org.eclipse.swt.examples.graphics.FontBounceTab.java Source code

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Here is the source code for org.eclipse.swt.examples.graphics.FontBounceTab.java

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/*******************************************************************************
 * Copyright (c) 2006, 2016 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/

package org.eclipse.swt.examples.graphics;

import org.eclipse.swt.SWT;
import org.eclipse.swt.graphics.Device;
import org.eclipse.swt.graphics.Font;
import org.eclipse.swt.graphics.GC;
import org.eclipse.swt.graphics.Path;
import org.eclipse.swt.graphics.Point;

/**
 * This tab is an animated graphic. It presents the word SWT in different fonts
 * as it bounces around the screen.
 */
public class FontBounceTab extends AnimatedGraphicsTab {

    float x, y;
    float incX = 10.0f; // units by which to move the word along X axis
    float incY = 5.0f; // units by which to move the word along Y axis
    int textWidth, textHeight; // width and height of the word SWT
    String text = GraphicsExample.getResourceString("SWT");
    int fontSize = 100;
    int fontFace = 0;
    int foreGrdColor, fillColor; // font colors
    int fontStyle; // represents various style attributes applicable to a Font

    public FontBounceTab(GraphicsExample example) {
        super(example);
    }

    @Override
    public String getCategory() {
        return GraphicsExample.getResourceString("Font"); //$NON-NLS-1$
    }

    @Override
    public String getText() {
        return GraphicsExample.getResourceString("Bounce"); //$NON-NLS-1$
    }

    @Override
    public String getDescription() {
        return GraphicsExample.getResourceString("FontBounceDescription"); //$NON-NLS-1$
    }

    @Override
    public void next(int width, int height) {
        x += incX;
        y += incY;
        float random = (float) Math.random();

        // collision with right side of screen
        if (x + textWidth > width) {
            x = width - textWidth;
            incX = random * -width / 16 - 1;
            fontFace = 0;
            fontSize = 125;
            fillColor = SWT.COLOR_DARK_BLUE;
            foreGrdColor = SWT.COLOR_YELLOW;
            fontStyle = SWT.ITALIC;
        }
        // collision with left side of screen
        if (x < 0) {
            x = 0;
            incX = random * width / 16 + 1;
            fontFace = 1;
            fontSize = 80;
            fillColor = SWT.COLOR_DARK_MAGENTA;
            foreGrdColor = SWT.COLOR_CYAN;
            fontStyle = SWT.NONE;
        }
        // collision with bottom side of screen
        if (y + textHeight > height) {
            y = (height - textHeight) - 2;
            incY = random * -height / 16 - 1;
            fontFace = 2;
            fontSize = 100;
            fillColor = SWT.COLOR_YELLOW;
            foreGrdColor = SWT.COLOR_BLACK;
            fontStyle = SWT.BOLD;
        }
        // collision with top side of screen
        if (y < 0) {
            y = 0;
            incY = random * height / 16 + 1;
            fontFace = 3;
            fontSize = 120;
            fillColor = SWT.COLOR_GREEN;
            foreGrdColor = SWT.COLOR_GRAY;
            fontStyle = SWT.NONE;
        }
    }

    @Override
    public void paint(GC gc, int width, int height) {
        if (!example.checkAdvancedGraphics())
            return;
        Device device = gc.getDevice();

        Font font = new Font(device, getPlatformFontFace(fontFace), fontSize, fontStyle);
        gc.setFont(font);

        Point size = gc.stringExtent(text);
        textWidth = size.x;
        textHeight = size.y;

        Path path = new Path(device);
        path.addString(text, x, y, font);

        gc.setForeground(device.getSystemColor(foreGrdColor));
        gc.setBackground(device.getSystemColor(fillColor));

        gc.fillPath(path);
        gc.drawPath(path);
        font.dispose();
        path.dispose();
    }

    /**
     * Returns the name of the font using the specified index.
     * This method takes into account the resident platform.
     *
     * @param index
     *          The index of the font to be used
     */
    static String getPlatformFontFace(int index) {
        if (SWT.getPlatform() == "win32") {
            return new String[] { "Arial", "Impact", "Times", "Verdana" }[index];
        } else if (SWT.getPlatform() == "gtk") {
            return new String[] { "URW Chancery L", "Baekmuk Batang", "Baekmuk Headline", "KacsTitleL" }[index];
        } else {
            return new String[] { "Arial", "Impact", "Times", "Verdana" }[index];
        }
    }
}