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

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Here is the source code for org.eclipse.swt.examples.graphics.GraphicAntialiasTab.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.GC;
import org.eclipse.swt.graphics.Path;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.graphics.Rectangle;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Combo;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Label;
import org.eclipse.swt.widgets.Menu;

/**
 * This tab demonstrates antialiasing for graphics. Antialiasing is used for
 * smoothing jagged edges in graphics. This tab allows the user to see the
 * effects of different antialiasing values.
 */
public class GraphicAntialiasTab extends GraphicsTab {

    Combo aliasCombo;
    int[] aliasValues = { SWT.OFF, SWT.DEFAULT, SWT.ON };

    Button colorButton;
    Menu menu;
    GraphicsBackground ovalColorGB;

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

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

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

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

    @Override
    public void dispose() {
        if (menu != null) {
            menu.dispose();
            menu = null;
        }
    }

    @Override
    public void createControlPanel(Composite parent) {

        Composite comp;

        // create drop down combo for antialiasing
        comp = new Composite(parent, SWT.NONE);
        comp.setLayout(new GridLayout(2, false));
        new Label(comp, SWT.CENTER).setText(GraphicsExample.getResourceString("Antialiasing")); //$NON-NLS-1$
        aliasCombo = new Combo(comp, SWT.DROP_DOWN);
        aliasCombo.add("OFF");
        aliasCombo.add("DEFAULT");
        aliasCombo.add("ON");
        aliasCombo.select(0);
        aliasCombo.addListener(SWT.Selection, event -> example.redraw());

        ColorMenu cm = new ColorMenu();
        cm.setColorItems(true);
        menu = cm.createMenu(parent.getParent(), gb -> {
            ovalColorGB = gb;
            colorButton.setImage(gb.getThumbNail());
            example.redraw();
        });

        // create color button
        comp = new Composite(parent, SWT.NONE);
        comp.setLayout(new GridLayout());

        // initialize the background to the 5th item in the menu (blue)
        ovalColorGB = (GraphicsBackground) menu.getItem(4).getData();

        // color button
        colorButton = new Button(comp, SWT.PUSH);
        colorButton.setText(GraphicsExample.getResourceString("Color")); //$NON-NLS-1$
        colorButton.setImage(ovalColorGB.getThumbNail());
        colorButton.addListener(SWT.Selection, event -> {
            final Button button = (Button) event.widget;
            final Composite parent1 = button.getParent();
            Rectangle bounds = button.getBounds();
            Point point = parent1.toDisplay(new Point(bounds.x, bounds.y));
            menu.setLocation(point.x, point.y + bounds.height);
            menu.setVisible(true);
        });
    }

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

        if (ovalColorGB != null && ovalColorGB.getBgColor1() != null)
            gc.setBackground(ovalColorGB.getBgColor1());

        gc.setAntialias(aliasValues[aliasCombo.getSelectionIndex()]);

        Path path = new Path(device);
        float offsetX = 2 * width / 3f, offsetY = height / 3f;
        for (int i = 0; i < 25; i++) {
            path.addArc(offsetX - (50 * i), offsetY - (25 * i), 50 + (100 * i), 25 + (50 * i), 0, 360);
        }
        gc.fillPath(path);
        path.dispose();
    }
}