package gui;import javax.swing.*;import java.awt.*;/** Class to display Image instance in a JPanel object */public class JJImgPanel extends JPanel {    /** Reference to the main frame's desktop */    private Main desktop;    /** Reference to Image instance to draw in the panel */    private Image image;    /** Image position and dimension in the canvas */    private Rectangle rect;    /** The number of components in the image */    private int nc;    /** Whether or not a shape has to be drawn */    private boolean drawing = false;    /** No shape */    private final static int NONE = 0;    /** Rectangular ROI */    private final static int RECT_ROI = 1;    /** Circular ROI */    private final static int CIRC_ROI = 2;    /** Tile partition */    private final static int TILE_PARTITION = 3;    /** Shape type */    private int shapeType = NONE;    /** Shape coordinates and dimension */    private int x,y,w,h;        /** Displayed image's zooming factor */    private double zf = 1;    /** Current view */    private Rectangle currentView = null;    /** Class constructor. It also determines the initial zooming factor     * such that all the image appears in the desktop */    public JJImgPanel(Image image,Rectangle rect,int nc,Main desktop) {        this.image = image;        this.rect = rect;        this.nc = nc;        this.desktop = desktop;        zf = 1;        int dw = desktop.getWidth();        int dh = desktop.getHeight();        while(rect.width/zf>0.8*dw || rect.height/zf>0.8*dh) {            zf *= 2;        }        setPreferredSize(new Dimension((int)(rect.width/zf),				       (int)(rect.height/zf)));    }    /** Returns the number of components in the image */    public int getNumComps() {        return nc;    }    /** Return the image's width beside any zooming */    public int getOrigWidth() {        return rect.width;    }    /** Return the image's height beside any zooming */    public int getOrigHeight() {        return rect.height;    }    /** Returns the current view */    public Rectangle getCurrentView() {	return currentView;    }    /** Image horizontal offset in canvas */    public int getOffX() {	return rect.x;    }    /** Image vertical offset in canvas */    public int getOffY() {	return rect.y;    }        /** Set whether or not a ROI's shape has to be drawn */    public void enableDrawing(boolean state) {        drawing = state;	if(state==false) {	    shapeType = NONE;	}        repaint();    }    /** Specify the tile partition */    public void setTilePartition(Rectangle tilePart) {	shapeType = TILE_PARTITION;	this.x = tilePart.x;	this.y = tilePart.y;	this.w = tilePart.width;	this.h = tilePart.height;	repaint();    }    /**      * Specify the coordinates and the dimension of the rectangular ROI to be     * drawn      * */    public void drawRect(int x,int y,int w,int h) {	shapeType = RECT_ROI;        this.x = x;        this.y = y;        this.w = w;        this.h = h;        repaint();    }        /** Specify the coordinates and the dimension of the circular ROI to be     * drawn */    public void drawOval(int x,int y,int w,int h) {        shapeType = CIRC_ROI;        this.x = x;        this.y = y;        this.w = w;        this.h = h;        repaint();    }    /** Specify a new image offset in canvas */    public void setOffset(int x,int y) {	rect.x = x;	rect.y = y;        setPreferredSize(new Dimension((int)((rect.width+x)/zf),				       (int)((rect.height+y)/zf)));	revalidate(); 	repaint();    }    /** Zoom in the image drawn in panel */    public void zoomIn() {        zf = zf*0.5;        setPreferredSize(new Dimension((int)(rect.width/zf),				       (int)(rect.height/zf)));        revalidate();        repaint();    }    /** Zoom out of the image drawn in panel */    public void zoomOut() {        zf = zf*2;        setPreferredSize(new Dimension((int)(rect.width/zf),				       (int)(rect.height/zf)));        revalidate();        repaint();    }    /** Display the image at its full resolution */    public void zoomFull() {        zf = 1;        setPreferredSize(new Dimension((int)(rect.width/zf),				       (int)(rect.height/zf)));        revalidate();        repaint();    }    /** Returns the zoom factor used to display the image */    public double getZoomFactor() {        return zf;    }    /** Paint the image and the specified shapes in the panel */    public void paintComponent(Graphics g) {	currentView = g.getClipBounds();        g.drawImage(image,(int)(rect.x/zf),(int)(rect.y/zf),		    (int)(rect.width/zf),(int)(rect.height/zf),desktop);        if(drawing) {            g.setColor(Color.white);	    switch(shapeType) {	    case RECT_ROI:                g.drawRect(x,y,w,h);		break;	    case CIRC_ROI:                g.drawOval(x,y,w,h);		break;	    case TILE_PARTITION:		int totWidth = (int)((rect.width+rect.x)/zf);		int totHeight = (int)((rect.height+rect.y)/zf);		// Horizontal lines		for(int i=y; i<totHeight; i+=h) {		    g.drawLine(x,i,totWidth,i);		}		// Vertical lines		for(int j=x; j<totWidth; j+=w) {		    g.drawLine(j,y,j,totHeight);		}		break;	    }        }    }}