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

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

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/*******************************************************************************
 * Copyright (c) 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.layout.GridLayout;
import org.eclipse.swt.layout.RowLayout;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Label;
import org.eclipse.swt.widgets.Listener;
import org.eclipse.swt.widgets.Spinner;
import org.eclipse.swt.widgets.ToolBar;
import org.eclipse.swt.widgets.ToolItem;

/**
 * This class extends the GraphicsTab class to create animated graphics.
 * */
public abstract class AnimatedGraphicsTab extends GraphicsTab {

    ToolBar toolBar;
    ToolItem playItem, pauseItem;
    Spinner timerSpinner; // to input the speed of the animation
    private boolean animate; // flag that indicates whether or not to animate the graphic

    public AnimatedGraphicsTab(GraphicsExample example) {
        super(example);
        animate = true;
    }

    /**
     * Sets the layout of the composite to RowLayout and creates the toolbar.
     *
     * @see org.eclipse.swt.examples.graphics.GraphicsTab#createControlPanel(org.eclipse.swt.widgets.Composite)
     */
    @Override
    public void createControlPanel(Composite parent) {

        // setup layout
        RowLayout layout = new RowLayout();
        layout.wrap = true;
        layout.spacing = 8;
        parent.setLayout(layout);

        createToolBar(parent);
    }

    /**
     * Creates the toolbar controls: play, pause and animation timer.
     *
     * @param parent A composite
     */
    void createToolBar(final Composite parent) {
        final Display display = parent.getDisplay();

        toolBar = new ToolBar(parent, SWT.FLAT);
        Listener toolBarListener = event -> {
            switch (event.type) {
            case SWT.Selection: {
                if (event.widget == playItem) {
                    animate = true;
                    playItem.setEnabled(!animate);
                    pauseItem.setEnabled(animate);
                } else if (event.widget == pauseItem) {
                    animate = false;
                    playItem.setEnabled(!animate);
                    pauseItem.setEnabled(animate);
                }
            }
                break;
            }
        };

        // play tool item
        playItem = new ToolItem(toolBar, SWT.PUSH);
        playItem.setText(GraphicsExample.getResourceString("Play")); //$NON-NLS-1$
        playItem.setImage(example.loadImage(display, "play.gif")); //$NON-NLS-1$
        playItem.addListener(SWT.Selection, toolBarListener);

        // pause tool item
        pauseItem = new ToolItem(toolBar, SWT.PUSH);
        pauseItem.setText(GraphicsExample.getResourceString("Pause")); //$NON-NLS-1$
        pauseItem.setImage(example.loadImage(display, "pause.gif")); //$NON-NLS-1$
        pauseItem.addListener(SWT.Selection, toolBarListener);

        // timer spinner
        Composite comp = new Composite(parent, SWT.NONE);
        GridLayout gridLayout = new GridLayout(2, false);
        comp.setLayout(gridLayout);

        Label label = new Label(comp, SWT.CENTER);
        label.setText(GraphicsExample.getResourceString("Animation")); //$NON-NLS-1$
        timerSpinner = new Spinner(comp, SWT.BORDER | SWT.WRAP);
        timerSpinner.setMaximum(1000);

        playItem.setEnabled(false);
        animate = true;

        timerSpinner.setSelection(getInitialAnimationTime());
    }

    /**
     *  Answer whether the receiver's drawing should be double bufferer.
     */
    @Override
    public boolean getDoubleBuffered() {
        return true;
    }

    /**
     * Gets the initial animation time to be used by the tab. Animation time:
     * number of milliseconds between the current drawing and the next (the time
     * interval between calls to the next method). Should be overridden to
     * return a value that is more appropriate for the tab.
     */
    public int getInitialAnimationTime() {
        return 30;
    }

    /**
     * Gets the animation time that is selected in the spinner. Animation time:
     * number of milliseconds between the current drawing and the next (the time
     * interval between calls to the next method). Should be overridden to
     * return a value that is more appropriate for the tab.
     */
    public int getAnimationTime() {
        return timerSpinner.getSelection();
    }

    /**
     * Returns the true if the tab is currently animated; false otherwise.
     */
    public boolean getAnimation() {
        return animate;
    }

    /**
     * Causes the animation to stop or start.
     *
     * @param flag
     *            true starts the animation; false stops the animation.
     */
    public void setAnimation(boolean flag) {
        animate = flag;
        playItem.setEnabled(!flag);
        pauseItem.setEnabled(flag);
    }

    /**
     * Advance the animation.
     */
    public abstract void next(int width, int height);

}