old-autovect-branch/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.Shape;
  45
  46 import javax.swing.JPasswordField;
  47
  48 public class PasswordView
  49   extends FieldView
  50 {
  51   /**
  52    * Buffer for putting the echo char into it and
  53    * then using it to draw it into the view.
  54    */
  55   private char[] oneCharBuffer = new char[1];
  56
  57   public PasswordView(Element elem)
  58   {
  59     super(elem);
  60   }
  61
  62   /**
  63    * Draws one echo character at a given position.
  64    *
  65    * @param g the <code>Graphics</code> object to draw to
  66    * @param x the x-position
  67    * @param y the y-position
  68    * @param ch the echo character
  69    *
  70    * @return the next x position right of the drawn character
  71    */
  72   protected int drawEchoCharacter(Graphics g, int x, int y, char ch)
  73   {
  74     // Update font metrics.
  75     updateMetrics();
  76
  77     // Draw character.
  78     oneCharBuffer[0] = ch;
  79     g.drawChars(oneCharBuffer, 0, 1, x, y);
  80
  81     // Return new x position right of drawn character.
  82     return x + metrics.charWidth(ch);
  83   }
  84
  85   private char getEchoChar()
  86   {
  87     char ch = ((JPasswordField) getContainer()).getEchoChar();
  88
  89     if (ch == 0)
  90       ch = '*';
  91
  92     return ch;
  93   }
  94
  95   /**
  96    * Draws selected text at a given position.
  97    *
  98    * @param g the <code>Graphics</code> object to draw to
  99    * @param x the x-position
 100    * @param y the y-position
 101    * @param p0 the position of the first character to draw
 102    * @param p1 the position of the first character not to draw
 103    *
 104    * @return the next x position right of the drawn character
 105    */
 106   protected int drawSelectedText(Graphics g, int x, int y, int p0, int p1)
 107     throws BadLocationException
 108   {
 109     // FIXME: Throw BadLocationException somehow.
 110
 111     // Update font metrics.
 112     updateMetrics();
 113
 114     // Get echo character.
 115     char ch = getEchoChar();
 116
 117     // Set color for selected text.
 118     g.setColor(selectedColor);
 119     g.setColor(Color.BLACK);
 120
 121     // Initialize buffer for faster drawing of all characters.
 122     int len = p1 - p0;
 123     char[] buffer = new char[len];
 124     for (int index = 0; index < len; ++index)
 125       buffer[index] = ch;
 126
 127     // Draw echo charaters.
 128     g.drawChars(buffer, 0, len, x, y);
 129
 130     // Return new x position right of all drawn characters.
 131     return x + len * metrics.charWidth(ch);
 132   }
 133
 134   /**
 135    * Draws unselected text at a given position.
 136    *
 137    * @param g the <code>Graphics</code> object to draw to
 138    * @param x the x-position
 139    * @param y the y-position
 140    * @param p0 the position of the first character to draw
 141    * @param p1 the position of the first character not to draw
 142    *
 143    * @return the next x position right of the drawn character
 144    */
 145   protected int drawUnselectedText(Graphics g, int x, int y, int p0, int p1)
 146     throws BadLocationException
 147   {
 148     // FIXME: Throw BadLocationException somehow.
 149
 150     // Update font metrics.
 151     updateMetrics();
 152
 153     // Get echo character.
 154     char ch = getEchoChar();
 155     Segment segment = new Segment();
 156
 157     // Set color for unselected text.
 158     g.setColor(unselectedColor);
 159     g.setColor(Color.BLACK);
 160
 161     // Initialize buffer for faster drawing of all characters.
 162     p1--;
 163     getDocument().getText(p0, p1 - p0, segment);
 164     int len = segment.toString().length();
 165
 166     char[] buffer = new char[len];
 167     for (int index = 0; index < len; ++index)
 168       buffer[index] = ch;
 169
 170     y += getPreferredSpan(Y_AXIS)/2;
 171
 172     // Draw echo charaters.
 173     g.drawChars(buffer, 0, len, x, y);
 174
 175     // Return new x position right of all drawn characters.
 176     return x + (len * metrics.charWidth(ch));
 177   }
 178
 179   /**
 180    * Determines the preferred span for this view along an axis.
 181    *
 182    * @param axis to get the preferred span of
 183    * @return the preferred span of the axis
 184    */
 185   public float getPreferredSpan(int axis)
 186   {
 187     if (axis != X_AXIS && axis != Y_AXIS)
 188       throw new IllegalArgumentException();
 189
 190     FontMetrics fm = getFontMetrics();
 191
 192     if (axis == Y_AXIS)
 193         return fm.getHeight();
 194
 195     String text;
 196     Element elem = getElement();
 197
 198     try
 199       {
 200         text = elem.getDocument().getText(elem.getStartOffset(),
 201                                           elem.getEndOffset());
 202       }
 203     catch (BadLocationException e)
 204       {
 205         // This should never happen.
 206         text = "";
 207       }
 208     return fm.stringWidth(text);
 209   }
 210
 211   /**
 212    * Provides a mapping from the document model coordinate space to the
 213    * coordinate space of the view mapped to it.
 214    *
 215    * @param pos - the position to convert >= 0
 216    * @param a - the allocated region to render into
 217    * @param b - typesafe enumeration to indicate bias to a position in the model.
 218    * @return the bounding box of the given position
 219    * @throws BadLocationException if the given position does not
 220    * represent a valid location in the associated document
 221    */
 222   public Shape modelToView(int pos, Shape a, Position.Bias b)
 223     throws BadLocationException
 224   {
 225     return super.modelToView(pos, a, b);
 226   }
 227
 228   /**
 229    * Provides a mapping from the view coordinate space to the logical
 230    * coordinate space of the model.
 231    *
 232    * @param fx - the X coordinate >= 0.0f
 233    * @param fy - the Y coordinate >= 0.0f
 234    * @param a - the allocated region to render into
 235    * @param bias - typesafe enumeration to indicate bias to a position in the model.
 236    * @return the location within the model that best represents
 237    * the given point in the view
 238    *
 239    */
 240   public int viewToModel(float fx, float fy, Shape a, Position.Bias[] bias)
 241   {
 242     return super.viewToModel(fx, fy, a, bias);
 243   }
 244 }