Class 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.

    • 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.
      • getExclusionSet

        protected java.util.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
      • 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 java.lang.Exception
        An archaic method name that has been left here to force use of the new name.
        Throws:
        java.lang.Exception - exc
      • 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
      • 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