Java tutorial
/******************************************************************************* * 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.Image; import org.eclipse.swt.graphics.Point; import org.eclipse.swt.graphics.Rectangle; import org.eclipse.swt.graphics.Transform; import org.eclipse.swt.layout.GridLayout; import org.eclipse.swt.widgets.Combo; import org.eclipse.swt.widgets.Composite; import org.eclipse.swt.widgets.Label; /** * This tab shows the effects of applying various interpolation algorithms to * images that have been stretched or shrunk. */ public class InterpolationTab extends GraphicsTab { Combo imageCb; // combo for selecting images public InterpolationTab(GraphicsExample example) { super(example); } @Override public String getCategory() { return GraphicsExample.getResourceString("Image"); //$NON-NLS-1$ } @Override public String getText() { return GraphicsExample.getResourceString("Interpolation"); //$NON-NLS-1$ } @Override public String getDescription() { return GraphicsExample.getResourceString("ImageInterpolationDesc"); //$NON-NLS-1$ } @Override public void createControlPanel(Composite parent) { Composite comp; GridLayout gridLayout = new GridLayout(2, false); // create drop down combo comp = new Composite(parent, SWT.NONE); comp.setLayout(gridLayout); new Label(comp, SWT.CENTER).setText(GraphicsExample.getResourceString("Image")); //$NON-NLS-1$ imageCb = new Combo(comp, SWT.DROP_DOWN); imageCb.add(GraphicsExample.getResourceString("House")); //$NON-NLS-1$ imageCb.add(GraphicsExample.getResourceString("Question")); //$NON-NLS-1$ imageCb.add(GraphicsExample.getResourceString("Task")); //$NON-NLS-1$ imageCb.add(GraphicsExample.getResourceString("Font")); //$NON-NLS-1$ imageCb.add(GraphicsExample.getResourceString("Cube")); //$NON-NLS-1$ imageCb.add(GraphicsExample.getResourceString("SWT")); //$NON-NLS-1$ imageCb.add(GraphicsExample.getResourceString("Ovals")); //$NON-NLS-1$ imageCb.select(0); imageCb.addListener(SWT.Selection, event -> example.redraw()); } @Override public void paint(GC gc, int width, int height) { if (!example.checkAdvancedGraphics()) return; Device device = gc.getDevice(); float scaleX = 10f; float scaleY = 10f; Image image = null; switch (imageCb.getSelectionIndex()) { case 0: image = GraphicsExample.loadImage(device, GraphicsExample.class, "home_nav.gif"); break; case 1: image = GraphicsExample.loadImage(device, GraphicsExample.class, "help.gif"); break; case 2: image = GraphicsExample.loadImage(device, GraphicsExample.class, "task.gif"); break; case 3: image = GraphicsExample.loadImage(device, GraphicsExample.class, "font.gif"); break; case 4: image = GraphicsExample.loadImage(device, GraphicsExample.class, "cube.png"); scaleX = 0.75f; scaleY = 0.5f; break; case 5: image = GraphicsExample.loadImage(device, GraphicsExample.class, "swt.png"); scaleX = 0.4f; scaleY = 0.8f; break; case 6: image = GraphicsExample.loadImage(device, GraphicsExample.class, "ovals.png"); scaleX = 1.1f; scaleY = 0.5f; break; } Rectangle bounds = image.getBounds(); // draw the original image gc.drawImage(image, (width - bounds.width) / 2, 20); Font font = new Font(device, getPlatformFont(), 20, SWT.NORMAL); gc.setFont(font); // write some text below the original image String text = GraphicsExample.getResourceString("OriginalImg"); //$NON-NLS-1$ Point size = gc.stringExtent(text); gc.drawString(text, (width - size.x) / 2, 25 + bounds.height, true); Transform transform = new Transform(device); transform.translate((width - (bounds.width * scaleX + 10) * 4) / 2, 25 + bounds.height + size.y + (height - (25 + bounds.height + size.y + bounds.height * scaleY)) / 2); transform.scale(scaleX, scaleY); // --- draw strings --- float[] point = new float[2]; text = GraphicsExample.getResourceString("None"); //$NON-NLS-1$ size = gc.stringExtent(text); point[0] = (scaleX * bounds.width + 5 - size.x) / (2 * scaleX); point[1] = bounds.height; transform.transform(point); gc.drawString(text, (int) point[0], (int) point[1], true); text = GraphicsExample.getResourceString("Low"); //$NON-NLS-1$ size = gc.stringExtent(text); point[0] = (scaleX * bounds.width + 5 - size.x) / (2 * scaleX) + bounds.width; point[1] = bounds.height; transform.transform(point); gc.drawString(text, (int) point[0], (int) point[1], true); text = GraphicsExample.getResourceString("Default"); //$NON-NLS-1$ size = gc.stringExtent(text); point[0] = (scaleX * bounds.width + 5 - size.x) / (2 * scaleX) + 2 * bounds.width; point[1] = bounds.height; transform.transform(point); gc.drawString(text, (int) point[0], (int) point[1], true); text = GraphicsExample.getResourceString("High"); //$NON-NLS-1$ size = gc.stringExtent(text); point[0] = (scaleX * bounds.width + 5 - size.x) / (2 * scaleX) + 3 * bounds.width; point[1] = bounds.height; transform.transform(point); gc.drawString(text, (int) point[0], (int) point[1], true); gc.setTransform(transform); transform.dispose(); // --- draw images --- // no interpolation gc.setInterpolation(SWT.NONE); gc.drawImage(image, 0, 0); // low interpolation gc.setInterpolation(SWT.LOW); gc.drawImage(image, bounds.width, 0); // default interpolation gc.setInterpolation(SWT.DEFAULT); gc.drawImage(image, 2 * bounds.width, 0); // high interpolation gc.setInterpolation(SWT.HIGH); gc.drawImage(image, 3 * bounds.width, 0); font.dispose(); if (image != null) image.dispose(); } /** * Returns the name of a valid font for the host platform. */ static String getPlatformFont() { if (SWT.getPlatform() == "win32") { return "Arial"; } else if (SWT.getPlatform() == "gtk") { return "Baekmuk Batang"; } else { return "Verdana"; } } }