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.Path; import org.eclipse.swt.graphics.Pattern; 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 how to apply a path clipping and the effects of * applying one. */ public class PathClippingTab extends GraphicsTab { private Combo clippingCb; private Button colorButton; private GraphicsBackground background; private Menu menu; public PathClippingTab(GraphicsExample example) { super(example); } @Override public String getCategory() { return GraphicsExample.getResourceString("Clipping"); //$NON-NLS-1$ } @Override public String getText() { return GraphicsExample.getResourceString("PathClipping"); //$NON-NLS-1$ } @Override public String getDescription() { return GraphicsExample.getResourceString("PathClippingDesc"); //$NON-NLS-1$ } @Override public void dispose() { if (menu != null) { menu.dispose(); menu = null; } } /** * Creates the widgets used to control the drawing. */ @Override public void createControlPanel(Composite parent) { // create drop down combo for choosing clipping Composite comp = new Composite(parent, SWT.NONE); comp.setLayout(new GridLayout(2, false)); new Label(comp, SWT.CENTER).setText(GraphicsExample.getResourceString("Clipping")); //$NON-NLS-1$ clippingCb = new Combo(comp, SWT.DROP_DOWN); clippingCb.add(GraphicsExample.getResourceString("Circles")); //$NON-NLS-1$ clippingCb.add(GraphicsExample.getResourceString("Rectangle")); //$NON-NLS-1$ clippingCb.add(GraphicsExample.getResourceString("Oval")); //$NON-NLS-1$ clippingCb.add(GraphicsExample.getResourceString("Word")); //$NON-NLS-1$ clippingCb.add(GraphicsExample.getResourceString("Star")); //$NON-NLS-1$ clippingCb.add(GraphicsExample.getResourceString("Triangles")); //$NON-NLS-1$ clippingCb.add(GraphicsExample.getResourceString("Default")); //$NON-NLS-1$ clippingCb.select(0); clippingCb.addListener(SWT.Selection, event -> example.redraw()); // color menu ColorMenu cm = new ColorMenu(); cm.setPatternItems(example.checkAdvancedGraphics()); menu = cm.createMenu(parent.getParent(), gb -> { background = gb; colorButton.setImage(gb.getThumbNail()); example.redraw(); }); // initialize the background to the 5th item in the menu (blue) background = (GraphicsBackground) menu.getItem(4).getData(); // color button comp = new Composite(parent, SWT.NONE); comp.setLayout(new GridLayout(2, false)); colorButton = new Button(comp, SWT.PUSH); colorButton.setText(GraphicsExample.getResourceString("Color")); //$NON-NLS-1$ colorButton.setImage(background.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(); int clipping = clippingCb.getSelectionIndex(); switch (clipping) { case 0: // circles Path path = new Path(device); path.addArc((width - width / 5) / 2, (height - height / 5) / 2, width / 5, height / 5, 0, 360); path.addArc(5 * (width - width / 8) / 12, 4 * (height - height / 8) / 12, width / 8, height / 8, 0, 360); path.addArc(7 * (width - width / 8) / 12, 8 * (height - height / 8) / 12, width / 8, height / 8, 0, 360); path.addArc(6 * (width - width / 12) / 12, 3 * (height - height / 12) / 12, width / 12, height / 12, 0, 360); path.addArc(6 * (width - width / 12) / 12, 9 * (height - height / 12) / 12, width / 12, height / 12, 0, 360); path.addArc(11.5f * (width - width / 18) / 20, 5 * (height - height / 18) / 18, width / 18, height / 18, 0, 360); path.addArc(8.5f * (width - width / 18) / 20, 13 * (height - height / 18) / 18, width / 18, height / 18, 0, 360); gc.setClipping(path); path.dispose(); break; case 1: // rectangle path = new Path(device); path.addRectangle(100, 100, width - 200, height - 200); path.addRectangle(120, 120, width - 240, height - 240); path.addRectangle(140, 140, width - 280, height - 280); gc.setClipping(path); path.dispose(); break; case 2: // circle path = new Path(device); path.addArc(100, 100, width - 200, height - 200, 0, 360); path.addArc((width - width / 5) / 2, (height - height / 5) / 2, width / 5, height / 5, 0, 360); path.addArc(5 * (width - width / 8) / 12, 4 * (height - height / 8) / 12, width / 8, height / 8, 0, 360); path.addArc(7 * (width - width / 8) / 12, 8 * (height - height / 8) / 12, width / 8, height / 8, 0, 360); path.addArc(6 * (width - width / 12) / 12, 3 * (height - height / 12) / 12, width / 12, height / 12, 0, 360); path.addArc(6 * (width - width / 12) / 12, 9 * (height - height / 12) / 12, width / 12, height / 12, 0, 360); path.addArc(11.5f * (width - width / 18) / 20, 5 * (height - height / 18) / 18, width / 18, height / 18, 0, 360); path.addArc(8.5f * (width - width / 18) / 20, 13 * (height - height / 18) / 18, width / 18, height / 18, 0, 360); gc.setClipping(path); path.dispose(); break; case 3: // word path = new Path(device); String text = GraphicsExample.getResourceString("SWT"); //$NON-NLS-1$ Font font = new Font(device, "Times", 200, SWT.NORMAL); gc.setFont(font); Point size = gc.stringExtent(text); path.addString(text, (width - size.x) / 2, (height - size.y) / 2, font); font.dispose(); gc.setClipping(path); path.dispose(); break; case 4: // star path = new Path(device); path.lineTo(width / 2, 0); path.lineTo(5 * width / 8, height / 3); path.lineTo(width, height / 3); path.lineTo(3 * width / 4, 10 * height / 16); path.lineTo(7 * width / 8, height); path.lineTo(width / 2, 3 * height / 4); path.lineTo(width / 8, height); path.lineTo(width / 4, 10 * height / 16); path.lineTo(0, height / 3); path.lineTo(3 * width / 8, height / 3); path.lineTo(width / 2, 0); Path ovalPath = new Path(device); ovalPath.addArc(90, 90, width - 180, height - 180, 0, 360); path.addPath(ovalPath); gc.setClipping(path); ovalPath.dispose(); path.dispose(); break; case 5: // triangles path = new Path(device); path.addRectangle(0, 0, width, height); path.lineTo(width / 4, 0); path.lineTo(width / 4, height / 2); path.lineTo(0, height / 2); path.lineTo(width / 4, 0); Path path2 = new Path(device); path2.lineTo(width / 2, 0); path2.lineTo(width / 4, height / 2); path2.lineTo(3 * width / 4, height / 2); path2.lineTo(width / 2, 0); Path path3 = new Path(device); path3.lineTo(3 * width / 4, 0); path3.lineTo(3 * width / 4, height / 2); path3.lineTo(width, height / 2); path3.lineTo(3 * width / 4, 0); Path path4 = new Path(device); path4.lineTo(0, height); path4.lineTo(width / 4, height / 2); path4.lineTo(width / 2, height); path4.lineTo(0, height); Path path5 = new Path(device); path5.lineTo(width / 2, height); path5.lineTo(3 * width / 4, height / 2); path5.lineTo(width, height); path5.lineTo(width / 2, height); path.addPath(path2); path.addPath(path3); path.addPath(path4); path.addPath(path5); gc.setClipping(path); path5.dispose(); path4.dispose(); path3.dispose(); path2.dispose(); path.dispose(); break; case 6: // default gc.setClipping(0, 0, width, height); break; } Pattern pattern = null; if (background.getBgColor1() != null) { gc.setBackground(background.getBgColor1()); } else if (background.getBgImage() != null) { pattern = new Pattern(device, background.getBgImage()); gc.setBackgroundPattern(pattern); } gc.fillRectangle(0, 0, width, height); if (pattern != null) pattern.dispose(); } }