Java examples for 2D Graphics:Text
Java Select text with TextLayout
import java.awt.Color; import java.awt.Dimension; import java.awt.Graphics; import java.awt.Graphics2D; import java.awt.Shape; import java.awt.font.FontRenderContext; import java.awt.font.TextAttribute; import java.awt.font.TextHitInfo; import java.awt.font.TextLayout; import java.awt.geom.Point2D; import java.awt.event.MouseAdapter; import java.awt.event.MouseMotionAdapter; import java.awt.event.MouseEvent; import java.text.AttributedCharacterIterator; import java.text.AttributedString; import java.util.Hashtable; import javax.swing.JFrame; import javax.swing.JPanel; import javax.swing.SwingUtilities; import javax.swing.UIManager; /**// www .j av a 2 s . c om * This class demonstrates how to select text with TextLayout. * * When the mouse is dragged inside this panel, the selection range is updated * to reflect the mouse position. TextLayout's hitTestChar() method is used to * get the selection endpoint corresponding to the mouse position. * getLogicalHighlightShape() returns the Shape which is filled with the * highlight color to show the selection range. */ public class SelectionSample extends JPanel { private static String mixed = "\u05D0\u05E0\u05D9 Hello \u05DC\u05D0 \u05DE\u05D1\u05D9\u05DF " + "\u05E2\u05D1\u05E8\u05D9\u05EA Arabic \u0644\u0645\u062C\u0645\u0648\u0639\u0629"; private static final FontRenderContext DEFAULT_FRC = new FontRenderContext( null, false, false); private static JFrame frame; private static final Hashtable<TextAttribute, Object> map = new Hashtable<TextAttribute, Object>(); static { map.put(TextAttribute.FAMILY, "Serif"); map.put(TextAttribute.SIZE, new Float(24.0)); } // Colors to use for the strong and weak carets. private static final Color STRONG_CARET_COLOR = Color.red; private static final Color WEAK_CARET_COLOR = Color.black; // Color to use for highlighting. private static final Color HIGHLIGHT_COLOR = Color.pink; // Color to use for text. private static final Color TEXT_COLOR = Color.black; // The TextLayout to hit-test and select. private TextLayout textLayout; // The insertion index of the initial mouse click; one // end of the selection range. During a mouse drag this end // of the selection is constant. private int anchorEnd; // The insertion index of the current mouse location; the // other end of the selection range. This changes during a mouse // drag. private int activeEnd; public SelectionSample() { AttributedString attributedMixed = new AttributedString(mixed, map); AttributedCharacterIterator text = attributedMixed.getIterator(); // Create a new TextLayout from the given text. textLayout = new TextLayout(text, DEFAULT_FRC); // Initialize activeEnd and anchorEnd. anchorEnd = 0; activeEnd = 0; addMouseListener(new SelectionMouseListener()); addMouseMotionListener(new SelectionMouseMotionListener()); } private static void createAndShowGUI() { // Create and set up the window. SelectionSample demo = new SelectionSample(); frame = new JFrame("Selection Sample"); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); // Add contents to the window. frame.add(demo); frame.setBackground(Color.white); // Display the window. frame.pack(); frame.setSize(new Dimension(400, 250)); frame.setVisible(true); } /** * Compute a location within this Panel for textLayout's origin, such that * textLayout is centered horizontally and vertically. * * Note that this location is unknown to textLayout; it is used only by this * Panel for positioning. */ private Point2D computeLayoutOrigin() { Dimension size = getSize(); Point2D.Float origin = new Point2D.Float(); origin.x = (size.width - textLayout.getAdvance()) / 2; origin.y = (size.height - textLayout.getDescent() + textLayout .getAscent()) / 2; return origin; } /** * Draw textLayout and either: the selection range (if a range of characters * is selected), or the carets (if the selection range is 0-length). */ public void paint(Graphics g) { Graphics2D graphics2D = (Graphics2D) g; Point2D origin = computeLayoutOrigin(); // Since the selection and caret Shapes are relative to the // origin of textLayout, we'll translate the graphics so that // the origin of the graphics is where we want textLayout to // appear. graphics2D.translate(origin.getX(), origin.getY()); // If the insertion indices of the two selection endpoints // are equal, the method we will draw caret(s) at the insertion index. // Otherwise we will draw a highlight region between the // insertion indices. boolean haveCaret = anchorEnd == activeEnd; if (!haveCaret) { // Retrieve highlight region for selection range. Shape highlight = textLayout.getLogicalHighlightShape( anchorEnd, activeEnd); // Fill the highlight region with the highlight color. graphics2D.setColor(HIGHLIGHT_COLOR); graphics2D.fill(highlight); } // Draw textLayout. graphics2D.setColor(TEXT_COLOR); textLayout.draw(graphics2D, 0, 0); if (haveCaret) { // Retrieve caret Shapes for the insertion index. Shape[] carets = textLayout.getCaretShapes(anchorEnd); // Draw the carets. carets[0] is the strong caret, and // is never null. carets[1], if it is not null, is the // weak caret. graphics2D.setColor(STRONG_CARET_COLOR); graphics2D.draw(carets[0]); if (carets[1] != null) { graphics2D.setColor(WEAK_CARET_COLOR); graphics2D.draw(carets[1]); } } } /** * Set the active selection endpoint to the character position of the mouse. */ private class SelectionMouseMotionListener extends MouseMotionAdapter { public void mouseDragged(MouseEvent e) { Point2D origin = computeLayoutOrigin(); // Compute the mouse location relative to // textLayout's origin. float clickX = (float) (e.getX() - origin.getX()); float clickY = (float) (e.getY() - origin.getY()); // Get the character position of the mouse location. TextHitInfo position = textLayout.hitTestChar(clickX, clickY); int newActiveEnd = position.getInsertionIndex(); // If newActiveEnd is different from activeEnd, update activeEnd // and repaint the Panel so the new selection will be displayed. if (activeEnd != newActiveEnd) { activeEnd = newActiveEnd; frame.repaint(); } } } /** * Set the active and anchor selection endpoints to the character position of * the mouse click. */ private class SelectionMouseListener extends MouseAdapter { public void mousePressed(MouseEvent e) { Point2D origin = computeLayoutOrigin(); // Compute the mouse location relative to // TextLayout's origin. float clickX = (float) (e.getX() - origin.getX()); float clickY = (float) (e.getY() - origin.getY()); // Set the anchor and active ends of the selection // to the character position of the mouse location. TextHitInfo position = textLayout.hitTestChar(clickX, clickY); anchorEnd = position.getInsertionIndex(); activeEnd = anchorEnd; // Repaint the Panel so the new selection will be displayed. frame.repaint(); } } public static void main(String[] args) { // Schedule a job for the event dispatch thread: // creating and showing this application's GUI. SwingUtilities.invokeLater(new Runnable() { public void run() { // Turn off metal's use of bold fonts UIManager.put("swing.boldMetal", Boolean.FALSE); createAndShowGUI(); } }); } } /* * Copyright (c) 2011, Oracle and/or its affiliates. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * - Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * - Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * - Neither the name of Oracle or the names of its * contributors may be used to endorse or promote products derived * from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */