org.eclipse.gef4.mvc.fx.policies

Class FXBendPolicy

java.lang.Object

org.eclipse.gef4.mvc.policies.AbstractPolicy<VR>

org.eclipse.gef4.mvc.policies.AbstractTransactionPolicy<javafx.scene.Node>

org.eclipse.gef4.mvc.fx.policies.FXBendPolicy

All Implemented Interfaces:

IAdaptable.Bound<IVisualPart<javafx.scene.Node,? extends javafx.scene.Node>>, IPolicy<javafx.scene.Node>

public class FXBendPolicy
extends AbstractTransactionPolicy<javafx.scene.Node>

The FXBendPolicy can be used to manipulate the points constituting an Connection, i.e. its start, way, and end points. Each point is realized though an IAnchor, which may either be local to the Connection (i.e. the anchor refers to the Connection as anchorage), or it may be provided by another IVisualPart (i.e. the anchor is provided by a Provider adapted to the part), to which the connection is being connected. When moving a point the policy takes care of:

• Removing overlaid neighbor points.
• Re-adding temporarily removed neighbor points.
• Reconnecting points to the IVisualPart under mouse when applicable.

Field Summary

Fields

Modifier and Type	Field and Description
protected static double	DEFAULT_OVERLAY_THRESHOLD The overlay threshold, i.e. the distance between two points so that they are regarded as overlying.

Constructor Summary

Constructors

Constructor and Description
FXBendPolicy()

Method Summary

Modifier and Type	Method and Description
protected boolean	canConnect(int pointIndex) Returns true if the currently modified start, end, or way point can be connected, i.e. realized by an anchor that is not anchored to the Connection itself (see IAnchor.getAnchorage() ), but provided through a IVisualPart's anchor provider (i.e. a Provider<IAnchor> adapted to the IVisualPart).
ITransactionalOperation	commit() Returns an ITransactionalOperation that performs all manipulations applied by the policy since the last AbstractTransactionPolicy.init() call.
void	createAndSelectPoint(int segmentIndex, Point mouseInScene) Creates a new point at the given segment.
protected FXBendOperation	createOperation() Creates an ITransactionalOperation that is used to encapsulate the changes that are applied by this AbstractTransactionPolicy through its "work" methods.
protected ReverseUndoCompositeOperation	createReselectOperation() Create an IUndoableOperation to re-select the host part.
protected IAnchor	createUnconnectedAnchor(Point selectedPointCurrentPositionInLocal) Creates an (unconnected) anchor (i.e. one anchored on the Connection) for the given position (in scene coordinates).
protected IAnchor	findOrCreateAnchor(Point positionInLocal, boolean canConnect) Determines the IAnchor that should replace the anchor of the currently selected point.
protected FXBendOperation	getBendOperation() Returns an FXBendOperation that is extracted from the operation created by createOperation().
protected Connection	getConnection() Returns the Connection that is manipulated by this policy.
IVisualPart<javafx.scene.Node,Connection>	getHost() Returns the host of this IPolicy, i.e. the IVisualPart this IPolicy is attached to.
protected Point	getMouseDeltaInLocal(Point currentMousePositionInScene) Computes the mouse movement delta (w.r.t. to the initial mouse position) in local coordinates .
protected IAnchor	getOverlayAnchor(int candidateIndex, Point mouseInScene) If the point at the given index is overlain by the currently selected point, i.e. their distance is smaller than the overlay threshold and they are above the same anchorage, returns the anchor that can be found at the candidate location.
protected double	getOverlayThreshold() Removes the overlay threshold, i.e. the distance between two points, so that they are regarded as overlaying.
protected Point	getSelectedPointInitialPositionInLocal() Returns the initial position of the currently selected point in the local coordinate system of the Connection.
protected void	handleOverlay(Point mouseInScene) Handles the hiding of an overlain point as well as the expose of a previously overlain point.
void	init() Initializes the policy, so that the policy's "work" methods can be used.
void	moveSelectedPoint(Point mouseInScene) Moves the currently selected point to the given mouse position in scene coordinates.
void	selectPoint(int segmentIndex, double segmentParameter, Point mouseInScene) Selects the point specified by the given segment index and parameter for manipulation.
java.lang.String	toString()

Methods inherited from class org.eclipse.gef4.mvc.policies.AbstractTransactionPolicy

checkInitialized, getOperation, isInitialized, locallyExecuteOperation, rollback

Methods inherited from class org.eclipse.gef4.mvc.policies.AbstractPolicy

getAdaptable, setAdaptable

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_OVERLAY_THRESHOLD

protected static final double DEFAULT_OVERLAY_THRESHOLD

The overlay threshold, i.e. the distance between two points so that they are regarded as overlying.

See Also:

Constant Field Values

Constructor Detail

FXBendPolicy

public FXBendPolicy()

Method Detail

canConnect

protected boolean canConnect(int pointIndex)

Returns true if the currently modified start, end, or way point can be connected, i.e. realized by an anchor that is not anchored to the Connection itself (see IAnchor.getAnchorage() ), but provided through a IVisualPart's anchor provider (i.e. a Provider<IAnchor> adapted to the IVisualPart). Otherwise returns false. Per default, only the start and the end point can be attached.

Parameters:

pointIndex - The index of the currently modified connection point.

Returns:

true if the currently modified point can be realized through an IAnchor not anchored on the Connection . Otherwise returns false.

See Also:

Connection.isStartConnected(), Connection.isWayConnected(int), Connection.isEndConnected()

commit

public ITransactionalOperation commit()

Description copied from class: AbstractTransactionPolicy

Returns an ITransactionalOperation that performs all manipulations applied by the policy since the last AbstractTransactionPolicy.init() call. When called multiple times in sequence, only the first call will yield an operation, the subsequent calls will yield null.

Overrides:

commit in class AbstractTransactionPolicy<javafx.scene.Node>

Returns:

An ITransactionalOperation that performs all manipulations applied by the policy since the last AbstractTransactionPolicy.init() call.

createAndSelectPoint

public void createAndSelectPoint(int segmentIndex,
                                 Point mouseInScene)

Creates a new point at the given segment. The new way point is then selected for further manipulation.

Parameters:

segmentIndex - The index of the segment for which a new way point is created.

mouseInScene - The mouse position in scene coordinates.

createOperation

protected FXBendOperation createOperation()

Description copied from class: AbstractTransactionPolicy

Creates an ITransactionalOperation that is used to encapsulate the changes that are applied by this AbstractTransactionPolicy through its "work" methods. The created operation should allow for local execution at each time.

Specified by:

createOperation in class AbstractTransactionPolicy<javafx.scene.Node>

Returns:

A new ITransactionalOperation to encapsulate all applied changes.

createReselectOperation

protected ReverseUndoCompositeOperation createReselectOperation()

Create an IUndoableOperation to re-select the host part.

Returns:

An IUndoableOperation that deselects and selects the root part.

createUnconnectedAnchor

protected IAnchor createUnconnectedAnchor(Point selectedPointCurrentPositionInLocal)

Creates an (unconnected) anchor (i.e. one anchored on the Connection) for the given position (in scene coordinates).

Parameters:

selectedPointCurrentPositionInLocal - The location in local coordinates of the connection

Returns:

An IAnchor that yields the given position.

findOrCreateAnchor

protected IAnchor findOrCreateAnchor(Point positionInLocal,
                                     boolean canConnect)

Determines the IAnchor that should replace the anchor of the currently selected point. If the point can connect, the IVisualPart at the mouse position is queried for an IAnchor via a Provider<IAnchor> adapter. Otherwise an (unconnected) anchor is create using createUnconnectedAnchor(Point) .

Parameters:

positionInLocal - A position in local coordinates of the connection.

canConnect - true if the point can be attached to an underlying IVisualPart, otherwise false.

Returns:

The IAnchor that replaces the anchor of the currently modified point.

getBendOperation

protected FXBendOperation getBendOperation()

Returns an FXBendOperation that is extracted from the operation created by createOperation().

Returns:

an FXBendOperation that is extracted from the operation created by createOperation().

getConnection

protected Connection getConnection()

Returns the Connection that is manipulated by this policy.

Returns:

The Connection that is manipulated by this policy.

getHost

public IVisualPart<javafx.scene.Node,Connection> getHost()

Description copied from interface: IPolicy

Returns the host of this IPolicy, i.e. the IVisualPart this IPolicy is attached to.

Specified by:

getHost in interface IPolicy<javafx.scene.Node>

Overrides:

getHost in class AbstractPolicy<javafx.scene.Node>

Returns:

The host of this IPolicy.

getMouseDeltaInLocal

protected Point getMouseDeltaInLocal(Point currentMousePositionInScene)

Computes the mouse movement delta (w.r.t. to the initial mouse position) in local coordinates .

Parameters:

currentMousePositionInScene - The current mouse position in scene coordinates.

Returns:

The movement delta, translated into local coordinates of the connection

getOverlayAnchor

protected IAnchor getOverlayAnchor(int candidateIndex,
                                   Point mouseInScene)

If the point at the given index is overlain by the currently selected point, i.e. their distance is smaller than the overlay threshold and they are above the same anchorage, returns the anchor that can be found at the candidate location.

Parameters:

candidateIndex - The candidate index.

mouseInScene - The current mouse position in scene coordinates.

Returns:

The overlaid IAnchor to be used for the currently selected point

getOverlayThreshold

protected double getOverlayThreshold()

Removes the overlay threshold, i.e. the distance between two points, so that they are regarded as overlaying. When the background grid is enables ( GridModel.isShowGrid(), then the grid cell size is used to determine the overlay threshold. Otherwise, the DEFAULT_OVERLAY_THRESHOLD is used.

Returns:

The overlay threshold.

getSelectedPointInitialPositionInLocal

protected Point getSelectedPointInitialPositionInLocal()

Returns the initial position of the currently selected point in the local coordinate system of the Connection.

Returns:

The initial position in the local coordinate system of the Connection.

See Also:

selectPoint(int, double, Point)

handleOverlay

protected void handleOverlay(Point mouseInScene)

Handles the hiding of an overlain point as well as the expose of a previously overlain point.

1. Restores a point that was previously removed because it was overlaid.
2. Checks if the currently modified point overlays another point of the Connection. The overlaid point is removed and saved so that it can be restored later.

Parameters:

mouseInScene - The current mouse position in scene coordinates.

init

public void init()

Description copied from class: AbstractTransactionPolicy

Initializes the policy, so that the policy's "work" methods can be used. Calling a "work" method while the policy is not initialized will result in an IllegalStateException. It is safe to call AbstractTransactionPolicy.init() multiple times in sequence.

Overrides:

init in class AbstractTransactionPolicy<javafx.scene.Node>

moveSelectedPoint

public void moveSelectedPoint(Point mouseInScene)

Moves the currently selected point to the given mouse position in scene coordinates. Checks if the selected point overlays another point using handleOverlay(Point).

Parameters:

mouseInScene - The current mouse position in scene coordinates.

selectPoint

public void selectPoint(int segmentIndex,
                        double segmentParameter,
                        Point mouseInScene)

Selects the point specified by the given segment index and parameter for manipulation. Captures the initial position of the selected point (see getSelectedPointInitialPositionInLocal()) and the related initial mouse location.

Parameters:

segmentIndex - The index of the segment of which a point is to be manipulated.

segmentParameter - The parameter on the segment to identify if its the end point.

mouseInScene - The current mouse position in scene coordinates.

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object