src/jexer/TText.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 static jexer.TKeypress.kbDown;
  32 import static jexer.TKeypress.kbEnd;
  33 import static jexer.TKeypress.kbHome;
  34 import static jexer.TKeypress.kbLeft;
  35 import static jexer.TKeypress.kbPgDn;
  36 import static jexer.TKeypress.kbPgUp;
  37 import static jexer.TKeypress.kbRight;
  38 import static jexer.TKeypress.kbUp;
  39
  40 import java.util.LinkedList;
  41 import java.util.List;
  42
  43 import jexer.bits.CellAttributes;
  44 import jexer.event.TKeypressEvent;
  45 import jexer.event.TMouseEvent;
  46
  47 /**
  48  * TText implements a simple scrollable text area. It reflows automatically on
  49  * resize.
  50  */
  51 public final class TText extends TWidget {
  52
  53     /**
  54      * Text to display.
  55      */
  56     private String text;
  57
  58     /**
  59      * Text converted to lines.
  60      */
  61     private List<String> lines;
  62
  63     /**
  64      * Text color.
  65      */
  66     private String colorKey;
  67
  68     /**
  69      * Vertical scrollbar.
  70      */
  71     private TVScroller vScroller;
  72
  73     /**
  74      * Horizontal scrollbar.
  75      */
  76     private THScroller hScroller;
  77
  78     /**
  79      * Maximum width of a single line.
  80      */
  81     private int maxLineWidth;
  82
  83     /**
  84      * Number of lines between each paragraph.
  85      */
  86     private int lineSpacing = 1;
  87
  88     /**
  89      * Convenience method used by TWindowLoggerOutput.
  90      *
  91      * @param line new line to add
  92      */
  93     public void addLine(final String line) {
  94         if (text.length() == 0) {
  95             text = line;
  96         } else {
  97             text += "\n\n";
  98             text += line;
  99         }
 100         reflow();
 101     }
 102
 103     /**
 104      * Recompute the bounds for the scrollbars.
 105      */
 106     private void computeBounds() {
 107         maxLineWidth = 0;
 108         for (String line : lines) {
 109             if (line.length() > maxLineWidth) {
 110                 maxLineWidth = line.length();
 111             }
 112         }
 113
 114         vScroller.setBottomValue((lines.size() - getHeight()) + 1);
 115         if (vScroller.getBottomValue() < 0) {
 116             vScroller.setBottomValue(0);
 117         }
 118         if (vScroller.getValue() > vScroller.getBottomValue()) {
 119             vScroller.setValue(vScroller.getBottomValue());
 120         }
 121
 122         hScroller.setRightValue((maxLineWidth - getWidth()) + 1);
 123         if (hScroller.getRightValue() < 0) {
 124             hScroller.setRightValue(0);
 125         }
 126         if (hScroller.getValue() > hScroller.getRightValue()) {
 127             hScroller.setValue(hScroller.getRightValue());
 128         }
 129     }
 130
 131     /**
 132      * Insert newlines into a string to wrap it to a maximum column. Terminate
 133      * the final string with a newline. Note that interior newlines are
 134      * converted to spaces.
 135      *
 136      * @param str the string
 137      * @param n the maximum number of characters in a line
 138      * @return the wrapped string
 139      */
 140     private String wrap(final String str, final int n) {
 141         assert (n > 0);
 142
 143         StringBuilder sb = new StringBuilder();
 144         StringBuilder word = new StringBuilder();
 145         int col = 0;
 146         for (int i = 0; i < str.length(); i++) {
 147             char ch = str.charAt(i);
 148             if (ch == '\n') {
 149                 ch = ' ';
 150             }
 151             if (ch == ' ') {
 152                 sb.append(word.toString());
 153                 sb.append(ch);
 154                 if (word.length() >= (n - 1)) {
 155                     sb.append('\n');
 156                     col = 0;
 157                 }
 158                 word = new StringBuilder();
 159             } else {
 160                 word.append(ch);
 161             }
 162
 163             col++;
 164             if (col >= (n - 1)) {
 165                 sb.append('\n');
 166                 col = 0;
 167             }
 168         }
 169         sb.append(word.toString());
 170         sb.append('\n');
 171         return sb.toString();
 172     }
 173
 174     /**
 175      * Resize text and scrollbars for a new width/height.
 176      */
 177     public void reflow() {
 178         // Reset the lines
 179         lines.clear();
 180
 181         // Break up text into paragraphs
 182         String[] paragraphs = text.split("\n\n");
 183         for (String p : paragraphs) {
 184             String paragraph = wrap(p, getWidth() - 1);
 185             for (String line : paragraph.split("\n")) {
 186                 lines.add(line);
 187             }
 188             for (int i = 0; i < lineSpacing; i++) {
 189                 lines.add("");
 190             }
 191         }
 192
 193         // Start at the top
 194         if (vScroller == null) {
 195             vScroller = new TVScroller(this, getWidth() - 1, 0, getHeight() - 1);
 196             vScroller.setTopValue(0);
 197             vScroller.setValue(0);
 198         } else {
 199             vScroller.setX(getWidth() - 1);
 200             vScroller.setHeight(getHeight() - 1);
 201         }
 202         vScroller.setBigChange(getHeight() - 1);
 203
 204         // Start at the left
 205         if (hScroller == null) {
 206             hScroller = new THScroller(this, 0, getHeight() - 1, getWidth() - 1);
 207             hScroller.setLeftValue(0);
 208             hScroller.setValue(0);
 209         } else {
 210             hScroller.setY(getHeight() - 1);
 211             hScroller.setWidth(getWidth() - 1);
 212         }
 213         hScroller.setBigChange(getWidth() - 1);
 214
 215         computeBounds();
 216     }
 217
 218     /**
 219      * Public constructor.
 220      *
 221      * @param parent parent widget
 222      * @param text text on the screen
 223      * @param x column relative to parent
 224      * @param y row relative to parent
 225      * @param width width of text area
 226      * @param height height of text area
 227      */
 228     public TText(final TWidget parent, final String text, final int x,
 229             final int y, final int width, final int height) {
 230
 231         this(parent, text, x, y, width, height, "ttext");
 232     }
 233
 234     /**
 235      * Public constructor.
 236      *
 237      * @param parent parent widget
 238      * @param text text on the screen
 239      * @param x column relative to parent
 240      * @param y row relative to parent
 241      * @param width width of text area
 242      * @param height height of text area
 243      * @param colorKey ColorTheme key color to use for foreground
 244      * text. Default is "ttext".
 245      */
 246     public TText(final TWidget parent, final String text, final int x,
 247             final int y, final int width, final int height,
 248             final String colorKey) {
 249
 250         // Set parent and window
 251         super(parent, x, y, width, height);
 252
 253         this.text = text;
 254         this.colorKey = colorKey;
 255
 256         lines = new LinkedList<String>();
 257
 258         reflow();
 259     }
 260
 261     /**
 262      * Draw the text box.
 263      */
 264     @Override
 265     public void draw() {
 266         // Setup my color
 267         CellAttributes color = getTheme().getColor(colorKey);
 268
 269         int begin = vScroller.getValue();
 270         int topY = 0;
 271         for (int i = begin; i < lines.size(); i++) {
 272             String line = lines.get(i);
 273             if (hScroller.getValue() < line.length()) {
 274                 line = line.substring(hScroller.getValue());
 275             } else {
 276                 line = "";
 277             }
 278             String formatString = "%-" + Integer.toString(getWidth() - 1) + "s";
 279             getScreen().putStringXY(0, topY, String.format(formatString, line),
 280                     color);
 281             topY++;
 282
 283             if (topY >= (getHeight() - 1)) {
 284                 break;
 285             }
 286         }
 287
 288         // Pad the rest with blank lines
 289         for (int i = topY; i < (getHeight() - 1); i++) {
 290             getScreen().hLineXY(0, i, getWidth() - 1, ' ', color);
 291         }
 292
 293     }
 294
 295     /**
 296      * Handle mouse press events.
 297      *
 298      * @param mouse mouse button press event
 299      */
 300     @Override
 301     public void onMouseDown(final TMouseEvent mouse) {
 302         if (mouse.isMouseWheelUp()) {
 303             vScroller.decrement();
 304             return;
 305         }
 306         if (mouse.isMouseWheelDown()) {
 307             vScroller.increment();
 308             return;
 309         }
 310
 311         // Pass to children
 312         super.onMouseDown(mouse);
 313     }
 314
 315     /**
 316      * Handle keystrokes.
 317      *
 318      * @param keypress keystroke event
 319      */
 320     @Override
 321     public void onKeypress(final TKeypressEvent keypress) {
 322         if (keypress.equals(kbLeft)) {
 323             hScroller.decrement();
 324         } else if (keypress.equals(kbRight)) {
 325             hScroller.increment();
 326         } else if (keypress.equals(kbUp)) {
 327             vScroller.decrement();
 328         } else if (keypress.equals(kbDown)) {
 329             vScroller.increment();
 330         } else if (keypress.equals(kbPgUp)) {
 331             vScroller.bigDecrement();
 332         } else if (keypress.equals(kbPgDn)) {
 333             vScroller.bigIncrement();
 334         } else if (keypress.equals(kbHome)) {
 335             vScroller.toTop();
 336         } else if (keypress.equals(kbEnd)) {
 337             vScroller.toBottom();
 338         } else {
 339             // Pass other keys (tab etc.) on
 340             super.onKeypress(keypress);
 341         }
 342     }
 343
 344 }