org.eclipse.gef.rulers
Class RulerProvider

java.lang.Object
  org.eclipse.gef.rulers.RulerProvider

public abstract class RulerProvider

extends java.lang.Object

This class provides an interface to interact with the ruler/guide feature provided in GEF. A RulerProvider represents a ruler (and the guides contained within), and provides the necessary information about them.

Clients wishing to utilize this GEF feature should do the following:

• Extend this class and override the necessary methods. Also provide a notification mechanism to notify registered RulerChangeListeners of changes in ruler properties.
• Set instances of that class as properties on the diagram's graphical viewer (PROPERTY_HORIZONTAL_RULER and/or PROPERTY_VERTICAL_RULER)
• Set PROPERTY_RULER_VISIBILITY to be true on the graphical viewer.

Since:

3.0

Field Summary

protected java.util.List	listeners A list of RulerChangeListeners that have to be notified of changes in ruler/guide properties.
static java.lang.String	PROPERTY_HORIZONTAL_RULER The following property should be set on the graphical viewer.
static java.lang.String	PROPERTY_RULER_VISIBILITY The following property should be set on the graphical viewer.
static java.lang.String	PROPERTY_VERTICAL_RULER The following property should be set on the graphical viewer.
static int	UNIT_CENTIMETERS Constant indicating that the ruler should display centimeters.
static int	UNIT_INCHES Constant indicating that the ruler should display inches.
static int	UNIT_PIXELS Constant indicating that the ruler should display pixel count.

Constructor Summary

RulerProvider()

Method Summary

void	addRulerChangeListener(RulerChangeListener listener) The given listener will be notified of changes in ruler properties.
void	getAccGuideDescription(org.eclipse.swt.accessibility.AccessibleEvent e, java.lang.Object guide) Return the description of the control or specified child in the result field of the event object.
void	getAccGuideName(org.eclipse.swt.accessibility.AccessibleEvent e, java.lang.Object guide) Return the given guide's name/label in the result field of the given event.
void	getAccGuideValue(org.eclipse.swt.accessibility.AccessibleControlEvent e, java.lang.Object guide) Return the guide's position in the result field of the given event.
java.util.List	getAttachedEditParts(java.lang.Object guide, GraphicalViewer viewer) Returns a List of EditParts that are attached to the given guide.
java.util.List	getAttachedModelObjects(java.lang.Object guide) Returns a List of model objects that are attached to the given guide.
Command	getCreateGuideCommand(int position) Clients should override this method to return a Command to create a new guide at the given position.
Command	getDeleteGuideCommand(java.lang.Object guide) Clients should override this method to return a Command to delete the given guide.
java.lang.Object	getGuideAt(int position) In most cases, there should be no need for clients to override this method.
int	getGuidePosition(java.lang.Object guide) Clients should override this method to return the position (in pixels) of the given guide.
int[]	getGuidePositions() Clients should override this method to return an array of all the positions of all the guides on this ruler.
java.util.List	getGuides() Clients should override this method to return a list of all the guides set on this ruler.
Command	getMoveGuideCommand(java.lang.Object guide, int positionDelta) Clients should override this method to return a Command to move the given guide by the given amount.
java.lang.Object	getRuler() Clients should override this method to return a model representation of the ruler.
int	getUnit() Clients should override this method to return the units that the ruler should display: one of UNIT_INCHES, UNIT_CENTIMETERS, UNIT_PIXELS.
void	removeRulerChangeListener(RulerChangeListener listener) The given listener will not be notified of changes in the ruler anymore.
void	setUnit(int newUnit) This method will be invoked when the user requests that the ruler display a different measurement.

Methods inherited from class java.lang.Object

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

Field Detail

PROPERTY_HORIZONTAL_RULER

public static final java.lang.String PROPERTY_HORIZONTAL_RULER

The following property should be set on the graphical viewer. PROPERTY_HORIZONTAL_RULER should have a RulerProvider as its value.

See Also:

Constant Field Values

PROPERTY_RULER_VISIBILITY

public static final java.lang.String PROPERTY_RULER_VISIBILITY

The following property should be set on the graphical viewer. PROPERTY_RULER_VISIBILITY should have a Boolean value.

See Also:

Constant Field Values

PROPERTY_VERTICAL_RULER

public static final java.lang.String PROPERTY_VERTICAL_RULER

The following property should be set on the graphical viewer. PROPERTY_VERTICAL_RULER should have a RulerProvider as its value.

See Also:

Constant Field Values

UNIT_CENTIMETERS

public static final int UNIT_CENTIMETERS

Constant indicating that the ruler should display centimeters. Note that this setting does not affect how a guide's position is interpreted (it is always taken as pixels).

See Also:

Constant Field Values

UNIT_INCHES

public static final int UNIT_INCHES

Constant indicating that the ruler should display inches. Note that this setting does not affect how a guide's position is interpreted (it is always taken as pixels).

See Also:

Constant Field Values

UNIT_PIXELS

public static final int UNIT_PIXELS

Constant indicating that the ruler should display pixel count.

See Also:

Constant Field Values

listeners

protected java.util.List listeners

A list of RulerChangeListeners that have to be notified of changes in ruler/guide properties.

Constructor Detail

RulerProvider

public RulerProvider()

Method Detail

addRulerChangeListener

public void addRulerChangeListener(RulerChangeListener listener)

The given listener will be notified of changes in ruler properties.

Parameters:

listener - the listener that is to be notified of changes in ruler properties

getAccGuideDescription

public void getAccGuideDescription(org.eclipse.swt.accessibility.AccessibleEvent e,
                                   java.lang.Object guide)

Return the description of the control or specified child in the result field of the event object. Returning an empty string tells the client that the control or child does not have a description, and returning null tells the client to use the platform description.

Parameters:

e - AccessibleEvent

guide - The guide whose accessibility information is requested

See Also:

AccessibleAdapter.getDescription(org.eclipse.swt.accessibility.AccessibleEvent)

getAccGuideName

public void getAccGuideName(org.eclipse.swt.accessibility.AccessibleEvent e,
                            java.lang.Object guide)

Return the given guide's name/label in the result field of the given event.

Parameters:

e - AccessibleEvent

guide - The guide whose accessibility information is requested

See Also:

AccessibleAdapter.getName(org.eclipse.swt.accessibility.AccessibleEvent)

getAccGuideValue

public void getAccGuideValue(org.eclipse.swt.accessibility.AccessibleControlEvent e,
                             java.lang.Object guide)

Return the guide's position in the result field of the given event.

Parameters:

e - AccessibleEvent

guide - The guide whose accessibility information is requested

See Also:

AccessibleControlAdapter.getValue(org.eclipse.swt.accessibility.AccessibleControlEvent)

getAttachedModelObjects

public java.util.List getAttachedModelObjects(java.lang.Object guide)

Returns a List of model objects that are attached to the given guide.

Parameters:

guide - the guide to which the model parts are attached.

Returns:

list of attached model objects

getAttachedEditParts

public java.util.List getAttachedEditParts(java.lang.Object guide,
                                           GraphicalViewer viewer)

Returns a List of EditParts that are attached to the given guide.

Parameters:

guide - the guide to which the EditParts are attached.

viewer - the GraphicalViewer in which these EditParts are shown.

Returns:

list of attached edit parts

getCreateGuideCommand

public Command getCreateGuideCommand(int position)

Clients should override this method to return a Command to create a new guide at the given position.

Parameters:

position - The pixel position where the new guide is to be created

Returns:

UnexecutableCommand

getDeleteGuideCommand

public Command getDeleteGuideCommand(java.lang.Object guide)

Clients should override this method to return a Command to delete the given guide.

Parameters:

guide - The guide that is to be deleted

Returns:

UnexecutableCommand

getGuideAt

public java.lang.Object getGuideAt(int position)

In most cases, there should be no need for clients to override this method.

Parameters:

position - The position of the guide that is to be found

Returns:

The guide object at the given position; null if no guide exists at the given position

getMoveGuideCommand

public Command getMoveGuideCommand(java.lang.Object guide,
                                   int positionDelta)

Clients should override this method to return a Command to move the given guide by the given amount.

Parameters:

guide - The guide that is to be moved

positionDelta - The amount by which the guide is to be moved

Returns:

UnexecutableCommand

getGuides

public java.util.List getGuides()

Clients should override this method to return a list of all the guides set on this ruler.

Returns:

an empty list

getGuidePositions

public int[] getGuidePositions()

Clients should override this method to return an array of all the positions of all the guides on this ruler.

Returns:

an empty array

getGuidePosition

public int getGuidePosition(java.lang.Object guide)

Clients should override this method to return the position (in pixels) of the given guide.

Parameters:

guide - The guide whose position is to be determined

Returns:

Integer.MIN_VALUE

getRuler

public java.lang.Object getRuler()

Clients should override this method to return a model representation of the ruler.

Returns:

null

getUnit

public int getUnit()

Clients should override this method to return the units that the ruler should display: one of UNIT_INCHES, UNIT_CENTIMETERS, UNIT_PIXELS.

Returns:

UNIT_INCHES

removeRulerChangeListener

public void removeRulerChangeListener(RulerChangeListener listener)

The given listener will not be notified of changes in the ruler anymore.

Parameters:

listener - the listener that is to be removed

setUnit

public void setUnit(int newUnit)

This method will be invoked when the user requests that the ruler display a different measurement. The default implementation ignores the user's request.

Parameters:

newUnit - the new unit of measurement; will be one of UNIT_CENTIMETERS, UNIT_INCHES, or UNIT_PIXELS