AwtGraphics.java

/*******************************************************************************
 * Copyright (c) 2004, 2008 John Krasnay and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 * 
 * Contributors:
 *     John Krasnay - initial API and implementation
 *******************************************************************************/
package net.sf.vex.swing;

import java.awt.BasicStroke;
import java.awt.GraphicsEnvironment;
import java.awt.Stroke;
import java.util.HashSet;
import java.util.Set;

import javax.swing.UIManager;

import net.sf.vex.core.Color;
import net.sf.vex.core.ColorResource;
import net.sf.vex.core.FontMetrics;
import net.sf.vex.core.FontResource;
import net.sf.vex.core.FontSpec;
import net.sf.vex.core.Graphics;
import net.sf.vex.core.Rectangle;

/**
 * Implementation of the Vex Graphics interface, mapping it to a 
 * org.eclipse.swt.graphics.GC object.
 */
public class AwtGraphics implements Graphics {

    private java.awt.Graphics2D g;
    private int originX;
    private int originY;
    
    private static Set availableFontFamilies = new HashSet();
        
    static {
        GraphicsEnvironment ge = 
            GraphicsEnvironment.getLocalGraphicsEnvironment();
        String[] names = ge.getAvailableFontFamilyNames();
        for (int i = 0; i < names.length; i++) {
            availableFontFamilies.add(names[i].toLowerCase());
        }
    }

    /**
     * Class constructor.
     * @param gc SWT GC to which we are drawing.
     */
    public AwtGraphics(java.awt.Graphics2D g) {
        this.g = g;
    }
    
    public void dispose() {
    }
    
    public void drawChars(char[] chars, int offset, int length, int x, int y) {
        this.g.drawString(new String(chars, offset, length), x + originX, y + originY + this.g.getFontMetrics().getAscent());
    }

    public void drawLine(int x1, int y1, int x2, int y2) {
        this.g.drawLine(x1 + originX, y1 + originY, x2 + originX, y2 + originY);
    }

    public void drawOval(int x, int y, int width, int height) {
        this.g.drawOval(x + originX, y + originY, width, height);
    }

    public void drawRect(int x, int y, int width, int height) {
        this.g.drawRect(x + originX, y + originY, width, height);
    }

    public void drawString(String s, int x, int y) {
        this.g.drawString(s, x + originX, y + originY + this.g.getFontMetrics().getAscent());
    }

    public void fillOval(int x, int y, int width, int height) {
        this.g.fillOval(x + originX, y + originY, width, height);
    }

    public void fillRect(int x, int y, int width, int height) {
        this.g.fillRect(x + originX, y + originY, width, height);
    }

    public Rectangle getClipBounds() {
        java.awt.Rectangle r = this.g.getClipBounds();
        return new Rectangle(r.x - originX, r.y - originY , r.width, r.height);
    }

    public ColorResource getColor() {
        return new AwtColor(this.g.getColor());
    }

    public FontResource getFont() {
        return new AwtFont(this.g.getFont());
    }

    public FontMetrics getFontMetrics() {
        return new AwtFontMetrics(this.g.getFontMetrics());
    }

    public int getLineStyle() {
        return this.lineStyle;
    }
    
    public int getLineWidth() {
        return this.lineWidth;
    }
    
    public boolean isAntiAliased() {
        return false;
    }

    public void setAntiAliased(boolean antiAliased) {
    }

    public ColorResource setColor(ColorResource color) {
        ColorResource oldColor = this.getColor();
        this.g.setColor(((AwtColor) color).getAwtColor());
        return oldColor;
    }

    public FontResource setFont(FontResource font) {
        FontResource oldFont = this.getFont();
        this.g.setFont(((AwtFont) font).getAwtFont());
        return oldFont;
    }

    public void setLineStyle(int lineStyle) {
        this.lineStyle = lineStyle;
        this.makeStroke();
    }
    
    public void setLineWidth(int lineWidth) {
        this.lineWidth = lineWidth;
        this.makeStroke();
    }
    
    public int charsWidth(char[] data, int offset, int length) {
        return this.stringWidth(new String(data, offset, length));
    }

    public void setOrigin(int x, int y) {
        this.originX = x;
        this.originY = y;
    }
    
    public ColorResource createColor(Color rgb) {
        return new AwtColor( 
            new java.awt.Color(
                rgb.getRed(), rgb.getGreen(), rgb.getBlue())); 
    }

    public FontResource createFont(FontSpec fontSpec) {
        int style = java.awt.Font.PLAIN;
        if ((fontSpec.getStyle() & FontSpec.BOLD) > 0) {
            style |= java.awt.Font.BOLD;
        }
        if ((fontSpec.getStyle() & FontSpec.ITALIC) > 0) {
            style |= java.awt.Font.ITALIC;
        }
        int size = Math.round(fontSpec.getSize());

        String name = "sans-serif";
        String[] names = fontSpec.getNames();
        for (int i = 0; i < names.length; i++) {
            if (availableFontFamilies.contains(names[i])) {
                name = names[i];
                break;        
            }
        }
        return new AwtFont(new java.awt.Font(name, style, size));
    }

    public ColorResource getSystemColor(int id) {
        
        if (id == ColorResource.SELECTION_BACKGROUND) {
            return new AwtColor(UIManager.getColor("TextPane.selectionBackground"));
        } else if (id == ColorResource.SELECTION_FOREGROUND) {
            return new AwtColor(UIManager.getColor("TextPane.selectionForeground"));
        } else {
            return new AwtColor(java.awt.Color.BLACK);
        }
    }

    public int stringWidth(String s) {
        return this.g.getFontMetrics().stringWidth(s);
    }
    
    //============================================================= PRIVATE
    
    private int lineWidth = 1;
    private int lineStyle;

    private void makeStroke() {
        
        float dashLength = this.lineWidth;
        if (this.lineStyle == LINE_DASH) {
            dashLength = 3 * this.lineWidth;
        }
        
        Stroke stroke = new BasicStroke(
            (float) this.lineWidth,
            BasicStroke.CAP_SQUARE, // to be compatible with SWT GC
            BasicStroke.JOIN_MITER,
            1.0f,
            new float[] { dashLength, dashLength },
            0.0f);
        
        this.g.setStroke(stroke);
    }

}