libjava/classpath/javax/swing/text/PasswordView.java

   1 /* PasswordView.java --
   2  Copyright (C) 2004 Free Software Foundation, Inc.
   3
   4  This file is part of GNU Classpath.
   5
   6  GNU Classpath is free software; you can redistribute it and/or modify
   7  it under the terms of the GNU General Public License as published by
   8  the Free Software Foundation; either version 2, or (at your option)
   9  any later version.
  10
  11  GNU Classpath is distributed in the hope that it will be useful, but
  12  WITHOUT ANY WARRANTY; without even the implied warranty of
  13  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  General Public License for more details.
  15
  16  You should have received a copy of the GNU General Public License
  17  along with GNU Classpath; see the file COPYING.  If not, write to the
  18  Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  19  02110-1301 USA.
  20
  21  Linking this library statically or dynamically with other modules is
  22  making a combined work based on this library.  Thus, the terms and
  23  conditions of the GNU General Public License cover the whole
  24  combination.
  25
  26  As a special exception, the copyright holders of this library give you
  27  permission to link this library with independent modules to produce an
  28  executable, regardless of the license terms of these independent
  29  modules, and to copy and distribute the resulting executable under
  30  terms of your choice, provided that you also meet, for each linked
  31  independent module, the terms and conditions of the license of that
  32  module.  An independent module is a module which is not derived from
  33  or based on this library.  If you modify this library, you may extend
  34  this exception to your version of the library, but you are not
  35  obligated to do so.  If you do not wish to do so, delete this
  36  exception statement from your version. */
  37
  38
  39 package javax.swing.text;
  40
  41 import java.awt.Color;
  42 import java.awt.FontMetrics;
  43 import java.awt.Graphics;
  44 import java.awt.Rectangle;
  45 import java.awt.Shape;
  46
  47 import javax.swing.JPasswordField;
  48
  49 public class PasswordView
  50   extends FieldView
  51 {
  52   /**
  53    * Buffer for putting the echo char into it and
  54    * then using it to draw it into the view.
  55    */
  56   private char[] oneCharBuffer = new char[1];
  57
  58   public PasswordView(Element elem)
  59   {
  60     super(elem);
  61   }
  62
  63   /**
  64    * Draws one echo character at a given position.
  65    *
  66    * @param g the <code>Graphics</code> object to draw to
  67    * @param x the x-position
  68    * @param y the y-position
  69    * @param ch the echo character
  70    *
  71    * @return the next x position right of the drawn character
  72    */
  73   protected int drawEchoCharacter(Graphics g, int x, int y, char ch)
  74   {
  75     // Update font metrics.
  76     updateMetrics();
  77
  78     // Draw character.
  79     oneCharBuffer[0] = ch;
  80     g.drawChars(oneCharBuffer, 0, 1, x, y);
  81
  82     // Return new x position right of drawn character.
  83     return x + metrics.charWidth(ch);
  84   }
  85
  86   private char getEchoChar()
  87   {
  88     char ch = ((JPasswordField) getContainer()).getEchoChar();
  89
  90     if (ch == 0)
  91       ch = '*';
  92
  93     return ch;
  94   }
  95
  96   /**
  97    * Draws selected text at a given position.
  98    *
  99    * @param g the <code>Graphics</code> object to draw to
 100    * @param x the x-position
 101    * @param y the y-position
 102    * @param p0 the position of the first character to draw
 103    * @param p1 the position of the first character not to draw
 104    *
 105    * @return the next x position right of the drawn character
 106    */
 107   protected int drawSelectedText(Graphics g, int x, int y, int p0, int p1)
 108     throws BadLocationException
 109   {
 110     // Update font metrics.
 111     updateMetrics();
 112
 113     // Get echo character.
 114     char ch = getEchoChar();
 115
 116     // Set color for selected text.
 117     g.setColor(selectedColor);
 118     g.setColor(Color.BLACK);
 119
 120     // Draw echo character using drawEchoCharacter() method.
 121     for (int index = p0; index < p1; ++index)
 122       x = drawEchoCharacter(g, x, y, ch);
 123     return x;
 124   }
 125
 126   /**
 127    * Draws unselected text at a given position.
 128    *
 129    * @param g the <code>Graphics</code> object to draw to
 130    * @param x the x-position of the start of the baseline
 131    * @param y the y-position of the start of the baseline
 132    * @param p0 the position of the first character to draw
 133    * @param p1 the position of the first character not to draw
 134    *
 135    * @return the next x position right of the drawn character
 136    */
 137   protected int drawUnselectedText(Graphics g, int x, int y, int p0, int p1)
 138     throws BadLocationException
 139   {
 140     // Update font metrics.
 141     updateMetrics();
 142
 143     // Get echo character.
 144     char ch = getEchoChar();
 145
 146     // Set color for unselected text.
 147     g.setColor(unselectedColor);
 148     g.setColor(Color.BLACK);
 149
 150     // Draw echo character using drawEchoCharacter() method.
 151     for (int index = p0; index < p1; ++index)
 152       x = drawEchoCharacter(g, x, y, ch);
 153     return x;
 154   }
 155
 156   /**
 157    * Determines the preferred span for this view along an axis.
 158    *
 159    * @param axis to get the preferred span of
 160    * @return the preferred span of the axis
 161    */
 162   public float getPreferredSpan(int axis)
 163   {
 164     if (axis != X_AXIS && axis != Y_AXIS)
 165       throw new IllegalArgumentException();
 166
 167     FontMetrics fm = getFontMetrics();
 168
 169     if (axis == Y_AXIS)
 170         return fm.getHeight();
 171
 172     String text;
 173     Element elem = getElement();
 174
 175     try
 176       {
 177         text = elem.getDocument().getText(elem.getStartOffset(),
 178                                           elem.getEndOffset());
 179       }
 180     catch (BadLocationException e)
 181       {
 182         // This should never happen.
 183         text = "";
 184       }
 185     return fm.stringWidth(text);
 186   }
 187
 188   /**
 189    * Provides a mapping from the document model coordinate space to the
 190    * coordinate space of the view mapped to it.
 191    *
 192    * This method is overridden to provide a correct mapping with respect to the
 193    * echo char and not to the real content.
 194    *
 195    * @param pos - the position to convert >= 0
 196    * @param a - the allocated region to render into
 197    * @param b - typesafe enumeration to indicate bias to a position in the model.
 198    * @return the bounding box of the given position
 199    * @throws BadLocationException if the given position does not
 200    * represent a valid location in the associated document
 201    */
 202   public Shape modelToView(int pos, Shape a, Position.Bias b)
 203     throws BadLocationException
 204   {
 205     Shape newAlloc = adjustAllocation(a);
 206
 207     // Ensure metrics are up-to-date.
 208     updateMetrics();
 209
 210     // Get rectangle of the line containing position.
 211     int lineIndex = getElement().getElementIndex(pos);
 212     Rectangle rect = lineToRect(newAlloc, lineIndex);
 213
 214     // Get the rectangle for position.
 215     Element line = getElement().getElement(lineIndex);
 216     int lineStart = line.getStartOffset();
 217     Segment segment = getLineBuffer();
 218     segment.array = new char[pos - lineStart];
 219     char echoChar = getEchoChar();
 220     for (int i = 0; i < segment.array.length; ++i)
 221       segment.array[i] = echoChar;
 222     segment.offset = 0;
 223     segment.count = segment.array.length;
 224
 225     int xoffset = Utilities.getTabbedTextWidth(segment, metrics, rect.x,
 226                            this, lineStart);
 227
 228     // Calc the real rectangle.
 229     rect.x += xoffset;
 230     rect.width = 1;
 231     rect.height = metrics.getHeight();
 232
 233     return rect;
 234   }
 235
 236   /**
 237    * Provides a mapping from the view coordinate space to the logical
 238    * coordinate space of the model.
 239    *
 240    * @param fx - the X coordinate >= 0.0f
 241    * @param fy - the Y coordinate >= 0.0f
 242    * @param a - the allocated region to render into
 243    * @param bias - typesafe enumeration to indicate bias to a position in the model.
 244    * @return the location within the model that best represents
 245    * the given point in the view
 246    *
 247    */
 248   public int viewToModel(float fx, float fy, Shape a, Position.Bias[] bias)
 249   {
 250     // FIXME: This only provides a view->model mapping for the real text
 251     // content and does not respect the echo char.
 252     return super.viewToModel(fx, fy, a, bias);
 253   }
 254 }