org.jhotdraw.standard
Class NullDrawingView

java.lang.Object
  java.awt.Component
      java.awt.Container
          javax.swing.JComponent
              javax.swing.JPanel
                  org.jhotdraw.standard.NullDrawingView

All Implemented Interfaces:

java.awt.image.ImageObserver, java.awt.MenuContainer, java.io.Serializable, javax.accessibility.Accessible, DrawingListener, DrawingView

public class NullDrawingView
extends javax.swing.JPanel
implements DrawingView

This DrawingView provides a very basic implementation. It does not perform any functionality apart from keeping track of its state represented by some important fields. It is a Null-value object and is used instead of a null reference to avoid null pointer exception. This concept is known as the Null-value object bug pattern.

Version:

<$CURRENT_VERSION$>

Author:

Wolfram Kaiser

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class javax.swing.JPanel

javax.swing.JPanel.AccessibleJPanel

Nested classes/interfaces inherited from class javax.swing.JComponent

javax.swing.JComponent.AccessibleJComponent

Nested classes/interfaces inherited from class java.awt.Container

java.awt.Container.AccessibleAWTContainer

Nested classes/interfaces inherited from class java.awt.Component

java.awt.Component.AccessibleAWTComponent, java.awt.Component.BaselineResizeBehavior, java.awt.Component.BltBufferStrategy, java.awt.Component.FlipBufferStrategy

Field Summary

private static java.util.Hashtable	drawingViewManager
private java.awt.Color	myBackgroundColor
private Drawing	myDrawing
private DrawingEditor	myDrawingEditor
private Painter	myUpdateStrategy

Fields inherited from class javax.swing.JComponent

accessibleContext, listenerList, TOOL_TIP_TEXT_KEY, ui, UNDEFINED_CONDITION, WHEN_ANCESTOR_OF_FOCUSED_COMPONENT, WHEN_FOCUSED, WHEN_IN_FOCUSED_WINDOW

Fields inherited from class java.awt.Component

BOTTOM_ALIGNMENT, CENTER_ALIGNMENT, LEFT_ALIGNMENT, RIGHT_ALIGNMENT, TOP_ALIGNMENT

Fields inherited from interface java.awt.image.ImageObserver

ABORT, ALLBITS, ERROR, FRAMEBITS, HEIGHT, PROPERTIES, SOMEBITS, WIDTH

Constructor Summary

protected

NullDrawingView(DrawingEditor editor)

Method Summary

Figure	add(Figure figure) Adds a figure to the drawing.
void	addAll(java.util.Collection figures) Adds a collection of figures to the drawing.
void	addFigureSelectionListener(FigureSelectionListener fsl) Add a listener for selection changes in this DrawingView.
void	addToSelection(Figure figure) Adds a figure to the current selection.
void	addToSelectionAll(java.util.Collection figures) Adds a Collection of figures to the current selection.
void	addToSelectionAll(FigureEnumeration fe) Adds a FigureEnumeration to the current selection.
void	checkDamage() Checks whether the drawing has some accumulated damage
void	clearSelection() Clears the current selection.
java.awt.Image	createImage(int width, int height) Creates an image with the given dimensions
void	draw(java.awt.Graphics g, FigureEnumeration fe) Draws the given figures.
void	drawAll(java.awt.Graphics g) Draws the contents of the drawing view.
void	drawBackground(java.awt.Graphics g) Draws the background.
void	drawDrawing(java.awt.Graphics g) Draws the drawing.
void	drawHandles(java.awt.Graphics g) Draws the currently active handles.
Drawing	drawing() Gets the drawing.
void	drawingInvalidated(DrawingEvent e) Sent when an area is invalid
void	drawingRequestUpdate(DrawingEvent e) Sent when the drawing wants to be refreshed
void	drawingTitleChanged(DrawingEvent e) Sent when the drawing Title has changed
DrawingEditor	editor() Gets the editor.
Handle	findHandle(int x, int y) Finds a handle at the given coordinates.
void	freezeView() Freezes the view by acquiring the drawing lock.
java.awt.Color	getBackground() Gets the background color of the DrawingView
FigureEnumeration	getConnectionFigures(Figure inFigure) Returns a FigureEnumeration of connection figures
PointConstrainer	getConstrainer() Gets the current grid setting.
Painter	getDisplayUpdate() Gets the current display update strategy.
FigureSelection	getFigureSelection() Gets the current selection as a FigureSelection.
java.awt.Graphics	getGraphics() Gets a graphic to draw into
static DrawingView	getManagedDrawingView(DrawingEditor editor)
java.awt.Dimension	getMinimumSize() Gets the minimum dimension of the drawing.
java.awt.Dimension	getPreferredSize() Gets the preferred dimension of the drawing..
java.awt.Dimension	getSize() Gets the size of the drawing.
FigureEnumeration	insertFigures(FigureEnumeration inFigures, int dx, int dy, boolean bCheck) Inserts figures in a drawing at given offset.
boolean	isFigureSelected(Figure checkFigure) Test whether a given figure is selected.
boolean	isInteractive() Check whether the DrawingView is interactive, i.e.
java.awt.Point	lastClick() Gets the position of the last click inside the view.
void	paint(java.awt.Graphics g) Paints the drawing view.
Figure	remove(Figure figure) Removes a figure from the drawing.
void	removeFigureSelectionListener(FigureSelectionListener fsl) Remove a listener for selection changes in this DrawingView.
void	removeFromSelection(Figure figure) Removes a figure from the selection.
void	repairDamage() Repair the damaged area
FigureEnumeration	selection() Gets an enumeration over the currently selected figures.
int	selectionCount() Gets the number of selected figures.
FigureEnumeration	selectionZOrdered() Gets the currently seleced figures in Z order.
void	setBackground(java.awt.Color c) Sets the background color of the DrawingView
void	setConstrainer(PointConstrainer p) Sets the current point constrainer.
void	setCursor(Cursor c) Sets the cursor of the DrawingView
void	setDisplayUpdate(Painter newUpdateStrategy) Sets the current display update strategy.
void	setDrawing(Drawing d) Sets and installs another drawing in the view.
void	setEditor(DrawingEditor editor) Sets the view's editor.
void	toggleSelection(Figure figure) If a figure isn't selected it is added to the selection.
Tool	tool() Gets the current tool.
void	unfreezeView() Unfreezes the view by releasing the drawing lock.

Methods inherited from class javax.swing.JPanel

getAccessibleContext, getUI, getUIClassID, paramString, setUI, updateUI

Methods inherited from class javax.swing.JComponent

addAncestorListener, addNotify, addVetoableChangeListener, computeVisibleRect, contains, createToolTip, disable, enable, firePropertyChange, firePropertyChange, firePropertyChange, fireVetoableChange, getActionForKeyStroke, getActionMap, getAlignmentX, getAlignmentY, getAncestorListeners, getAutoscrolls, getBaseline, getBaselineResizeBehavior, getBorder, getBounds, getClientProperty, getComponentGraphics, getComponentPopupMenu, getConditionForKeyStroke, getDebugGraphicsOptions, getDefaultLocale, getFontMetrics, getHeight, getInheritsPopupMenu, getInputMap, getInputMap, getInputVerifier, getInsets, getInsets, getListeners, getLocation, getMaximumSize, getNextFocusableComponent, getPopupLocation, getRegisteredKeyStrokes, getRootPane, getSize, getToolTipLocation, getToolTipText, getToolTipText, getTopLevelAncestor, getTransferHandler, getVerifyInputWhenFocusTarget, getVetoableChangeListeners, getVisibleRect, getWidth, getX, getY, grabFocus, isDoubleBuffered, isLightweightComponent, isManagingFocus, isOpaque, isOptimizedDrawingEnabled, isPaintingForPrint, isPaintingTile, isRequestFocusEnabled, isValidateRoot, paintBorder, paintChildren, paintComponent, paintImmediately, paintImmediately, print, printAll, printBorder, printChildren, printComponent, processComponentKeyEvent, processKeyBinding, processKeyEvent, processMouseEvent, processMouseMotionEvent, putClientProperty, registerKeyboardAction, registerKeyboardAction, removeAncestorListener, removeNotify, removeVetoableChangeListener, repaint, repaint, requestDefaultFocus, requestFocus, requestFocus, requestFocusInWindow, requestFocusInWindow, resetKeyboardActions, reshape, revalidate, scrollRectToVisible, setActionMap, setAlignmentX, setAlignmentY, setAutoscrolls, setBorder, setComponentPopupMenu, setDebugGraphicsOptions, setDefaultLocale, setDoubleBuffered, setEnabled, setFocusTraversalKeys, setFont, setForeground, setInheritsPopupMenu, setInputMap, setInputVerifier, setMaximumSize, setMinimumSize, setNextFocusableComponent, setOpaque, setPreferredSize, setRequestFocusEnabled, setToolTipText, setTransferHandler, setUI, setVerifyInputWhenFocusTarget, setVisible, unregisterKeyboardAction, update

Methods inherited from class java.awt.Container

add, add, add, add, add, addContainerListener, addImpl, addPropertyChangeListener, addPropertyChangeListener, applyComponentOrientation, areFocusTraversalKeysSet, countComponents, deliverEvent, doLayout, findComponentAt, findComponentAt, getComponent, getComponentAt, getComponentAt, getComponentCount, getComponents, getComponentZOrder, getContainerListeners, getFocusTraversalKeys, getFocusTraversalPolicy, getLayout, getMousePosition, insets, invalidate, isAncestorOf, isFocusCycleRoot, isFocusCycleRoot, isFocusTraversalPolicyProvider, isFocusTraversalPolicySet, layout, list, list, locate, minimumSize, paintComponents, preferredSize, printComponents, processContainerEvent, processEvent, remove, remove, removeAll, removeContainerListener, setComponentZOrder, setFocusCycleRoot, setFocusTraversalPolicy, setFocusTraversalPolicyProvider, setLayout, transferFocusBackward, transferFocusDownCycle, validate, validateTree

Methods inherited from class java.awt.Component

action, add, addComponentListener, addFocusListener, addHierarchyBoundsListener, addHierarchyListener, addInputMethodListener, addKeyListener, addMouseListener, addMouseMotionListener, addMouseWheelListener, bounds, checkImage, checkImage, coalesceEvents, contains, createImage, createVolatileImage, createVolatileImage, disableEvents, dispatchEvent, enable, enableEvents, enableInputMethods, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, getBounds, getColorModel, getComponentListeners, getComponentOrientation, getCursor, getDropTarget, getFocusCycleRootAncestor, getFocusListeners, getFocusTraversalKeysEnabled, getFont, getForeground, getGraphicsConfiguration, getHierarchyBoundsListeners, getHierarchyListeners, getIgnoreRepaint, getInputContext, getInputMethodListeners, getInputMethodRequests, getKeyListeners, getLocale, getLocation, getLocationOnScreen, getMouseListeners, getMouseMotionListeners, getMousePosition, getMouseWheelListeners, getName, getParent, getPeer, getPropertyChangeListeners, getPropertyChangeListeners, getToolkit, getTreeLock, gotFocus, handleEvent, hasFocus, hide, imageUpdate, inside, isBackgroundSet, isCursorSet, isDisplayable, isEnabled, isFocusable, isFocusOwner, isFocusTraversable, isFontSet, isForegroundSet, isLightweight, isMaximumSizeSet, isMinimumSizeSet, isPreferredSizeSet, isShowing, isValid, isVisible, keyDown, keyUp, list, list, list, location, lostFocus, mouseDown, mouseDrag, mouseEnter, mouseExit, mouseMove, mouseUp, move, nextFocus, paintAll, postEvent, prepareImage, prepareImage, processComponentEvent, processFocusEvent, processHierarchyBoundsEvent, processHierarchyEvent, processInputMethodEvent, processMouseWheelEvent, remove, removeComponentListener, removeFocusListener, removeHierarchyBoundsListener, removeHierarchyListener, removeInputMethodListener, removeKeyListener, removeMouseListener, removeMouseMotionListener, removeMouseWheelListener, removePropertyChangeListener, removePropertyChangeListener, repaint, repaint, repaint, resize, resize, setBounds, setBounds, setComponentOrientation, setCursor, setDropTarget, setFocusable, setFocusTraversalKeysEnabled, setIgnoreRepaint, setLocale, setLocation, setLocation, setName, setSize, setSize, show, show, size, toString, transferFocus, transferFocusUpCycle

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.awt.image.ImageObserver

imageUpdate

Field Detail

myDrawingEditor

private DrawingEditor myDrawingEditor

myDrawing

private Drawing myDrawing

myUpdateStrategy

private Painter myUpdateStrategy

myBackgroundColor

private java.awt.Color myBackgroundColor

drawingViewManager

private static java.util.Hashtable drawingViewManager

Constructor Detail

NullDrawingView

protected NullDrawingView(DrawingEditor editor)

Method Detail

setEditor

public void setEditor(DrawingEditor editor)

Sets the view's editor.

Specified by:

setEditor in interface DrawingView

tool

public Tool tool()

Gets the current tool.

Specified by:

tool in interface DrawingView

drawing

public Drawing drawing()

Gets the drawing.

Specified by:

drawing in interface DrawingView

setDrawing

public void setDrawing(Drawing d)

Sets and installs another drawing in the view.

Specified by:

setDrawing in interface DrawingView

editor

public DrawingEditor editor()

Gets the editor.

Specified by:

editor in interface DrawingView

add

public Figure add(Figure figure)

Adds a figure to the drawing.

Specified by:

add in interface DrawingView

Returns:

the added figure.

remove

public Figure remove(Figure figure)

Removes a figure from the drawing.

Specified by:

remove in interface DrawingView

Returns:

the removed figure

addAll

public void addAll(java.util.Collection figures)

Adds a collection of figures to the drawing.

Specified by:

addAll in interface DrawingView

getSize

public java.awt.Dimension getSize()

Gets the size of the drawing.

Specified by:

getSize in interface DrawingView

Overrides:

getSize in class java.awt.Component

getMinimumSize

public java.awt.Dimension getMinimumSize()

Gets the minimum dimension of the drawing.

Specified by:

getMinimumSize in interface DrawingView

Overrides:

getMinimumSize in class javax.swing.JComponent

getPreferredSize

public java.awt.Dimension getPreferredSize()

Gets the preferred dimension of the drawing..

Specified by:

getPreferredSize in interface DrawingView

Overrides:

getPreferredSize in class javax.swing.JComponent

setDisplayUpdate

public void setDisplayUpdate(Painter newUpdateStrategy)

Sets the current display update strategy.

Specified by:

setDisplayUpdate in interface DrawingView

See Also:

Painter

getDisplayUpdate

public Painter getDisplayUpdate()

Gets the current display update strategy.

Specified by:

getDisplayUpdate in interface DrawingView

See Also:

Painter

selection

public FigureEnumeration selection()

Gets an enumeration over the currently selected figures. The selection is a snapshot of the current selection which does not get changed anymore

Specified by:

selection in interface DrawingView

Returns:

an enumeration with the currently selected figures.

selectionZOrdered

public FigureEnumeration selectionZOrdered()

Gets the currently seleced figures in Z order.

Specified by:

selectionZOrdered in interface DrawingView

Returns:

a FigureEnumeration with the selected figures. This enumeration represents a snapshot of the current selection.

See Also:

selection()

selectionCount

public int selectionCount()

Gets the number of selected figures.

Specified by:

selectionCount in interface DrawingView

isFigureSelected

public boolean isFigureSelected(Figure checkFigure)

Test whether a given figure is selected.

Specified by:

isFigureSelected in interface DrawingView

addToSelection

public void addToSelection(Figure figure)

Adds a figure to the current selection.

Specified by:

addToSelection in interface DrawingView

addToSelectionAll

public void addToSelectionAll(java.util.Collection figures)

Adds a Collection of figures to the current selection.

Specified by:

addToSelectionAll in interface DrawingView

addToSelectionAll

public void addToSelectionAll(FigureEnumeration fe)

Adds a FigureEnumeration to the current selection.

Specified by:

addToSelectionAll in interface DrawingView

removeFromSelection

public void removeFromSelection(Figure figure)

Removes a figure from the selection.

Specified by:

removeFromSelection in interface DrawingView

toggleSelection

public void toggleSelection(Figure figure)

If a figure isn't selected it is added to the selection. Otherwise it is removed from the selection.

Specified by:

toggleSelection in interface DrawingView

clearSelection

public void clearSelection()

Clears the current selection.

Specified by:

clearSelection in interface DrawingView

getFigureSelection

public FigureSelection getFigureSelection()

Gets the current selection as a FigureSelection. A FigureSelection can be cut, copied, pasted.

Specified by:

getFigureSelection in interface DrawingView

findHandle

public Handle findHandle(int x,
                         int y)

Finds a handle at the given coordinates.

Specified by:

findHandle in interface DrawingView

Returns:

the hit handle, null if no handle is found.

lastClick

public java.awt.Point lastClick()

Gets the position of the last click inside the view.

Specified by:

lastClick in interface DrawingView

setConstrainer

public void setConstrainer(PointConstrainer p)

Sets the current point constrainer.

Specified by:

setConstrainer in interface DrawingView

getConstrainer

public PointConstrainer getConstrainer()

Gets the current grid setting.

Specified by:

getConstrainer in interface DrawingView

checkDamage

public void checkDamage()

Checks whether the drawing has some accumulated damage

Specified by:

checkDamage in interface DrawingView

repairDamage

public void repairDamage()

Repair the damaged area

Specified by:

repairDamage in interface DrawingView

paint

public void paint(java.awt.Graphics g)

Paints the drawing view. The actual drawing is delegated to the current update strategy.

Specified by:

paint in interface DrawingView

Overrides:

paint in class javax.swing.JComponent

See Also:

Painter

createImage

public java.awt.Image createImage(int width,
                                  int height)

Creates an image with the given dimensions

Specified by:

createImage in interface DrawingView

Overrides:

createImage in class java.awt.Component

getGraphics

public java.awt.Graphics getGraphics()

Gets a graphic to draw into

Specified by:

getGraphics in interface DrawingView

Overrides:

getGraphics in class javax.swing.JComponent

getBackground

public java.awt.Color getBackground()

Gets the background color of the DrawingView

Specified by:

getBackground in interface DrawingView

Overrides:

getBackground in class java.awt.Component

setBackground

public void setBackground(java.awt.Color c)

Sets the background color of the DrawingView

Specified by:

setBackground in interface DrawingView

Overrides:

setBackground in class javax.swing.JComponent

drawAll

public void drawAll(java.awt.Graphics g)

Draws the contents of the drawing view. The view has three layers: background, drawing, handles. The layers are drawn in back to front order.

Specified by:

drawAll in interface DrawingView

draw

public void draw(java.awt.Graphics g,
                 FigureEnumeration fe)

Draws the given figures. The view has three layers: background, drawing, handles. The layers are drawn in back to front order.

Specified by:

draw in interface DrawingView

drawHandles

public void drawHandles(java.awt.Graphics g)

Draws the currently active handles.

Specified by:

drawHandles in interface DrawingView

drawDrawing

public void drawDrawing(java.awt.Graphics g)

Draws the drawing.

Specified by:

drawDrawing in interface DrawingView

drawBackground

public void drawBackground(java.awt.Graphics g)

Draws the background. If a background pattern is set it is used to fill the background. Otherwise the background is filled in the background color.

Specified by:

drawBackground in interface DrawingView

setCursor

public void setCursor(Cursor c)

Sets the cursor of the DrawingView

Specified by:

setCursor in interface DrawingView

freezeView

public void freezeView()

Freezes the view by acquiring the drawing lock.

Specified by:

freezeView in interface DrawingView

See Also:

Drawing.lock()

unfreezeView

public void unfreezeView()

Unfreezes the view by releasing the drawing lock.

Specified by:

unfreezeView in interface DrawingView

See Also:

Drawing.unlock()

addFigureSelectionListener

public void addFigureSelectionListener(FigureSelectionListener fsl)

Add a listener for selection changes in this DrawingView.

Specified by:

addFigureSelectionListener in interface DrawingView

Parameters:

fsl - jhotdraw.framework.FigureSelectionListener

removeFigureSelectionListener

public void removeFigureSelectionListener(FigureSelectionListener fsl)

Remove a listener for selection changes in this DrawingView.

Specified by:

removeFigureSelectionListener in interface DrawingView

Parameters:

fsl - jhotdraw.framework.FigureSelectionListener

getConnectionFigures

public FigureEnumeration getConnectionFigures(Figure inFigure)

Returns a FigureEnumeration of connection figures

Specified by:

getConnectionFigures in interface DrawingView

insertFigures

public FigureEnumeration insertFigures(FigureEnumeration inFigures,
                                       int dx,
                                       int dy,
                                       boolean bCheck)

Inserts figures in a drawing at given offset. Optional check for connection figures

Specified by:

insertFigures in interface DrawingView

Returns:

enumeration which has been added to the drawing. The figures in the enumeration can have changed during adding them (e.g. they could have been decorated).

drawingInvalidated

public void drawingInvalidated(DrawingEvent e)

Description copied from interface: DrawingListener

Sent when an area is invalid

Specified by:

drawingInvalidated in interface DrawingListener

drawingRequestUpdate

public void drawingRequestUpdate(DrawingEvent e)

Description copied from interface: DrawingListener

Sent when the drawing wants to be refreshed

Specified by:

drawingRequestUpdate in interface DrawingListener

drawingTitleChanged

public void drawingTitleChanged(DrawingEvent e)

Description copied from interface: DrawingListener

Sent when the drawing Title has changed

Specified by:

drawingTitleChanged in interface DrawingListener

isInteractive

public boolean isInteractive()

Description copied from interface: DrawingView

Check whether the DrawingView is interactive, i.e. whether it accepts user input and whether it can display a drawing.

Specified by:

isInteractive in interface DrawingView

getManagedDrawingView

public static DrawingView getManagedDrawingView(DrawingEditor editor)