src/jexer/TTerminalWidget.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 java.awt.Font;
  32 import java.awt.FontMetrics;
  33 import java.awt.Graphics2D;
  34 import java.awt.image.BufferedImage;
  35
  36 import java.io.InputStream;
  37 import java.io.IOException;
  38 import java.lang.reflect.Field;
  39 import java.text.MessageFormat;
  40 import java.util.ArrayList;
  41 import java.util.HashMap;
  42 import java.util.List;
  43 import java.util.Map;
  44 import java.util.ResourceBundle;
  45
  46 import jexer.backend.ECMA48Terminal;
  47 import jexer.backend.GlyphMaker;
  48 import jexer.backend.MultiScreen;
  49 import jexer.backend.SwingTerminal;
  50 import jexer.bits.Cell;
  51 import jexer.bits.CellAttributes;
  52 import jexer.event.TKeypressEvent;
  53 import jexer.event.TMenuEvent;
  54 import jexer.event.TMouseEvent;
  55 import jexer.event.TResizeEvent;
  56 import jexer.menu.TMenu;
  57 import jexer.tterminal.DisplayLine;
  58 import jexer.tterminal.DisplayListener;
  59 import jexer.tterminal.ECMA48;
  60 import static jexer.TKeypress.*;
  61
  62 /**
  63  * TTerminalWindow exposes a ECMA-48 / ANSI X3.64 style terminal in a widget.
  64  */
  65 public class TTerminalWidget extends TScrollableWidget
  66                              implements DisplayListener {
  67
  68     /**
  69      * Translated strings.
  70      */
  71     private static final ResourceBundle i18n = ResourceBundle.getBundle(TTerminalWidget.class.getName());
  72
  73     // ------------------------------------------------------------------------
  74     // Variables --------------------------------------------------------------
  75     // ------------------------------------------------------------------------
  76
  77     /**
  78      * The emulator.
  79      */
  80     private ECMA48 emulator;
  81
  82     /**
  83      * The Process created by the shell spawning constructor.
  84      */
  85     private Process shell;
  86
  87     /**
  88      * If true, we are using the ptypipe utility to support dynamic window
  89      * resizing.  ptypipe is available at
  90      * https://gitlab.com/klamonte/ptypipe .
  91      */
  92     private boolean ptypipe = false;
  93
  94     /**
  95      * Double-height font.
  96      */
  97     private GlyphMaker doubleFont;
  98
  99     /**
 100      * Last text width value.
 101      */
 102     private int lastTextWidth = -1;
 103
 104     /**
 105      * Last text height value.
 106      */
 107     private int lastTextHeight = -1;
 108
 109     /**
 110      * The blink state, used only by ECMA48 backend and when double-width
 111      * chars must be drawn.
 112      */
 113     private boolean blinkState = true;
 114
 115     /**
 116      * Timer flag, used only by ECMA48 backend and when double-width chars
 117      * must be drawn.
 118      */
 119     private boolean haveTimer = false;
 120
 121     /**
 122      * The last seen scrollback lines.
 123      */
 124     private List<DisplayLine> scrollback;
 125
 126     /**
 127      * The last seen display lines.
 128      */
 129     private List<DisplayLine> display;
 130
 131     /**
 132      * If true, the display has changed and needs updating.
 133      */
 134     private volatile boolean dirty = true;
 135
 136     /**
 137      * Time that the display was last updated.
 138      */
 139     private long lastUpdateTime = 0;
 140
 141     /**
 142      * If true, hide the mouse after typing a keystroke.
 143      */
 144     private boolean hideMouseWhenTyping = true;
 145
 146     /**
 147      * If true, the mouse should not be displayed because a keystroke was
 148      * typed.
 149      */
 150     private boolean typingHidMouse = false;
 151
 152     /**
 153      * The return value from the emulator.
 154      */
 155     private int exitValue = -1;
 156
 157     /**
 158      * Title to expose to a window.
 159      */
 160     private String title = "";
 161
 162     // ------------------------------------------------------------------------
 163     // Constructors -----------------------------------------------------------
 164     // ------------------------------------------------------------------------
 165
 166     /**
 167      * Public constructor spawns a custom command line.
 168      *
 169      * @param parent parent widget
 170      * @param x column relative to parent
 171      * @param y row relative to parent
 172      * @param commandLine the command line to execute
 173      */
 174     public TTerminalWidget(final TWidget parent, final int x,
 175         final int y, final String commandLine) {
 176
 177         this(parent, x, y, commandLine.split("\\s+"));
 178     }
 179
 180     /**
 181      * Public constructor spawns a custom command line.
 182      *
 183      * @param parent parent widget
 184      * @param x column relative to parent
 185      * @param y row relative to parent
 186      * @param command the command line to execute
 187      */
 188     public TTerminalWidget(final TWidget parent, final int x,
 189         final int y, final String [] command) {
 190
 191         super(parent, x, y, 80, 24);
 192
 193         String [] fullCommand;
 194
 195         // Spawn a shell and pass its I/O to the other constructor.
 196         if ((System.getProperty("jexer.TTerminal.ptypipe") != null)
 197             && (System.getProperty("jexer.TTerminal.ptypipe").
 198                 equals("true"))
 199         ) {
 200             ptypipe = true;
 201             fullCommand = new String[command.length + 1];
 202             fullCommand[0] = "ptypipe";
 203             System.arraycopy(command, 0, fullCommand, 1, command.length);
 204         } else if (System.getProperty("os.name").startsWith("Windows")) {
 205             fullCommand = new String[3];
 206             fullCommand[0] = "cmd";
 207             fullCommand[1] = "/c";
 208             fullCommand[2] = stringArrayToString(command);
 209         } else if (System.getProperty("os.name").startsWith("Mac")) {
 210             fullCommand = new String[6];
 211             fullCommand[0] = "script";
 212             fullCommand[1] = "-q";
 213             fullCommand[2] = "-F";
 214             fullCommand[3] = "/dev/null";
 215             fullCommand[4] = "-c";
 216             fullCommand[5] = stringArrayToString(command);
 217         } else {
 218             // Default: behave like Linux
 219             fullCommand = new String[5];
 220             fullCommand[0] = "script";
 221             fullCommand[1] = "-fqe";
 222             fullCommand[2] = "/dev/null";
 223             fullCommand[3] = "-c";
 224             fullCommand[4] = stringArrayToString(command);
 225         }
 226         spawnShell(fullCommand);
 227     }
 228
 229     /**
 230      * Public constructor spawns a shell.
 231      *
 232      * @param parent parent widget
 233      * @param x column relative to parent
 234      * @param y row relative to parent
 235      */
 236     public TTerminalWidget(final TWidget parent, final int x, final int y) {
 237
 238         super(parent, x, y, 80, 24);
 239
 240         if (System.getProperty("jexer.TTerminal.shell") != null) {
 241             String shell = System.getProperty("jexer.TTerminal.shell");
 242             if (shell.trim().startsWith("ptypipe")) {
 243                 ptypipe = true;
 244             }
 245             spawnShell(shell.split("\\s+"));
 246             return;
 247         }
 248
 249         String cmdShellWindows = "cmd.exe";
 250
 251         // You cannot run a login shell in a bare Process interactively, due
 252         // to libc's behavior of buffering when stdin/stdout aren't a tty.
 253         // Use 'script' instead to run a shell in a pty.  And because BSD and
 254         // GNU differ on the '-f' vs '-F' flags, we need two different
 255         // commands.  Lovely.
 256         String cmdShellGNU = "script -fqe /dev/null";
 257         String cmdShellBSD = "script -q -F /dev/null";
 258
 259         // ptypipe is another solution that permits dynamic window resizing.
 260         String cmdShellPtypipe = "ptypipe /bin/bash --login";
 261
 262         // Spawn a shell and pass its I/O to the other constructor.
 263         if ((System.getProperty("jexer.TTerminal.ptypipe") != null)
 264             && (System.getProperty("jexer.TTerminal.ptypipe").
 265                 equals("true"))
 266         ) {
 267             ptypipe = true;
 268             spawnShell(cmdShellPtypipe.split("\\s+"));
 269         } else if (System.getProperty("os.name").startsWith("Windows")) {
 270             spawnShell(cmdShellWindows.split("\\s+"));
 271         } else if (System.getProperty("os.name").startsWith("Mac")) {
 272             spawnShell(cmdShellBSD.split("\\s+"));
 273         } else if (System.getProperty("os.name").startsWith("Linux")) {
 274             spawnShell(cmdShellGNU.split("\\s+"));
 275         } else {
 276             // When all else fails, assume GNU.
 277             spawnShell(cmdShellGNU.split("\\s+"));
 278         }
 279     }
 280
 281     // ------------------------------------------------------------------------
 282     // TScrollableWidget ------------------------------------------------------
 283     // ------------------------------------------------------------------------
 284
 285     /**
 286      * Draw the display buffer.
 287      */
 288     @Override
 289     public void draw() {
 290         int width = getDisplayWidth();
 291         boolean syncEmulator = false;
 292         if ((System.currentTimeMillis() - lastUpdateTime >= 25)
 293             && (dirty == true)
 294         ) {
 295             // Too much time has passed, draw it all.
 296             syncEmulator = true;
 297         } else if (emulator.isReading() && (dirty == false)) {
 298             // Wait until the emulator has brought more data in.
 299             syncEmulator = false;
 300         } else if (!emulator.isReading() && (dirty == true)) {
 301             // The emulator won't receive more data, update the display.
 302             syncEmulator = true;
 303         }
 304
 305         if ((syncEmulator == true)
 306             || (scrollback == null)
 307             || (display == null)
 308         ) {
 309             // We want to minimize the amount of time we have the emulator
 310             // locked.  Grab a copy of its display.
 311             synchronized (emulator) {
 312                 // Update the scroll bars
 313                 reflowData();
 314
 315                 if ((scrollback == null) || emulator.isReading()) {
 316                     scrollback = copyBuffer(emulator.getScrollbackBuffer());
 317                     display = copyBuffer(emulator.getDisplayBuffer());
 318                 }
 319                 width = emulator.getWidth();
 320             }
 321             dirty = false;
 322         }
 323
 324         // Draw the box using my superclass
 325         super.draw();
 326
 327         // Put together the visible rows
 328         int visibleHeight = getHeight();
 329         int visibleBottom = scrollback.size() + display.size()
 330                 + getVerticalValue();
 331         assert (visibleBottom >= 0);
 332
 333         List<DisplayLine> preceedingBlankLines = new ArrayList<DisplayLine>();
 334         int visibleTop = visibleBottom - visibleHeight;
 335         if (visibleTop < 0) {
 336             for (int i = visibleTop; i < 0; i++) {
 337                 preceedingBlankLines.add(emulator.getBlankDisplayLine());
 338             }
 339             visibleTop = 0;
 340         }
 341         assert (visibleTop >= 0);
 342
 343         List<DisplayLine> displayLines = new ArrayList<DisplayLine>();
 344         displayLines.addAll(scrollback);
 345         displayLines.addAll(display);
 346
 347         List<DisplayLine> visibleLines = new ArrayList<DisplayLine>();
 348         visibleLines.addAll(preceedingBlankLines);
 349         visibleLines.addAll(displayLines.subList(visibleTop,
 350                 visibleBottom));
 351
 352         visibleHeight -= visibleLines.size();
 353         assert (visibleHeight >= 0);
 354
 355         // Now draw the emulator screen
 356         int row = 0;
 357         for (DisplayLine line: visibleLines) {
 358             int widthMax = width;
 359             if (line.isDoubleWidth()) {
 360                 widthMax /= 2;
 361             }
 362             if (widthMax > getWidth()) {
 363                 widthMax = getWidth();
 364             }
 365             for (int i = 0; i < widthMax; i++) {
 366                 Cell ch = line.charAt(i);
 367
 368                 if (ch.isImage()) {
 369                     putCharXY(i, row, ch);
 370                     continue;
 371                 }
 372
 373                 Cell newCell = new Cell(ch);
 374                 boolean reverse = line.isReverseColor() ^ ch.isReverse();
 375                 newCell.setReverse(false);
 376                 if (reverse) {
 377                     if (ch.getForeColorRGB() < 0) {
 378                         newCell.setBackColor(ch.getForeColor());
 379                         newCell.setBackColorRGB(-1);
 380                     } else {
 381                         newCell.setBackColorRGB(ch.getForeColorRGB());
 382                     }
 383                     if (ch.getBackColorRGB() < 0) {
 384                         newCell.setForeColor(ch.getBackColor());
 385                         newCell.setForeColorRGB(-1);
 386                     } else {
 387                         newCell.setForeColorRGB(ch.getBackColorRGB());
 388                     }
 389                 }
 390                 if (line.isDoubleWidth()) {
 391                     putDoubleWidthCharXY(line, (i * 2), row, newCell);
 392                 } else {
 393                     putCharXY(i, row, newCell);
 394                 }
 395             }
 396             row++;
 397             if (row == getHeight()) {
 398                 // Don't overwrite the box edge
 399                 break;
 400             }
 401         }
 402         CellAttributes background = new CellAttributes();
 403         // Fill in the blank lines on bottom
 404         for (int i = 0; i < visibleHeight; i++) {
 405             hLineXY(0, i + row, getWidth(), ' ', background);
 406         }
 407
 408     }
 409
 410     /**
 411      * Handle window close.
 412      */
 413     @Override
 414     public void close() {
 415         emulator.close();
 416         if (shell != null) {
 417             terminateShellChildProcess();
 418             shell.destroy();
 419             shell = null;
 420         }
 421     }
 422
 423     /**
 424      * Handle window/screen resize events.
 425      *
 426      * @param resize resize event
 427      */
 428     @Override
 429     public void onResize(final TResizeEvent resize) {
 430
 431         // Synchronize against the emulator so we don't stomp on its reader
 432         // thread.
 433         synchronized (emulator) {
 434
 435             if (resize.getType() == TResizeEvent.Type.WIDGET) {
 436                 // Resize the scroll bars
 437                 reflowData();
 438                 placeScrollbars();
 439
 440                 // Get out of scrollback
 441                 setVerticalValue(0);
 442
 443                 if (ptypipe) {
 444                     emulator.setWidth(getWidth());
 445                     emulator.setHeight(getHeight());
 446
 447                     emulator.writeRemote("\033[8;" + getHeight() + ";" +
 448                         getWidth() + "t");
 449                 }
 450             }
 451             return;
 452
 453         } // synchronized (emulator)
 454     }
 455
 456     /**
 457      * Resize scrollbars for a new width/height.
 458      */
 459     @Override
 460     public void reflowData() {
 461
 462         // Synchronize against the emulator so we don't stomp on its reader
 463         // thread.
 464         synchronized (emulator) {
 465
 466             // Pull cursor information
 467             readEmulatorState();
 468
 469             // Vertical scrollbar
 470             setTopValue(getHeight()
 471                 - (emulator.getScrollbackBuffer().size()
 472                     + emulator.getDisplayBuffer().size()));
 473             setVerticalBigChange(getHeight());
 474
 475         } // synchronized (emulator)
 476     }
 477
 478     /**
 479      * Handle keystrokes.
 480      *
 481      * @param keypress keystroke event
 482      */
 483     @Override
 484     public void onKeypress(final TKeypressEvent keypress) {
 485         if (hideMouseWhenTyping) {
 486             typingHidMouse = true;
 487         }
 488
 489         // Scrollback up/down
 490         if (keypress.equals(kbShiftPgUp)
 491             || keypress.equals(kbCtrlPgUp)
 492             || keypress.equals(kbAltPgUp)
 493         ) {
 494             bigVerticalDecrement();
 495             return;
 496         }
 497         if (keypress.equals(kbShiftPgDn)
 498             || keypress.equals(kbCtrlPgDn)
 499             || keypress.equals(kbAltPgDn)
 500         ) {
 501             bigVerticalIncrement();
 502             return;
 503         }
 504
 505         if (emulator.isReading()) {
 506             // Get out of scrollback
 507             setVerticalValue(0);
 508             emulator.addUserEvent(keypress);
 509
 510             // UGLY HACK TIME!  cmd.exe needs CRLF, not just CR, so if
 511             // this is kBEnter then also send kbCtrlJ.
 512             if (keypress.equals(kbEnter)) {
 513                 if (System.getProperty("os.name").startsWith("Windows")
 514                     && (System.getProperty("jexer.TTerminal.cmdHack",
 515                             "true").equals("true"))
 516                 ) {
 517                     emulator.addUserEvent(new TKeypressEvent(kbCtrlJ));
 518                 }
 519             }
 520
 521             readEmulatorState();
 522             return;
 523         }
 524
 525         // Process is closed, honor "normal" TUI keystrokes
 526         super.onKeypress(keypress);
 527     }
 528
 529     /**
 530      * Handle mouse press events.
 531      *
 532      * @param mouse mouse button press event
 533      */
 534     @Override
 535     public void onMouseDown(final TMouseEvent mouse) {
 536         if (hideMouseWhenTyping) {
 537             typingHidMouse = false;
 538         }
 539
 540         // If the emulator is tracking mouse buttons, it needs to see wheel
 541         // events.
 542         if (emulator.getMouseProtocol() == ECMA48.MouseProtocol.OFF) {
 543             if (mouse.isMouseWheelUp()) {
 544                 verticalDecrement();
 545                 return;
 546             }
 547             if (mouse.isMouseWheelDown()) {
 548                 verticalIncrement();
 549                 return;
 550             }
 551         }
 552         if (mouseOnEmulator(mouse)) {
 553             emulator.addUserEvent(mouse);
 554             readEmulatorState();
 555             return;
 556         }
 557
 558         // Emulator didn't consume it, pass it on
 559         super.onMouseDown(mouse);
 560     }
 561
 562     /**
 563      * Handle mouse release events.
 564      *
 565      * @param mouse mouse button release event
 566      */
 567     @Override
 568     public void onMouseUp(final TMouseEvent mouse) {
 569         if (hideMouseWhenTyping) {
 570             typingHidMouse = false;
 571         }
 572
 573         if (mouseOnEmulator(mouse)) {
 574             emulator.addUserEvent(mouse);
 575             readEmulatorState();
 576             return;
 577         }
 578
 579         // Emulator didn't consume it, pass it on
 580         super.onMouseUp(mouse);
 581     }
 582
 583     /**
 584      * Handle mouse motion events.
 585      *
 586      * @param mouse mouse motion event
 587      */
 588     @Override
 589     public void onMouseMotion(final TMouseEvent mouse) {
 590         if (hideMouseWhenTyping) {
 591             typingHidMouse = false;
 592         }
 593
 594         if (mouseOnEmulator(mouse)) {
 595             emulator.addUserEvent(mouse);
 596             readEmulatorState();
 597             return;
 598         }
 599
 600         // Emulator didn't consume it, pass it on
 601         super.onMouseMotion(mouse);
 602     }
 603
 604     // ------------------------------------------------------------------------
 605     // TTerminalWidget --------------------------------------------------------
 606     // ------------------------------------------------------------------------
 607
 608     /**
 609      * Get the desired window title.
 610      *
 611      * @return the title
 612      */
 613     public String getTitle() {
 614         return title;
 615     }
 616
 617     /**
 618      * Returns true if this window does not want the application-wide mouse
 619      * cursor drawn over it.
 620      *
 621      * @return true if this window does not want the application-wide mouse
 622      * cursor drawn over it
 623      */
 624     public boolean hasHiddenMouse() {
 625         return (emulator.hasHiddenMousePointer() || typingHidMouse);
 626     }
 627
 628     /**
 629      * See if the terminal is still running.
 630      *
 631      * @return if true, we are still connected to / reading from the remote
 632      * side
 633      */
 634     public boolean isReading() {
 635         return emulator.isReading();
 636     }
 637
 638     /**
 639      * Convert a string array to a whitespace-separated string.
 640      *
 641      * @param array the string array
 642      * @return a single string
 643      */
 644     private String stringArrayToString(final String [] array) {
 645         StringBuilder sb = new StringBuilder(array[0].length());
 646         for (int i = 0; i < array.length; i++) {
 647             sb.append(array[i]);
 648             if (i < array.length - 1) {
 649                 sb.append(' ');
 650             }
 651         }
 652         return sb.toString();
 653     }
 654
 655     /**
 656      * Spawn the shell.
 657      *
 658      * @param command the command line to execute
 659      */
 660     private void spawnShell(final String [] command) {
 661
 662         /*
 663         System.err.printf("spawnShell(): '%s'\n",
 664             stringArrayToString(command));
 665         */
 666
 667         // We will have vScroller for its data fields and mouse event
 668         // handling, but do not want to draw it.
 669         vScroller = new TVScroller(null, getWidth(), 0, getHeight());
 670         vScroller.setVisible(false);
 671         setBottomValue(0);
 672
 673         title = i18n.getString("windowTitle");
 674
 675         // Assume XTERM
 676         ECMA48.DeviceType deviceType = ECMA48.DeviceType.XTERM;
 677
 678         try {
 679             ProcessBuilder pb = new ProcessBuilder(command);
 680             Map<String, String> env = pb.environment();
 681             env.put("TERM", ECMA48.deviceTypeTerm(deviceType));
 682             env.put("LANG", ECMA48.deviceTypeLang(deviceType, "en"));
 683             env.put("COLUMNS", "80");
 684             env.put("LINES", "24");
 685             pb.redirectErrorStream(true);
 686             shell = pb.start();
 687             emulator = new ECMA48(deviceType, shell.getInputStream(),
 688                 shell.getOutputStream(), this);
 689         } catch (IOException e) {
 690             messageBox(i18n.getString("errorLaunchingShellTitle"),
 691                 MessageFormat.format(i18n.getString("errorLaunchingShellText"),
 692                     e.getMessage()));
 693         }
 694
 695         // Setup the scroll bars
 696         onResize(new TResizeEvent(TResizeEvent.Type.WIDGET, getWidth(),
 697                 getHeight()));
 698
 699         // Pass the correct text cell width/height to the emulator
 700         emulator.setTextWidth(getScreen().getTextWidth());
 701         emulator.setTextHeight(getScreen().getTextHeight());
 702
 703         // Hide mouse when typing option
 704         if (System.getProperty("jexer.TTerminal.hideMouseWhenTyping",
 705                 "true").equals("false")) {
 706
 707             hideMouseWhenTyping = false;
 708         }
 709     }
 710
 711     /**
 712      * Terminate the child of the 'script' process used on POSIX.  This may
 713      * or may not work.
 714      */
 715     private void terminateShellChildProcess() {
 716         int pid = -1;
 717         if (shell.getClass().getName().equals("java.lang.UNIXProcess")) {
 718             /* get the PID on unix/linux systems */
 719             try {
 720                 Field field = shell.getClass().getDeclaredField("pid");
 721                 field.setAccessible(true);
 722                 pid = field.getInt(shell);
 723             } catch (Throwable e) {
 724                 // SQUASH, this didn't work.  Just bail out quietly.
 725                 return;
 726             }
 727         }
 728         if (pid != -1) {
 729             // shell.destroy() works successfully at killing this side of
 730             // 'script'.  But we need to make sure the other side (child
 731             // process) is also killed.
 732             String [] cmdKillIt = {
 733                 "pkill", "-P", Integer.toString(pid)
 734             };
 735             try {
 736                 Runtime.getRuntime().exec(cmdKillIt);
 737             } catch (Throwable e) {
 738                 // SQUASH, this didn't work.  Just bail out quietly.
 739                 return;
 740             }
 741         }
 742     }
 743
 744     /**
 745      * Hook for subclasses to be notified of the shell termination.
 746      */
 747     public void onShellExit() {
 748         if (getParent() instanceof TTerminalWindow) {
 749             ((TTerminalWindow) getParent()).onShellExit();
 750         }
 751         getApplication().postEvent(new TMenuEvent(TMenu.MID_REPAINT));
 752     }
 753
 754     /**
 755      * Copy out variables from the emulator that TTerminal has to expose on
 756      * screen.
 757      */
 758     private void readEmulatorState() {
 759         // Synchronize against the emulator so we don't stomp on its reader
 760         // thread.
 761         synchronized (emulator) {
 762
 763             setCursorX(emulator.getCursorX());
 764             setCursorY(emulator.getCursorY()
 765                 + (getHeight() - emulator.getHeight())
 766                 - getVerticalValue());
 767             setCursorVisible(emulator.isCursorVisible());
 768             if (getCursorX() > getWidth()) {
 769                 setCursorVisible(false);
 770             }
 771             if ((getCursorY() >= getHeight()) || (getCursorY() < 0)) {
 772                 setCursorVisible(false);
 773             }
 774             if (emulator.getScreenTitle().length() > 0) {
 775                 // Only update the title if the shell is still alive
 776                 if (shell != null) {
 777                     title = emulator.getScreenTitle();
 778                 }
 779             }
 780
 781             // Check to see if the shell has died.
 782             if (!emulator.isReading() && (shell != null)) {
 783                 try {
 784                     int rc = shell.exitValue();
 785                     // The emulator exited on its own, all is fine
 786                     title = MessageFormat.format(i18n.
 787                         getString("windowTitleCompleted"), title, rc);
 788                     exitValue = rc;
 789                     shell = null;
 790                     emulator.close();
 791                     onShellExit();
 792                 } catch (IllegalThreadStateException e) {
 793                     // The emulator thread has exited, but the shell Process
 794                     // hasn't figured that out yet.  Do nothing, we will see
 795                     // this in a future tick.
 796                 }
 797             } else if (emulator.isReading() && (shell != null)) {
 798                 // The shell might be dead, let's check
 799                 try {
 800                     int rc = shell.exitValue();
 801                     // If we got here, the shell died.
 802                     title = MessageFormat.format(i18n.
 803                         getString("windowTitleCompleted"), title, rc);
 804                     exitValue = rc;
 805                     shell = null;
 806                     emulator.close();
 807                     onShellExit();
 808                 } catch (IllegalThreadStateException e) {
 809                     // The shell is still running, do nothing.
 810                 }
 811             }
 812
 813         } // synchronized (emulator)
 814     }
 815
 816     /**
 817      * Check if a mouse press/release/motion event coordinate is over the
 818      * emulator.
 819      *
 820      * @param mouse a mouse-based event
 821      * @return whether or not the mouse is on the emulator
 822      */
 823     private boolean mouseOnEmulator(final TMouseEvent mouse) {
 824
 825         if (!emulator.isReading()) {
 826             return false;
 827         }
 828
 829         if ((mouse.getX() >= 0)
 830             && (mouse.getX() < getWidth() - 1)
 831             && (mouse.getY() >= 0)
 832             && (mouse.getY() < getHeight())
 833         ) {
 834             return true;
 835         }
 836         return false;
 837     }
 838
 839     /**
 840      * Copy a display buffer.
 841      *
 842      * @param buffer the buffer to copy
 843      * @return a deep copy of the buffer's data
 844      */
 845     private List<DisplayLine> copyBuffer(final List<DisplayLine> buffer) {
 846         ArrayList<DisplayLine> result = new ArrayList<DisplayLine>(buffer.size());
 847         for (DisplayLine line: buffer) {
 848             result.add(new DisplayLine(line));
 849         }
 850         return result;
 851     }
 852
 853     /**
 854      * Draw glyphs for a double-width or double-height VT100 cell to two
 855      * screen cells.
 856      *
 857      * @param line the line this VT100 cell is in
 858      * @param x the X position to draw the left half to
 859      * @param y the Y position to draw to
 860      * @param cell the cell to draw
 861      */
 862     private void putDoubleWidthCharXY(final DisplayLine line, final int x,
 863         final int y, final Cell cell) {
 864
 865         int textWidth = getScreen().getTextWidth();
 866         int textHeight = getScreen().getTextHeight();
 867         boolean cursorBlinkVisible = true;
 868
 869         if (getScreen() instanceof SwingTerminal) {
 870             SwingTerminal terminal = (SwingTerminal) getScreen();
 871             cursorBlinkVisible = terminal.getCursorBlinkVisible();
 872         } else if (getScreen() instanceof ECMA48Terminal) {
 873             ECMA48Terminal terminal = (ECMA48Terminal) getScreen();
 874
 875             if (!terminal.hasSixel()) {
 876                 // The backend does not have sixel support, draw this as text
 877                 // and bail out.
 878                 putCharXY(x, y, cell);
 879                 putCharXY(x + 1, y, ' ', cell);
 880                 return;
 881             }
 882             cursorBlinkVisible = blinkState;
 883         } else {
 884             // We don't know how to dray glyphs to this screen, draw them as
 885             // text and bail out.
 886             putCharXY(x, y, cell);
 887             putCharXY(x + 1, y, ' ', cell);
 888             return;
 889         }
 890
 891         if ((textWidth != lastTextWidth) || (textHeight != lastTextHeight)) {
 892             // Screen size has changed, reset the font.
 893             setupFont(textHeight);
 894             lastTextWidth = textWidth;
 895             lastTextHeight = textHeight;
 896         }
 897         assert (doubleFont != null);
 898
 899         BufferedImage image;
 900         if (line.getDoubleHeight() == 1) {
 901             // Double-height top half: don't draw the underline.
 902             Cell newCell = new Cell(cell);
 903             newCell.setUnderline(false);
 904             image = doubleFont.getImage(newCell, textWidth * 2, textHeight * 2,
 905                 cursorBlinkVisible);
 906         } else {
 907             image = doubleFont.getImage(cell,  textWidth * 2, textHeight * 2,
 908                 cursorBlinkVisible);
 909         }
 910
 911         // Now that we have the double-wide glyph drawn, copy the right
 912         // pieces of it to the cells.
 913         Cell left = new Cell(cell);
 914         Cell right = new Cell(cell);
 915         right.setChar(' ');
 916         BufferedImage leftImage = null;
 917         BufferedImage rightImage = null;
 918         /*
 919         System.err.println("image " + image + " textWidth " + textWidth +
 920             " textHeight " + textHeight);
 921          */
 922
 923         switch (line.getDoubleHeight()) {
 924         case 1:
 925             // Top half double height
 926             leftImage = image.getSubimage(0, 0, textWidth, textHeight);
 927             rightImage = image.getSubimage(textWidth, 0, textWidth, textHeight);
 928             break;
 929         case 2:
 930             // Bottom half double height
 931             leftImage = image.getSubimage(0, textHeight, textWidth, textHeight);
 932             rightImage = image.getSubimage(textWidth, textHeight,
 933                 textWidth, textHeight);
 934             break;
 935         default:
 936             // Either single height double-width, or error fallback
 937             BufferedImage wideImage = new BufferedImage(textWidth * 2,
 938                 textHeight, BufferedImage.TYPE_INT_ARGB);
 939             Graphics2D grWide = wideImage.createGraphics();
 940             grWide.drawImage(image, 0, 0, wideImage.getWidth(),
 941                 wideImage.getHeight(), null);
 942             grWide.dispose();
 943             leftImage = wideImage.getSubimage(0, 0, textWidth, textHeight);
 944             rightImage = wideImage.getSubimage(textWidth, 0, textWidth,
 945                 textHeight);
 946             break;
 947         }
 948         left.setImage(leftImage);
 949         right.setImage(rightImage);
 950         // Since we have image data, ditch the character here.  Otherwise, a
 951         // drawBoxShadow() over the terminal window will show the characters
 952         // which looks wrong.
 953         left.setChar(' ');
 954         right.setChar(' ');
 955         putCharXY(x, y, left);
 956         putCharXY(x + 1, y, right);
 957     }
 958
 959     /**
 960      * Set up the double-width font.
 961      *
 962      * @param fontSize the size of font to request for the single-width font.
 963      * The double-width font will be 2x this value.
 964      */
 965     private void setupFont(final int fontSize) {
 966         doubleFont = GlyphMaker.getInstance(fontSize * 2);
 967
 968         // Special case: the ECMA48 backend needs to have a timer to drive
 969         // its blink state.
 970         if (getScreen() instanceof jexer.backend.ECMA48Terminal) {
 971             if (!haveTimer) {
 972                 // Blink every 500 millis.
 973                 long millis = 500;
 974                 getApplication().addTimer(millis, true,
 975                     new TAction() {
 976                         public void DO() {
 977                             blinkState = !blinkState;
 978                             getApplication().doRepaint();
 979                         }
 980                     }
 981                 );
 982                 haveTimer = true;
 983             }
 984         }
 985     }
 986
 987     // ------------------------------------------------------------------------
 988     // DisplayListener --------------------------------------------------------
 989     // ------------------------------------------------------------------------
 990
 991     /**
 992      * Called by emulator when fresh data has come in.
 993      */
 994     public void displayChanged() {
 995         dirty = true;
 996         getApplication().postEvent(new TMenuEvent(TMenu.MID_REPAINT));
 997     }
 998
 999     /**
1000      * Function to call to obtain the display width.
1001      *
1002      * @return the number of columns in the display
1003      */
1004     public int getDisplayWidth() {
1005         if (ptypipe) {
1006             return getWidth();
1007         }
1008         return 80;
1009     }
1010
1011     /**
1012      * Function to call to obtain the display height.
1013      *
1014      * @return the number of rows in the display
1015      */
1016     public int getDisplayHeight() {
1017         if (ptypipe) {
1018             return getHeight();
1019         }
1020         return 24;
1021     }
1022
1023 }