/*
 * ImageSelector.java
 */

import java.awt.*;

/* Image Selector Object */
public class ImageSelector extends ImageCanvas {
    int type;           /* VERTICAL/HORIZONTAL Type */
    int pos;            /* Current Position */
    int value;          /* Current Value */
    int minimum;        /* Minimum Value */
    int maximum;        /* Maximum Value */
    Color color = gray; /* Line Color */
    boolean visible = false; /* Is Line Visible */

    /** Constructor */
    public ImageSelector(int _type, int _value,
        int _minimum, int _maximum) {
        type = _type;
        minimum = _minimum;
        maximum = _maximum;
        setValue(_value, false);
    }

    /** Set Line Color */
    public void setColor(Color _color) {
        if ( _color == color ) return;
        color = _color;
        drawPos();
    }

    /** Drawing Action Here */
    public void update(Graphics g) {
        super.update(g);
        drawPos(g);
    }

    /** Get Current Window Length */
    private int getSelectHeight() {
        return ((type == Scrollbar.VERTICAL) ?
          size().height : size().width)-d2-1;
    }

    /** Draw Current Line */
    private synchronized void drawPos() {
        if ( !visible ) return;
        Graphics g = getGraphics();
        if ( g == null ) return;
        drawPos(g);
        g.dispose();
    }

    /** Draw Current Line */
    private void drawPos(Graphics g) {
        if ( (g == null) || !visible ) return;
        g.setColor(color);
        if ( type == Scrollbar.VERTICAL )
          g.drawLine(depth, pos, size().width-depth-1, pos);
        else g.drawLine(pos, depth, pos, size().height-depth-1);
    }

    /** Translate Value to Window Position */
    private int Value2Pos(int _value) {
        return (_value-minimum)*
          getSelectHeight()/(maximum-minimum)+depth;
    }

    /** Translate Window Position to Value */
    private int Pos2Value(int _pos) {
        int h = getSelectHeight();
        if ( (_pos-=depth) < 0 ) _pos = 0;
        if ( _pos > h ) _pos = h;
        return _pos*(maximum-minimum)/h+minimum;
    }

    /** Get Current Value */
    public int getValue() { return value;}

    /** Set Current Value */
    public synchronized boolean setValue(int _value, boolean repaint) {
        int oldval = value;
        int oldpos = pos;
        if ( _value < minimum ) _value = minimum;
        if ( _value >= maximum ) _value = maximum-1;
        pos = Value2Pos(value = _value);
        if ( (pos != oldpos) && repaint ) repaint();
        return (value != oldval);
    }

    /** Reflect Current Mouse Position */
    private boolean setMouse(int x, int y) {
        return setValue(Pos2Value(
          (type == Scrollbar.VERTICAL) ? y : x), true);
    }

    /** Update Current Image */
    public void updateImage(Image _img) {
        visible = false;
        super.updateImage(_img);
    }

    /** Image is Prepare Complete */
    public void imageComplete() {
        needTrack = false;
        setValue(value, false);
        visible = true;
        repaint();
    }

    /** Mouse Down Event */
    public boolean mouseDown(Event ev, int x, int y) {
        int npos = (type == Scrollbar.VERTICAL) ? y : x;
        if ( (pos-4 < npos) && (npos < pos+4) ) {
          setValue(Pos2Value(npos), true);
          Notify(ev, this);
          mousePressed = true;
        } else {
          ev.id = Event.KEY_PRESS;
          Notify(ev, this);
        }
        return true;
    }

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

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