Support TTerminalWindow resizing via ptypipe

README.md

@@ -196,6 +196,14 @@ The following properties control features of Jexer:
   be faster on slower systems but also more likely to have screen
   tearing.  Default: true.
 
+  jexer.TTerminal.ptypipe
+  -----------------------
+
+  Used by jexer.TTerminalWindow.  If true, spawn shell using the
+  'ptypipe' utility rather than 'script'.  This permits terminals to
+  resize with the window.  ptypipe is a separate C language utility,
+  available at https://github.com/klamonte/ptypipe.  Default: false.
+
 
 
 Known Issues / Arbitrary Decisions
@@ -213,19 +221,19 @@ ambiguous.  This section describes such issues.
     input (see the ENABLE_LINE_INPUT flag for GetConsoleMode() and
     SetConsoleMode()).
 
-  - TTerminalWindow launches 'script -fqe /dev/null' or 'script -q -F
-    /dev/null' on non-Windows platforms.  This is a workaround for the
-    C library behavior of checking for a tty: script launches $SHELL
-    in a pseudo-tty.  This works on Linux and Mac but might not on
-    other Posix-y platforms.
+  - TTerminalWindow by default launches 'script -fqe /dev/null' or
+    'script -q -F /dev/null' on non-Windows platforms.  This is a
+    workaround for the C library behavior of checking for a tty:
+    script launches $SHELL in a pseudo-tty.  This works on Linux and
+    Mac but might not on other Posix-y platforms.
 
   - Closing a TTerminalWindow without exiting the process inside it
     may result in a zombie 'script' process.
 
-  - TTerminalWindow cannot notify the child process of changes in
-    window size, due to Java's lack of support for forkpty() and
-    similar.  Solving this requires C, and will be pursued only if
-    sufficient user requests come in.
+  - TTerminalWindow can only notify the child process of changes in
+    window size if using the 'ptypipe' utility, due to Java's lack of
+    support for forkpty() and similar.  ptypipe is available at
+    https://github.com/klamonte/ptypipe.
 
   - Java's InputStreamReader as used by the ECMA48 backend requires a
     valid UTF-8 stream.  The default X10 encoding for mouse

docs/TODO.md

@@ -80,10 +80,6 @@ Roadmap
 1.1.0 Wishlist
 --------------
 
-- TTerminal
-  - Handle resize events (pass to child process).  Will need to switch
-    to forkpty(), or ship a C wrapper process.
-
 - Screen
   - Allow complex characters in putCharXY() and detect them in putStringXY().
 

src/jexer/TTerminalWindow.java

@@ -60,6 +60,13 @@ public class TTerminalWindow extends TScrollableWindow
      */
     private Process shell;
 
+    /**
+     * If true, we are using the ptypipe utility to support dynamic window
+     * resizing.  ptypipe is available at
+     * https://github.com/klamonte/ptypipe .
+     */
+    private boolean ptypipe = false;
+
     /**
      * Claim the keystrokes the emulator will need.
      */
@@ -165,10 +172,19 @@ public class TTerminalWindow extends TScrollableWindow
             String [] cmdShellBSD = {
                 "script", "-q", "-F", "/dev/null"
             };
+            String [] cmdShellPtypipe = {
+                "ptypipe", "/bin/bash", "--login"
+            };
             // Spawn a shell and pass its I/O to the other constructor.
 
             ProcessBuilder pb;
-            if (System.getProperty("os.name").startsWith("Windows")) {
+            if ((System.getProperty("jexer.TTerminal.ptypipe") != null)
+                && (System.getProperty("jexer.TTerminal.ptypipe").
+                    equals("true"))
+            ) {
+                pb = new ProcessBuilder(cmdShellPtypipe);
+                ptypipe = true;
+            } else if (System.getProperty("os.name").startsWith("Windows")) {
                 pb = new ProcessBuilder(cmdShellWindows);
             } else if (System.getProperty("os.name").startsWith("Mac")) {
                 pb = new ProcessBuilder(cmdShellBSD);
@@ -429,6 +445,14 @@ public class TTerminalWindow extends TScrollableWindow
 
                 // Get out of scrollback
                 setVerticalValue(0);
+
+                if (ptypipe) {
+                    emulator.setWidth(getWidth() - 2);
+                    emulator.setHeight(getHeight() - 2);
+
+                    emulator.writeRemote("\033[8;" + (getHeight() - 2) + ";" +
+                        (getWidth() - 2) + "t");
+                }
             }
             return;
 

src/jexer/tterminal/ECMA48.java

@@ -204,7 +204,7 @@ public class ECMA48 implements Runnable {
      *
      * @param str string to send
      */
-    private void writeRemote(final String str) {
+    public void writeRemote(final String str) {
         if (stopReaderThread) {
             // Reader hit EOF, bail out now.
             close();
@@ -221,6 +221,7 @@ public class ECMA48 implements Runnable {
                 return;
             }
             try {
+                outputStream.flush();
                 for (int i = 0; i < str.length(); i++) {
                     outputStream.write(str.charAt(i));
                 }
@@ -235,6 +236,7 @@ public class ECMA48 implements Runnable {
                 return;
             }
             try {
+                output.flush();
                 output.write(str);
                 output.flush();
             } catch (IOException e) {
@@ -538,6 +540,22 @@ public class ECMA48 implements Runnable {
         return width;
     }
 
+    /**
+     * Set the display width.
+     *
+     * @param width the new width
+     */
+    public final void setWidth(final int width) {
+        this.width = width;
+        rightMargin = width - 1;
+        if (currentState.cursorX >= width) {
+            currentState.cursorX = width - 1;
+        }
+        if (savedState.cursorX >= width) {
+            savedState.cursorX = width - 1;
+        }
+    }
+
     /**
      * Physical display height.  We start at 80x24, but the user can resize
      * us bigger/smaller.
@@ -553,6 +571,33 @@ public class ECMA48 implements Runnable {
         return height;
     }
 
+    /**
+     * Set the display height.
+     *
+     * @param height the new height
+     */
+    public final void setHeight(final int height) {
+        this.height = height;
+        scrollRegionBottom = height - 1;
+        if (scrollRegionTop >= scrollRegionBottom) {
+            scrollRegionTop = 0;
+        }
+        if (currentState.cursorY >= height) {
+            currentState.cursorY = height - 1;
+        }
+        if (savedState.cursorY >= height) {
+            savedState.cursorY = height - 1;
+        }
+        while (display.size() < height) {
+            DisplayLine line = new DisplayLine(currentState.attr);
+            line.setReverseColor(reverseVideo);
+            display.add(line);
+        }
+        while (display.size() > height) {
+            scrollback.add(display.remove(0));
+        }
+    }
+
     /**
      * Top margin of the scrolling region.
      */