#49 reduce use of synchronized
[fanfix.git] / src / jexer / TTerminalWindow.java
index 74f71edc7c0af8b9387dddca88a246d275810a9a..5970b6c77aff4791a389d13a7aa9a1012dbf5147 100644 (file)
@@ -3,7 +3,7 @@
  *
  * The MIT License (MIT)
  *
- * Copyright (C) 2017 Kevin Lamonte
+ * Copyright (C) 2019 Kevin Lamonte
  *
  * Permission is hereby granted, free of charge, to any person obtaining a
  * copy of this software and associated documentation files (the "Software"),
  */
 package jexer;
 
+import java.awt.Font;
+import java.awt.FontMetrics;
+import java.awt.Graphics2D;
+import java.awt.image.BufferedImage;
+
+import java.io.InputStream;
 import java.io.IOException;
 import java.lang.reflect.Field;
 import java.text.MessageFormat;
-import java.util.LinkedList;
+import java.util.ArrayList;
+import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.ResourceBundle;
 
+import jexer.backend.ECMA48Terminal;
+import jexer.backend.GlyphMaker;
+import jexer.backend.MultiScreen;
+import jexer.backend.SwingTerminal;
 import jexer.bits.Cell;
 import jexer.bits.CellAttributes;
 import jexer.event.TKeypressEvent;
@@ -54,7 +65,6 @@ import static jexer.TKeypress.*;
 public class TTerminalWindow extends TScrollableWindow
                              implements DisplayListener {
 
-
     /**
      * Translated strings.
      */
@@ -77,10 +87,62 @@ public class TTerminalWindow extends TScrollableWindow
     /**
      * If true, we are using the ptypipe utility to support dynamic window
      * resizing.  ptypipe is available at
-     * https://github.com/klamonte/ptypipe .
+     * https://gitlab.com/klamonte/ptypipe .
      */
     private boolean ptypipe = false;
 
+    /**
+     * If true, close the window when the shell exits.
+     */
+    private boolean closeOnExit = false;
+
+    /**
+     * Double-height font.
+     */
+    private GlyphMaker doubleFont;
+
+    /**
+     * Last text width value.
+     */
+    private int lastTextWidth = -1;
+
+    /**
+     * Last text height value.
+     */
+    private int lastTextHeight = -1;
+
+    /**
+     * The blink state, used only by ECMA48 backend and when double-width
+     * chars must be drawn.
+     */
+    private boolean blinkState = true;
+
+    /**
+     * Timer flag, used only by ECMA48 backend and when double-width chars
+     * must be drawn.
+     */
+    private boolean haveTimer = false;
+
+    /**
+     * The last seen scrollback lines.
+     */
+    private List<DisplayLine> scrollback;
+
+    /**
+     * The last seen display lines.
+     */
+    private List<DisplayLine> display;
+
+    /**
+     * If true, the display has changed and needs updating.
+     */
+    private volatile boolean dirty = true;
+
+    /**
+     * Time that the display was last updated.
+     */
+    private long lastUpdateTime = 0;
+
     // ------------------------------------------------------------------------
     // Constructors -----------------------------------------------------------
     // ------------------------------------------------------------------------
@@ -96,7 +158,25 @@ public class TTerminalWindow extends TScrollableWindow
     public TTerminalWindow(final TApplication application, final int x,
         final int y, final String commandLine) {
 
-        this(application, x, y, RESIZABLE, commandLine.split("\\s"));
+        this(application, x, y, RESIZABLE, commandLine.split("\\s+"),
+            System.getProperty("jexer.TTerminal.closeOnExit",
+                "false").equals("true"));
+    }
+
+    /**
+     * Public constructor spawns a custom command line.
+     *
+     * @param application TApplication that manages this window
+     * @param x column relative to parent
+     * @param y row relative to parent
+     * @param commandLine the command line to execute
+     * @param closeOnExit if true, close the window when the command exits
+     */
+    public TTerminalWindow(final TApplication application, final int x,
+        final int y, final String commandLine, final boolean closeOnExit) {
+
+        this(application, x, y, RESIZABLE, commandLine.split("\\s+"),
+            closeOnExit);
     }
 
     /**
@@ -111,9 +191,30 @@ public class TTerminalWindow extends TScrollableWindow
     public TTerminalWindow(final TApplication application, final int x,
         final int y, final int flags, final String [] command) {
 
+        this(application, x, y, flags, command,
+            System.getProperty("jexer.TTerminal.closeOnExit",
+                "false").equals("true"));
+    }
+
+    /**
+     * Public constructor spawns a custom command line.
+     *
+     * @param application TApplication that manages this window
+     * @param x column relative to parent
+     * @param y row relative to parent
+     * @param flags mask of CENTERED, MODAL, or RESIZABLE
+     * @param command the command line to execute
+     * @param closeOnExit if true, close the window when the command exits
+     */
+    public TTerminalWindow(final TApplication application, final int x,
+        final int y, final int flags, final String [] command,
+        final boolean closeOnExit) {
+
         super(application, i18n.getString("windowTitle"), x, y,
             80 + 2, 24 + 2, flags);
 
+        this.closeOnExit = closeOnExit;
+
         String [] fullCommand;
 
         // Spawn a shell and pass its I/O to the other constructor.
@@ -161,9 +262,29 @@ public class TTerminalWindow extends TScrollableWindow
     public TTerminalWindow(final TApplication application, final int x,
         final int y, final int flags) {
 
+        this(application, x, y, flags,
+            System.getProperty("jexer.TTerminal.closeOnExit",
+                "false").equals("true"));
+
+    }
+
+    /**
+     * Public constructor spawns a shell.
+     *
+     * @param application TApplication that manages this window
+     * @param x column relative to parent
+     * @param y row relative to parent
+     * @param flags mask of CENTERED, MODAL, or RESIZABLE
+     * @param closeOnExit if true, close the window when the shell exits
+     */
+    public TTerminalWindow(final TApplication application, final int x,
+        final int y, final int flags, final boolean closeOnExit) {
+
         super(application, i18n.getString("windowTitle"), x, y,
             80 + 2, 24 + 2, flags);
 
+        this.closeOnExit = closeOnExit;
+
         String cmdShellWindows = "cmd.exe";
 
         // You cannot run a login shell in a bare Process interactively, due
@@ -183,16 +304,16 @@ public class TTerminalWindow extends TScrollableWindow
                 equals("true"))
         ) {
             ptypipe = true;
-            spawnShell(cmdShellPtypipe.split("\\s"));
+            spawnShell(cmdShellPtypipe.split("\\s+"));
         } else if (System.getProperty("os.name").startsWith("Windows")) {
-            spawnShell(cmdShellWindows.split("\\s"));
+            spawnShell(cmdShellWindows.split("\\s+"));
         } else if (System.getProperty("os.name").startsWith("Mac")) {
-            spawnShell(cmdShellBSD.split("\\s"));
+            spawnShell(cmdShellBSD.split("\\s+"));
         } else if (System.getProperty("os.name").startsWith("Linux")) {
-            spawnShell(cmdShellGNU.split("\\s"));
+            spawnShell(cmdShellGNU.split("\\s+"));
         } else {
             // When all else fails, assume GNU.
-            spawnShell(cmdShellGNU.split("\\s"));
+            spawnShell(cmdShellGNU.split("\\s+"));
         }
     }
 
@@ -205,98 +326,125 @@ public class TTerminalWindow extends TScrollableWindow
      */
     @Override
     public void draw() {
-        // Synchronize against the emulator so we don't stomp on its reader
-        // thread.
-        synchronized (emulator) {
-
-            // Update the scroll bars
-            reflowData();
 
-            // Draw the box using my superclass
-            super.draw();
-
-            List<DisplayLine> scrollback = emulator.getScrollbackBuffer();
-            List<DisplayLine> display = emulator.getDisplayBuffer();
+        int width = getDisplayWidth();
+        boolean syncEmulator = false;
+        if ((System.currentTimeMillis() - lastUpdateTime > 125)
+            && (dirty == true)
+        ) {
+            // Too much time has passed, draw it all.
+            syncEmulator = true;
+        } else if (emulator.isReading() && (dirty == false)) {
+            // Wait until the emulator has brought more data in.
+            syncEmulator = false;
+        } else if (!emulator.isReading() && (dirty == true)) {
+            // The emulator won't receive more data, update the display.
+            syncEmulator = true;
+        }
 
-            // Put together the visible rows
-            int visibleHeight = getHeight() - 2;
-            int visibleBottom = scrollback.size() + display.size()
-                + getVerticalValue();
-            assert (visibleBottom >= 0);
+        if ((syncEmulator == true)
+            || (scrollback == null)
+            || (display == null)
+        ) {
+            // We want to minimize the amount of time we have the emulator
+            // locked.  Grab a copy of its display.
+            synchronized (emulator) {
+                // Update the scroll bars
+                reflowData();
 
-            List<DisplayLine> preceedingBlankLines = new LinkedList<DisplayLine>();
-            int visibleTop = visibleBottom - visibleHeight;
-            if (visibleTop < 0) {
-                for (int i = visibleTop; i < 0; i++) {
-                    preceedingBlankLines.add(emulator.getBlankDisplayLine());
+                if ((scrollback == null) || emulator.isReading()) {
+                    scrollback = copyBuffer(emulator.getScrollbackBuffer());
+                    display = copyBuffer(emulator.getDisplayBuffer());
                 }
-                visibleTop = 0;
+                width = emulator.getWidth();
             }
-            assert (visibleTop >= 0);
+            dirty = false;
+        }
 
-            List<DisplayLine> displayLines = new LinkedList<DisplayLine>();
-            displayLines.addAll(scrollback);
-            displayLines.addAll(display);
+        // Draw the box using my superclass
+        super.draw();
 
-            List<DisplayLine> visibleLines = new LinkedList<DisplayLine>();
-            visibleLines.addAll(preceedingBlankLines);
-            visibleLines.addAll(displayLines.subList(visibleTop,
-                    visibleBottom));
+        // Put together the visible rows
+        int visibleHeight = getHeight() - 2;
+        int visibleBottom = scrollback.size() + display.size()
+                + getVerticalValue();
+        assert (visibleBottom >= 0);
 
-            visibleHeight -= visibleLines.size();
-            assert (visibleHeight >= 0);
+        List<DisplayLine> preceedingBlankLines = new ArrayList<DisplayLine>();
+        int visibleTop = visibleBottom - visibleHeight;
+        if (visibleTop < 0) {
+            for (int i = visibleTop; i < 0; i++) {
+                preceedingBlankLines.add(emulator.getBlankDisplayLine());
+            }
+            visibleTop = 0;
+        }
+        assert (visibleTop >= 0);
+
+        List<DisplayLine> displayLines = new ArrayList<DisplayLine>();
+        displayLines.addAll(scrollback);
+        displayLines.addAll(display);
+
+        List<DisplayLine> visibleLines = new ArrayList<DisplayLine>();
+        visibleLines.addAll(preceedingBlankLines);
+        visibleLines.addAll(displayLines.subList(visibleTop,
+                visibleBottom));
+
+        visibleHeight -= visibleLines.size();
+        assert (visibleHeight >= 0);
+
+        // Now draw the emulator screen
+        int row = 1;
+        for (DisplayLine line: visibleLines) {
+            int widthMax = width;
+            if (line.isDoubleWidth()) {
+                widthMax /= 2;
+            }
+            if (widthMax > getWidth() - 2) {
+                widthMax = getWidth() - 2;
+            }
+            for (int i = 0; i < widthMax; i++) {
+                Cell ch = line.charAt(i);
 
-            // Now draw the emulator screen
-            int row = 1;
-            for (DisplayLine line: visibleLines) {
-                int widthMax = emulator.getWidth();
-                if (line.isDoubleWidth()) {
-                    widthMax /= 2;
+                if (ch.isImage()) {
+                    putCharXY(i + 1, row, ch);
+                    continue;
                 }
-                if (widthMax > getWidth() - 2) {
-                    widthMax = getWidth() - 2;
-                }
-                for (int i = 0; i < widthMax; i++) {
-                    Cell ch = line.charAt(i);
-                    Cell newCell = new Cell();
-                    newCell.setTo(ch);
-                    boolean reverse = line.isReverseColor() ^ ch.isReverse();
-                    newCell.setReverse(false);
-                    if (reverse) {
-                        if (ch.getForeColorRGB() < 0) {
-                            newCell.setBackColor(ch.getForeColor());
-                            newCell.setBackColorRGB(-1);
-                        } else {
-                            newCell.setBackColorRGB(ch.getForeColorRGB());
-                        }
-                        if (ch.getBackColorRGB() < 0) {
-                            newCell.setForeColor(ch.getBackColor());
-                            newCell.setForeColorRGB(-1);
-                        } else {
-                            newCell.setForeColorRGB(ch.getBackColorRGB());
-                        }
+
+                Cell newCell = new Cell();
+                newCell.setTo(ch);
+                boolean reverse = line.isReverseColor() ^ ch.isReverse();
+                newCell.setReverse(false);
+                if (reverse) {
+                    if (ch.getForeColorRGB() < 0) {
+                        newCell.setBackColor(ch.getForeColor());
+                        newCell.setBackColorRGB(-1);
+                    } else {
+                        newCell.setBackColorRGB(ch.getForeColorRGB());
                     }
-                    if (line.isDoubleWidth()) {
-                        getScreen().putCharXY((i * 2) + 1, row, newCell);
-                        getScreen().putCharXY((i * 2) + 2, row, ' ', newCell);
+                    if (ch.getBackColorRGB() < 0) {
+                        newCell.setForeColor(ch.getBackColor());
+                        newCell.setForeColorRGB(-1);
                     } else {
-                        getScreen().putCharXY(i + 1, row, newCell);
+                        newCell.setForeColorRGB(ch.getBackColorRGB());
                     }
                 }
-                row++;
-                if (row == getHeight() - 1) {
-                    // Don't overwrite the box edge
-                    break;
+                if (line.isDoubleWidth()) {
+                    putDoubleWidthCharXY(line, (i * 2) + 1, row, newCell);
+                } else {
+                    putCharXY(i + 1, row, newCell);
                 }
             }
-            CellAttributes background = new CellAttributes();
-            // Fill in the blank lines on bottom
-            for (int i = 0; i < visibleHeight; i++) {
-                getScreen().hLineXY(1, i + row, getWidth() - 2, ' ',
-                    background);
+            row++;
+            if (row == getHeight() - 1) {
+                // Don't overwrite the box edge
+                break;
             }
-
-        } // synchronized (emulator)
+        }
+        CellAttributes background = new CellAttributes();
+        // Fill in the blank lines on bottom
+        for (int i = 0; i < visibleHeight; i++) {
+            hLineXY(1, i + row, getWidth() - 2, ' ', background);
+        }
 
     }
 
@@ -392,25 +540,21 @@ public class TTerminalWindow extends TScrollableWindow
             return;
         }
 
-        // Synchronize against the emulator so we don't stomp on its reader
-        // thread.
-        synchronized (emulator) {
-            if (emulator.isReading()) {
-                // Get out of scrollback
-                setVerticalValue(0);
-                emulator.keypress(keypress.getKey());
+        if (emulator.isReading()) {
+            // Get out of scrollback
+            setVerticalValue(0);
+            emulator.addUserEvent(keypress);
 
-                // UGLY HACK TIME!  cmd.exe needs CRLF, not just CR, so if
-                // this is kBEnter then also send kbCtrlJ.
-                if (System.getProperty("os.name").startsWith("Windows")) {
-                    if (keypress.equals(kbEnter)) {
-                        emulator.keypress(kbCtrlJ);
-                    }
+            // UGLY HACK TIME!  cmd.exe needs CRLF, not just CR, so if
+            // this is kBEnter then also send kbCtrlJ.
+            if (System.getProperty("os.name").startsWith("Windows")) {
+                if (keypress.equals(kbEnter)) {
+                    emulator.addUserEvent(new TKeypressEvent(kbCtrlJ));
                 }
-
-                readEmulatorState();
-                return;
             }
+
+            readEmulatorState();
+            return;
         }
 
         // Process is closed, honor "normal" TUI keystrokes
@@ -430,22 +574,24 @@ public class TTerminalWindow extends TScrollableWindow
             return;
         }
 
-        if (mouse.isMouseWheelUp()) {
-            verticalDecrement();
-            return;
-        }
-        if (mouse.isMouseWheelDown()) {
-            verticalIncrement();
-            return;
-        }
-        if (mouseOnEmulator(mouse)) {
-            synchronized (emulator) {
-                mouse.setX(mouse.getX() - 1);
-                mouse.setY(mouse.getY() - 1);
-                emulator.mouse(mouse);
-                readEmulatorState();
+        // If the emulator is tracking mouse buttons, it needs to see wheel
+        // events.
+        if (emulator.getMouseProtocol() == ECMA48.MouseProtocol.OFF) {
+            if (mouse.isMouseWheelUp()) {
+                verticalDecrement();
                 return;
             }
+            if (mouse.isMouseWheelDown()) {
+                verticalIncrement();
+                return;
+            }
+        }
+        if (mouseOnEmulator(mouse)) {
+            mouse.setX(mouse.getX() - 1);
+            mouse.setY(mouse.getY() - 1);
+            emulator.addUserEvent(mouse);
+            readEmulatorState();
+            return;
         }
 
         // Emulator didn't consume it, pass it on
@@ -466,13 +612,11 @@ public class TTerminalWindow extends TScrollableWindow
         }
 
         if (mouseOnEmulator(mouse)) {
-            synchronized (emulator) {
-                mouse.setX(mouse.getX() - 1);
-                mouse.setY(mouse.getY() - 1);
-                emulator.mouse(mouse);
-                readEmulatorState();
-                return;
-            }
+            mouse.setX(mouse.getX() - 1);
+            mouse.setY(mouse.getY() - 1);
+            emulator.addUserEvent(mouse);
+            readEmulatorState();
+            return;
         }
 
         // Emulator didn't consume it, pass it on
@@ -493,13 +637,11 @@ public class TTerminalWindow extends TScrollableWindow
         }
 
         if (mouseOnEmulator(mouse)) {
-            synchronized (emulator) {
-                mouse.setX(mouse.getX() - 1);
-                mouse.setY(mouse.getY() - 1);
-                emulator.mouse(mouse);
-                readEmulatorState();
-                return;
-            }
+            mouse.setX(mouse.getX() - 1);
+            mouse.setY(mouse.getY() - 1);
+            emulator.addUserEvent(mouse);
+            readEmulatorState();
+            return;
         }
 
         // Emulator didn't consume it, pass it on
@@ -641,6 +783,10 @@ public class TTerminalWindow extends TScrollableWindow
 
         // Add shortcut text
         newStatusBar(i18n.getString("statusBarRunning"));
+
+        // Pass the correct text cell width/height to the emulator
+        emulator.setTextWidth(getScreen().getTextWidth());
+        emulator.setTextHeight(getScreen().getTextHeight());
     }
 
     /**
@@ -676,41 +822,13 @@ public class TTerminalWindow extends TScrollableWindow
         }
     }
 
-    /**
-     * Called by emulator when fresh data has come in.
-     */
-    public void displayChanged() {
-        getApplication().postEvent(new TMenuEvent(TMenu.MID_REPAINT));
-    }
-
-    /**
-     * Function to call to obtain the display width.
-     *
-     * @return the number of columns in the display
-     */
-    public int getDisplayWidth() {
-        if (ptypipe) {
-            return getWidth() - 2;
-        }
-        return 80;
-    }
-
-    /**
-     * Function to call to obtain the display height.
-     *
-     * @return the number of rows in the display
-     */
-    public int getDisplayHeight() {
-        if (ptypipe) {
-            return getHeight() - 2;
-        }
-        return 24;
-    }
-
     /**
      * Hook for subclasses to be notified of the shell termination.
      */
     public void onShellExit() {
+        if (closeOnExit) {
+            close();
+        }
         getApplication().postEvent(new TMenuEvent(TMenu.MID_REPAINT));
     }
 
@@ -722,6 +840,7 @@ public class TTerminalWindow extends TScrollableWindow
         // Synchronize against the emulator so we don't stomp on its reader
         // thread.
         synchronized (emulator) {
+            setHiddenMouse(emulator.hasHiddenMousePointer());
 
             setCursorX(emulator.getCursorX() + 1);
             setCursorY(emulator.getCursorY() + 1
@@ -787,12 +906,10 @@ public class TTerminalWindow extends TScrollableWindow
      * @param mouse a mouse-based event
      * @return whether or not the mouse is on the emulator
      */
-    private final boolean mouseOnEmulator(final TMouseEvent mouse) {
+    private boolean mouseOnEmulator(final TMouseEvent mouse) {
 
-        synchronized (emulator) {
-            if (!emulator.isReading()) {
-                return false;
-            }
+        if (!emulator.isReading()) {
+            return false;
         }
 
         if ((mouse.getAbsoluteX() >= getAbsoluteX() + 1)
@@ -805,4 +922,191 @@ public class TTerminalWindow extends TScrollableWindow
         return false;
     }
 
+    /**
+     * Copy a display buffer.
+     *
+     * @param buffer the buffer to copy
+     * @return a deep copy of the buffer's data
+     */
+    private List<DisplayLine> copyBuffer(final List<DisplayLine> buffer) {
+        ArrayList<DisplayLine> result = new ArrayList<DisplayLine>(buffer.size());
+        for (DisplayLine line: buffer) {
+            result.add(new DisplayLine(line));
+        }
+        return result;
+    }
+
+    /**
+     * Draw glyphs for a double-width or double-height VT100 cell to two
+     * screen cells.
+     *
+     * @param line the line this VT100 cell is in
+     * @param x the X position to draw the left half to
+     * @param y the Y position to draw to
+     * @param cell the cell to draw
+     */
+    private void putDoubleWidthCharXY(final DisplayLine line, final int x,
+        final int y, final Cell cell) {
+
+        int textWidth = getScreen().getTextWidth();
+        int textHeight = getScreen().getTextHeight();
+        boolean cursorBlinkVisible = true;
+
+        if (getScreen() instanceof SwingTerminal) {
+            SwingTerminal terminal = (SwingTerminal) getScreen();
+            cursorBlinkVisible = terminal.getCursorBlinkVisible();
+        } else if (getScreen() instanceof ECMA48Terminal) {
+            ECMA48Terminal terminal = (ECMA48Terminal) getScreen();
+
+            if (!terminal.hasSixel()) {
+                // The backend does not have sixel support, draw this as text
+                // and bail out.
+                putCharXY(x, y, cell);
+                putCharXY(x + 1, y, ' ', cell);
+                return;
+            }
+            cursorBlinkVisible = blinkState;
+        } else {
+            // We don't know how to dray glyphs to this screen, draw them as
+            // text and bail out.
+            putCharXY(x, y, cell);
+            putCharXY(x + 1, y, ' ', cell);
+            return;
+        }
+
+        if ((textWidth != lastTextWidth) || (textHeight != lastTextHeight)) {
+            // Screen size has changed, reset the font.
+            setupFont(textHeight);
+            lastTextWidth = textWidth;
+            lastTextHeight = textHeight;
+        }
+        assert (doubleFont != null);
+
+        BufferedImage image;
+        if (line.getDoubleHeight() == 1) {
+            // Double-height top half: don't draw the underline.
+            Cell newCell = new Cell();
+            newCell.setTo(cell);
+            newCell.setUnderline(false);
+            image = doubleFont.getImage(newCell, textWidth * 2, textHeight * 2,
+                cursorBlinkVisible);
+        } else {
+            image = doubleFont.getImage(cell,  textWidth * 2, textHeight * 2,
+                cursorBlinkVisible);
+        }
+
+        // Now that we have the double-wide glyph drawn, copy the right
+        // pieces of it to the cells.
+        Cell left = new Cell();
+        Cell right = new Cell();
+        left.setTo(cell);
+        right.setTo(cell);
+        right.setChar(' ');
+        BufferedImage leftImage = null;
+        BufferedImage rightImage = null;
+        /*
+        System.err.println("image " + image + " textWidth " + textWidth +
+            " textHeight " + textHeight);
+         */
+
+        switch (line.getDoubleHeight()) {
+        case 1:
+            // Top half double height
+            leftImage = image.getSubimage(0, 0, textWidth, textHeight);
+            rightImage = image.getSubimage(textWidth, 0, textWidth, textHeight);
+            break;
+        case 2:
+            // Bottom half double height
+            leftImage = image.getSubimage(0, textHeight, textWidth, textHeight);
+            rightImage = image.getSubimage(textWidth, textHeight,
+                textWidth, textHeight);
+            break;
+        default:
+            // Either single height double-width, or error fallback
+            BufferedImage wideImage = new BufferedImage(textWidth * 2,
+                textHeight, BufferedImage.TYPE_INT_ARGB);
+            Graphics2D grWide = wideImage.createGraphics();
+            grWide.drawImage(image, 0, 0, wideImage.getWidth(),
+                wideImage.getHeight(), null);
+            grWide.dispose();
+            leftImage = wideImage.getSubimage(0, 0, textWidth, textHeight);
+            rightImage = wideImage.getSubimage(textWidth, 0, textWidth,
+                textHeight);
+            break;
+        }
+        left.setImage(leftImage);
+        right.setImage(rightImage);
+        // Since we have image data, ditch the character here.  Otherwise, a
+        // drawBoxShadow() over the terminal window will show the characters
+        // which looks wrong.
+        left.setChar(' ');
+        right.setChar(' ');
+        putCharXY(x, y, left);
+        putCharXY(x + 1, y, right);
+    }
+
+    /**
+     * Set up the double-width font.
+     *
+     * @param fontSize the size of font to request for the single-width font.
+     * The double-width font will be 2x this value.
+     */
+    private void setupFont(final int fontSize) {
+        doubleFont = GlyphMaker.getInstance(fontSize * 2);
+
+        // Special case: the ECMA48 backend needs to have a timer to drive
+        // its blink state.
+        if (getScreen() instanceof jexer.backend.ECMA48Terminal) {
+            if (!haveTimer) {
+                // Blink every 500 millis.
+                long millis = 500;
+                getApplication().addTimer(millis, true,
+                    new TAction() {
+                        public void DO() {
+                            blinkState = !blinkState;
+                            getApplication().doRepaint();
+                        }
+                    }
+                );
+                haveTimer = true;
+            }
+        }
+    }
+
+    // ------------------------------------------------------------------------
+    // DisplayListener --------------------------------------------------------
+    // ------------------------------------------------------------------------
+
+    /**
+     * Called by emulator when fresh data has come in.
+     */
+    public void displayChanged() {
+        dirty = true;
+        getApplication().postEvent(new TMenuEvent(TMenu.MID_REPAINT));
+    }
+
+    /**
+     * Function to call to obtain the display width.
+     *
+     * @return the number of columns in the display
+     */
+    public int getDisplayWidth() {
+        if (ptypipe) {
+            return getWidth() - 2;
+        }
+        return 80;
+    }
+
+    /**
+     * Function to call to obtain the display height.
+     *
+     * @return the number of rows in the display
+     */
+    public int getDisplayHeight() {
+        if (ptypipe) {
+            return getHeight() - 2;
+        }
+        return 24;
+    }
+
 }