DrawingView

All Known Implementing Classes:

DefaultDrawingView
```
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.

Field Summary

Fields
Modifier and Type	Field and Description
`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

All Methods Instance Methods Abstract Methods
Modifier and Type	Method and Description
`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
```
Drawing getDrawing()
```
    Gets the drawing. This is a bound property.
  - setDrawing
```
void setDrawing(Drawing d)
```
    Sets and installs another drawing in the view. This is a bound property.
  - setCursor
```
void setCursor(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
```
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
```
Handle getActiveHandle()
```
    Gets the active handle.
  - findFigure
```
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
```
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
```
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(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
```
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.

Interface DrawingView

Field Summary

Method Summary

Field Detail

DRAWING_PROPERTY

CURSOR_PROPERTY

CONSTRAINER_PROPERTY

VISIBLE_CONSTRAINER_PROPERTY

INVISIBLE_CONSTRAINER_PROPERTY

CONSTRAINER_VISIBLE_PROPERTY

SCALE_FACTOR_PROPERTY

HANDLE_DETAIL_LEVEL_PROPERTY

ENABLED_PROPERTY

ACTIVE_HANDLE_PROPERTY

Method Detail

getDrawing

setDrawing

setCursor

isFigureSelected

addToSelection

addToSelection

removeFromSelection

toggleSelection

clearSelection

selectAll

getSelectedFigures

getSelectionCount

findHandle

getCompatibleHandles

setActiveHandle

getActiveHandle

findFigure

findFigures

findFiguresWithin

addNotify

removeNotify

getEditor

addFigureSelectionListener

removeFigureSelectionListener

requestFocus

drawingToView

viewToDrawing

drawingToView

viewToDrawing

getConstrainer

setVisibleConstrainer

getVisibleConstrainer

setInvisibleConstrainer

getInvisibleConstrainer

setConstrainerVisible

isConstrainerVisible

getComponent

getDrawingToViewTransform

getScaleFactor

setScaleFactor

setHandleDetailLevel

getHandleDetailLevel

setEnabled

isEnabled

repaintHandles

addPropertyChangeListener

removePropertyChangeListener

addMouseListener

removeMouseListener

addKeyListener

removeKeyListener

addMouseMotionListener

removeMouseMotionListener