src/jexer/TEditorWidget.java

   1 /*
   2  * Jexer - Java Text User Interface
   3  *
   4  * The MIT License (MIT)
   5  *
   6  * Copyright (C) 2017 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.event.TKeypressEvent;
  33 import jexer.event.TMouseEvent;
  34 import jexer.event.TResizeEvent;
  35 import jexer.teditor.Document;
  36 import jexer.teditor.Line;
  37 import jexer.teditor.Word;
  38 import static jexer.TKeypress.*;
  39
  40 /**
  41  * TEditorWidget displays an editable text document.  It is unaware of
  42  * scrolling behavior, but can respond to mouse and keyboard events.
  43  */
  44 public final class TEditorWidget extends TWidget {
  45
  46     /**
  47      * The document being edited.
  48      */
  49     private Document document;
  50
  51     /**
  52      * The default color for the TEditor class.
  53      */
  54     private CellAttributes defaultColor = null;
  55
  56     /**
  57      * The topmost line number in the visible area.  0-based.
  58      */
  59     private int topLine = 0;
  60
  61     /**
  62      * The leftmost column number in the visible area.  0-based.
  63      */
  64     private int leftColumn = 0;
  65
  66     /**
  67      * Public constructor.
  68      *
  69      * @param parent parent widget
  70      * @param text text on the screen
  71      * @param x column relative to parent
  72      * @param y row relative to parent
  73      * @param width width of text area
  74      * @param height height of text area
  75      */
  76     public TEditorWidget(final TWidget parent, final String text, final int x,
  77         final int y, final int width, final int height) {
  78
  79         // Set parent and window
  80         super(parent, x, y, width, height);
  81
  82         setCursorVisible(true);
  83
  84         defaultColor = getTheme().getColor("teditor");
  85         document = new Document(text, defaultColor);
  86     }
  87
  88     /**
  89      * Draw the text box.
  90      */
  91     @Override
  92     public void draw() {
  93         for (int i = 0; i < getHeight(); i++) {
  94             // Background line
  95             getScreen().hLineXY(0, i, getWidth(), ' ', defaultColor);
  96
  97             // Now draw document's line
  98             if (topLine + i < document.getLineCount()) {
  99                 Line line = document.getLine(topLine + i);
 100                 int x = 0;
 101                 for (Word word: line.getWords()) {
 102                     // For now, we are cheating: draw outside the left region
 103                     // if needed and let screen do the clipping.
 104                     getScreen().putStringXY(x - leftColumn, i, word.getText(),
 105                         word.getColor());
 106                     x += word.getDisplayLength();
 107                     if (x - leftColumn > getWidth()) {
 108                         break;
 109                     }
 110                 }
 111             }
 112         }
 113
 114     }
 115
 116     /**
 117      * Handle mouse press events.
 118      *
 119      * @param mouse mouse button press event
 120      */
 121     @Override
 122     public void onMouseDown(final TMouseEvent mouse) {
 123         if (mouse.isMouseWheelUp()) {
 124             if (getCursorY() == getHeight() - 1) {
 125                 if (document.up()) {
 126                     if (topLine > 0) {
 127                         topLine--;
 128                     }
 129                     alignCursor();
 130                 }
 131             } else {
 132                 if (topLine > 0) {
 133                     topLine--;
 134                     setCursorY(getCursorY() + 1);
 135                 }
 136             }
 137             return;
 138         }
 139         if (mouse.isMouseWheelDown()) {
 140             if (getCursorY() == 0) {
 141                 if (document.down()) {
 142                     if (topLine < document.getLineNumber()) {
 143                         topLine++;
 144                     }
 145                     alignCursor();
 146                 }
 147             } else {
 148                 if (topLine < document.getLineCount() - getHeight()) {
 149                     topLine++;
 150                     setCursorY(getCursorY() - 1);
 151                 }
 152             }
 153             return;
 154         }
 155
 156         if (mouse.isMouse1()) {
 157             // Set the row and column
 158             int newLine = topLine + mouse.getY();
 159             int newX = leftColumn + mouse.getX();
 160             if (newLine > document.getLineCount()) {
 161                 // Go to the end
 162                 document.setLineNumber(document.getLineCount() - 1);
 163                 document.end();
 164                 if (document.getLineCount() > getHeight()) {
 165                     setCursorY(getHeight() - 1);
 166                 } else {
 167                     setCursorY(document.getLineCount() - 1);
 168                 }
 169                 alignCursor();
 170                 return;
 171             }
 172
 173             document.setLineNumber(newLine);
 174             setCursorY(mouse.getY());
 175             if (newX > document.getCurrentLine().getDisplayLength()) {
 176                 document.end();
 177                 alignCursor();
 178             } else {
 179                 setCursorX(mouse.getX());
 180             }
 181             return;
 182         }
 183
 184         // Pass to children
 185         super.onMouseDown(mouse);
 186     }
 187
 188     /**
 189      * Align visible cursor with document cursor.
 190      */
 191     private void alignCursor() {
 192         int width = getWidth();
 193
 194         int desiredX = document.getCursor() - leftColumn;
 195         if (desiredX < 0) {
 196             // We need to push the screen to the left.
 197             leftColumn = document.getCursor();
 198         } else if (desiredX > width - 1) {
 199             // We need to push the screen to the right.
 200             leftColumn = document.getCursor() - (width - 1);
 201         }
 202
 203         /*
 204         System.err.println("document cursor " + document.getCursor() +
 205             " leftColumn " + leftColumn);
 206          */
 207
 208         setCursorX(document.getCursor() - leftColumn);
 209     }
 210
 211     /**
 212      * Handle keystrokes.
 213      *
 214      * @param keypress keystroke event
 215      */
 216     @Override
 217     public void onKeypress(final TKeypressEvent keypress) {
 218         if (keypress.equals(kbLeft)) {
 219             if (document.left()) {
 220                 alignCursor();
 221             }
 222         } else if (keypress.equals(kbRight)) {
 223             if (document.right()) {
 224                 alignCursor();
 225             }
 226         } else if (keypress.equals(kbUp)) {
 227             if (document.up()) {
 228                 if (getCursorY() > 0) {
 229                     setCursorY(getCursorY() - 1);
 230                 } else {
 231                     if (topLine > 0) {
 232                         topLine--;
 233                     }
 234                 }
 235                 alignCursor();
 236             }
 237         } else if (keypress.equals(kbDown)) {
 238             if (document.down()) {
 239                 if (getCursorY() < getHeight() - 1) {
 240                     setCursorY(getCursorY() + 1);
 241                 } else {
 242                     if (topLine < document.getLineCount() - getHeight()) {
 243                         topLine++;
 244                     }
 245                 }
 246                 alignCursor();
 247             }
 248         } else if (keypress.equals(kbPgUp)) {
 249             for (int i = 0; i < getHeight() - 1; i++) {
 250                 if (document.up()) {
 251                     if (getCursorY() > 0) {
 252                         setCursorY(getCursorY() - 1);
 253                     } else {
 254                         if (topLine > 0) {
 255                             topLine--;
 256                         }
 257                     }
 258                     alignCursor();
 259                 } else {
 260                     break;
 261                 }
 262             }
 263         } else if (keypress.equals(kbPgDn)) {
 264             for (int i = 0; i < getHeight() - 1; i++) {
 265                 if (document.down()) {
 266                     if (getCursorY() < getHeight() - 1) {
 267                         setCursorY(getCursorY() + 1);
 268                     } else {
 269                         if (topLine < document.getLineCount() - getHeight()) {
 270                             topLine++;
 271                         }
 272                     }
 273                     alignCursor();
 274                 } else {
 275                     break;
 276                 }
 277             }
 278         } else if (keypress.equals(kbHome)) {
 279             if (document.home()) {
 280                 leftColumn = 0;
 281                 if (leftColumn < 0) {
 282                     leftColumn = 0;
 283                 }
 284                 setCursorX(0);
 285             }
 286         } else if (keypress.equals(kbEnd)) {
 287             if (document.end()) {
 288                 alignCursor();
 289             }
 290         } else if (keypress.equals(kbCtrlHome)) {
 291             document.setLineNumber(0);
 292             document.home();
 293             topLine = 0;
 294             leftColumn = 0;
 295             setCursorX(0);
 296             setCursorY(0);
 297         } else if (keypress.equals(kbCtrlEnd)) {
 298             document.setLineNumber(document.getLineCount() - 1);
 299             document.end();
 300             topLine = document.getLineCount() - getHeight();
 301             if (topLine < 0) {
 302                 topLine = 0;
 303             }
 304             if (document.getLineCount() > getHeight()) {
 305                 setCursorY(getHeight() - 1);
 306             } else {
 307                 setCursorY(document.getLineCount() - 1);
 308             }
 309             alignCursor();
 310         } else if (keypress.equals(kbIns)) {
 311             document.setOverwrite(!document.getOverwrite());
 312         } else if (keypress.equals(kbDel)) {
 313             document.del();
 314         } else if (keypress.equals(kbBackspace)) {
 315             document.backspace();
 316             alignCursor();
 317         } else if (!keypress.getKey().isFnKey()
 318             && !keypress.getKey().isAlt()
 319             && !keypress.getKey().isCtrl()
 320         ) {
 321             // Plain old keystroke, process it
 322             document.addChar(keypress.getKey().getChar());
 323         } else {
 324             // Pass other keys (tab etc.) on to TWidget
 325             super.onKeypress(keypress);
 326         }
 327     }
 328
 329     /**
 330      * Method that subclasses can override to handle window/screen resize
 331      * events.
 332      *
 333      * @param resize resize event
 334      */
 335     @Override
 336     public void onResize(final TResizeEvent resize) {
 337         // Change my width/height, and pull the cursor in as needed.
 338         if (resize.getType() == TResizeEvent.Type.WIDGET) {
 339             setWidth(resize.getWidth());
 340             setHeight(resize.getHeight());
 341             // See if the cursor is now outside the window, and if so move
 342             // things.
 343             if (getCursorX() >= getWidth()) {
 344                 leftColumn += getCursorX() - (getWidth() - 1);
 345                 setCursorX(getWidth() - 1);
 346             }
 347             if (getCursorY() >= getHeight()) {
 348                 topLine += getCursorY() - (getHeight() - 1);
 349                 setCursorY(getHeight() - 1);
 350             }
 351         } else {
 352             // Let superclass handle it
 353             super.onResize(resize);
 354         }
 355     }
 356
 357 }