com.yworks.yfiles.view.input

Class ItemDropInputMode<T extends IModelItem>

java.lang.Object

com.yworks.yfiles.view.input.DropInputMode

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

All Implemented Interfaces:

IInputMode

Direct Known Subclasses:

NodeDropInputMode, StripeDropInputMode

public class ItemDropInputMode<T extends IModelItem>
extends DropInputMode

A DropInputMode providing a preview of the dragged item.

A dragged IModelItem is visualized during the drag operation. In addition, this input mode supports snapping of the dragged IModelItem via the SnapContext and highlighting the DropTarget.

Highlighting is done via a HighlightIndicatorManager.

Field Summary

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

DATA_FORMAT_DROP_ID

Constructor Summary

Constructors

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

Method Summary

Modifier and Type	Method and Description
void	addItemCreatedListener(IEventHandler<ItemEventArgs<T>> itemCreatedEvent) Adds the given listener for the ItemCreated event that occurs when a new item gets created by this input mode.
protected void	cleanup() Cleanup method that calls cleanupSnapContext(), cleanupPreview() and cleanupDropTarget().
protected void	cleanupDropTarget() Cleans up the drop target and its highlighting.
protected void	cleanupPreview() Cleans up the item preview.
protected void	cleanupSnapContext() Cleans up the snap context.
protected void	collectSnapResults(Object source, CollectSnapResultsEventArgs args) Callback registered on the SnapContext that collects SnapResults for the dragged element.
protected T	getDraggedItem() Gets the currently dragged IModelItem instance.
IModelItem	getDropTarget() Gets the drop target at SnappedMousePosition.
protected IModelItem	getDropTarget(PointD dragLocation) Returns the drop target at the specified location.
IDropCreationCallback<T>	getItemCreator() Gets the callback for item creation.
protected IGraph	getPreviewGraph() Returns the graph displayed as item preview.
SnapContext	getSnapContext() The SnapContext which is used to snap the dragged element during the drag.
PointD	getSnappedMousePosition() Gets the current snapped mouse position during drag operations.
protected void	initializeDropTarget() Initializes the drop target.
protected void	initializePreview() Initializes the item preview.
protected void	initializeSnapContext() Initializes the snapping context.
boolean	isDropTargetHighlightEnabled() Switches highlighting the drop target on and off.
boolean	isPreviewEnabled() Determines whether a preview of the dragged element is displayed during the drag.
boolean	isSnappingEnabled() Switches snapping on and off.
protected void	onConcurrencyControllerDeactivated() Called after the Active property of the installed ConcurrencyController has been set to false.
protected void	onDragDropped(InputModeEventArgs eventArgs) Called once a drag has been dropped on the canvas.
protected void	onDragEntered(InputModeEventArgs eventArgs) Called once a drag has entered the canvas.
protected void	onDragExited(InputModeEventArgs eventArgs) Called once a drag has left the canvas.
protected void	onDraggedOver(InputModeEventArgs eventArgs) Called whenever a drag is over the canvas.
protected void	onItemCreated(ItemEventArgs<T> args) Called whenever a new item is created.
protected void	populatePreviewGraph(IGraph previewGraph) Subclasses shall fill the specified graph that is used to preview the dragged item.
void	removeItemCreatedListener(IEventHandler<ItemEventArgs<T>> itemCreatedEvent) Removes the given listener for the ItemCreated event that occurs when a new item gets created by this input mode.
protected void	setDragLocation(PointD location) Sets the drag location and calls updatePreview(IGraph, PointD) to update the layout of item preview based on the mouse coordinates and the results of the SnapContext.
protected void	setDropTarget(IModelItem newDropTarget) Gets the drop target at SnappedMousePosition
void	setDropTargetHighlightEnabled(boolean value) Switches highlighting the drop target on and off.
void	setItemCreator(IDropCreationCallback<T> value) Sets the callback for item creation.
void	setPreviewEnabled(boolean value) Determines whether a preview of the dragged element is displayed during the drag.
void	setSnapContext(SnapContext value) The SnapContext which is used to snap the dragged element during the drag.
void	setSnappingEnabled(boolean value) Switches snapping on and off.
protected void	updateDropTarget(PointD dragLocation) Calls getDropTarget(PointD) for SnappedMousePosition and sets the returned item as DropTarget.
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.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

ItemDropInputMode

protected ItemDropInputMode(Class expectedType)

Constructs a new instance of class DropInputMode for the expected data type. This constructor only exists for usage in child class.

Method Detail

addItemCreatedListener

public final void addItemCreatedListener(IEventHandler<ItemEventArgs<T>> itemCreatedEvent)

Adds the given listener for the ItemCreated event that occurs when a new item gets created by this input mode.

Parameters:

itemCreatedEvent - The listener to add.

See Also:

removeItemCreatedListener(IEventHandler)

cleanup

protected void cleanup()

Cleanup method that calls cleanupSnapContext(), cleanupPreview() and cleanupDropTarget().

This method should be called for cleanup actions after a drag/drop gesture has been finished or canceled.

cleanupDropTarget

protected void cleanupDropTarget()

Cleans up the drop target and its highlighting.

cleanupPreview

protected void cleanupPreview()

Cleans up the item preview.

cleanupSnapContext

protected void cleanupSnapContext()

Cleans up the snap context.

collectSnapResults

protected void collectSnapResults(Object source,
                                  CollectSnapResultsEventArgs args)

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

The default implementation doesn't collect any snap results.

Parameters:

source - The SnapContext this callback is registered at.

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

getDraggedItem

protected T getDraggedItem()

Gets the currently dragged IModelItem instance.

This implementation simply tries to cast the DropData to the type of the dragged items.

Returns:

The DraggedItem.

getDropTarget

public final IModelItem getDropTarget()

Gets the drop target at SnappedMousePosition.

Returns:

The DropTarget.

See Also:

isDropTargetHighlightEnabled(), setDropTarget(IModelItem)

getDropTarget

protected IModelItem getDropTarget(PointD dragLocation)

Returns the drop target at the specified location.

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

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.

getItemCreator

public final IDropCreationCallback<T> getItemCreator()

Gets the callback for item creation.

Called by method onDragDropped(InputModeEventArgs).

Returns:

The ItemCreator.

See Also:

setItemCreator(IDropCreationCallback)

getPreviewGraph

protected final IGraph getPreviewGraph()

Returns the graph displayed as item preview.

Returns:

The preview graph or null if no preview is displayed at the moment.

getSnapContext

public final SnapContext getSnapContext()

The SnapContext which is used to snap the dragged element during the drag.

If set to null (the default) this input mode tries to obtain the SnapContext from the IInputModeContext. To explicitly disable snapping, a SnapContext implementation that does nothing has to be set to this instance.

Returns:

The SnapContext.

See Also:

setSnapContext(SnapContext)

getSnappedMousePosition

public final PointD getSnappedMousePosition()

Gets the current snapped mouse position during drag operations.

The position is returned in world coordinates according to the CanvasControl into which this input mode is installed. If SnappingEnabled is false, this value corresponds with MousePosition.

Returns:

The SnappedMousePosition.

initializeDropTarget

protected void initializeDropTarget()

Initializes the drop target.

initializePreview

protected void initializePreview()

Initializes the item preview.

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

initializeSnapContext

protected void initializeSnapContext()

Initializes the snapping context.

This method is called by onDragEntered(InputModeEventArgs)

isDropTargetHighlightEnabled

public final boolean isDropTargetHighlightEnabled()

Switches highlighting the drop target on and off.

Returns:

The DropTargetHighlightEnabled.

See Also:

setDropTargetHighlightEnabled(boolean)

isPreviewEnabled

public final boolean isPreviewEnabled()

Determines whether a preview of the dragged element is displayed during the drag.

Returns:

The PreviewEnabled.

See Also:

setPreviewEnabled(boolean)

isSnappingEnabled

public final boolean isSnappingEnabled()

Switches snapping on and off.

Returns:

The SnappingEnabled.

See Also:

setSnappingEnabled(boolean)

onConcurrencyControllerDeactivated

protected void onConcurrencyControllerDeactivated()

Description copied from class: DropInputMode

Called after the Active property of the installed ConcurrencyController has been set to false.

Can be overridden in subclasses to perform additional actions after the mode has been deactivated.

Overriding implementations should call the base implementation.

Overrides:

onConcurrencyControllerDeactivated in class DropInputMode

onDragDropped

protected void onDragDropped(InputModeEventArgs eventArgs)

Description copied from class: DropInputMode

Called once a drag has been dropped on the canvas.

Overrides:

onDragDropped in class DropInputMode

onDragEntered

protected void onDragEntered(InputModeEventArgs eventArgs)

Called once a drag has entered the canvas.

Calls initializeSnapContext(), initializePreview() and initializeDropTarget().

Overrides:

onDragEntered in class DropInputMode

onDragExited

protected void onDragExited(InputModeEventArgs eventArgs)

Description copied from class: DropInputMode

Called once a drag has left the canvas.

Overrides:

onDragExited in class DropInputMode

onDraggedOver

protected void onDraggedOver(InputModeEventArgs eventArgs)

Description copied from class: DropInputMode

Called whenever a drag is over the canvas.

Overrides:

onDraggedOver in class DropInputMode

onItemCreated

protected void onItemCreated(ItemEventArgs<T> args)

Called whenever a new item is created.

populatePreviewGraph

protected void populatePreviewGraph(IGraph previewGraph)

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

Parameters:

previewGraph - The preview graph to fill.

removeItemCreatedListener

public final void removeItemCreatedListener(IEventHandler<ItemEventArgs<T>> itemCreatedEvent)

Removes the given listener for the ItemCreated event that occurs when a new item gets created by this input mode.

Parameters:

itemCreatedEvent - The listener to remove.

See Also:

addItemCreatedListener(IEventHandler)

setDragLocation

protected void setDragLocation(PointD location)

Sets the drag location and calls updatePreview(IGraph, PointD) to update the layout of item preview based on the mouse coordinates and the results of the SnapContext.

Overrides:

setDragLocation in class DropInputMode

Parameters:

location - The current location of the mouse in world coordinates.

setDropTarget

protected final void setDropTarget(IModelItem newDropTarget)

Gets the drop target at SnappedMousePosition

Parameters:

newDropTarget - The DropTarget to set. HighlightDropTarget

See Also:

getDropTarget()

setDropTargetHighlightEnabled

public final void setDropTargetHighlightEnabled(boolean value)

Switches highlighting the drop target on and off.

Parameters:

value - The DropTargetHighlightEnabled to set.

See Also:

isDropTargetHighlightEnabled()

setItemCreator

public final void setItemCreator(IDropCreationCallback<T> value)

Sets the callback for item creation.

Called by method onDragDropped(InputModeEventArgs).

Parameters:

value - The ItemCreator to set.

See Also:

getItemCreator()

setPreviewEnabled

public final void setPreviewEnabled(boolean value)

Determines whether a preview of the dragged element is displayed during the drag.

Parameters:

value - The PreviewEnabled to set.

See Also:

isPreviewEnabled()

setSnapContext

public final void setSnapContext(SnapContext value)

The SnapContext which is used to snap the dragged element during the drag.

If set to null (the default) this input mode tries to obtain the SnapContext from the IInputModeContext. To explicitly disable snapping, a SnapContext implementation that does nothing has to be set to this instance.

Parameters:

value - The SnapContext to set.

See Also:

getSnapContext()

setSnappingEnabled

public final void setSnappingEnabled(boolean value)

Switches snapping on and off.

Parameters:

value - The SnappingEnabled to set.

See Also:

isSnappingEnabled()

updateDropTarget

protected void updateDropTarget(PointD dragLocation)

Calls getDropTarget(PointD) for SnappedMousePosition and sets the returned item as DropTarget.

If DropTargetHighlightEnabled is enabled, the highlight is updated as well.

Parameters:

dragLocation - The location to update the drop target for.

updatePreview

protected void updatePreview(IGraph previewGraph,
                             PointD dragLocation)

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

Parameters:

previewGraph - The preview graph to update.

dragLocation - The current drag location.