import java.awt.AWTEvent;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GraphicsEnvironment;
import java.awt.Image;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.RenderingHints;
import java.awt.Toolkit;
import java.awt.event.ComponentAdapter;
import java.awt.event.ComponentEvent;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionListener;
import java.awt.event.MouseWheelEvent;
import java.awt.event.MouseWheelListener;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.util.Arrays;
import javax.imageio.ImageIO;
import javax.swing.JFrame;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
/**
* <p>
* <code>NavigableImagePanel</code> is a lightweight container displaying
* an image that can be zoomed in and out and panned with ease and simplicity,
* using an adaptive rendering for high quality display and satisfactory performance.
* </p>
* <p>
* <h3>Image</h3>
* <p>An image is loaded either via a constructor:</p>
* <pre>
* NavigableImagePanel panel = new NavigableImagePanel(image);
* </pre>
* or using a setter:
* <pre>
* NavigableImagePanel panel = new NavigableImagePanel();
* panel.setImage(image);
* </pre>
* When an image is set, it is initially painted centered in the component,
* at the largest possible size, fully visible, with its aspect ratio is preserved.
* This is defined as 100% of the image size and its corresponding zoom level is 1.0.
* </p>
* <h3>Zooming</h3>
* <p>
* Zooming can be controlled interactively, using either the mouse scroll wheel (default)
* or the mouse two buttons, or programmatically, allowing the programmer to
* implement other custom zooming methods. If the mouse does not have a scroll wheel,
* set the zooming device to mouse buttons:
* <pre>
* panel.setZoomDevice(ZoomDevice.MOUSE_BUTTON);
* </pre>
* The left mouse button works as a toggle switch between zooming in and zooming out
* modes, and the right button zooms an image by one increment (default is 20%).
* You can change the zoom increment value by:
* <pre>
* panel.setZoomIncrement(newZoomIncrement);
* </pre>
* If you intend to provide programmatic zoom control, set the zoom device to none
* to disable both the mouse wheel and buttons for zooming purposes:
* <pre>
* panel.setZoomDevice(ZoomDevice.NONE);
* </pre>
* and use <code>setZoom()</code> to change the zoom level.
* </p>
* <p>
* Zooming is always around the point the mouse pointer is currently at, so that
* this point (called a zooming center) remains stationary ensuring that the area
* of an image we are zooming into does not disappear off the screen. The zooming center
* stays at the same location on the screen and all other points move radially away from
* it (when zooming in), or towards it (when zooming out). For programmatically
* controlled zooming the zooming center is either specified when <code>setZoom()</code>
* is called:
* <pre>
* panel.setZoom(newZoomLevel, newZoomingCenter);
* </pre>
* or assumed to be the point of an image which is
* the closest to the center of the panel, if no zooming center is specified:
* <pre>
* panel.setZoom(newZoomLevel);
* </pre>
* </p>
* <p>
* There are no lower or upper zoom level limits.
* </p>
* <h3>Navigation</h3>
* <p><code>NavigableImagePanel</code> does not use scroll bars for navigation,
* but relies on a navigation image located in the upper left corner of the panel.
* The navigation image is a small replica of the image displayed in the panel.
* When you click on any point of the navigation image that part of the image
* is displayed in the panel, centered. The navigation image can also be
* zoomed in the same way as the main image.</p>
* <p>In order to adjust the position of an image in the panel, it can be dragged
* with the mouse, using the left button.
* </p>
* <p>For programmatic image navigation, disable the navigation image:
* <pre>
* panel.setNavigationImageEnabled(false)
* </pre>
* and use <code>getImageOrigin()</code> and
* <code>setImageOrigin()</code> to move the image around the panel.
* </p>
* <h3>Rendering</h3>
* <p><code>NavigableImagePanel</code> uses the Nearest Neighbor interpolation
* for image rendering (default in Java).
* When the scaled image becomes larger than the original image,
* the Bilinear interpolation is applied, but only to the part
* of the image which is displayed in the panel. This interpolation change threshold
* can be controlled by adjusting the value of
* <code>HIGH_QUALITY_RENDERING_SCALE_THRESHOLD</code>.</p>
*/
public class NavigableImagePanel extends JPanel {
/**
* <p>Identifies a change to the zoom level.</p>
*/
public static final String ZOOM_LEVEL_CHANGED_PROPERTY = "zoomLevel";
/**
* <p>Identifies a change to the zoom increment.</p>
*/
public static final String ZOOM_INCREMENT_CHANGED_PROPERTY = "zoomIncrement";
/**
* <p>Identifies that the image in the panel has changed.</p>
*/
public static final String IMAGE_CHANGED_PROPERTY = "image";
private static final double SCREEN_NAV_IMAGE_FACTOR = 0.15; // 15% of panel's width
private static final double NAV_IMAGE_FACTOR = 0.3; // 30% of panel's width
private static final double HIGH_QUALITY_RENDERING_SCALE_THRESHOLD = 1.0;
private static final Object INTERPOLATION_TYPE =
RenderingHints.VALUE_INTERPOLATION_BILINEAR;
private double zoomIncrement = 0.2;
private double zoomFactor = 1.0 + zoomIncrement;
private double navZoomFactor = 1.0 + zoomIncrement;
private BufferedImage image;
private BufferedImage navigationImage;
private int navImageWidth;
private int navImageHeight;
private double initialScale = 0.0;
private double scale = 0.0;
private double navScale = 0.0;
private int originX = 0;
private int originY = 0;
private Point mousePosition;
private Dimension previousPanelSize;
private boolean navigationImageEnabled = true;
private boolean highQualityRenderingEnabled = true;
private WheelZoomDevice wheelZoomDevice = null;
private ButtonZoomDevice buttonZoomDevice = null;
/**
* <p>Defines zoom devices.</p>
*/
public static class ZoomDevice {
/**
* <p>Identifies that the panel does not implement zooming,
* but the component using the panel does (programmatic zooming method).</p>
*/
public static final ZoomDevice NONE = new ZoomDevice("none");
/**
* <p>Identifies the left and right mouse buttons as the zooming device.</p>
*/
public static final ZoomDevice MOUSE_BUTTON = new ZoomDevice("mouseButton");
/**
* <p>Identifies the mouse scroll wheel as the zooming device.</p>
*/
public static final ZoomDevice MOUSE_WHEEL = new ZoomDevice("mouseWheel");
private String zoomDevice;
private ZoomDevice(String zoomDevice) {
this.zoomDevice = zoomDevice;
}
public String toString() {
return zoomDevice;
}
}
//This class is required for high precision image coordinates translation.
private class Coords {
public double x;
public double y;
public Coords(double x, double y) {
this.x = x;
this.y = y;
}
public int getIntX() {
return (int)Math.round(x);
}
public int getIntY() {
return (int)Math.round(y);
}
public String toString() {
return "[Coords: x=" + x + ",y=" + y + "]";
}
}
private class WheelZoomDevice implements MouseWheelListener {
public void mouseWheelMoved(MouseWheelEvent e) {
Point p = e.getPoint();
boolean zoomIn = (e.getWheelRotation() < 0);
if (isInNavigationImage(p)) {
if (zoomIn) {
navZoomFactor = 1.0 + zoomIncrement;
} else {
navZoomFactor = 1.0 - zoomIncrement;
}
zoomNavigationImage();
} else if (isInImage(p)) {
if (zoomIn) {
zoomFactor = 1.0 + zoomIncrement;
} else {
zoomFactor = 1.0 - zoomIncrement;
}
zoomImage();
}
}
}
private class ButtonZoomDevice extends MouseAdapter {
public void mouseClicked(MouseEvent e) {
Point p = e.getPoint();
if (SwingUtilities.isRightMouseButton(e)) {
if (isInNavigationImage(p)) {
navZoomFactor = 1.0 - zoomIncrement;
zoomNavigationImage();
} else if (isInImage(p)) {
zoomFactor = 1.0 - zoomIncrement;
zoomImage();
}
} else {
if (isInNavigationImage(p)) {
navZoomFactor = 1.0 + zoomIncrement;
zoomNavigationImage();
} else if (isInImage(p)) {
zoomFactor = 1.0 + zoomIncrement;
zoomImage();
}
}
}
}
/**
* <p>Creates a new navigable image panel with no default image and
* the mouse scroll wheel as the zooming device.</p>
*/
public NavigableImagePanel() {
setOpaque(false);
addComponentListener(new ComponentAdapter() {
public void componentResized(ComponentEvent e) {
if (scale > 0.0) {
if (isFullImageInPanel()) {
centerImage();
} else if (isImageEdgeInPanel()) {
scaleOrigin();
}
if (isNavigationImageEnabled()) {
createNavigationImage();
}
repaint();
}
previousPanelSize = getSize();
}
});
addMouseListener(new MouseAdapter() {
public void mousePressed(MouseEvent e) {
if (SwingUtilities.isLeftMouseButton(e)) {
if (isInNavigationImage(e.getPoint())) {
Point p = e.getPoint();
displayImageAt(p);
}
}
}
});
addMouseMotionListener(new MouseMotionListener() {
public void mouseDragged(MouseEvent e) {
if (SwingUtilities.isLeftMouseButton(e)
&& !isInNavigationImage(e.getPoint())) {
Point p = e.getPoint();
moveImage(p);
}
}
public void mouseMoved(MouseEvent e) {
//we need the mouse position so that after zooming
//that position of the image is maintained
mousePosition = e.getPoint();
}
});
setZoomDevice(ZoomDevice.MOUSE_WHEEL);
}
/**
* <p>Creates a new navigable image panel with the specified image
* and the mouse scroll wheel as the zooming device.</p>
*/
public NavigableImagePanel(BufferedImage image) throws IOException {
this();
setImage(image);
}
private void addWheelZoomDevice() {
if (wheelZoomDevice == null) {
wheelZoomDevice = new WheelZoomDevice();
addMouseWheelListener(wheelZoomDevice);
}
}
private void addButtonZoomDevice() {
if (buttonZoomDevice == null) {
buttonZoomDevice = new ButtonZoomDevice();
addMouseListener(buttonZoomDevice);
}
}
private void removeWheelZoomDevice() {
if (wheelZoomDevice != null) {
removeMouseWheelListener(wheelZoomDevice);
wheelZoomDevice = null;
}
}
private void removeButtonZoomDevice() {
if (buttonZoomDevice != null) {
removeMouseListener(buttonZoomDevice);
buttonZoomDevice = null;
}
}
/**
* <p>Sets a new zoom device.</p>
*
* @param newZoomDevice specifies the type of a new zoom device.
*/
public void setZoomDevice(ZoomDevice newZoomDevice) {
if (newZoomDevice == ZoomDevice.NONE) {
removeWheelZoomDevice();
removeButtonZoomDevice();
} else if (newZoomDevice == ZoomDevice.MOUSE_BUTTON) {
removeWheelZoomDevice();
addButtonZoomDevice();
} else if (newZoomDevice == ZoomDevice.MOUSE_WHEEL) {
removeButtonZoomDevice();
addWheelZoomDevice();
}
}
/**
* <p>Gets the current zoom device.</p>
*/
public ZoomDevice getZoomDevice() {
if (buttonZoomDevice != null) {
return ZoomDevice.MOUSE_BUTTON;
} else if (wheelZoomDevice != null) {
return ZoomDevice.MOUSE_WHEEL;
} else {
return ZoomDevice.NONE;
}
}
//Called from paintComponent() when a new image is set.
private void initializeParams() {
double xScale = (double)getWidth() / image.getWidth();
double yScale = (double)getHeight() / image.getHeight();
initialScale = Math.min(xScale, yScale);
scale = initialScale;
//An image is initially centered
centerImage();
if (isNavigationImageEnabled()) {
createNavigationImage();
}
}
//Centers the current image in the panel.
private void centerImage() {
originX = (int)(getWidth() - getScreenImageWidth()) / 2;
originY = (int)(getHeight() - getScreenImageHeight()) / 2;
}
//Creates and renders the navigation image in the upper let corner of the panel.
private void createNavigationImage() {
//We keep the original navigation image larger than initially
//displayed to allow for zooming into it without pixellation effect.
navImageWidth = (int)(getWidth() * NAV_IMAGE_FACTOR);
navImageHeight = navImageWidth * image.getHeight() / image.getWidth();
int scrNavImageWidth = (int)(getWidth() * SCREEN_NAV_IMAGE_FACTOR);
int scrNavImageHeight = scrNavImageWidth * image.getHeight() / image.getWidth();
navScale = (double)scrNavImageWidth / navImageWidth;
navigationImage = new BufferedImage(navImageWidth, navImageHeight,
image.getType());
Graphics g = navigationImage.getGraphics();
g.drawImage(image, 0, 0, navImageWidth, navImageHeight, null);
}
/**
* <p>Sets an image for display in the panel.</p>
*
* @param image an image to be set in the panel
*/
public void setImage(BufferedImage image) {
BufferedImage oldImage = this.image;
this.image = image;
//Reset scale so that initializeParameters() is called in paintComponent()
//for the new image.
scale = 0.0;
firePropertyChange(IMAGE_CHANGED_PROPERTY, (Image)oldImage, (Image)image);
repaint();
}
/**
* <p>Tests whether an image uses the standard RGB color space.</p>
*/
public static boolean isStandardRGBImage(BufferedImage bImage) {
return bImage.getColorModel().getColorSpace().isCS_sRGB();
}
//Converts this panel's coordinates into the original image coordinates
private Coords panelToImageCoords(Point p) {
return new Coords((p.x - originX) / scale, (p.y - originY) / scale);
}
//Converts the original image coordinates into this panel's coordinates
private Coords imageToPanelCoords(Coords p) {
return new Coords((p.x * scale) + originX, (p.y * scale) + originY);
}
//Converts the navigation image coordinates into the zoomed image coordinates
private Point navToZoomedImageCoords(Point p) {
int x = p.x * getScreenImageWidth() / getScreenNavImageWidth();
int y = p.y * getScreenImageHeight() / getScreenNavImageHeight();
return new Point(x, y);
}
//The user clicked within the navigation image and this part of the image
//is displayed in the panel.
//The clicked point of the image is centered in the panel.
private void displayImageAt(Point p) {
Point scrImagePoint = navToZoomedImageCoords(p);
originX = -(scrImagePoint.x - getWidth() / 2);
originY = -(scrImagePoint.y - getHeight() / 2);
repaint();
}
//Tests whether a given point in the panel falls within the image boundaries.
private boolean isInImage(Point p) {
Coords coords = panelToImageCoords(p);
int x = coords.getIntX();
int y = coords.getIntY();
return (x >= 0 && x < image.getWidth() && y >= 0 && y < image.getHeight());
}
//Tests whether a given point in the panel falls within the navigation image
//boundaries.
private boolean isInNavigationImage(Point p) {
return (isNavigationImageEnabled() && p.x < getScreenNavImageWidth()
&& p.y < getScreenNavImageHeight());
}
//Used when the image is resized.
private boolean isImageEdgeInPanel() {
if (previousPanelSize == null) {
return false;
}
return (originX > 0 && originX < previousPanelSize.width
|| originY > 0 && originY < previousPanelSize.height);
}
//Tests whether the image is displayed in its entirety in the panel.
private boolean isFullImageInPanel() {
return (originX >= 0 && (originX + getScreenImageWidth()) < getWidth()
&& originY >= 0 && (originY + getScreenImageHeight()) < getHeight());
}
/**
* <p>Indicates whether the high quality rendering feature is enabled.</p>
*
* @return true if high quality rendering is enabled, false otherwise.
*/
public boolean isHighQualityRenderingEnabled() {
return highQualityRenderingEnabled;
}
/**
* <p>Enables/disables high quality rendering.</p>
*
* @param enabled enables/disables high quality rendering
*/
public void setHighQualityRenderingEnabled(boolean enabled) {
highQualityRenderingEnabled = enabled;
}
//High quality rendering kicks in when when a scaled image is larger
//than the original image. In other words,
//when image decimation stops and interpolation starts.
private boolean isHighQualityRendering() {
return (highQualityRenderingEnabled
&& scale > HIGH_QUALITY_RENDERING_SCALE_THRESHOLD);
}
/**
* <p>Indicates whether navigation image is enabled.<p>
*
* @return true when navigation image is enabled, false otherwise.
*/
public boolean isNavigationImageEnabled() {
return navigationImageEnabled;
}
/**
* <p>Enables/disables navigation with the navigation image.</p>
* <p>Navigation image should be disabled when custom, programmatic navigation
* is implemented.</p>
*
* @param enabled true when navigation image is enabled, false otherwise.
*/
public void setNavigationImageEnabled(boolean enabled) {
navigationImageEnabled = enabled;
repaint();
}
//Used when the panel is resized
private void scaleOrigin() {
originX = originX * getWidth() / previousPanelSize.width;
originY = originY * getHeight() / previousPanelSize.height;
repaint();
}
//Converts the specified zoom level to scale.
private double zoomToScale(double zoom) {
return initialScale * zoom;
}
/**
* <p>Gets the current zoom level.</p>
*
* @return the current zoom level
*/
public double getZoom() {
return scale / initialScale;
}
/**
* <p>Sets the zoom level used to display the image.</p>
* <p>This method is used in programmatic zooming. The zooming center is
* the point of the image closest to the center of the panel.
* After a new zoom level is set the image is repainted.</p>
*
* @param newZoom the zoom level used to display this panel's image.
*/
public void setZoom(double newZoom) {
Point zoomingCenter = new Point(getWidth() / 2, getHeight() / 2);
setZoom(newZoom, zoomingCenter);
}
/**
* <p>Sets the zoom level used to display the image, and the zooming center,
* around which zooming is done.</p>
* <p>This method is used in programmatic zooming.
* After a new zoom level is set the image is repainted.</p>
*
* @param newZoom the zoom level used to display this panel's image.
*/
public void setZoom(double newZoom, Point zoomingCenter) {
Coords imageP = panelToImageCoords(zoomingCenter);
if (imageP.x < 0.0) {
imageP.x = 0.0;
}
if (imageP.y < 0.0) {
imageP.y = 0.0;
}
if (imageP.x >= image.getWidth()) {
imageP.x = image.getWidth() - 1.0;
}
if (imageP.y >= image.getHeight()) {
imageP.y = image.getHeight() - 1.0;
}
Coords correctedP = imageToPanelCoords(imageP);
double oldZoom = getZoom();
scale = zoomToScale(newZoom);
Coords panelP = imageToPanelCoords(imageP);
originX += (correctedP.getIntX() - (int)panelP.x);
originY += (correctedP.getIntY() - (int)panelP.y);
firePropertyChange(ZOOM_LEVEL_CHANGED_PROPERTY, new Double(oldZoom),
new Double(getZoom()));
repaint();
}
/**
* <p>Gets the current zoom increment.</p>
*
* @return the current zoom increment
*/
public double getZoomIncrement() {
return zoomIncrement;
}
/**
* <p>Sets a new zoom increment value.</p>
*
* @param newZoomIncrement new zoom increment value
*/
public void setZoomIncrement(double newZoomIncrement) {
double oldZoomIncrement = zoomIncrement;
zoomIncrement = newZoomIncrement;
firePropertyChange(ZOOM_INCREMENT_CHANGED_PROPERTY,
new Double(oldZoomIncrement), new Double(zoomIncrement));
}
//Zooms an image in the panel by repainting it at the new zoom level.
//The current mouse position is the zooming center.
private void zoomImage() {
Coords imageP = panelToImageCoords(mousePosition);
double oldZoom = getZoom();
scale *= zoomFactor;
Coords panelP = imageToPanelCoords(imageP);
originX += (mousePosition.x - (int)panelP.x);
originY += (mousePosition.y - (int)panelP.y);
firePropertyChange(ZOOM_LEVEL_CHANGED_PROPERTY, new Double(oldZoom),
new Double(getZoom()));
repaint();
}
//Zooms the navigation image
private void zoomNavigationImage() {
navScale *= navZoomFactor;
repaint();
}
/**
* <p>Gets the image origin.</p>
* <p>Image origin is defined as the upper, left corner of the image in
* the panel's coordinate system.</p>
* @return the point of the upper, left corner of the image in the panel's coordinates
* system.
*/
public Point getImageOrigin() {
return new Point(originX, originY);
}
/**
* <p>Sets the image origin.</p>
* <p>Image origin is defined as the upper, left corner of the image in
* the panel's coordinate system. After a new origin is set, the image is repainted.
* This method is used for programmatic image navigation.</p>
* @param x the x coordinate of the new image origin
* @param y the y coordinate of the new image origin
*/
public void setImageOrigin(int x, int y) {
setImageOrigin(new Point(x, y));
}
/**
* <p>Sets the image origin.</p>
* <p>Image origin is defined as the upper, left corner of the image in
* the panel's coordinate system. After a new origin is set, the image is repainted.
* This method is used for programmatic image navigation.</p>
* @param newOrigin the value of a new image origin
*/
public void setImageOrigin(Point newOrigin) {
originX = newOrigin.x;
originY = newOrigin.y;
repaint();
}
//Moves te image (by dragging with the mouse) to a new mouse position p.
private void moveImage(Point p) {
int xDelta = p.x - mousePosition.x;
int yDelta = p.y - mousePosition.y;
originX += xDelta;
originY += yDelta;
mousePosition = p;
repaint();
}
//Gets the bounds of the image area currently displayed in the panel (in image
//coordinates).
private Rectangle getImageClipBounds() {
Coords startCoords = panelToImageCoords(new Point(0, 0));
Coords endCoords = panelToImageCoords(new Point(getWidth() - 1, getHeight() - 1));
int panelX1 = startCoords.getIntX();
int panelY1 = startCoords.getIntY();
int panelX2 = endCoords.getIntX();
int panelY2 = endCoords.getIntY();
//No intersection?
if (panelX1 >= image.getWidth() || panelX2 < 0 || panelY1 >= image.getHeight() || panelY2 < 0) {
return null;
}
int x1 = (panelX1 < 0) ? 0 : panelX1;
int y1 = (panelY1 < 0) ? 0 : panelY1;
int x2 = (panelX2 >= image.getWidth()) ? image.getWidth() - 1 : panelX2;
int y2 = (panelY2 >= image.getHeight()) ? image.getHeight() - 1 : panelY2;
return new Rectangle(x1, y1, x2 - x1 + 1, y2 - y1 + 1);
}
/**
* Paints the panel and its image at the current zoom level, location, and
* interpolation method dependent on the image scale.</p>
*
* @param g the <code>Graphics</code> context for painting
*/
protected void paintComponent(Graphics g) {
super.paintComponent(g); // Paints the background
if (image == null) {
return;
}
if (scale == 0.0) {
initializeParams();
}
if (isHighQualityRendering()) {
Rectangle rect = getImageClipBounds();
if (rect == null || rect.width == 0 || rect.height == 0) { // no part of image is displayed in the panel
return;
}
BufferedImage subimage = image.getSubimage(rect.x, rect.y, rect.width,
rect.height);
Graphics2D g2 = (Graphics2D)g;
g2.setRenderingHint(RenderingHints.KEY_INTERPOLATION, INTERPOLATION_TYPE);
g2.drawImage(subimage, Math.max(0, originX), Math.max(0, originY),
Math.min((int)(subimage.getWidth() * scale), getWidth()),
Math.min((int)(subimage.getHeight() * scale), getHeight()), null);
} else {
g.drawImage(image, originX, originY, getScreenImageWidth(),
getScreenImageHeight(), null);
}
//Draw navigation image
if (isNavigationImageEnabled()) {
g.drawImage(navigationImage, 0, 0, getScreenNavImageWidth(),
getScreenNavImageHeight(), null);
drawZoomAreaOutline(g);
}
}
//Paints a white outline over the navigation image indicating
//the area of the image currently displayed in the panel.
private void drawZoomAreaOutline(Graphics g) {
if (isFullImageInPanel()) {
return;
}
int x = -originX * getScreenNavImageWidth() / getScreenImageWidth();
int y = -originY * getScreenNavImageHeight() / getScreenImageHeight();
int width = getWidth() * getScreenNavImageWidth() / getScreenImageWidth();
int height = getHeight() * getScreenNavImageHeight() / getScreenImageHeight();
g.setColor(Color.white);
g.drawRect(x, y, width, height);
}
private int getScreenImageWidth() {
return (int)(scale * image.getWidth());
}
private int getScreenImageHeight() {
return (int)(scale * image.getHeight());
}
private int getScreenNavImageWidth() {
return (int)(navScale * navImageWidth);
}
private int getScreenNavImageHeight() {
return (int)(navScale * navImageHeight);
}
private static String[] getImageFormatExtensions() {
String[] names = ImageIO.getReaderFormatNames();
for(int i = 0; i < names.length; i++) {
names[i] = names[i].toLowerCase();
}
Arrays.sort(names);
return names;
}
private static boolean endsWithImageFormatExtension(String name) {
int dotIndex = name.lastIndexOf(".");
if (dotIndex == -1) {
return false;
}
String extension = name.substring(dotIndex + 1).toLowerCase();
return (Arrays.binarySearch(getImageFormatExtensions(), extension) >= 0);
}
public static void main(String[] args) {
if (args.length == 0) {
System.out.println("Usage: java NavigableImagePanel imageFilename");
System.exit(1);
}
final String filename = args[0];
SwingUtilities.invokeLater(new Runnable() {
public void run() {
final JFrame frame = new JFrame("Navigable Image Panel");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
NavigableImagePanel panel = new NavigableImagePanel();
try {
final BufferedImage image = ImageIO.read(new File(filename));
panel.setImage(image);
} catch (IOException e) {
JOptionPane.showMessageDialog(null, e.getMessage(), "",
JOptionPane.ERROR_MESSAGE);
System.exit(1);
}
frame.getContentPane().add(panel, BorderLayout.CENTER);
GraphicsEnvironment ge =
GraphicsEnvironment.getLocalGraphicsEnvironment();
Rectangle bounds = ge.getMaximumWindowBounds();
frame.setSize(new Dimension(bounds.width, bounds.height));
frame.setVisible(true);
}
});
}
}