com.ccg.awt
Class ImageViewer

java.lang.Object
  java.awt.Component
      com.ccg.awt.ImageViewer

All Implemented Interfaces:

ImageObserver, MenuContainer, Serializable

public class ImageViewer
extends Component
implements ImageObserver

Simple lightweight component to display a image.

The component is intended to display a bitmap in a window. Currently, it simply blits the image starting at the coordinates (0,0). However, as it is used more and more in the future, other capabilities will be added including:

• The option of displaying centered text when the image is not yet available (or set) for display (this is implemented now).
• Centering of image if the image is smaller than the window.
• Scrolling of the image if it is larger than the window.
• Scaling of the image to the best fit into the window.
• An extensible pop-up menu with options for the image.

This class was originally create to test out the ImageHolder class. The sample program, Viewer.java has been provided to demonstrate its usage. Viewer.html has also been provided so you can see what it looks like in an applet.

Since:

1.0

Version:

$Revision: 1.2 $

Author:

$Author: pkb $

See Also:

ImageHolder, Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class java.awt.Component

Component.AccessibleAWTComponent, Component.BltBufferStrategy, Component.FlipBufferStrategy

Field Summary

Fields inherited from class java.awt.Component

BOTTOM_ALIGNMENT, CENTER_ALIGNMENT, LEFT_ALIGNMENT, RIGHT_ALIGNMENT, TOP_ALIGNMENT

Fields inherited from interface java.awt.image.ImageObserver

ABORT, ALLBITS, ERROR, FRAMEBITS, HEIGHT, PROPERTIES, SOMEBITS, WIDTH

Constructor Summary

ImageViewer()
Initializes such that there is no image/text to display.

Method Summary

Image	getImage() Get the displayed image
String	getText() Get the status message to display
boolean	imageUpdate(Image im, int flags, int x, int y, int w, int h) Our implementation of the ImageObserver.
void	paint(Graphics g) Paints the image or text.
void	setImage(Image val) Set the displayed image
void	setText(String val) Set the status message to display

Methods inherited from class java.awt.Component

action, add, addComponentListener, addFocusListener, addHierarchyBoundsListener, addHierarchyListener, addInputMethodListener, addKeyListener, addMouseListener, addMouseMotionListener, addMouseWheelListener, addNotify, addPropertyChangeListener, addPropertyChangeListener, applyComponentOrientation, areFocusTraversalKeysSet, bounds, checkImage, checkImage, coalesceEvents, contains, contains, createImage, createImage, createVolatileImage, createVolatileImage, deliverEvent, disable, disableEvents, dispatchEvent, doLayout, enable, enable, enableEvents, enableInputMethods, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, getAccessibleContext, getAlignmentX, getAlignmentY, getBackground, getBounds, getBounds, getColorModel, getComponentAt, getComponentAt, getComponentListeners, getComponentOrientation, getCursor, getDropTarget, getFocusCycleRootAncestor, getFocusListeners, getFocusTraversalKeys, getFocusTraversalKeysEnabled, getFont, getFontMetrics, getForeground, getGraphics, getGraphicsConfiguration, getHeight, getHierarchyBoundsListeners, getHierarchyListeners, getIgnoreRepaint, getInputContext, getInputMethodListeners, getInputMethodRequests, getKeyListeners, getListeners, getLocale, getLocation, getLocation, getLocationOnScreen, getMaximumSize, getMinimumSize, getMouseListeners, getMouseMotionListeners, getMousePosition, getMouseWheelListeners, getName, getParent, getPeer, getPreferredSize, getPropertyChangeListeners, getPropertyChangeListeners, getSize, getSize, getToolkit, getTreeLock, getWidth, getX, getY, gotFocus, handleEvent, hasFocus, hide, inside, invalidate, isBackgroundSet, isCursorSet, isDisplayable, isDoubleBuffered, isEnabled, isFocusable, isFocusCycleRoot, isFocusOwner, isFocusTraversable, isFontSet, isForegroundSet, isLightweight, isMaximumSizeSet, isMinimumSizeSet, isOpaque, isPreferredSizeSet, isShowing, isValid, isVisible, keyDown, keyUp, layout, list, list, list, list, list, locate, location, lostFocus, minimumSize, mouseDown, mouseDrag, mouseEnter, mouseExit, mouseMove, mouseUp, move, nextFocus, paintAll, paramString, postEvent, preferredSize, prepareImage, prepareImage, print, printAll, processComponentEvent, processEvent, processFocusEvent, processHierarchyBoundsEvent, processHierarchyEvent, processInputMethodEvent, processKeyEvent, processMouseEvent, processMouseMotionEvent, processMouseWheelEvent, remove, removeComponentListener, removeFocusListener, removeHierarchyBoundsListener, removeHierarchyListener, removeInputMethodListener, removeKeyListener, removeMouseListener, removeMouseMotionListener, removeMouseWheelListener, removeNotify, removePropertyChangeListener, removePropertyChangeListener, repaint, repaint, repaint, repaint, requestFocus, requestFocus, requestFocusInWindow, requestFocusInWindow, reshape, resize, resize, setBackground, setBounds, setBounds, setComponentOrientation, setCursor, setDropTarget, setEnabled, setFocusable, setFocusTraversalKeys, setFocusTraversalKeysEnabled, setFont, setForeground, setIgnoreRepaint, setLocale, setLocation, setLocation, setMaximumSize, setMinimumSize, setName, setPreferredSize, setSize, setSize, setVisible, show, show, size, toString, transferFocus, transferFocusBackward, transferFocusUpCycle, update, validate

Methods inherited from class java.lang.Object

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

Constructor Detail

ImageViewer

public ImageViewer()

Initializes such that there is no image/text to display. After initializing the object in this fashion, its paint routine will do nothing until you set the image and/or text to display.

Since:

1.0

See Also:

setImage(java.awt.Image)

Method Detail

setImage

public void setImage(Image val)

Set the displayed image

Parameters:

val - New Image value to assign.

See Also:

getImage()

getImage

public Image getImage()

Get the displayed image

Returns:

Current Image value assigned.

See Also:

setImage(java.awt.Image)

setText

public void setText(String val)

Set the status message to display

Parameters:

val - New String value to assign.

See Also:

getText()

getText

public String getText()

Get the status message to display

Returns:

Current String value assigned.

See Also:

setText(java.lang.String)

paint

public void paint(Graphics g)

Paints the image or text. This method is called when the component needs to paint itself. If a image object has been assigned and is ready for display, it will be displayed. If there isn't an image ready for display, then the current text associated with the object (its status) will be displayed centered in the objects area.

Overrides:

paint in class Component

Parameters:

g - Standard Graphics object to do the drawing onto.

Since:

1.0

See Also:

setImage(java.awt.Image)

imageUpdate

public boolean imageUpdate(Image im,
                           int flags,
                           int x,
                           int y,
                           int w,
                           int h)

Our implementation of the ImageObserver. Since images can take time to load, this component registers itself as an observer of its associated image object. When the image loader determines that the image is fully loaded, it will invoke this method and we will then repaint ourselves to display the image to the user.

Specified by:

imageUpdate in interface ImageObserver

Overrides:

imageUpdate in class Component

Parameters:

im - Image which new information is available.

flags - Current state of image loading (we look for ImageObserver.ALLBITS)

x - We ignore this.

y - We ignore this.

w - We ignore this.

h - We ignore this.

Returns:

true - once the entire image we are waiting for is available.

Since:

1.0

See Also:

paint(java.awt.Graphics)