ImagePreview is a component to preview
* GIF and JPEG images.
*
* The preview adapts (shrinks) images to its size upon their * assignment. When the preview is resized, its image is adapted again.
* *Alternately, when altering the image width, height and scale properties * with respective setters, the image is resized within the preview without * the preview itself adapting in size.
* *Scroll bars are displayed as appropriate.
* * @author Ulrich Hilger * @author Light Development * @author http://www.lightdev.com * @author info@lightdev.com * @author published under the terms and conditions of the * GNU General Public License, * for details see file gpl.txt in the distribution * package of this software * * */ class ImagePreview extends JComponent implements Scrollable { /** * scroll increment (for Scrollable implementation) */ private int maxUnitIncrement = 1; /** * the image to be previewed */ private ImageIcon pic; /** * Construct anImagePreview.
*
* @param pic - the image to be previewed
*/
public ImagePreview(final ImageIcon pic) {
setImage(pic);
}
/**
* Construct an ImagePreview without an image
* associated.
*/
public ImagePreview() {
this(null);
}
/**
* Get the original width of the image previewed in this component
*
* @return the original width of the image previewed in this component
* or -1 if no image is assigned
*/
public int getOriginalWidth() {
if (pic != null) {
return pic.getIconWidth();
}
else {
return -1;
}
}
/**
* Get the original height of the image previewed in this component
*
* @return the original height of the image previewed in this component
* or -1 if no image is assigned
*/
public int getOriginalHeight() {
if (pic != null) {
return pic.getIconHeight();
}
else {
return -1;
}
}
/**
* Set the image to be previewed.
*/
public void setImage(final ImageIcon pic) {
this.pic = pic;
if (pic != null) {
this.getGraphics().clearRect(0, 0, getWidth(), getHeight());
this.paint(this.getGraphics());
}
}
/**
* Paints this component.
* If the image associated with this component is smaller than the size
* of the component, the image is painted in its original size. Otherwise,
* the image is scaled down to the size of this component.
*
* @param g - The graphics context to use for painting.
*/
public void paint(final Graphics g) {
if (pic != null) {
int dWidth = pic.getIconWidth();
int dHeight = pic.getIconHeight();
final int scale = getScale();
dWidth = dWidth * scale / 100;
dHeight = dHeight * scale / 100;
g.drawImage(pic.getImage(), 0, 0, dWidth, dHeight, this);
}
}
/**
* Gets the size adjustment necessary for the image to fit into this
* component and returns the resulting scale percentage.
*
* @return the scale percentage of the image
*/
public int getScale() {
int scale = 100;
if (pic != null) {
int vPct = 100;
int hPct = 100;
final Dimension ps = getPreferredSize();
hPct = (int) (ps.getWidth() / ((double) pic.getIconWidth() / (double) 100));
//System.out.println("ImagePreview getScale ps.getWidth " + ps.getWidth());
//System.out.println("ImagePreview getScale pic.getIconWidth() " + pic.getIconWidth());
//System.out.println("ImagePreview getScale hPct " + hPct + "\r\n\r\n");
vPct = (int) (ps.getHeight() / ((double) pic.getIconHeight() / (double) 100));
//System.out.println("ImagePreview getScale ps.getHeight() " + ps.getHeight());
//System.out.println("ImagePreview getScale pic.getIconHeight() " + pic.getIconHeight());
//System.out.println("ImagePreview getScale vPct " + vPct + "\r\n\r\n");
if (hPct < vPct) {
scale = hPct;
}
else {
scale = vPct;
}
}
//System.out.println("ImagePreview getScale=" + scale + "\r\n\r\n");
return scale;
}
/**
* set the preview to a new width maintaining the image proportions
*
* @param newWidth the new width for the image preview
*/
public void setPreviewWidth(final int newWidth) {
//System.out.println("ImagePreview setPreviewWidth newWidth=" + newWidth);
if (pic != null) {
try {
final int hPct = (int) (newWidth / ((double) getOriginalWidth() / (double) 100));
final int newHeight = getOriginalHeight() * hPct / 100;
setPreferredSize(new Dimension(newWidth, newHeight));
}
catch (final Exception e) {
e.printStackTrace();
setPreferredSize(new Dimension(20, 20));
}
revalidate();
}
}
/**
* set the preview to a new height maintaining the image proportions
*
* @param newHeight the new height for the image preview
*/
public void setPreviewHeight(final int newHeight) {
if (pic != null) {
try {
final int vPct = (int) (newHeight / ((double) getOriginalHeight() / (double) 100));
final int newWidth = getOriginalWidth() * vPct / 100;
setPreferredSize(new Dimension(newWidth, newHeight));
}
catch (final Exception e) {
e.printStackTrace();
setPreferredSize(new Dimension(20, 20));
}
revalidate();
}
}
/**
* Adapt the size of the image previewed by this component to a new
* scale.
*
* @param newScale the new scale the image shall adapt to in size
*/
public void setScale(final int newScale) {
int newWidth;
int newHeight;
newWidth = getOriginalWidth() * newScale / 100;
newHeight = getOriginalHeight() * newScale / 100;
setPreferredSize(new Dimension(newWidth, newHeight));
revalidate();
}
/*
------------ Scrollable implementation start ----------------------
*/
public Dimension getPreferredScrollableViewportSize() {
return getPreferredSize();
}
public int getScrollableUnitIncrement(final Rectangle visibleRect, final int orientation, final int direction) {
//Get the current position.
int currentPosition = 0;
if (orientation == SwingConstants.HORIZONTAL) {
currentPosition = visibleRect.x;
}
else {
currentPosition = visibleRect.y;
}
//Return the number of pixels between currentPosition
//and the nearest tick mark in the indicated direction.
if (direction < 0) {
final int newPosition = currentPosition - (currentPosition / maxUnitIncrement) * maxUnitIncrement;
return (newPosition == 0) ? maxUnitIncrement : newPosition;
}
else {
return ((currentPosition / maxUnitIncrement) + 1) * maxUnitIncrement - currentPosition;
}
}
public int getScrollableBlockIncrement(final Rectangle visibleRect, final int orientation, final int direction) {
if (orientation == SwingConstants.HORIZONTAL) {
return visibleRect.width - maxUnitIncrement;
}
else {
return visibleRect.height - maxUnitIncrement;
}
}
public boolean getScrollableTracksViewportWidth() {
return false;
}
public boolean getScrollableTracksViewportHeight() {
return false;
}
public void setMaxUnitIncrement(final int pixels) {
maxUnitIncrement = pixels;
}
/*
--------- Scrollable implementation end ---------------------------
*/
}