stanford.androidlib.graphics

Class GCompound

java.lang.Object

stanford.androidlib.graphics.GObject

stanford.androidlib.graphics.GCompound

All Implemented Interfaces:

Iterable<GObject>, GScalable

public class GCompound
extends GObject
implements GScalable, Iterable<GObject>

This class defines a graphical object that consists of a collection of other graphical objects. Once assembled, the internal objects can be manipulated as a unit.

Constructor Summary

Constructors

Constructor and Description
GCompound() Creates a new GCompound object with no internal components.
GCompound(GCanvas canvas) Creates a new GCompound object with no internal components.

Method Summary

Modifier and Type	Method and Description
GCompound	add(GObject gobj) Adds a new graphical object to this GCompound.
GCompound	add(GObject gobj, float x, float y) Adds the graphical object to this canvas and sets its location to the point (x, y).
GCompound	add(GObject gobj, GPoint pt) Adds the graphical object to this canvas and sets its location to the specified point.
boolean	contains(float x, float y) Checks to see whether a point is "inside" the compound, which means that it is inside one of the components.
GRectangle	getBounds() Returns the bounding rectangle for this compound object, which consists of the union of the bounding rectangles for each of the components.
GObject	getElement(int index) Returns the graphical object at the specified index, numbering from back to front in the the z dimension.
GObject	getElementAt(float x, float y) Returns the topmost graphical object that contains the point (x, y), or null if no such object exists.
GObject	getElementAt(GPoint pt) Returns the topmost graphical object that contains the specified point, or null if no such object exists.
int	getElementCount() Returns the number of graphical objects stored in this container.
Iterator<GObject>	iterator() Returns an Iterator that cycles through the elements within this container in the default direction, which is from back to front.
GCompound	markAsComplete() Calling this method makes it illegal to add or remove elements from the compound object.
void	paint(Canvas canvas) Implements the paint operation for this graphical object.
GCompound	remove(GObject gobj) Removes a graphical object from this GCompound.
GCompound	removeAll() Removes all graphical objects from this GCompound.
GObject	scale(float sx, float sy) Scales every object contained in this compound by the scale factors sx and sy.
protected GCompound	sendBackward(GObject gobj) Implements the sendBackward function from the GContainer interface.
protected GCompound	sendForward(GObject gobj) Implements the sendForward function from the GContainer interface.
protected GCompound	sendToBack(GObject gobj) Implements the sendToBack function from the GContainer interface.
protected GCompound	sendToFront(GObject gobj) Implements the sendToFront function from the GContainer interface.

Methods inherited from class stanford.androidlib.graphics.GObject

addTo, addTo, addTo, contains, getBottomY, getCenterX, getCenterY, getColor, getFillColor, getGCanvas, getHeight, getLeftX, getLocation, getPaint, getRightX, getSize, getTopY, getWidth, getX, getY, intersects, isFilled, isVisible, moveBy, moveByPolar, moveTo, moveTo, moveTo, moveToPolar, remove, repaint, scale, sendBackward, sendForward, sendToBack, sendToFront, setBottomY, setBounds, setBounds, setBounds, setCanvas, setColor, setFillColor, setFilled, setGCanvas, setLocation, setLocation, setLocation, setPaint, setRightX, setSize, setSize, setVisible, setX, setY, toString, translate

Methods inherited from class java.lang.Object

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

Methods inherited from interface stanford.androidlib.graphics.GScalable

scale

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Constructor Detail

GCompound

public GCompound()

Creates a new GCompound object with no internal components.

Usage:

GCompound gcomp = new GCompound();

GCompound

public GCompound(GCanvas canvas)

Creates a new GCompound object with no internal components.

Usage:

GCompound gcomp = new GCompound();

Method Detail

add

public GCompound add(GObject gobj)

Adds a new graphical object to this GCompound.

Parameters:

gobj - The graphical object to add

Throws:

NullPointerException - if gobj is null

Usage:

gcomp.add(gobj);

add

public final GCompound add(GObject gobj,
                           float x,
                           float y)

Adds the graphical object to this canvas and sets its location to the point (x, y).

Parameters:

gobj - The graphical object to add

x - The new x-coordinate for the object

y - The new y-coordinate for the object

Throws:

NullPointerException - if gobj is null

Usage:

gc.add(gobj, x, y);

add

public final GCompound add(GObject gobj,
                           GPoint pt)

Adds the graphical object to this canvas and sets its location to the specified point.

Parameters:

gobj - The graphical object to add

pt - A GPoint object giving the coordinates of the point

Throws:

NullPointerException - if gobj is null

Usage:

gc.add(gobj, pt);

contains

public boolean contains(float x,
                        float y)

Checks to see whether a point is "inside" the compound, which means that it is inside one of the components.

Overrides:

contains in class GObject

Parameters:

x - The x-coordinate of the point being tested

y - The y-coordinate of the point being tested

Returns:

true if the point (x, y) is inside the compound, and false otherwise

Usage:

if (gcomp.contains(x, y)) . . .

getBounds

public GRectangle getBounds()

Returns the bounding rectangle for this compound object, which consists of the union of the bounding rectangles for each of the components.

Overrides:

getBounds in class GObject

Returns:

A GRectangle that bounds the components of this object

Usage:

GRectangle bounds = gcomp.getBounds();

getElementCount

public int getElementCount()

Returns the number of graphical objects stored in this container.

Returns:

The number of graphical objects in this container

Usage:

int n = gcomp.getElementCount();

getElement

public GObject getElement(int index)

Returns the graphical object at the specified index, numbering from back to front in the the z dimension.

Parameters:

index - The index of the component to return

Returns:

The graphical object at the specified index

Usage:

GObject gobj = gcomp.getElement(index);

getElementAt

public GObject getElementAt(float x,
                            float y)

Returns the topmost graphical object that contains the point (x, y), or null if no such object exists. Note that these coordinates are relative to the location of the compound object and not to the canvas in which it is displayed.

Parameters:

x - The x-coordinate of the point being tested

y - The y-coordinate of the point being tested

Returns:

The graphical object at the specified location, or null if no such object exists

Usage:

GObject gobj = gcomp.getElementAt(x, y);

getElementAt

public final GObject getElementAt(GPoint pt)

Returns the topmost graphical object that contains the specified point, or null if no such object exists.

Parameters:

pt - The coordinates being tested

Returns:

The graphical object at the specified location, or null if no such object exists

Usage:

GObject gobj = gc.getElementAt(pt);

iterator

public Iterator<GObject> iterator()

Returns an Iterator that cycles through the elements within this container in the default direction, which is from back to front. You can also run the iterator in the opposite direction by using the iterator(direction) form of this method.

Specified by:

iterator in interface Iterable<GObject>

Returns:

An Iterator ranging over the elements of the container from back to front

Usage:

Iterator<GObject> i = gc.iterator();

paint

public void paint(Canvas canvas)

Implements the paint operation for this graphical object. This method is not called directly by clients.

Specified by:

paint in class GObject

Throws:

NullPointerException - if canvas is null

Noshow:

remove

public GCompound remove(GObject gobj)

Removes a graphical object from this GCompound.

Parameters:

gobj - The graphical object to remove

Throws:

NullPointerException - if gobj is null

Usage:

gcomp.remove(gobj);

removeAll

public GCompound removeAll()

Removes all graphical objects from this GCompound.

Usage:

gcomp.removeAll();

scale

public GObject scale(float sx,
                     float sy)

Scales every object contained in this compound by the scale factors sx and sy. Automatic repaint is turned off during the scaling operation so that at most one repaint is performed.

Specified by:

scale in interface GScalable

Overrides:

scale in class GObject

Parameters:

sx - The factor used to scale all coordinates in the x direction

sy - The factor used to scale all coordinates in the y direction

Throws:

IllegalArgumentException - if sx or sy is not a positive number

Usage:

gcomp.scale(sx, sy);

markAsComplete

public GCompound markAsComplete()

Calling this method makes it illegal to add or remove elements from the compound object. Subclasses can invoke this method to protect the integrity of the structure from changes by the client.

Usage:

gcomp.markAsComplete();

sendToFront

protected GCompound sendToFront(GObject gobj)

Implements the sendToFront function from the GContainer interface. Clients should not be calling this method, but the semantics of interfaces forces it to be exported.

Throws:

NullPointerException - if gobj is null

Noshow:

sendToBack

protected GCompound sendToBack(GObject gobj)

Implements the sendToBack function from the GContainer interface. Clients should not be calling this method, but the semantics of interfaces forces it to be exported.

Throws:

NullPointerException - if gobj is null

Noshow:

sendForward

protected GCompound sendForward(GObject gobj)

Implements the sendForward function from the GContainer interface. Clients should not be calling this method, but the semantics of interfaces forces it to be exported.

Throws:

NullPointerException - if gobj is null

Noshow:

sendBackward

protected GCompound sendBackward(GObject gobj)

Implements the sendBackward function from the GContainer interface. Clients should not be calling this method, but the semantics of interfaces forces it to be exported.

Throws:

NullPointerException - if gobj is null

Noshow: