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