src/jexer/TMessageBox.java

   1 /**
   2  * Jexer - Java Text User Interface
   3  *
   4  * License: LGPLv3 or later
   5  *
   6  * This module is licensed under the GNU Lesser General Public License
   7  * Version 3.  Please see the file "COPYING" in this directory for more
   8  * information about the GNU Lesser General Public License Version 3.
   9  *
  10  *     Copyright (C) 2015  Kevin Lamonte
  11  *
  12  * This program is free software; you can redistribute it and/or
  13  * modify it under the terms of the GNU Lesser General Public License
  14  * as published by the Free Software Foundation; either version 3 of
  15  * the License, or (at your option) any later version.
  16  *
  17  * This program is distributed in the hope that it will be useful, but
  18  * WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  20  * General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU Lesser General Public
  23  * License along with this program; if not, see
  24  * http://www.gnu.org/licenses/, or write to the Free Software
  25  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
  26  * 02110-1301 USA
  27  *
  28  * @author Kevin Lamonte [kevin.lamonte@gmail.com]
  29  * @version 1
  30  */
  31 package jexer;
  32
  33 import java.util.ArrayList;
  34 import java.util.List;
  35
  36 import jexer.event.TKeypressEvent;
  37 import static jexer.TKeypress.*;
  38
  39 /**
  40  * TMessageBox is a system-modal dialog with buttons for OK, Cancel, Yes, or
  41  * No.  Call it like:
  42  *
  43  * <p>
  44  * <pre>
  45  * {@code
  46  *     box = application.messageBox(title, caption,
  47  *         TMessageBox.Type.OK | TMessageBox.Type.CANCEL);
  48  *
  49  *     if (box.getResult() == TMessageBox.OK) {
  50  *         ... the user pressed OK, do stuff ...
  51  *     }
  52  * }
  53  * </pre>
  54  *
  55  */
  56 public class TMessageBox extends TWindow {
  57
  58     /**
  59      * Message boxes have these supported types.
  60      */
  61     public enum Type {
  62         /**
  63          * Show an OK button.
  64          */
  65         OK,
  66
  67         /**
  68          * Show both OK and Cancel buttons.
  69          */
  70         OKCANCEL,
  71
  72         /**
  73          * Show both Yes and No buttons.
  74          */
  75         YESNO,
  76
  77         /**
  78          * Show Yes, No, and Cancel buttons.
  79          */
  80         YESNOCANCEL
  81     };
  82
  83     /**
  84      * The type of this message box.
  85      */
  86     private Type type;
  87
  88     /**
  89      * My buttons.
  90      */
  91     List<TButton> buttons;
  92
  93     /**
  94      * Message boxes have these possible results.
  95      */
  96     public enum Result {
  97         /**
  98          * User clicked "OK".
  99          */
 100         OK,
 101
 102         /**
 103          * User clicked "Cancel".
 104          */
 105         CANCEL,
 106
 107         /**
 108          * User clicked "Yes".
 109          */
 110         YES,
 111
 112         /**
 113          * User clicked "No".
 114          */
 115         NO
 116     };
 117
 118     /**
 119      * Which button was clicked: OK, CANCEL, YES, or NO.
 120      */
 121     private Result result = Result.OK;
 122
 123     /**
 124      * Get the result.
 125      *
 126      * @return the result: OK, CANCEL, YES, or NO.
 127      */
 128     public final Result getResult() {
 129         return result;
 130     }
 131
 132     /**
 133      * Public constructor.  The message box will be centered on screen.
 134      *
 135      * @param application TApplication that manages this window
 136      * @param title window title, will be centered along the top border
 137      * @param caption message to display.  Use embedded newlines to get a
 138      * multi-line box.
 139      */
 140     public TMessageBox(final TApplication application, final String title,
 141         final String caption) {
 142
 143         this(application, title, caption, Type.OK, true);
 144     }
 145
 146     /**
 147      * Public constructor.  The message box will be centered on screen.
 148      *
 149      * @param application TApplication that manages this window
 150      * @param title window title, will be centered along the top border
 151      * @param caption message to display.  Use embedded newlines to get a
 152      * multi-line box.
 153      * @param type one of the Type constants.  Default is Type.OK.
 154      */
 155     public TMessageBox(final TApplication application, final String title,
 156         final String caption, final Type type) {
 157
 158         this(application, title, caption, type, true);
 159     }
 160
 161     /**
 162      * Public constructor.  The message box will be centered on screen.
 163      *
 164      * @param application TApplication that manages this window
 165      * @param title window title, will be centered along the top border
 166      * @param caption message to display.  Use embedded newlines to get a
 167      * multi-line box.
 168      * @param type one of the Type constants.  Default is Type.OK.
 169      * @param yield if true, yield this Thread.  Subclasses need to set this
 170      * to false and yield at their end of their constructor intead.
 171      */
 172     protected TMessageBox(final TApplication application, final String title,
 173         final String caption, final Type type, final boolean yield) {
 174
 175         // Start as 50x50 at (1, 1).  These will be changed later.
 176         super(application, title, 1, 1, 100, 100, CENTERED | MODAL);
 177
 178         // Hang onto type so that we can provide more convenience in
 179         // onKeypress().
 180         this.type = type;
 181
 182         // Determine width and height
 183         String [] lines = caption.split("\n");
 184         int width = title.length() + 12;
 185         setHeight(6 + lines.length);
 186         for (String line: lines) {
 187             if (line.length() + 4 > width) {
 188                 width = line.length() + 4;
 189             }
 190         }
 191         setWidth(width);
 192         if (getWidth() > getScreen().getWidth()) {
 193             setWidth(getScreen().getWidth());
 194         }
 195         // Re-center window to get an appropriate (x, y)
 196         center();
 197
 198         // Now add my elements
 199         int lineI = 1;
 200         for (String line: lines) {
 201             addLabel(line, 1, lineI, "twindow.background.modal");
 202             lineI++;
 203         }
 204
 205         // The button line
 206         lineI++;
 207         buttons = new ArrayList<TButton>();
 208
 209         int buttonX = 0;
 210
 211         // Setup button actions
 212         switch (type) {
 213
 214         case OK:
 215             result = Result.OK;
 216             if (getWidth() < 15) {
 217                 setWidth(15);
 218             }
 219             buttonX = (getWidth() - 11) / 2;
 220             buttons.add(addButton("  &OK  ", buttonX, lineI,
 221                     new TAction() {
 222                         public void DO() {
 223                             result = Result.OK;
 224                             getApplication().closeWindow(TMessageBox.this);
 225                         }
 226                     }
 227                 )
 228             );
 229             break;
 230
 231         case OKCANCEL:
 232             result = Result.CANCEL;
 233             if (getWidth() < 26) {
 234                 setWidth(26);
 235             }
 236             buttonX = (getWidth() - 22) / 2;
 237             buttons.add(addButton("  &OK  ", buttonX, lineI,
 238                     new TAction() {
 239                         public void DO() {
 240                             result = Result.OK;
 241                             getApplication().closeWindow(TMessageBox.this);
 242                         }
 243                     }
 244                 )
 245             );
 246             buttonX += 8 + 4;
 247             buttons.add(addButton("&Cancel", buttonX, lineI,
 248                     new TAction() {
 249                         public void DO() {
 250                             result = Result.CANCEL;
 251                             getApplication().closeWindow(TMessageBox.this);
 252                         }
 253                     }
 254                 )
 255             );
 256             break;
 257
 258         case YESNO:
 259             result = Result.NO;
 260             if (getWidth() < 20) {
 261                 setWidth(20);
 262             }
 263             buttonX = (getWidth() - 16) / 2;
 264             buttons.add(addButton("&Yes", buttonX, lineI,
 265                     new TAction() {
 266                         public void DO() {
 267                             result = Result.YES;
 268                             getApplication().closeWindow(TMessageBox.this);
 269                         }
 270                     }
 271                 )
 272             );
 273             buttonX += 5 + 4;
 274             buttons.add(addButton("&No", buttonX, lineI,
 275                     new TAction() {
 276                         public void DO() {
 277                             result = Result.NO;
 278                             getApplication().closeWindow(TMessageBox.this);
 279                         }
 280                     }
 281                 )
 282             );
 283             break;
 284
 285         case YESNOCANCEL:
 286             result = Result.CANCEL;
 287             if (getWidth() < 31) {
 288                 setWidth(31);
 289             }
 290             buttonX = (getWidth() - 27) / 2;
 291             buttons.add(addButton("&Yes", buttonX, lineI,
 292                     new TAction() {
 293                         public void DO() {
 294                             result = Result.YES;
 295                             getApplication().closeWindow(TMessageBox.this);
 296                         }
 297                     }
 298                 )
 299             );
 300             buttonX += 5 + 4;
 301             buttons.add(addButton("&No", buttonX, lineI,
 302                     new TAction() {
 303                         public void DO() {
 304                             result = Result.NO;
 305                             getApplication().closeWindow(TMessageBox.this);
 306                         }
 307                     }
 308                 )
 309             );
 310             buttonX += 4 + 4;
 311             buttons.add(addButton("&Cancel", buttonX, lineI,
 312                     new TAction() {
 313                         public void DO() {
 314                             result = Result.CANCEL;
 315                             getApplication().closeWindow(TMessageBox.this);
 316                         }
 317                     }
 318                 )
 319             );
 320             break;
 321
 322         default:
 323             throw new IllegalArgumentException("Invalid message box type: " + type);
 324         }
 325
 326         // Set the secondaryThread to run me
 327         getApplication().enableSecondaryEventReceiver(this);
 328
 329         if (yield) {
 330             // Yield to the secondary thread.  When I come back from the
 331             // constructor response will already be set.
 332             getApplication().yield();
 333         }
 334     }
 335
 336     /**
 337      * Handle keystrokes.
 338      *
 339      * @param keypress keystroke event
 340      */
 341     @Override
 342     public void onKeypress(final TKeypressEvent keypress) {
 343
 344         if (this instanceof TInputBox) {
 345             super.onKeypress(keypress);
 346             return;
 347         }
 348
 349         // Some convenience for message boxes: Alt won't be needed for the
 350         // buttons.
 351         switch (type) {
 352
 353         case OK:
 354             if (keypress.equals(kbO)) {
 355                 buttons.get(0).dispatch();
 356                 return;
 357             }
 358             break;
 359
 360         case OKCANCEL:
 361             if (keypress.equals(kbO)) {
 362                 buttons.get(0).dispatch();
 363                 return;
 364             } else if (keypress.equals(kbC)) {
 365                 buttons.get(1).dispatch();
 366                 return;
 367             }
 368             break;
 369
 370         case YESNO:
 371             if (keypress.equals(kbY)) {
 372                 buttons.get(0).dispatch();
 373                 return;
 374             } else if (keypress.equals(kbN)) {
 375                 buttons.get(1).dispatch();
 376                 return;
 377             }
 378             break;
 379
 380         case YESNOCANCEL:
 381             if (keypress.equals(kbY)) {
 382                 buttons.get(0).dispatch();
 383                 return;
 384             } else if (keypress.equals(kbN)) {
 385                 buttons.get(1).dispatch();
 386                 return;
 387             } else if (keypress.equals(kbC)) {
 388                 buttons.get(2).dispatch();
 389                 return;
 390             }
 391             break;
 392
 393         default:
 394             throw new IllegalArgumentException("Invalid message box type: " + type);
 395         }
 396
 397         super.onKeypress(keypress);
 398     }
 399
 400 }