no group nodes.

If this property is enabled, dropping a node on a non-group node will effectively convert the non-group node to a real group node. By default this feature is disabled. In any case the IsValidParentPredicate will be queried additionally if the node is a valid parent.

Parameters:

value - true if non-group node parents are allowed as valid drop targets; false otherwise.

See Also:

isNonGroupNodeAsParentAllowed()

updatePreview

protected void updatePreview(IGraph previewGraph,
                             PointD dragLocation)

Description copied from class: ItemDropInputMode

Subclasses shall update the preview graph so the dragged item is displayed at the specified dragLocation.

Overrides:

updatePreview in class ItemDropInputMode<INode>

Parameters:

previewGraph - The preview graph to update.

dragLocation - The current drag location.