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.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 text. Antialiasing is used for * smoothing jagged edges in graphics. This tab allows the user to see the * effects of different antialiasing values. */ public class TextAntialiasTab extends GraphicsTab { Combo aliasCombo; static int[] aliasValues = { SWT.OFF, SWT.DEFAULT, SWT.ON }; Button colorButton; Menu menu; GraphicsBackground textColor; String text = GraphicsExample.getResourceString("SWT"); public TextAntialiasTab(GraphicsExample example) { super(example); } @Override public String getCategory() { return GraphicsExample.getResourceString("Antialiasing"); //$NON-NLS-1$ } @Override public String getText() { return GraphicsExample.getResourceString("Text"); //$NON-NLS-1$ } @Override public String getDescription() { return GraphicsExample.getResourceString("AntialiasingTextDesc"); //$NON-NLS-1$ } @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 -> { textColor = gb; colorButton.setImage(gb.getThumbNail()); example.redraw(); }); // create color button comp = new Composite(parent, SWT.NONE); comp.setLayout(new GridLayout()); // initialize the color to black textColor = (GraphicsBackground) menu.getItem(1).getData(); colorButton = new Button(comp, SWT.PUSH); colorButton.setText(GraphicsExample.getResourceString("Color")); //$NON-NLS-1$ colorButton.setImage(textColor.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 (textColor != null && textColor.getBgColor1() != null) gc.setForeground(textColor.getBgColor1()); gc.setTextAntialias(aliasValues[aliasCombo.getSelectionIndex()]); // column 1, row 1 Font font = new Font(device, getPlatformFontFace(0), 100, SWT.NORMAL); gc.setFont(font); Point size = gc.stringExtent(text); gc.drawString(text, width / 4 - size.x / 2, height / 4 - size.y / 2, true); font.dispose(); // column 1, row 2 font = new Font(device, getPlatformFontFace(1), 100, SWT.NORMAL); gc.setFont(font); size = gc.stringExtent(text); gc.drawString(text, width / 4 - size.x / 2, 3 * height / 4 - size.y / 2, true); font.dispose(); // column 2, row 1 font = new Font(device, getPlatformFontFace(2), 50, SWT.NORMAL); gc.setFont(font); size = gc.stringExtent(text); gc.drawString(text, (width - size.x) / 2, 0, true); font.dispose(); // column 2, row 2 font = new Font(device, getPlatformFontFace(3), 100, SWT.ITALIC); gc.setFont(font); size = gc.stringExtent(text); gc.drawString(text, (width - size.x) / 2, (height - size.y) / 2, true); font.dispose(); // column 2, row 3 font = new Font(device, getPlatformFontFace(4), 50, SWT.NORMAL); gc.setFont(font); size = gc.stringExtent(text); gc.drawString(text, (width - size.x) / 2, height - size.y, true); font.dispose(); // column 3, row 1 font = new Font(device, getPlatformFontFace(5), 100, SWT.NORMAL); gc.setFont(font); size = gc.stringExtent(text); gc.drawString(text, 3 * width / 4 - size.x / 2, height / 4 - size.y / 2, true); font.dispose(); // column 3, row 2 font = new Font(device, getPlatformFontFace(6), 100, SWT.NORMAL); gc.setFont(font); size = gc.stringExtent(text); gc.drawString(text, 3 * width / 4 - size.x / 2, 3 * height / 4 - size.y / 2, true); font.dispose(); } /** * Returns the name of a valid font for the host platform. * * @param index * index is used to determine the appropriate font face */ static String getPlatformFontFace(int index) { if (SWT.getPlatform() == "win32") { return new String[] { "Bookman Old Style", "Century Gothic", "Comic Sans MS", "Impact", "Garamond", "Lucida Console", "Monotype Corsiva" }[index]; } else if (SWT.getPlatform() == "gtk") { return new String[] { "Luxi Mono", "KacstTitleL", "Baekmuk Batang", "Baekmuk Headline", "KacstFarsi", "Baekmuk Gulim", "URW Chancery L" }[index]; } else { return new String[] { "Courier", "Verdana", "Verdana", "Verdana", "Verdana", "Verdana", "Verdana" }[index]; } } }