src/jexer/TField.java

   1 /*
   2  * Jexer - Java Text User Interface
   3  *
   4  * The MIT License (MIT)
   5  *
   6  * Copyright (C) 2019 Kevin Lamonte
   7  *
   8  * Permission is hereby granted, free of charge, to any person obtaining a
   9  * copy of this software and associated documentation files (the "Software"),
  10  * to deal in the Software without restriction, including without limitation
  11  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  12  * and/or sell copies of the Software, and to permit persons to whom the
  13  * Software is furnished to do so, subject to the following conditions:
  14  *
  15  * The above copyright notice and this permission notice shall be included in
  16  * all copies or substantial portions of the Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  19  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  20  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  21  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  22  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  23  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  24  * DEALINGS IN THE SOFTWARE.
  25  *
  26  * @author Kevin Lamonte [kevin.lamonte@gmail.com]
  27  * @version 1
  28  */
  29 package jexer;
  30
  31 import jexer.bits.CellAttributes;
  32 import jexer.bits.GraphicsChars;
  33 import jexer.bits.StringUtils;
  34 import jexer.event.TKeypressEvent;
  35 import jexer.event.TMouseEvent;
  36 import static jexer.TKeypress.*;
  37
  38 /**
  39  * TField implements an editable text field.
  40  */
  41 public class TField extends TWidget {
  42
  43     // ------------------------------------------------------------------------
  44     // Variables --------------------------------------------------------------
  45     // ------------------------------------------------------------------------
  46
  47     /**
  48      * Background character for unfilled-in text.
  49      */
  50     protected char backgroundChar = GraphicsChars.HATCH;
  51
  52     /**
  53      * Field text.
  54      */
  55     protected String text = "";
  56
  57     /**
  58      * If true, only allow enough characters that will fit in the width.  If
  59      * false, allow the field to scroll to the right.
  60      */
  61     protected boolean fixed = false;
  62
  63     /**
  64      * Current editing position within text.
  65      */
  66     protected int position = 0;
  67
  68     /**
  69      * Current editing position screen column number.
  70      */
  71     protected int screenPosition = 0;
  72
  73     /**
  74      * Beginning of visible portion.
  75      */
  76     protected int windowStart = 0;
  77
  78     /**
  79      * If true, new characters are inserted at position.
  80      */
  81     protected boolean insertMode = true;
  82
  83     /**
  84      * Remember mouse state.
  85      */
  86     protected TMouseEvent mouse;
  87
  88     /**
  89      * The action to perform when the user presses enter.
  90      */
  91     protected TAction enterAction;
  92
  93     /**
  94      * The action to perform when the text is updated.
  95      */
  96     protected TAction updateAction;
  97
  98     /**
  99      * The color to use when this field is active.
 100      */
 101     private String activeColorKey = "tfield.active";
 102
 103     /**
 104      * The color to use when this field is not active.
 105      */
 106     private String inactiveColorKey = "tfield.inactive";
 107
 108     // ------------------------------------------------------------------------
 109     // Constructors -----------------------------------------------------------
 110     // ------------------------------------------------------------------------
 111
 112     /**
 113      * Public constructor.
 114      *
 115      * @param parent parent widget
 116      * @param x column relative to parent
 117      * @param y row relative to parent
 118      * @param width visible text width
 119      * @param fixed if true, the text cannot exceed the display width
 120      */
 121     public TField(final TWidget parent, final int x, final int y,
 122         final int width, final boolean fixed) {
 123
 124         this(parent, x, y, width, fixed, "", null, null);
 125     }
 126
 127     /**
 128      * Public constructor.
 129      *
 130      * @param parent parent widget
 131      * @param x column relative to parent
 132      * @param y row relative to parent
 133      * @param width visible text width
 134      * @param fixed if true, the text cannot exceed the display width
 135      * @param text initial text, default is empty string
 136      */
 137     public TField(final TWidget parent, final int x, final int y,
 138         final int width, final boolean fixed, final String text) {
 139
 140         this(parent, x, y, width, fixed, text, null, null);
 141     }
 142
 143     /**
 144      * Public constructor.
 145      *
 146      * @param parent parent widget
 147      * @param x column relative to parent
 148      * @param y row relative to parent
 149      * @param width visible text width
 150      * @param fixed if true, the text cannot exceed the display width
 151      * @param text initial text, default is empty string
 152      * @param enterAction function to call when enter key is pressed
 153      * @param updateAction function to call when the text is updated
 154      */
 155     public TField(final TWidget parent, final int x, final int y,
 156         final int width, final boolean fixed, final String text,
 157         final TAction enterAction, final TAction updateAction) {
 158
 159         // Set parent and window
 160         super(parent, x, y, width, 1);
 161
 162         setCursorVisible(true);
 163         this.fixed = fixed;
 164         this.text = text;
 165         this.enterAction = enterAction;
 166         this.updateAction = updateAction;
 167     }
 168
 169     // ------------------------------------------------------------------------
 170     // Event handlers ---------------------------------------------------------
 171     // ------------------------------------------------------------------------
 172
 173     /**
 174      * Returns true if the mouse is currently on the field.
 175      *
 176      * @return if true the mouse is currently on the field
 177      */
 178     protected boolean mouseOnField() {
 179         int rightEdge = getWidth() - 1;
 180         if ((mouse != null)
 181             && (mouse.getY() == 0)
 182             && (mouse.getX() >= 0)
 183             && (mouse.getX() <= rightEdge)
 184         ) {
 185             return true;
 186         }
 187         return false;
 188     }
 189
 190     /**
 191      * Handle mouse button presses.
 192      *
 193      * @param mouse mouse button event
 194      */
 195     @Override
 196     public void onMouseDown(final TMouseEvent mouse) {
 197         this.mouse = mouse;
 198
 199         if ((mouseOnField()) && (mouse.isMouse1())) {
 200             // Move cursor
 201             int deltaX = mouse.getX() - getCursorX();
 202             screenPosition += deltaX;
 203             if (screenPosition > StringUtils.width(text)) {
 204                 screenPosition = StringUtils.width(text);
 205             }
 206             position = screenToTextPosition(screenPosition);
 207             updateCursor();
 208             return;
 209         }
 210     }
 211
 212     /**
 213      * Handle keystrokes.
 214      *
 215      * @param keypress keystroke event
 216      */
 217     @Override
 218     public void onKeypress(final TKeypressEvent keypress) {
 219
 220         if (keypress.equals(kbLeft)) {
 221             if (position > 0) {
 222                 if (position < text.length()) {
 223                     screenPosition -= StringUtils.width(text.charAt(position));
 224                 } else {
 225                     screenPosition--;
 226                 }
 227                 position--;
 228             }
 229             if (fixed == false) {
 230                 if ((screenPosition == windowStart) && (windowStart > 0)) {
 231                     windowStart -= StringUtils.width(text.charAt(
 232                         screenToTextPosition(windowStart)));
 233                 }
 234             }
 235             normalizeWindowStart();
 236             return;
 237         }
 238
 239         if (keypress.equals(kbRight)) {
 240             if (position < text.length()) {
 241                 screenPosition += StringUtils.width(text.charAt(position));
 242                 position++;
 243                 if (fixed == true) {
 244                     if (screenPosition == getWidth()) {
 245                         screenPosition--;
 246                         position--;
 247                     }
 248                 } else {
 249                     if ((screenPosition - windowStart) >= getWidth()) {
 250                         windowStart += StringUtils.width(text.charAt(
 251                             screenToTextPosition(windowStart)));
 252                     }
 253                 }
 254             }
 255             return;
 256         }
 257
 258         if (keypress.equals(kbEnter)) {
 259             dispatch(true);
 260             return;
 261         }
 262
 263         if (keypress.equals(kbIns)) {
 264             insertMode = !insertMode;
 265             return;
 266         }
 267         if (keypress.equals(kbHome)) {
 268             home();
 269             return;
 270         }
 271
 272         if (keypress.equals(kbEnd)) {
 273             end();
 274             return;
 275         }
 276
 277         if (keypress.equals(kbDel)) {
 278             if ((text.length() > 0) && (position < text.length())) {
 279                 text = text.substring(0, position)
 280                         + text.substring(position + 1);
 281                 screenPosition = StringUtils.width(text.substring(0, position));
 282             }
 283             dispatch(false);
 284             return;
 285         }
 286
 287         if (keypress.equals(kbBackspace) || keypress.equals(kbBackspaceDel)) {
 288             if (position > 0) {
 289                 position--;
 290                 text = text.substring(0, position)
 291                         + text.substring(position + 1);
 292                 screenPosition = StringUtils.width(text.substring(0, position));
 293             }
 294             if (fixed == false) {
 295                 if ((screenPosition >= windowStart)
 296                     && (windowStart > 0)
 297                 ) {
 298                     windowStart -= StringUtils.width(text.charAt(
 299                         screenToTextPosition(windowStart)));
 300                 }
 301             }
 302             dispatch(false);
 303             normalizeWindowStart();
 304             return;
 305         }
 306
 307         if (!keypress.getKey().isFnKey()
 308             && !keypress.getKey().isAlt()
 309             && !keypress.getKey().isCtrl()
 310         ) {
 311             // Plain old keystroke, process it
 312             if ((position == text.length())
 313                 && (StringUtils.width(text) < getWidth())) {
 314
 315                 // Append case
 316                 appendChar(keypress.getKey().getChar());
 317             } else if ((position < text.length())
 318                 && (StringUtils.width(text) < getWidth())) {
 319
 320                 // Overwrite or insert a character
 321                 if (insertMode == false) {
 322                     // Replace character
 323                     text = text.substring(0, position)
 324                             + keypress.getKey().getChar()
 325                             + text.substring(position + 1);
 326                     screenPosition += StringUtils.width(text.charAt(position));
 327                     position++;
 328                 } else {
 329                     // Insert character
 330                     insertChar(keypress.getKey().getChar());
 331                 }
 332             } else if ((position < text.length())
 333                 && (StringUtils.width(text) >= getWidth())) {
 334
 335                 // Multiple cases here
 336                 if ((fixed == true) && (insertMode == true)) {
 337                     // Buffer is full, do nothing
 338                 } else if ((fixed == true) && (insertMode == false)) {
 339                     // Overwrite the last character, maybe move position
 340                     text = text.substring(0, position)
 341                             + keypress.getKey().getChar()
 342                             + text.substring(position + 1);
 343                     if (screenPosition < getWidth() - 1) {
 344                         screenPosition += StringUtils.width(text.charAt(position));
 345                         position++;
 346                     }
 347                 } else if ((fixed == false) && (insertMode == false)) {
 348                     // Overwrite the last character, definitely move position
 349                     text = text.substring(0, position)
 350                             + keypress.getKey().getChar()
 351                             + text.substring(position + 1);
 352                     screenPosition += StringUtils.width(text.charAt(position));
 353                     position++;
 354                 } else {
 355                     if (position == text.length()) {
 356                         // Append this character
 357                         appendChar(keypress.getKey().getChar());
 358                     } else {
 359                         // Insert this character
 360                         insertChar(keypress.getKey().getChar());
 361                     }
 362                 }
 363             } else {
 364                 assert (!fixed);
 365
 366                 // Append this character
 367                 appendChar(keypress.getKey().getChar());
 368             }
 369             dispatch(false);
 370             return;
 371         }
 372
 373         // Pass to parent for the things we don't care about.
 374         super.onKeypress(keypress);
 375     }
 376
 377     // ------------------------------------------------------------------------
 378     // TWidget ----------------------------------------------------------------
 379     // ------------------------------------------------------------------------
 380
 381     /**
 382      * Draw the text field.
 383      */
 384     @Override
 385     public void draw() {
 386         CellAttributes fieldColor;
 387
 388         if (isAbsoluteActive()) {
 389             fieldColor = getTheme().getColor(activeColorKey);
 390         } else {
 391             fieldColor = getTheme().getColor(inactiveColorKey);
 392         }
 393
 394         int end = windowStart + getWidth();
 395         if (end > StringUtils.width(text)) {
 396             end = StringUtils.width(text);
 397         }
 398         hLineXY(0, 0, getWidth(), backgroundChar, fieldColor);
 399         putStringXY(0, 0, text.substring(screenToTextPosition(windowStart),
 400                 screenToTextPosition(end)), fieldColor);
 401
 402         // Fix the cursor, it will be rendered by TApplication.drawAll().
 403         updateCursor();
 404     }
 405
 406     // ------------------------------------------------------------------------
 407     // TField -----------------------------------------------------------------
 408     // ------------------------------------------------------------------------
 409
 410     /**
 411      * Get field background character.
 412      *
 413      * @return background character
 414      */
 415     public final char getBackgroundChar() {
 416         return backgroundChar;
 417     }
 418
 419     /**
 420      * Set field background character.
 421      *
 422      * @param backgroundChar the background character
 423      */
 424     public void setBackgroundChar(final char backgroundChar) {
 425         this.backgroundChar = backgroundChar;
 426     }
 427
 428     /**
 429      * Get field text.
 430      *
 431      * @return field text
 432      */
 433     public final String getText() {
 434         return text;
 435     }
 436
 437     /**
 438      * Set field text.
 439      *
 440      * @param text the new field text
 441      */
 442     public void setText(final String text) {
 443         assert (text != null);
 444         this.text = text;
 445         position = 0;
 446         windowStart = 0;
 447     }
 448
 449     /**
 450      * Dispatch to the action function.
 451      *
 452      * @param enter if true, the user pressed Enter, else this was an update
 453      * to the text.
 454      */
 455     protected void dispatch(final boolean enter) {
 456         if (enter) {
 457             if (enterAction != null) {
 458                 enterAction.DO();
 459             }
 460         } else {
 461             if (updateAction != null) {
 462                 updateAction.DO();
 463             }
 464         }
 465     }
 466
 467     /**
 468      * Determine string position from screen position.
 469      *
 470      * @param screenPosition the position on screen
 471      * @return the equivalent position in text
 472      */
 473     protected int screenToTextPosition(final int screenPosition) {
 474         if (screenPosition == 0) {
 475             return 0;
 476         }
 477
 478         int n = 0;
 479         for (int i = 0; i < text.length(); i++) {
 480             n += StringUtils.width(text.charAt(i));
 481             if (n >= screenPosition) {
 482                 return i + 1;
 483             }
 484         }
 485         // screenPosition exceeds the available text length.
 486         throw new IndexOutOfBoundsException("screenPosition " + screenPosition +
 487             " exceeds available text length " + text.length());
 488     }
 489
 490     /**
 491      * Update the visible cursor position to match the location of position
 492      * and windowStart.
 493      */
 494     protected void updateCursor() {
 495         if ((screenPosition > getWidth()) && fixed) {
 496             setCursorX(getWidth());
 497         } else if ((screenPosition - windowStart >= getWidth()) && !fixed) {
 498             setCursorX(getWidth() - 1);
 499         } else {
 500             setCursorX(screenPosition - windowStart);
 501         }
 502     }
 503
 504     /**
 505      * Normalize windowStart such that most of the field data if visible.
 506      */
 507     protected void normalizeWindowStart() {
 508         if (fixed) {
 509             // windowStart had better be zero, there is nothing to do here.
 510             assert (windowStart == 0);
 511             return;
 512         }
 513         windowStart = screenPosition - (getWidth() - 1);
 514         if (windowStart < 0) {
 515             windowStart = 0;
 516         }
 517
 518         updateCursor();
 519     }
 520
 521     /**
 522      * Append char to the end of the field.
 523      *
 524      * @param ch = char to append
 525      */
 526     protected void appendChar(final char ch) {
 527         // Append the LAST character
 528         text += ch;
 529         position++;
 530         screenPosition += StringUtils.width(ch);
 531
 532         assert (position == text.length());
 533
 534         if (fixed) {
 535             if (screenPosition >= getWidth()) {
 536                 position--;
 537                 screenPosition -= StringUtils.width(ch);
 538             }
 539         } else {
 540             if ((screenPosition - windowStart) >= getWidth()) {
 541                 windowStart++;
 542             }
 543         }
 544     }
 545
 546     /**
 547      * Insert char somewhere in the middle of the field.
 548      *
 549      * @param ch char to append
 550      */
 551     protected void insertChar(final char ch) {
 552         text = text.substring(0, position) + ch + text.substring(position);
 553         position++;
 554         screenPosition += StringUtils.width(ch);
 555         if ((screenPosition - windowStart) == getWidth()) {
 556             assert (!fixed);
 557             windowStart++;
 558         }
 559     }
 560
 561     /**
 562      * Position the cursor at the first column.  The field may adjust the
 563      * window start to show as much of the field as possible.
 564      */
 565     public void home() {
 566         position = 0;
 567         screenPosition = 0;
 568         windowStart = 0;
 569     }
 570
 571     /**
 572      * Set the editing position to the last filled character.  The field may
 573      * adjust the window start to show as much of the field as possible.
 574      */
 575     public void end() {
 576         position = text.length();
 577         screenPosition = StringUtils.width(text);
 578         if (fixed == true) {
 579             if (screenPosition >= getWidth()) {
 580                 position = text.length() - 1;
 581                 screenPosition = StringUtils.width(text) - 1;
 582              }
 583         } else {
 584             windowStart = StringUtils.width(text) - getWidth() + 1;
 585             if (windowStart < 0) {
 586                 windowStart = 0;
 587             }
 588         }
 589     }
 590
 591     /**
 592      * Set the editing position.  The field may adjust the window start to
 593      * show as much of the field as possible.
 594      *
 595      * @param position the new position
 596      * @throws IndexOutOfBoundsException if position is outside the range of
 597      * the available text
 598      */
 599     public void setPosition(final int position) {
 600         if ((position < 0) || (position >= text.length())) {
 601             throw new IndexOutOfBoundsException("Max length is " +
 602                 StringUtils.width(text) + ", requested position " + position);
 603         }
 604         this.position = position;
 605         normalizeWindowStart();
 606     }
 607
 608     /**
 609      * Set the active color key.
 610      *
 611      * @param activeColorKey ColorTheme key color to use when this field is
 612      * active
 613      */
 614     public void setActiveColorKey(final String activeColorKey) {
 615         this.activeColorKey = activeColorKey;
 616     }
 617
 618     /**
 619      * Set the inactive color key.
 620      *
 621      * @param inactiveColorKey ColorTheme key color to use when this field is
 622      * inactive
 623      */
 624     public void setInactiveColorKey(final String inactiveColorKey) {
 625         this.inactiveColorKey = inactiveColorKey;
 626     }
 627
 628     /**
 629      * Set the action to perform when the user presses enter.
 630      *
 631      * @param action the action to perform when the user presses enter
 632      */
 633     public void setEnterAction(final TAction action) {
 634         enterAction = action;
 635     }
 636
 637     /**
 638      * Set the action to perform when the field is updated.
 639      *
 640      * @param action the action to perform when the field is updated
 641      */
 642     public void setUpdateAction(final TAction action) {
 643         updateAction = action;
 644     }
 645
 646 }