org.eclipse.gef.tools
Class TargetingTool

java.lang.Object
  org.eclipse.gef.util.FlagSupport
      org.eclipse.gef.tools.AbstractTool
          org.eclipse.gef.tools.TargetingTool

All Implemented Interfaces:

RequestConstants, Tool

Direct Known Subclasses:

AbstractConnectionCreationTool, ConnectionEndpointTracker, CreationTool, SelectEditPartTracker, SelectionTool

public abstract class TargetingTool
extends AbstractTool

The base implementation for tools which perform targeting of editparts. Targeting tools may operate using either mouse drags or just mouse moves. Targeting tools work with a target request. This request is used along with the mouse location to obtain an active target from the current EditPartViewer. This target is then asked for the Command that performs the given request. The target is also asked to show target feedback.

TargetingTool also provides support for auto-expose (a.k.a. auto-scrolling). Subclasses that wish to commence auto-expose can do so by calling updateAutoexposeHelper(). An an AutoExposeHelper is found, auto-scrolling begins. Whenever that helper scrolls the diagram of performs any other change, handleMove will be called as if the mouse had moved. This is because the target has probably moved, but there is no input event to trigger an update of the operation.

Nested Class Summary

Nested classes/interfaces inherited from class org.eclipse.gef.tools.AbstractTool

AbstractTool.Input

Field Summary

protected static int

MAX_FLAG The max flag.

Fields inherited from class org.eclipse.gef.tools.AbstractTool

MAX_STATE, MOUSE_BUTTON_ANY, MOUSE_BUTTON1, MOUSE_BUTTON2, MOUSE_BUTTON3, PROPERTY_UNLOAD_WHEN_FINISHED, STATE_ACCESSIBLE_DRAG, STATE_ACCESSIBLE_DRAG_IN_PROGRESS, STATE_DRAG, STATE_DRAG_IN_PROGRESS, STATE_INITIAL, STATE_INVALID, STATE_TERMINAL

Fields inherited from interface org.eclipse.gef.RequestConstants

REQ_ADD, REQ_ALIGN, REQ_ALIGN_CHILDREN, REQ_CLONE, REQ_CONNECTION_END, REQ_CONNECTION_START, REQ_CREATE, REQ_CREATE_BENDPOINT, REQ_DELETE, REQ_DELETE_DEPENDANT, REQ_DIRECT_EDIT, REQ_MOVE, REQ_MOVE_BENDPOINT, REQ_MOVE_CHILDREN, REQ_OPEN, REQ_ORPHAN, REQ_ORPHAN_CHILDREN, REQ_RECONNECT_SOURCE, REQ_RECONNECT_TARGET, REQ_RESIZE, REQ_RESIZE_CHILDREN, REQ_SELECTION, REQ_SELECTION_HOVER

Constructor Summary

TargetingTool()

Method Summary

protected Request	createTargetRequest() Creates the target request that will be used with the target editpart.
void	deactivate() Deactivates the tool.
protected void	doAutoexpose() Called to perform an iteration of the autoexpose process.
protected void	eraseTargetFeedback() Asks the current target editpart to erase target feedback using the target request.
protected AutoexposeHelper	getAutoexposeHelper() Returns null or the current autoexpose helper.
protected Command	getCommand() Queries the target editpart for a command.
protected Collection	getExclusionSet() Returns a List of objects that should be excluded as potential targets for the operation.
protected EditPart	getTargetEditPart() Returns null or the current target editpart.
protected EditPartViewer.Conditional	getTargetingConditional() Returns the conditional object used for obtaining the target editpart from the current viewer.
protected Request	getTargetRequest() Lazily creates and returns the request used when communicating with the target editpart.
protected void	handleAutoexpose() This method is called whenever an autoexpose occurs.
protected boolean	handleEnteredEditPart() Called whenever the target editpart has changed.
protected boolean	handleExitingEditPart() Called whenever the target editpart is about to change.
protected boolean	handleHoverStop() Called from resetHover() iff hover is active.
protected boolean	handleInvalidInput() Called when invalid input is encountered.
protected void	handleLeavingEditPart() An archaic method name that has been left here to force use of the new name.
protected boolean	handleViewerExited() Sets the target to null.
protected boolean	isShowingTargetFeedback() Returns true if target feedback is being shown.
protected boolean	isTargetLocked() Return true if the current target is locked.
protected void	lockTargetEditPart(EditPart editpart) Locks-in the given editpart as the target.
protected void	resetFlags() Extended to reset the target lock flag.
protected void	resetHover() Resets hovering to inactive.
protected void	setAutoexposeHelper(AutoexposeHelper helper) Sets the active autoexpose helper to the given helper, or null.
protected void	setTargetEditPart(EditPart editpart) Sets the target editpart.
protected void	setTargetRequest(Request req) Sets the target request.
protected void	showTargetFeedback() Asks the target editpart to show target feedback and sets the target feedback flag.
protected void	unlockTargetEditPart() Releases the targeting lock, and updates the target in case the mouse is already over a new target.
protected void	updateAutoexposeHelper() Updates the active AutoexposeHelper.
protected void	updateTargetRequest() Subclasses should override to update the target request.
protected boolean	updateTargetUnderMouse() Updates the target editpart and returns true if the target changes.

Methods inherited from class org.eclipse.gef.tools.AbstractTool

acceptArrowKey, activate, addFeedback, applyProperty, calculateCursor, commitDrag, createOperationSet, debug, executeCommand, executeCurrentCommand, focusGained, focusLost, getCommandName, getCurrentCommand, getCurrentInput, getCurrentViewer, getDebugName, getDebugNameForState, getDefaultCursor, getDisabledCursor, getDomain, getDragMoveDelta, getLocation, getOperationSet, getStartLocation, getState, handleButtonDown, handleButtonUp, handleCommandStackChanged, handleDoubleClick, handleDrag, handleDragInProgress, handleDragStarted, handleFinished, handleFocusGained, handleFocusLost, handleHover, handleKeyDown, handleKeyTraversed, handleKeyUp, handleMove, handleNativeDragFinished, handleNativeDragStarted, handleViewerEntered, isActive, isHoverActive, isInState, isViewerImportant, keyDown, keyTraversed, keyUp, mouseDoubleClick, mouseDown, mouseDrag, mouseHover, mouseMove, mouseUp, mouseWheelScrolled, movedPastThreshold, nativeDragFinished, nativeDragStarted, performViewerMouseWheel, placeMouseInViewer, reactivate, refreshCursor, releaseToolCapture, removeFeedback, setCurrentCommand, setCursor, setDefaultCursor, setDisabledCursor, setEditDomain, setHoverActive, setProperties, setStartLocation, setState, setToolCapture, setUnloadWhenFinished, setViewer, stateTransition, unloadWhenFinished, viewerEntered, viewerExited

Methods inherited from class org.eclipse.gef.util.FlagSupport

getFlag, setFlag

Methods inherited from class java.lang.Object

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

Field Detail

MAX_FLAG

protected static final int MAX_FLAG

The max flag.

See Also:

Constant Field Values

Constructor Detail

TargetingTool

public TargetingTool()

Method Detail

createTargetRequest

protected Request createTargetRequest()

Creates the target request that will be used with the target editpart. This request will be cached and updated as needed.

Returns:

the new target request

See Also:

getTargetRequest()

deactivate

public void deactivate()

Description copied from class: AbstractTool

Deactivates the tool. This method is called whenever the user switches to another tool. Use this method to do some clean-up when the tool is switched. The abstract tool allows cursors for viewers to be changed. When the tool is deactivated it must revert to normal the cursor of the last tool it changed.

Specified by:

deactivate in interface Tool

Overrides:

deactivate in class AbstractTool

See Also:

Tool.deactivate()

doAutoexpose

protected void doAutoexpose()

Called to perform an iteration of the autoexpose process. If the expose helper is set, it will be asked to step at the current mouse location. If it returns true, another expose iteration will be queued. There is no delay between autoexpose events, other than the time required to perform the step().

eraseTargetFeedback

protected void eraseTargetFeedback()

Asks the current target editpart to erase target feedback using the target request. If target feedback is not being shown, this method does nothing and returns. Otherwise, the target feedback flag is reset to false, and the target editpart is asked to erase target feedback. This methods should rarely be overridden.

getCommand

protected Command getCommand()

Queries the target editpart for a command.

Overrides:

getCommand in class AbstractTool

Returns:

a newly obtained command

See Also:

AbstractTool.getCommand()

getExclusionSet

protected Collection getExclusionSet()

Returns a List of objects that should be excluded as potential targets for the operation.

Returns:

the list of objects to be excluded as targets

getTargetingConditional

protected EditPartViewer.Conditional getTargetingConditional()

Returns the conditional object used for obtaining the target editpart from the current viewer. By default, a conditional is returned that tests whether an editpart at the current mouse location indicates a target for the operation's request, using EditPart.getTargetEditPart(Request). If null is returned, then the conditional fails, and the search continues.

Returns:

the targeting conditional

See Also:

EditPartViewer.findObjectAtExcluding(Point, Collection, EditPartViewer.Conditional)

getTargetEditPart

protected EditPart getTargetEditPart()

Returns null or the current target editpart.

Returns:

null or a target part

getTargetRequest

protected Request getTargetRequest()

Lazily creates and returns the request used when communicating with the target editpart.

Returns:

the target request

handleAutoexpose

protected void handleAutoexpose()

This method is called whenever an autoexpose occurs. When an autoexpose occurs, it is possible that everything in the viewer has moved a little. Therefore, by default, handleMove() is called to simulate the mouse moving even though it didn't.

handleEnteredEditPart

protected boolean handleEnteredEditPart()

Called whenever the target editpart has changed. By default, the target request is updated, and the new target is asked to show feedback. Subclasses may extend this method if needed.

Returns:

true

handleExitingEditPart

protected boolean handleExitingEditPart()

Called whenever the target editpart is about to change. By default, hover is reset, in the case that a hover was showing something, and the target being exited is asked to erase its feedback.

Returns:

true

handleHoverStop

protected boolean handleHoverStop()

Called from resetHover() iff hover is active. Subclasses may extend this method to handle the hover stop event. Returns true if something was done in response to the call.

Returns:

true if the hover stop is processed in some way

See Also:

AbstractTool.isHoverActive()

handleInvalidInput

protected boolean handleInvalidInput()

Called when invalid input is encountered. By default, feedback is erased, and the current command is set to the unexecutable command. The state does not change, so the caller must set the state to AbstractTool.STATE_INVALID.

Overrides:

handleInvalidInput in class AbstractTool

Returns:

true

handleLeavingEditPart

protected final void handleLeavingEditPart()
                                    throws Exception

An archaic method name that has been left here to force use of the new name.

Throws:

Exception - exc

handleViewerExited

protected boolean handleViewerExited()

Sets the target to null.

Overrides:

handleViewerExited in class AbstractTool

Returns:

true if the viewer exited was handled

See Also:

AbstractTool.handleViewerExited()

isShowingTargetFeedback

protected boolean isShowingTargetFeedback()

Returns true if target feedback is being shown.

Returns:

true if showing target feedback

isTargetLocked

protected boolean isTargetLocked()

Return true if the current target is locked.

Returns:

true if the target is locked

See Also:

lockTargetEditPart(EditPart)

lockTargetEditPart

protected void lockTargetEditPart(EditPart editpart)

Locks-in the given editpart as the target. Updating of the target will not occur until unlockTargetEditPart() is called.

Parameters:

editpart - the target to be locked-in

resetFlags

protected void resetFlags()

Extended to reset the target lock flag.

Overrides:

resetFlags in class AbstractTool

See Also:

AbstractTool.resetFlags(), lockTargetEditPart(EditPart)

resetHover

protected void resetHover()

Resets hovering to inactive.

Since:

3.4

setAutoexposeHelper

protected void setAutoexposeHelper(AutoexposeHelper helper)

Sets the active autoexpose helper to the given helper, or null. If the helper is not null, a runnable is queued on the event thread that will trigger a subsequent doAutoexpose(). The helper is typically updated only on a hover event.

Parameters:

helper - the new autoexpose helper or null

setTargetEditPart

protected void setTargetEditPart(EditPart editpart)

Sets the target editpart. If the target editpart is changing, this method will call handleExitingEditPart() for the previous target if not null, and handleEnteredEditPart() for the new target, if not null.

Parameters:

editpart - the new target

setTargetRequest

protected void setTargetRequest(Request req)

Sets the target request. This method is typically not called; subclasses normally override createTargetRequest().

Parameters:

req - the target request

showTargetFeedback

protected void showTargetFeedback()

Asks the target editpart to show target feedback and sets the target feedback flag.

unlockTargetEditPart

protected void unlockTargetEditPart()

Releases the targeting lock, and updates the target in case the mouse is already over a new target.

updateAutoexposeHelper

protected void updateAutoexposeHelper()

Updates the active AutoexposeHelper. Does nothing if there is still an active helper. Otherwise, obtains a new helper (possible null) at the current mouse location and calls setAutoexposeHelper(AutoexposeHelper).

updateTargetRequest

protected void updateTargetRequest()

Subclasses should override to update the target request.

updateTargetUnderMouse

protected boolean updateTargetUnderMouse()

Updates the target editpart and returns true if the target changes. The target is updated by using the target conditional and the target request. If the target has been locked, this method does nothing and returns false.

Returns:

true if the target was changed

getAutoexposeHelper

protected AutoexposeHelper getAutoexposeHelper()

Returns null or the current autoexpose helper.

Returns:

null or a helper