/*
 * ImageCanvas.java
 */

import java.awt.*;

/* Image Canvas Object */
public class ImageCanvas extends Canvas3D {
    static int timeout = 1000;   /* Image Tracking Interval */
    Image img;                   /* Current Image */
    double scale = 1.0;          /* Current Image Scale */
    int offsetX, offsetY;        /* Image Offset Pair */
    int mouseX, mouseY;          /* Last Mouse Down Position */
    int imageWidth, imageHeight; /* Image Width and Height */
    int pszx = 12;               /* Preferred Size X */
    int pszy = 12;               /* Preferred Size Y */
    int xScale = 1;              /* Extra X Scale */
    int yScale = 1;              /* Extra Y Scale */
    boolean mousePressed = false;/* If Mouse Pressed */
    boolean needTrack = false;   /* If Need Image Tracking */

    /** Constructor */
    public ImageCanvas() { setBackground(black);}

    /* Setting Parameters */
    public Image getImage() { return img;}
    public double getScale() { return scale;}
    public int getOffsetX() { return offsetX;}
    public int getOffsetY() { return offsetY;}
    public int getImageWidth() { return imageWidth;}
    public int getImageHeight() { return imageHeight;}
    public int getScaledWidth() { return (int)(scale*xScale*imageWidth+0.5);}
    public int getScaledHeight() { return (int)(scale*yScale*imageHeight+0.5);}
    public void setScale(int _xScale, int _yScale) {
        xScale = _xScale;
        yScale = _yScale;
    }

    /* Preferred Size Setting */
    public void setPreferredSize(int _x, int _y)
    {   pszx = _x; pszy = _y;}
    public Dimension preferredSize()
    {   return new Dimension(pszx, pszy);}

    /** Drawing Action Here */
    public void update(Graphics g) {
        int w = size().width-d2;
        int h = size().height-d2;
        super.update(g);
        g.setColor(getBackground());
        if ( img != null ) {
          imageWidth = img.getWidth(this); 
          imageHeight = img.getHeight(this);
          int bx = depth-offsetX;
          int by = depth-offsetY;
          int iw = getScaledWidth();
          int ih = getScaledHeight();
          g.drawImage(img, bx, by, iw, ih, this);
          if ( offsetX < 0 )
            g.fillRect(depth, depth, -offsetX, h);
          if ( offsetY < 0 )
            g.fillRect(depth, depth, w, -offsetY);
          if ( iw-offsetX < w )
            g.fillRect(iw+bx, depth, w-iw+offsetX, ih);
          if ( ih-offsetY < h )
            g.fillRect(depth, ih+by, w, h-ih+offsetY);
        } else g.fillRect(depth, depth, w, h);
    }

    /** Change Image Scale */
    public void setScale(double _scale, boolean frepaint) {
        if ( scale == _scale ) return;
        scale = _scale;
        if ( img != null ) {
          Notify(null, img);
          if ( frepaint ) repaint();
        }
    }

    /* Change Image Offset */
    public synchronized void setOffset(int x, int y, boolean frepaint) {
        if ((x == offsetX) && (y == offsetY)) return;
        offsetX = x;
        offsetY = y;
        if ( frepaint ) repaint();
    }

    /** Image Update Tracking */
    public boolean imageUpdate(Image img, int infoFlags,
        int x, int y, int width, int height) {
	boolean ret = true;
        if ( img != this.img ) return false;
        if ((infoFlags & WIDTH) != 0) imageWidth = width;
        if ((infoFlags & HEIGHT) != 0) imageHeight = height;
        if (((infoFlags & WIDTH) != 0) &&
            ((infoFlags & HEIGHT) != 0))
            Notify(null, img);
        if ((infoFlags & (FRAMEBITS | ALLBITS)) != 0) {
	    ret = false;
            imageComplete();
        } else if ((infoFlags & SOMEBITS) != 0) {
            if ( !needTrack && (img == this.img) ) {
              needTrack = true;
              new Delay(timeout, -1, this);
            }
        }
        if ((infoFlags & ERROR) != 0) ret = false;
	return ret;
    }

    /** Change Current Image */
    public void updateImage(Image _img) {
        img = _img;
        if ( (img != null) && !prepareImage(img, this) ) {
          if ( !needTrack ) {
            needTrack = true;
            repaint();
            new Delay(timeout, -1, this);
          }
        } else imageComplete();
    }

    /** Called when Image is Prepared Complete */
    public void imageComplete() {
        needTrack = false;
        repaint();
        Notify(null, img);
    }

    /** Respong to Delay Event Action */
    public boolean keyDown(Event ev, int key) {
        if ( key < 0 ) {
          if ( needTrack ) {
            if ( !prepareImage(img, this) ) {
              repaint();
              new Delay(timeout, key, this);
            } else imageComplete();
          }
        }
        return true;
    }

    /** X Delta relative to Last Mouse Down Position */
    public int mouseDeltaX(int x)
    {   return mouseX-x;}

    /** Y Delta relative to Last Mouse Down Position */
    public int mouseDeltaY(int y)
    {   return mouseY-y;}

    /** Mouse Down Event */
    public boolean mouseDown(Event ev, int x, int y) {
        mousePressed = true;
        mouseX = x+offsetX;
        mouseY = y+offsetY;
        Notify(ev, this);
        return true;
    }

    /** Delay Mouse Drag Event */
    public boolean delayDrag(Event ev, int x, int y) {
        if ( mousePressed )
          Notify(ev, this);
        return true;
    }

    /** Mouse Up Event */
    public boolean mouseUp(Event ev, int x, int y) {
        mousePressed = false;
        return true;
    }
}