CD Actual Thematic 7: Programming/CDAT7.iso/Share/Java/JDesignerPro/Jdp3_0.exe/data1.cab/Program_Files/Applications/Layouts/JDPComponentTemplate.java

Java Source | 1999-04-09 | 4.3 KB | 190 lines

import java.awt.*;
import java.applet.*;
import java.util.*;


/**
 * Class to represent a graphical component.
 */
public class JDPComponentTemplate extends Panel {

    Image offscreen;
    Rectangle offscreensize;
    Graphics gr;
    Rectangle Bounds;
    Font prevFont;
    Color prevForeground;
    Color prevBackground;
    int minimumWidth = 140;
    int minimumHeight = 140;
    /*
     * Used when an event needs to be sent from this component
     */
    Event thisEvent = null;
    /*
     * Used to signify that the last image should simply be redrawn
     */
     boolean nothingChanged = false;
    /*
     * Display a 3D border
     */
    boolean threeDBorder = true;

    /**
     * Creates a new graphical component
     */
    public JDPComponentTemplate () {


    }

    /**
     * Redraw the component.
     */
    public void reDraw() {

        nothingChanged = false;
        repaint();

    }

    public void layout() {

        repaint();
    }

    public void paint(Graphics g) {

        update(g);
    }

    public void update(Graphics g) {

        Dimension newSize = size();
        if ((Bounds == null) || (newSize.width != Bounds.width) ||
            (newSize.height != Bounds.height) || (!getFont().equals(prevFont)) ||
            (!prevForeground.equals(getForeground())) ||
            (!prevBackground.equals(getBackground()))) {
            nothingChanged = false;
        }
        if ((nothingChanged) && (offscreen != null) && (thisEvent == null)) {
            g.drawImage(offscreen, 0, 0, null);
            return;
        }
        nothingChanged = true;
        prevFont = getFont();
        prevForeground = getForeground();
        prevBackground = getBackground();

        Rectangle d = bounds();
        if ((offscreen == null) || (d.width != offscreensize.width) || (d.height != offscreensize.height)) {
            offscreen = createImage(d.width, d.height);
            offscreensize = d;
            gr = offscreen.getGraphics();
            gr.setFont(getFont());
        }

        Bounds = this.bounds();
        gr.setColor(getBackground());
        gr.fillRect(2,2,Bounds.width,Bounds.height);

        drawComponent(gr);

        if (threeDBorder) {
            gr.setColor(Color.gray);
            gr.drawLine(0,0,Bounds.width,0);
            gr.drawLine(0,0,0,Bounds.height);
            gr.setColor(Color.black);
            gr.drawLine(1,1,Bounds.width-1,1);
            gr.drawLine(1,1,1,Bounds.height-1);
            gr.setColor(Color.lightGray);
            gr.drawLine(Bounds.width-2,2,Bounds.width-2,Bounds.height-2);
            gr.drawLine(2,Bounds.height-2,Bounds.width-2,Bounds.height-2);
            gr.setColor(Color.white);
            gr.drawLine(Bounds.width-1,1,Bounds.width-1,Bounds.height-1);
            gr.drawLine(1,Bounds.height-1,Bounds.width-1,Bounds.height-1);
        } else {
            gr.setColor(Color.white);
            gr.drawRect(1,1,Bounds.width-2,Bounds.height-2);
            gr.setColor(Color.black);
            gr.drawRect(0,0,Bounds.width-1,Bounds.height-1);
        }

        g.drawImage(offscreen, 0, 0, Bounds.width, Bounds.height, null);

        if (thisEvent != null) {
            Event newEvent = thisEvent;
            thisEvent = null;
            super.postEvent(newEvent);
        }

    }

    /**
     * Draw the component
     * @param gr the graphics instance to draw to
     */
    public void drawComponent(Graphics gr) {

        gr.setColor(Color.blue);
        gr.drawString("Here is some text",20,20);

    }

    public boolean handleEvent(Event evt) {

        if (!this.isEnabled()) return true;

        switch (evt.id) {
        case Event.MOUSE_DOWN:
            Date now = new Date();
            thisEvent = new Event(this,now.getTime(),Event.ACTION_EVENT,evt.x,evt.y,evt.key,evt.modifiers,null);
            reDraw();
            return true;

        }
        return false;
    }

        /**
     * Set the minimum width of the grid
     * @param the width in pixels.
     */
    public void setMinimumWidth(int width) {
        minimumWidth = width;
    }
    /**
     * Get the minimum width of the grid
     * @return the width in pixels.
     */
    public int getMinimumWidth() {
        return minimumWidth;
    }
    /**
     * Set the minimum height of the grid
     * @param the height in pixels.
     */
    public void setMinimumHeight(int height) {
        minimumHeight = height;
    }
    /**
     * Get the minimum height of the grid
     * @return the height in pixels.
     */
    public int getMinimumHeight() {
        return minimumHeight;
    }

    public Dimension preferredSize() {

        Dimension d = new Dimension(minimumWidth,minimumHeight);
        return d;
    }
    public Dimension minimumSize() {

        Dimension d = new Dimension(minimumWidth,minimumHeight);
        return d;
    }

}