org.jhotdraw.draw
Interface DrawingView

All Known Implementing Classes:

DefaultDrawingView

@NotNull
public interface DrawingView

A drawing view paints a Drawing on a JComponent. A drawing view can hold only one drawing at a time, but a drawing can be in multiple drawing views at the same time.

To support editing, a drawing view needs to be added to a DrawingEditor. The current Tool of the drawing editor receives mouse and key events from all drawing views of the drawing editor.

DrawingView can paint the drawing with a scale factor. It supports conversion between view coordinates and drawing coordinates.

DrawingView maintains a selection of the Figures contained in the drawing. The selected figures can be the target of the current tool of the drawing editor.

The painting process of DrawingView view usually involves the following steps:

1. Paint the background of the drawing view.
2. Invoke Drawing.drawCanvas(java.awt.Graphics2D).
3. Invoke Constrainer.draw(java.awt.Graphics2D, org.jhotdraw.draw.DrawingView) if a constrainer is set.
4. Invoke Figure.draw(java.awt.Graphics2D).
5. Invoke Handle.draw(java.awt.Graphics2D) on the handles of selected figures.
6. Invoke Tool.draw(java.awt.Graphics2D) if the drawing view is the active view of the DrawingEditor.

Design Patterns

Framework
The following interfaces define the contracts of a framework for structured drawing editors:
Contract: Drawing, Figure, DrawingView, DrawingEditor, Handle and Tool.

Chain of responsibility
Mouse and keyboard events of the user occur on the drawing view, and are preprocessed by the DragTracker of a SelectionTool. In turn org.jhotdraw.draw.selectiontool.DragTracker invokes "track" methods on a Handle which in turn changes an aspect of a figure.
Client: SelectionTool; Handler: DragTracker, Handle.

Mediator
DrawingEditor acts as a mediator for coordinating drawing tools and drawing views:
Mediator: DrawingEditor; Colleagues: DrawingView, Tool.

Model-View-Controller
The following classes implement together the Model-View-Controller design pattern:
Model: Drawing; View: DrawingView; Controller: DrawingEditor.

Observer
Selection changes of DrawingView are observed by user interface components which act on selected figures.
Subject: DrawingView; Observer: FigureSelectionListener; Event: FigureSelectionEvent.

Observer
State changes of figures can be observed by other objects. Specifically CompositeFigure observes area invalidations and remove requests of its child figures. DrawingView also observes area invalidations of its drawing object. Subject: Figure; Observer: FigureListener; Event: FigureEvent; Concrete Observer: CompositeFigure, DrawingView.

Observer
State changes of handles can be observed by other objects. Specifically DrawingView observes area invalidations and remove requests of handles.
Subject: Handle; Observer: HandleListener; Event: HandleEvent; Concrete Observer: DrawingView.

Strategy
Editing can be constrained by a constrainer which is associated to a drawing view.
Context: DrawingView; Strategy: Constrainer.

Version:

$Id: DrawingView.java 662 2010-07-19 09:44:28Z rawcoder $

Author:

Werner Randelshofer

Field Summary

static java.lang.String	ACTIVE_HANDLE_PROPERTY This constant is used to identify the activeHandle property of the DrawingView.
static java.lang.String	CONSTRAINER_PROPERTY This constant is used to identify the constrainer property of the DrawingView.
static java.lang.String	CONSTRAINER_VISIBLE_PROPERTY This constant is used to identify the constrainer visible property of the DrawingView.
static java.lang.String	CURSOR_PROPERTY This constant is used to identify the cursor property of the DrawingView.
static java.lang.String	DRAWING_PROPERTY This constant is used to identify the drawing property of the DrawingView.
static java.lang.String	ENABLED_PROPERTY This constant is used to identify the enabled property of the DrawingView.
static java.lang.String	HANDLE_DETAIL_LEVEL_PROPERTY This constant is used to identify the handle detail level property of the DrawingView.
static java.lang.String	INVISIBLE_CONSTRAINER_PROPERTY This constant is used to identify the invisible constrainer property of the DrawingView.
static java.lang.String	SCALE_FACTOR_PROPERTY This constant is used to identify the scale factor property of the DrawingView.
static java.lang.String	VISIBLE_CONSTRAINER_PROPERTY This constant is used to identify the visible constrainer property of the DrawingView.

Method Summary

void	addFigureSelectionListener(FigureSelectionListener fsl) Add a listener for selection changes in this DrawingView.
void	addKeyListener(java.awt.event.KeyListener l) Adds a key listener to the drawing view.
void	addMouseListener(java.awt.event.MouseListener l) Adds a mouse listener to the drawing view.
void	addMouseMotionListener(java.awt.event.MouseMotionListener l) Adds a mouse motion listener to the drawing view.
void	addNotify(DrawingEditor editor) Informs the view that it has been added to the specified editor.
void	addPropertyChangeListener(java.beans.PropertyChangeListener listener) Adds a property change listener to the drawing view.
void	addToSelection(java.util.Collection<Figure> figures) Adds a collection of figures to the current selection.
void	addToSelection(Figure figure) Adds a figure to the current selection.
void	clearSelection() Clears the current selection.
java.awt.Point	drawingToView(java.awt.geom.Point2D.Double p) Converts drawing coordinates to view coordinates.
java.awt.Rectangle	drawingToView(java.awt.geom.Rectangle2D.Double p) Converts drawing coordinates to view coordinates.
Figure	findFigure(java.awt.Point p) Finds a figure at the given point.
java.util.Collection<Figure>	findFigures(java.awt.Rectangle r) Returns all figures that lie within or intersect the specified bounds.
java.util.Collection<Figure>	findFiguresWithin(java.awt.Rectangle r) Returns all figures that lie within the specified bounds.
Handle	findHandle(java.awt.Point p) Finds a handle at the given coordinates.
Handle	getActiveHandle() Gets the active handle.
java.util.Collection<Handle>	getCompatibleHandles(Handle handle) Gets compatible handles.
javax.swing.JComponent	getComponent() Returns the JComponent of the drawing view.
Constrainer	getConstrainer() Gets the current constrainer of this view.
Drawing	getDrawing() Gets the drawing.
java.awt.geom.AffineTransform	getDrawingToViewTransform() Gets an transform which can be used to convert drawing coordinates to view coordinates.
DrawingEditor	getEditor() Gets the drawing editor associated to the DrawingView.
int	getHandleDetailLevel() Returns the detail level of the handles.
Constrainer	getInvisibleConstrainer() Gets the editor's constrainer for this view, for use, when the visible constrainer is turned off.
double	getScaleFactor() Gets the scale factor of the drawing view.
java.util.Set<Figure>	getSelectedFigures() Gets the selected figures.
int	getSelectionCount() Gets the number of selected figures.
Constrainer	getVisibleConstrainer() Gets the editor's constrainer for this view, for use, when the visible constrainer is turned on.
boolean	isConstrainerVisible() Returns true, if the visible Constrainer is in use, returns false, if the invisible Constrainer is in use.
boolean	isEnabled() Gets the enabled state of the drawing view.
boolean	isFigureSelected(Figure checkFigure) Test whether a given figure is selected.
void	removeFigureSelectionListener(FigureSelectionListener fsl) Remove a listener for selection changes in this DrawingView.
void	removeFromSelection(Figure figure) Removes a figure from the selection.
void	removeKeyListener(java.awt.event.KeyListener l) Removes a key listener to the drawing view.
void	removeMouseListener(java.awt.event.MouseListener l) Removes a mouse listener to the drawing view.
void	removeMouseMotionListener(java.awt.event.MouseMotionListener l) Removes a mouse motion listener to the drawing view.
void	removeNotify(DrawingEditor editor) Informs the view that it has been removed from the specified editor.
void	removePropertyChangeListener(java.beans.PropertyChangeListener listener) Removes a property change listener to the drawing view.
void	repaintHandles() Repaints the handles of the view.
void	requestFocus() This is a convenience method for invoking getComponent().requestFocus().
void	selectAll() Selects all figures.
void	setActiveHandle(Handle newValue) Sets the active handle.
void	setConstrainerVisible(boolean newValue) Changes between a visible Constrainer and an invisible Constrainer.
void	setCursor(java.awt.Cursor c) Sets the cursor of the DrawingView.
void	setDrawing(Drawing d) Sets and installs another drawing in the view.
void	setEnabled(boolean newValue) Sets the enabled state of the drawing view.
void	setHandleDetailLevel(int newValue) The detail level of the handles.
void	setInvisibleConstrainer(Constrainer constrainer) Sets the editor's constrainer for this view, for use, when the visible constrainer is turned off.
void	setScaleFactor(double newValue) Sets the scale factor of the drawing view.
void	setVisibleConstrainer(Constrainer constrainer) Sets the editor's constrainer for this view, for use, when the visible constrainer is turned on.
void	toggleSelection(Figure figure) If a figure isn't selected it is added to the selection.
java.awt.geom.Point2D.Double	viewToDrawing(java.awt.Point p) Converts view coordinates to drawing coordinates.
java.awt.geom.Rectangle2D.Double	viewToDrawing(java.awt.Rectangle p) Converts view coordinates to drawing coordinates.

Field Detail

DRAWING_PROPERTY

static final java.lang.String DRAWING_PROPERTY

This constant is used to identify the drawing property of the DrawingView.

See Also:

Constant Field Values

CURSOR_PROPERTY

static final java.lang.String CURSOR_PROPERTY

This constant is used to identify the cursor property of the DrawingView.

See Also:

Constant Field Values

CONSTRAINER_PROPERTY

static final java.lang.String CONSTRAINER_PROPERTY

This constant is used to identify the constrainer property of the DrawingView.

See Also:

Constant Field Values

VISIBLE_CONSTRAINER_PROPERTY

static final java.lang.String VISIBLE_CONSTRAINER_PROPERTY

This constant is used to identify the visible constrainer property of the DrawingView.

See Also:

Constant Field Values

INVISIBLE_CONSTRAINER_PROPERTY

static final java.lang.String INVISIBLE_CONSTRAINER_PROPERTY

This constant is used to identify the invisible constrainer property of the DrawingView.

See Also:

Constant Field Values

CONSTRAINER_VISIBLE_PROPERTY

static final java.lang.String CONSTRAINER_VISIBLE_PROPERTY

This constant is used to identify the constrainer visible property of the DrawingView.

See Also:

Constant Field Values

SCALE_FACTOR_PROPERTY

static final java.lang.String SCALE_FACTOR_PROPERTY

This constant is used to identify the scale factor property of the DrawingView.

See Also:

Constant Field Values

HANDLE_DETAIL_LEVEL_PROPERTY

static final java.lang.String HANDLE_DETAIL_LEVEL_PROPERTY

This constant is used to identify the handle detail level property of the DrawingView.

See Also:

Constant Field Values

ENABLED_PROPERTY

static final java.lang.String ENABLED_PROPERTY

This constant is used to identify the enabled property of the DrawingView.

See Also:

Constant Field Values

ACTIVE_HANDLE_PROPERTY

static final java.lang.String ACTIVE_HANDLE_PROPERTY

This constant is used to identify the activeHandle property of the DrawingView.

See Also:

Constant Field Values

Method Detail

getDrawing

@Nullable
Drawing getDrawing()

Gets the drawing. This is a bound property.

setDrawing

@Nullable
void setDrawing(Drawing d)

Sets and installs another drawing in the view. This is a bound property.

setCursor

void setCursor(@Nullable
               java.awt.Cursor c)

Sets the cursor of the DrawingView. This is a bound property.

isFigureSelected

boolean isFigureSelected(Figure checkFigure)

Test whether a given figure is selected.

addToSelection

void addToSelection(Figure figure)

Adds a figure to the current selection.

addToSelection

void addToSelection(java.util.Collection<Figure> figures)

Adds a collection of figures to the current selection.

removeFromSelection

void removeFromSelection(Figure figure)

Removes a figure from the selection.

toggleSelection

void toggleSelection(Figure figure)

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

clearSelection

void clearSelection()

Clears the current selection.

selectAll

void selectAll()

Selects all figures.

getSelectedFigures

java.util.Set<Figure> getSelectedFigures()

Gets the selected figures. Returns an empty set, if no figures are selected.

getSelectionCount

int getSelectionCount()

Gets the number of selected figures.

findHandle

@Nullable
Handle findHandle(java.awt.Point p)

Finds a handle at the given coordinates.

Returns:

A handle, null if no handle is found.

getCompatibleHandles

java.util.Collection<Handle> getCompatibleHandles(Handle handle)

Gets compatible handles.

Returns:

A collection containing the handle and all compatible handles.

setActiveHandle

void setActiveHandle(Handle newValue)

Sets the active handle.

getActiveHandle

@Nullable
Handle getActiveHandle()

Gets the active handle.

findFigure

@Nullable
Figure findFigure(java.awt.Point p)

Finds a figure at the given point.

Returns:

A figure, null if no figure is found.

findFigures

java.util.Collection<Figure> findFigures(java.awt.Rectangle r)

Returns all figures that lie within or intersect the specified bounds. The figures are returned in Z-order from back to front.

findFiguresWithin

java.util.Collection<Figure> findFiguresWithin(java.awt.Rectangle r)

Returns all figures that lie within the specified bounds. The figures are returned in Z-order from back to front.

addNotify

void addNotify(DrawingEditor editor)

Informs the view that it has been added to the specified editor. The view must draw the tool of the editor, if getActiveView() of the editor returns the view.

removeNotify

void removeNotify(DrawingEditor editor)

Informs the view that it has been removed from the specified editor. The view must not draw the tool from the editor anymore.

getEditor

@Nullable
DrawingEditor getEditor()

Gets the drawing editor associated to the DrawingView. This is a bound property.

addFigureSelectionListener

void addFigureSelectionListener(FigureSelectionListener fsl)

Add a listener for selection changes in this DrawingView.

Parameters:

fsl - jhotdraw.framework.FigureSelectionListener

removeFigureSelectionListener

void removeFigureSelectionListener(FigureSelectionListener fsl)

Remove a listener for selection changes in this DrawingView.

Parameters:

fsl - jhotdraw.framework.FigureSelectionListener

requestFocus

void requestFocus()

This is a convenience method for invoking getComponent().requestFocus().

drawingToView

java.awt.Point drawingToView(java.awt.geom.Point2D.Double p)

Converts drawing coordinates to view coordinates.

viewToDrawing

java.awt.geom.Point2D.Double viewToDrawing(java.awt.Point p)

Converts view coordinates to drawing coordinates.

drawingToView

java.awt.Rectangle drawingToView(java.awt.geom.Rectangle2D.Double p)

Converts drawing coordinates to view coordinates.

viewToDrawing

java.awt.geom.Rectangle2D.Double viewToDrawing(java.awt.Rectangle p)

Converts view coordinates to drawing coordinates.

getConstrainer

@Nullable
Constrainer getConstrainer()

Gets the current constrainer of this view. If isConstrainerVisible is true, this method returns getVisibleConstrainer, otherwise it returns getInvisibleConstrainer. This is a bound property.

setVisibleConstrainer

void setVisibleConstrainer(@Nullable
                           Constrainer constrainer)

Sets the editor's constrainer for this view, for use, when the visible constrainer is turned on. This is a bound property.

getVisibleConstrainer

@Nullable
Constrainer getVisibleConstrainer()

Gets the editor's constrainer for this view, for use, when the visible constrainer is turned on. This is a bound property.

setInvisibleConstrainer

void setInvisibleConstrainer(Constrainer constrainer)

Sets the editor's constrainer for this view, for use, when the visible constrainer is turned off. This is a bound property.

getInvisibleConstrainer

Constrainer getInvisibleConstrainer()

Gets the editor's constrainer for this view, for use, when the visible constrainer is turned off. This is a bound property.

setConstrainerVisible

void setConstrainerVisible(boolean newValue)

Changes between a visible Constrainer and an invisible Constrainer. This is a bound property.

isConstrainerVisible

boolean isConstrainerVisible()

Returns true, if the visible Constrainer is in use, returns false, if the invisible Constrainer is in use. This is a bound property.

getComponent

javax.swing.JComponent getComponent()

Returns the JComponent of the drawing view.

getDrawingToViewTransform

java.awt.geom.AffineTransform getDrawingToViewTransform()

Gets an transform which can be used to convert drawing coordinates to view coordinates.

getScaleFactor

double getScaleFactor()

Gets the scale factor of the drawing view. This is a bound property.

setScaleFactor

void setScaleFactor(double newValue)

Sets the scale factor of the drawing view. This is a bound property.

setHandleDetailLevel

void setHandleDetailLevel(int newValue)

The detail level of the handles. This is a bound property.

getHandleDetailLevel

int getHandleDetailLevel()

Returns the detail level of the handles. This is a bound property.

setEnabled

void setEnabled(boolean newValue)

Sets the enabled state of the drawing view. This is a bound property.

isEnabled

boolean isEnabled()

Gets the enabled state of the drawing view. This is a bound property.

repaintHandles

void repaintHandles()

Repaints the handles of the view.

addPropertyChangeListener

void addPropertyChangeListener(java.beans.PropertyChangeListener listener)

Adds a property change listener to the drawing view.

Parameters:

listener -

removePropertyChangeListener

void removePropertyChangeListener(java.beans.PropertyChangeListener listener)

Removes a property change listener to the drawing view.

Parameters:

listener -

addMouseListener

void addMouseListener(java.awt.event.MouseListener l)

Adds a mouse listener to the drawing view.

Parameters:

l - the listener.

removeMouseListener

void removeMouseListener(java.awt.event.MouseListener l)

Removes a mouse listener to the drawing view.

Parameters:

l - the listener.

addKeyListener

void addKeyListener(java.awt.event.KeyListener l)

Adds a key listener to the drawing view.

Parameters:

l - the listener.

removeKeyListener

void removeKeyListener(java.awt.event.KeyListener l)

Removes a key listener to the drawing view.

Parameters:

l - the listener.

addMouseMotionListener

void addMouseMotionListener(java.awt.event.MouseMotionListener l)

Adds a mouse motion listener to the drawing view.

Parameters:

l - the listener.

removeMouseMotionListener

void removeMouseMotionListener(java.awt.event.MouseMotionListener l)

Removes a mouse motion listener to the drawing view.

Parameters:

l - the listener.