diva.canvas

Class OverlayLayer

java.lang.Object

diva.canvas.CanvasLayer

diva.canvas.OverlayLayer

All Implemented Interfaces:

CanvasComponent, VisibleComponent

public class OverlayLayer
extends CanvasLayer
implements VisibleComponent

OutlineLayer is a layer that is used to display the grey figures commonly used for drag-selection, reshaping items, and so on. It can have shapes added to it, which are all drawn in outline in grey (by default -- the color can be changed). There is no concept of a display list or z-depth in this layer, as all shapes are drawn in exactly the same color.

Although currently it does not do so, this class will become optimized so that repaints of this layer do not require a repaint of backing layers.

Version:

$Revision: 1.7 $

Author:

Michael Shilman (michaels@eecs.berkeley.edu), John Reekie (johnr@eecs.berkeley.edu)

Constructor Summary

Constructors

Constructor and Description
OverlayLayer() Create a new OverlayLayer with a default one-pixel stroke and a light grey stroke color.
OverlayLayer(Stroke s, Paint p) Create a new OverlayLayer with the given stroke and paint

Method Summary

Modifier and Type	Method and Description
void	add(Shape s) Add a new shape to the list of shapes in this layer
void	clear() Clear the layer
Paint	getPaint() Get the current paint
Stroke	getStroke() Get the current paint stroke
boolean	isVisible() Test the visibility flag of this layer.
void	paint(Graphics2D g) Paint this layer onto a 2D graphics object.
void	paint(Graphics2D g, Rectangle2D region) Paint this layer onto a 2D graphics object, within the given region.
void	remove(Shape s) Remove a shape from the list of shapes in this layer
void	repaint(Rectangle2D region) Schedule a repaint of this layer over the given shape.
void	repaint(Shape shape) Schedule a repaint of this layer over the given shape.
void	setPaint(Paint p) Set the paint.
void	setStroke(Stroke s) Set the stroke.
void	setVisible(boolean flag) Set the visibility flag of this layer.
Iterator	shapes() Return an iterator over the shapes currently in this layer.

Methods inherited from class diva.canvas.CanvasLayer

getCanvasPane, getLayerBounds, getParent, getToolTipText, getTransformContext, repaint, repaint, setParent

Methods inherited from class java.lang.Object

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

Methods inherited from interface diva.canvas.CanvasComponent

getParent, getTransformContext, repaint, repaint

Constructor Detail

OverlayLayer

public OverlayLayer()

Create a new OverlayLayer with a default one-pixel stroke and a light grey stroke color.

OverlayLayer

public OverlayLayer(Stroke s,
                    Paint p)

Create a new OverlayLayer with the given stroke and paint

Method Detail

add

public void add(Shape s)

Add a new shape to the list of shapes in this layer

clear

public void clear()

Clear the layer

getStroke

public Stroke getStroke()

Get the current paint stroke

getPaint

public Paint getPaint()

Get the current paint

isVisible

public boolean isVisible()

Test the visibility flag of this layer. Note that this flag does not indicate whether the layer is actually visible on the screen, as its pane or one if its ancestors may not be visible.

Specified by:

isVisible in interface VisibleComponent

paint

public void paint(Graphics2D g)

Paint this layer onto a 2D graphics object. If the layer is not visible, return immediately. Otherwise draw all shapes with the current stroke and paint.

Specified by:

paint in interface VisibleComponent

paint

public void paint(Graphics2D g,
                  Rectangle2D region)

Paint this layer onto a 2D graphics object, within the given region. If the layer is not visible, return immediately. Otherwise draw all figures that overlap the given region.

Specified by:

paint in interface VisibleComponent

remove

public void remove(Shape s)

Remove a shape from the list of shapes in this layer

repaint

public void repaint(Rectangle2D region)

Schedule a repaint of this layer over the given shape. The shape is assumed to be a shape that is on this layer. It is made larger by the line width of the outlines, to ensure that enough of the canvas is repainted. This particular version of this method is optimized for rectangles.

repaint

public void repaint(Shape shape)

Schedule a repaint of this layer over the given shape. The shape is assumed to be a shape that is on this layer. The width of the outline is taken into account when repainting the canvas.

shapes

public Iterator shapes()

Return an iterator over the shapes currently in this layer.

setStroke

public void setStroke(Stroke s)

Set the stroke. All shapes will be stroked with the same stroke.

setPaint

public void setPaint(Paint p)

Set the paint. All shopes will be drawn with the same paint.

setVisible

public void setVisible(boolean flag)

Set the visibility flag of this layer. If the flag is false, then the layer will not be drawn on the screen.

Specified by:

setVisible in interface VisibleComponent