/*
 * Copyright (c) 2011, Oracle and/or its affiliates. All rights reserved.
 *
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 * modification, are permitted provided that the following conditions
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 *
 *   - 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,
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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.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;

/**
 * This class demonstrates how to hit-test a TextLayout. Hit-testing is the
 * mapping of a graphical location to a character position within text.
 * 
 * This class constructs a TextLayout from an AttributedCharacterIterator and
 * displays the TextLayout. When the mouse is clicked inside this Component, the
 * mouse position is mapped to a character position, and the carets for this
 * character position are displayed.
 */
public class HitTestSample 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 long serialVersionUID = 1L;

  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;

  // The TextLayout to draw and hit-test.
  private TextLayout textLayout;

  // The insertion index of the most recent mouse click.
  private int insertionIndex;

  public HitTestSample() {

    AttributedString attributedMixed;
    attributedMixed = new AttributedString(mixed, map);
    AttributedCharacterIterator text = attributedMixed.getIterator();

    // Create a new TextLayout from the given text.
    textLayout = new TextLayout(text, DEFAULT_FRC);

    // Initialize insertionIndex.
    insertionIndex = 0;

    addMouseListener(new HitTestMouseListener());
  }

  private static void createAndShowGUI() {

    // Create and set up the window.
    HitTestSample demo = new HitTestSample();
    frame = new JFrame("Hit Test 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 Component 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
   * Component 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 the carets corresponding to the most recent mouse click
   * (if any).
   */
  public void paint(Graphics g) {

    Graphics2D graphics2D = (Graphics2D) g;

    Point2D origin = computeLayoutOrigin();

    // Since the 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());

    // Draw textLayout.
    textLayout.draw(graphics2D, 0, 0);

    // Retrieve caret Shapes for insertionIndex.
    Shape[] carets = textLayout.getCaretShapes(insertionIndex);

    // 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]);
    }
  }

  /**
   * Compute the character position of the mouse click.
   */

  private class HitTestMouseListener extends MouseAdapter {

    public void mouseClicked(MouseEvent e) {

      Point2D origin = computeLayoutOrigin();

      // Compute the mouse click 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 click.
      TextHitInfo currentHit = textLayout.hitTestChar(clickX, clickY);
      insertionIndex = currentHit.getInsertionIndex();

      // Repaint the Component so the new caret(s) 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();
      }
    });
  }
}