diva.canvas

Class GraphicsPane

java.lang.Object

diva.canvas.CanvasPane

diva.canvas.GraphicsPane

All Implemented Interfaces:

CanvasComponent, EventAcceptor

Direct Known Subclasses:

GraphPane, SimplePane

public class GraphicsPane
extends CanvasPane

A CanvasPane which has a default set of layers that are useful for interactive drawing and editing applications. The layers are organized as follows:

   (front)  Foreground event
            Overlay
            Foreground graphics
            Background graphics
            Background event
 

This organization allows applications to easily overlay and underlay graphics and event handling around the main application window.

Typical uses of each of these layers include:

Foreground event layer

Grid or object snapping, stroke filtering, event monitoring and debugging, event grab, etc. By default, this layer is not enabled. If you enable it, but still want events to go through to the underlying figure layers, use setConsuming(false).

Overlay

An overlay layer for drag-selection outlining and so on. By default, this layer is an instance of OverlayLayer and is set visible.

Foreground graphics

The main application graphics. By default, this layer is an instance of FigureLayer and is set enabled and visible.

Background graphics

Auxiliary, non-interactive graphics. By default, this layer is an instance of FigureLayer but is set not visible and not enabled.

Background Event

"Last chance" event handling layer, for things such as drag-selection rectangle, panning/zooming, etc. By default, this layer is enabled.

Version:

$Id$

Author:

Michael Shilman, John Reekie

Pt.AcceptedRating:

Yellow

Field Summary

Fields

Modifier and Type	Field and Description
protected EventLayer	_backgroundEventLayer
protected CanvasLayer	_backgroundLayer
protected EventLayer	_foregroundEventLayer
protected FigureLayer	_foregroundLayer
protected CanvasLayer[]	_layers
protected OverlayLayer	_overlayLayer

Constructor Summary

Constructors

Constructor and Description
GraphicsPane() Create a new Graphics pane with an instance of FigureLayer as the main figure layer.
GraphicsPane(FigureLayer foregroundLayer) Create a new Graphics pane with the passed Layer as the main graphics pane.

Method Summary

Modifier and Type	Method and Description
protected void	_rebuildLayerArray() Rebuild the array of layers for use by iterators.
EventLayer	getBackgroundEventLayer() Get the background event layer.
CanvasLayer	getBackgroundLayer() Get the background layer.
EventLayer	getForegroundEventLayer() Get the foreground event layer.
FigureLayer	getForegroundLayer() Get the foreground layer.
OverlayLayer	getOverlayLayer() Get the overlay layer.
java.util.Iterator	layersFromBack() Return an iteration of the layers, in redraw order (that is, from back to front).
java.util.Iterator	layersFromFront() Return an iteration of the layers, in event-processing order (that is, from front to back).
void	setBackgroundEventLayer(EventLayer l) Set the background event layer.
void	setBackgroundLayer(CanvasLayer l) Set the background figure layer.
void	setForegroundEventLayer(EventLayer l) Set the foreground event layer.
void	setForegroundLayer(FigureLayer l) Set the foreground figure layer.
void	setOverlayLayer(OverlayLayer l) Set the overlay layer.

Methods inherited from class diva.canvas.CanvasPane

_initNewLayer, _nullifyLayer, dispatchEvent, getCanvas, getParent, getSize, getToolTipText, getTransformContext, isAntialiasing, isEnabled, layers, paint, paint, processLayerEvent, repaint, repaint, scale, setAntialiasing, setCanvas, setEnabled, setParent, setSize, setSize, setTransform, translate

Methods inherited from class java.lang.Object

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

Field Detail

_layers

protected CanvasLayer[] _layers

_foregroundEventLayer

protected EventLayer _foregroundEventLayer

_overlayLayer

protected OverlayLayer _overlayLayer

_foregroundLayer

protected FigureLayer _foregroundLayer

_backgroundLayer

protected CanvasLayer _backgroundLayer

_backgroundEventLayer

protected EventLayer _backgroundEventLayer

Constructor Detail

GraphicsPane

public GraphicsPane()

Create a new Graphics pane with an instance of FigureLayer as the main figure layer.

GraphicsPane

public GraphicsPane(FigureLayer foregroundLayer)

Create a new Graphics pane with the passed Layer as the main graphics pane.

Parameters:

foregroundLayer - The foreground layer

Method Detail

getBackgroundEventLayer

public EventLayer getBackgroundEventLayer()

Get the background event layer.

Returns:

The layer.

See Also:

setBackgroundEventLayer(EventLayer)

getBackgroundLayer

public CanvasLayer getBackgroundLayer()

Get the background layer.

Returns:

The layer.

See Also:

setBackgroundLayer(CanvasLayer)

getForegroundLayer

public FigureLayer getForegroundLayer()

Get the foreground layer.

Returns:

The layer.

See Also:

setForegroundLayer(FigureLayer)

getOverlayLayer

public OverlayLayer getOverlayLayer()

Get the overlay layer.

Returns:

The layer.

See Also:

setOverlayLayer(OverlayLayer)

getForegroundEventLayer

public EventLayer getForegroundEventLayer()

Get the foreground event layer.

Returns:

The layer.

See Also:

setForegroundEventLayer(EventLayer)

layersFromFront

public java.util.Iterator layersFromFront()

Return an iteration of the layers, in event-processing order (that is, from front to back).

Specified by:

layersFromFront in class CanvasPane

Returns:

The iterator.

layersFromBack

public java.util.Iterator layersFromBack()

Return an iteration of the layers, in redraw order (that is, from back to front).

Specified by:

layersFromBack in class CanvasPane

Returns:

The iterator.

setBackgroundEventLayer

public void setBackgroundEventLayer(EventLayer l)

Set the background event layer.

Parameters:

l - The layer.

See Also:

getBackgroundEventLayer()

setBackgroundLayer

public void setBackgroundLayer(CanvasLayer l)

Set the background figure layer.

Parameters:

l - The layer.

See Also:

getBackgroundLayer()

setForegroundLayer

public void setForegroundLayer(FigureLayer l)

Set the foreground figure layer.

Parameters:

l - The layer.

See Also:

getForegroundLayer()

setOverlayLayer

public void setOverlayLayer(OverlayLayer l)

Set the overlay layer.

Parameters:

l - The layer.

See Also:

getOverlayLayer()

setForegroundEventLayer

public void setForegroundEventLayer(EventLayer l)

Set the foreground event layer.

Parameters:

l - The layer.

See Also:

getForegroundEventLayer()

_rebuildLayerArray

protected void _rebuildLayerArray()

Rebuild the array of layers for use by iterators.