com.google.gapid.widgets.GlComposite.java Source code

Introduction

Here is the source code for com.google.gapid.widgets.GlComposite.java

Source

/*
 * Copyright (C) 2017 Google Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.google.gapid.widgets;

import com.google.gapid.glcanvas.GlCanvas;

import org.eclipse.swt.SWT;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.internal.DPIUtil;
import org.eclipse.swt.layout.FillLayout;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Event;
import org.lwjgl.opengl.GL;
import org.lwjgl.opengl.GLCapabilities;

/**
 * {@link Composite} containing a {@link GlCanvas} to use OpenGL to render the contents.
 */
public class GlComposite extends Composite {
    private final GlCanvas canvas;
    private final GLCapabilities caps;

    public GlComposite(Composite parent) {
        super(parent, SWT.NO_BACKGROUND);
        setLayout(new FillLayout(SWT.VERTICAL));
        canvas = new GlCanvas(this, SWT.NO_BACKGROUND);
        canvas.setCurrent();
        caps = GL.createCapabilities();
    }

    public void addListener(Listener listener) {
        canvas.addListener(SWT.Resize, e -> {
            render(() -> {
                Point size = DPIUtil.autoScaleUp(getSize());
                listener.reshape(0, 0, size.x, size.y);
                listener.display();
            }, true);
        });
        canvas.addListener(SWT.Paint, e -> {
            render(listener::display, true);
        });
        addListener(SWT.Dispose, e -> {
            render(listener::dispose, false);
        });

        render(() -> {
            listener.init();
            Point size = DPIUtil.autoScaleUp(getSize());
            listener.reshape(0, 0, size.x, size.y);
            listener.display();
        }, true);
    }

    private void render(Runnable r, boolean swap) {
        canvas.setCurrent();
        GL.setCapabilities(caps);
        r.run();
        if (swap) {
            canvas.swapBuffers();
        }
    }

    public Control getControl() {
        return canvas;
    }

    public void paint() {
        canvas.notifyListeners(SWT.Paint, new Event());
    }

    public static interface Listener {
        public void init();

        public void reshape(int x, int y, int w, int h);

        public void display();

        public void dispose();
    }
}