/**

* @(#)ThumbnailIcon.java 1.0 04/12/12

*/

package darrylbu.icon;

import java.awt.Image;

import java.awt.image.BufferedImage;

import java.net.URL;

/**

* An <CODE>Icon</CODE> that maintains a defined size independent of the size of the

* image it contains. If needed, the size of its image is reduced to fit; otherwise

* the image is displayed at its natural size, padded and centered horizontally and/or

* vertically. The size of an individual <code>ThumbnailIcon</code>, or the default

* size of all <CODE>ThumbnailIcon</CODE>s, can be changed by the static method provided.

* <P>

* Swing components that use icons are not notified when the icon's size is changed.

* In case the size of a <CODE>ThumbnailIcon</CODE> displayed in an already realized

* component is changed, either by setting its size or the default size, it is the

* caller's responsibility to revalidate the component hierarchy affected by the change.

* <P>

* The class is a drop-in replacement for <CODE>ImageIcon</CODE>, except that

* the no-argument constructor is not supported.

* <P>

* <CODE>ThumbnailIcon</CODE>, as its name implies, is useful for displaying

* multiple images of different sizes, reduced or padded as necessary to fit the

* same dimensions.

* <P>

* If not set, the default size of <CODE>ThumbnailIcon</CODE> is 160 X 120 pixels.

*

* @version 1.0 04/12/12

* @author Darryl

*/

public class ThumbnailIcon extends ShrinkIcon {

/**

* The constant for setting the width and/or height to use the default

* for the class.

*/

public static final int DEFAULT = -1;

/**

* The constant for setting the width, height, default width or default height

* to be computed from the other dimension in a way that maintains the aspect

* ratio of the contained image.

* <P>

* If both the width and height evaluate to <CODE>COMPUTED</CODE>, the image

* will be displayed at its natural size, essentially mimicking the behavior

* of <CODE>ImageIcon</CODE>.

*/

public static final int COMPUTED = 0;

private static int defaultWidth = 160;

private static int defaultHeight = 120;

private int thumbWidth = DEFAULT;

private int thumbHeight = DEFAULT;

/**

* Creates a <CODE>ThumbnailIcon</CODE> from an array of bytes.

*

* @param imageData an array of pixels in an image format supported by

* the AWT Toolkit, such as GIF, JPEG, or (as of 1.3) PNG

*

* @see ImageIcon#ImageIcon(byte[])

*/

public ThumbnailIcon(byte[] imageData) {

super(imageData);

}

/**

* Creates a <CODE>ThumbnailIcon</CODE> from an array of bytes.

*

* @param imageData an array of pixels in an image format supported by

* the AWT Toolkit, such as GIF, JPEG, or (as of 1.3) PNG

* @param description a brief textual description of the image

*

* @see ImageIcon#ImageIcon(byte[], java.lang.String)

*/

public ThumbnailIcon(byte[] imageData, String description) {

super(imageData, description);

}

/**

* Creates a <CODE>ThumbnailIcon</CODE> from the image.

*

* @param image the image

*

* @see ImageIcon#ImageIcon(java.awt.Image)

*/

public ThumbnailIcon(Image image) {

super(image);

}

/**

* Creates a <CODE>ThumbnailIcon</CODE> from the image.

*

* @param image the image

* @param description a brief textual description of the image

*

* @see ImageIcon#ImageIcon(java.awt.Image, java.lang.String)

*/

public ThumbnailIcon(Image image, String description) {

super(image, description);

}

/**

* Creates a <CODE>ThumbnailIcon</CODE> from the specified file.

*

* @param filename a String specifying a filename or path

*

* @see ImageIcon#ImageIcon(java.lang.String)

*/

public ThumbnailIcon(String filename) {

super(filename);

}

/**

* Creates a <CODE>ThumbnailIcon</CODE> from the specified file.

*

* @param filename a String specifying a filename or path

* @param description a brief textual description of the image

*

* @see ImageIcon#ImageIcon(java.lang.String, java.lang.String)

*/

public ThumbnailIcon(String filename, String description) {

super(filename, description);

}

/**

* Creates a <CODE>ThumbnailIcon</CODE> from the specified URL.

*

* @param location the URL for the image

*

* @see ImageIcon#ImageIcon(java.net.URL)

*/

public ThumbnailIcon(URL location) {

super(location);

}

/**

* Creates a <CODE>ThumbnailIcon</CODE> from the specified URL.

*

* @param location the URL for the image

* @param description a brief textual description of the image

*

* @see ImageIcon#ImageIcon(java.net.URL, java.lang.String)

*/

public ThumbnailIcon(URL location, String description) {

super(location, description);

}

/**

* Sets the width of an individual <CODE>ThumbnailIcon</CODE>.

* <P>

* Set the width to <CODE>DEFAULT</CODE> to use the default width for the class,

* or set it to <CODE>COMPUTED</CODE> for the width to be computed form the height,

* maintaining the aspect ratio of the contained image.

* <P>

* If both the width and height evaluate to <CODE>COMPUTED</CODE>, the image

* will be displayed at its natural size, essentially mimicking the behavior

* of <CODE>ImageIcon</CODE>.

* <P>

* Setting a value less than <CODE>DEFAULT</CODE> is not permitted.

*

* @param width The width to set

*/

public void setThumbWidth(int width) {

if (width < DEFAULT) {

throw new IllegalArgumentException("Width cannot be less than ThumbnailIcon.DEFAULT");

}

thumbWidth = width;

}

/**

* Returns the width that has been set, or <CODE>DEFAULT</CODE>. Note that this

* is not the same value as that returned by <CODE>getIconWidth()</CODE>.

*

* @return the set width, or <CODE>DEFAULT</CODE> if none has been set.

*/

public int getThumbWidth() {

return thumbWidth;

}

/**

* Sets the height of an individual <CODE>ThumbnailIcon</CODE>.

* <P>

* Set the height to <CODE>DEFAULT</CODE> to use the default height for the class,

* or set it to <CODE>COMPUTED</CODE> for the height to be computed form the width,

* maintaining the aspect ratio of the contained image.

* <P>

* If both the width and height evaluate to <CODE>COMPUTED</CODE>, the image

* will be displayed at its natural size, essentially mimicking the behavior

* of <CODE>ImageIcon</CODE>.

* <P>

* Setting a value less than <CODE>DEFAULT</CODE> is not permitted.

*

* @param height The height to set

*/

public void setThumbHeight(int height) {

if (height < DEFAULT) {

throw new IllegalArgumentException("Height cannot be less than ThumbnailIcon.DEFAULT");

}

thumbHeight = height;

}

/**

* Returns the height that has been set, or <CODE>DEFAULT</CODE>. Note that this

* is not the same value as that returned by <CODE>getIconHeight()</CODE>.

*

* @return the set height, or <CODE>DEFAULT</CODE> if none has been set.

*/

public int getThumbHeight() {

return thumbHeight;

}

/**

* Sets the default size of all <CODE>ThumbnailIcon</CODE>s.

* <P>

* If either the width or height is zero it will be computed from the other

* dimension, according to the aspect ratio of each <CODE>ThumbnaiIcon</CODE>'s

* contained image. Setting the default width to zero may be useful for a horizontal

* layout of components that display a <CODE>ThumbnailIcon</CODE>; correspondingly,

* a default height of zero can be useful in a vertical layout.

* <P>

* If both width and height are zero, a <CODE>ThumbnailIcon</CODE> that respects the

* default width and height will be sized to its contained image, essentially

* mimicking the behavior of <CODE>ImageIcon</CODE>.

*

* @param width The default width to set.

* @param height The default height to set.

*/

public static void setDefaultSize(int width, int height) {

if (width < 0 || height < 0) {

throw new IllegalArgumentException("Default width and/or height cannot be negative");

}

defaultWidth = width;

defaultHeight = height;

}

/**

* Gets the default width of all <CODE>ThumbnailIcon</CODE>s. A return value

* of zero indicates that the default width will be computed from the default

* height so as to maintain the aspect ratio of the contained image.

*

* @return The default width for all <CODE>ThumbnailIcon</CODE>s

*/

public static int getDefaultWidth() {

return defaultWidth;

}

/**

* Gets the default height of all <CODE>ThumbnailIcon</CODE>s. A return value

* of zero indicates that the default height will be computed from the default

* width so as to maintain the aspect ratio of the contained image.

*

* @return The default width for all <CODE>ThumbnailIcon</CODE>s

*/

public static int getDefaultHeight() {

return defaultHeight;

}

/**

* Gets the width of the icon.

*

* @return The width in pixels of this icon

*/

@Override

public int getIconWidth() {

if (thumbWidth > 0) {

return thumbWidth;

}

Image image = getImage();

int w = image.getWidth(component);

int h = image.getHeight(component);

if (thumbWidth < 0) {

if (defaultWidth > 0) {

return defaultWidth;

}

if (defaultHeight > 0) {

return (defaultHeight * w) / h;

}

if (thumbHeight <= 0) {

return w;

}

}

return (getIconHeight() * w) / h;

}

/**

* Gets the height of the icon.

*

* @return The height in pixels of this icon

*/

@Override

public int getIconHeight() {

if (thumbHeight > 0) {

return thumbHeight;

}

Image image = getImage();

int w = image.getWidth(component);

int h = image.getHeight(component);

if (thumbHeight < 0) {

if (defaultHeight > 0) {

return defaultHeight;

}

if (defaultWidth > 0) {

return (defaultWidth * h) / w;

}

if (thumbWidth <= 0) {

return h;

}

}

return (getIconWidth() * h) / w;

}

/**

* Convenience method to obtain the icon's image at the size at which it is displayed.

* Note that a thumbnail obtained from an animated image will not itself be animated.

*

* @return The thumbnail image.

*/

public BufferedImage getThumbnail() {

Image image = getImage();

int w = image.getWidth(component);

int h = image.getHeight(component);

int tw = getIconWidth();

int th = getIconHeight();

if (w * th < h * tw) {

tw = (th * w) / h;

} else {

th = (tw * h) / w;

}

tw = tw > w ? w : tw;

th = th > h ? h : th;

BufferedImage retVal = new BufferedImage(tw, th, BufferedImage.TYPE_INT_RGB);

image.getGraphics().drawImage(getImage(), 0, 0, tw, th, component);

return retVal;

}

}