src/jexer/io/ECMA48Screen.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.io;
  32
  33 import jexer.bits.Cell;
  34 import jexer.bits.CellAttributes;
  35
  36 /**
  37  * This Screen implementation draws to an xterm/ANSI X3.64/ECMA-48 type
  38  * terminal.
  39  */
  40 public final class ECMA48Screen extends Screen {
  41
  42     /**
  43      * Emit debugging to stderr.
  44      */
  45     private boolean debugToStderr;
  46
  47     /**
  48      * We call terminal.cursor() so need the instance.
  49      */
  50     private ECMA48Terminal terminal;
  51
  52     /**
  53      * Public constructor.
  54      *
  55      * @param terminal ECMA48Terminal to use
  56      */
  57     public ECMA48Screen(final ECMA48Terminal terminal) {
  58         debugToStderr = false;
  59
  60         this.terminal = terminal;
  61
  62         // Query the screen size
  63         setDimensions(terminal.getSessionInfo().getWindowWidth(),
  64             terminal.getSessionInfo().getWindowHeight());
  65     }
  66
  67     /**
  68      * Perform a somewhat-optimal rendering of a line.
  69      *
  70      * @param y row coordinate.  0 is the top-most row.
  71      * @param sb StringBuilder to write escape sequences to
  72      * @param lastAttr cell attributes from the last call to flushLine
  73      */
  74     private void flushLine(final int y, final StringBuilder sb,
  75         CellAttributes lastAttr) {
  76
  77         int lastX = -1;
  78         int textEnd = 0;
  79         for (int x = 0; x < width; x++) {
  80             Cell lCell = logical[x][y];
  81             if (!lCell.isBlank()) {
  82                 textEnd = x;
  83             }
  84         }
  85         // Push textEnd to first column beyond the text area
  86         textEnd++;
  87
  88         // DEBUG
  89         // reallyCleared = true;
  90
  91         for (int x = 0; x < width; x++) {
  92             Cell lCell = logical[x][y];
  93             Cell pCell = physical[x][y];
  94
  95             if (!lCell.equals(pCell) || reallyCleared) {
  96
  97                 if (debugToStderr) {
  98                     System.err.printf("\n--\n");
  99                     System.err.printf(" Y: %d X: %d\n", y, x);
 100                     System.err.printf("   lCell: %s\n", lCell);
 101                     System.err.printf("   pCell: %s\n", pCell);
 102                     System.err.printf("    ====    \n");
 103                 }
 104
 105                 if (lastAttr == null) {
 106                     lastAttr = new CellAttributes();
 107                     sb.append(terminal.normal());
 108                 }
 109
 110                 // Place the cell
 111                 if ((lastX != (x - 1)) || (lastX == -1)) {
 112                     // Advancing at least one cell, or the first gotoXY
 113                     sb.append(terminal.gotoXY(x, y));
 114                 }
 115
 116                 assert (lastAttr != null);
 117
 118                 if ((x == textEnd) && (textEnd < width - 1)) {
 119                     assert (lCell.isBlank());
 120
 121                     for (int i = x; i < width; i++) {
 122                         assert (logical[i][y].isBlank());
 123                         // Physical is always updatesd
 124                         physical[i][y].reset();
 125                     }
 126
 127                     // Clear remaining line
 128                     sb.append(terminal.clearRemainingLine());
 129                     lastAttr.reset();
 130                     return;
 131                 }
 132
 133                 // Now emit only the modified attributes
 134                 if ((lCell.getForeColor() != lastAttr.getForeColor())
 135                     && (lCell.getBackColor() != lastAttr.getBackColor())
 136                     && (lCell.isBold() == lastAttr.isBold())
 137                     && (lCell.isReverse() == lastAttr.isReverse())
 138                     && (lCell.isUnderline() == lastAttr.isUnderline())
 139                     && (lCell.isBlink() == lastAttr.isBlink())
 140                 ) {
 141                     // Both colors changed, attributes the same
 142                     sb.append(terminal.color(lCell.getForeColor(),
 143                             lCell.getBackColor()));
 144
 145                     if (debugToStderr) {
 146                         System.err.printf("1 Change only fore/back colors\n");
 147                     }
 148                 } else if ((lCell.getForeColor() != lastAttr.getForeColor())
 149                     && (lCell.getBackColor() != lastAttr.getBackColor())
 150                     && (lCell.isBold() != lastAttr.isBold())
 151                     && (lCell.isReverse() != lastAttr.isReverse())
 152                     && (lCell.isUnderline() != lastAttr.isUnderline())
 153                     && (lCell.isBlink() != lastAttr.isBlink())
 154                 ) {
 155                     // Everything is different
 156                     sb.append(terminal.color(lCell.getForeColor(),
 157                             lCell.getBackColor(),
 158                             lCell.isBold(), lCell.isReverse(),
 159                             lCell.isBlink(),
 160                             lCell.isUnderline()));
 161
 162                     if (debugToStderr) {
 163                         System.err.printf("2 Set all attributes\n");
 164                     }
 165                 } else if ((lCell.getForeColor() != lastAttr.getForeColor())
 166                     && (lCell.getBackColor() == lastAttr.getBackColor())
 167                     && (lCell.isBold() == lastAttr.isBold())
 168                     && (lCell.isReverse() == lastAttr.isReverse())
 169                     && (lCell.isUnderline() == lastAttr.isUnderline())
 170                     && (lCell.isBlink() == lastAttr.isBlink())
 171                 ) {
 172
 173                     // Attributes same, foreColor different
 174                     sb.append(terminal.color(lCell.getForeColor(), true));
 175
 176                     if (debugToStderr) {
 177                         System.err.printf("3 Change foreColor\n");
 178                     }
 179                 } else if ((lCell.getForeColor() == lastAttr.getForeColor())
 180                     && (lCell.getBackColor() != lastAttr.getBackColor())
 181                     && (lCell.isBold() == lastAttr.isBold())
 182                     && (lCell.isReverse() == lastAttr.isReverse())
 183                     && (lCell.isUnderline() == lastAttr.isUnderline())
 184                     && (lCell.isBlink() == lastAttr.isBlink())
 185                 ) {
 186                     // Attributes same, backColor different
 187                     sb.append(terminal.color(lCell.getBackColor(), false));
 188
 189                     if (debugToStderr) {
 190                         System.err.printf("4 Change backColor\n");
 191                     }
 192                 } else if ((lCell.getForeColor() == lastAttr.getForeColor())
 193                     && (lCell.getBackColor() == lastAttr.getBackColor())
 194                     && (lCell.isBold() == lastAttr.isBold())
 195                     && (lCell.isReverse() == lastAttr.isReverse())
 196                     && (lCell.isUnderline() == lastAttr.isUnderline())
 197                     && (lCell.isBlink() == lastAttr.isBlink())
 198                 ) {
 199
 200                     // All attributes the same, just print the char
 201                     // NOP
 202
 203                     if (debugToStderr) {
 204                         System.err.printf("5 Only emit character\n");
 205                     }
 206                 } else {
 207                     // Just reset everything again
 208                     sb.append(terminal.color(lCell.getForeColor(),
 209                             lCell.getBackColor(),
 210                             lCell.isBold(),
 211                             lCell.isReverse(),
 212                             lCell.isBlink(),
 213                             lCell.isUnderline()));
 214
 215                     if (debugToStderr) {
 216                         System.err.printf("6 Change all attributes\n");
 217                     }
 218                 }
 219                 // Emit the character
 220                 sb.append(lCell.getChar());
 221
 222                 // Save the last rendered cell
 223                 lastX = x;
 224                 lastAttr.setTo(lCell);
 225
 226                 // Physical is always updated
 227                 physical[x][y].setTo(lCell);
 228
 229             } // if (!lCell.equals(pCell) || (reallyCleared == true))
 230
 231         } // for (int x = 0; x < width; x++)
 232     }
 233
 234     /**
 235      * Render the screen to a string that can be emitted to something that
 236      * knows how to process ECMA-48/ANSI X3.64 escape sequences.
 237      *
 238      * @return escape sequences string that provides the updates to the
 239      * physical screen
 240      */
 241     private String flushString() {
 242         if (!dirty) {
 243             assert (!reallyCleared);
 244             return "";
 245         }
 246
 247         CellAttributes attr = null;
 248
 249         StringBuilder sb = new StringBuilder();
 250         if (reallyCleared) {
 251             attr = new CellAttributes();
 252             sb.append(terminal.clearAll());
 253         }
 254
 255         for (int y = 0; y < height; y++) {
 256             flushLine(y, sb, attr);
 257         }
 258
 259         dirty = false;
 260         reallyCleared = false;
 261
 262         String result = sb.toString();
 263         if (debugToStderr) {
 264             System.err.printf("flushString(): %s\n", result);
 265         }
 266         return result;
 267     }
 268
 269     /**
 270      * Push the logical screen to the physical device.
 271      */
 272     @Override
 273     public void flushPhysical() {
 274         String result = flushString();
 275         if ((cursorVisible)
 276             && (cursorY <= height - 1)
 277             && (cursorX <= width - 1)
 278         ) {
 279             result += terminal.cursor(true);
 280             result += terminal.gotoXY(cursorX, cursorY);
 281         } else {
 282             result += terminal.cursor(false);
 283         }
 284         terminal.getOutput().write(result);
 285         terminal.flush();
 286     }
 287 }