Cursor reporting support, fixes #40

src/main/java/org/jline/terminal/Cursor.java

@@ -0,0 +1,53 @@
+/*
+ * Copyright (c) 2002-2016, the original author or authors.
+ *
+ * This software is distributable under the BSD license. See the terms of the
+ * BSD license in the documentation provided with this software.
+ *
+ * http://www.opensource.org/licenses/bsd-license.php
+ */
+package org.jline.terminal;
+
+/**
+ * Class holding the cursor position.
+ *
+ * @see Terminal#getCursorPosition(java.util.function.IntConsumer)
+ */
+public class Cursor {
+
+    private final int x;
+    private final int y;
+
+    public Cursor(int x, int y) {
+        this.x = x;
+        this.y = y;
+    }
+
+    public int getX() {
+        return x;
+    }
+
+    public int getY() {
+        return y;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (o instanceof Cursor) {
+            Cursor c = (Cursor) o;
+            return x == c.x && y == c.y;
+        } else {
+            return false;
+        }
+    }
+
+    @Override
+    public int hashCode() {
+        return x * 31 + y;
+    }
+
+    @Override
+    public String toString() {
+        return "Cursor[" + "x=" + x + ", y=" + y + ']';
+    }
+}

src/main/java/org/jline/terminal/Terminal.java

@@ -13,6 +13,7 @@
 import java.io.InputStream;
 import java.io.OutputStream;
 import java.io.PrintWriter;
+import java.util.function.IntConsumer;
 
 import org.jline.terminal.impl.NativeSignalHandler;
 import org.jline.utils.InfoCmp.Capability;
@@ -112,4 +113,22 @@ default int getHeight() {
 
     String getStringCapability(Capability capability);
 
+    //
+    // Cursor support
+    //
+
+    /**
+     * Query the terminal to report the cursor position.
+     *
+     * As the response is read from the input stream, some
+     * characters may be read before the cursor position is actually
+     * read. Those characters can be given back using
+     * {@link org.jline.keymap.BindingReader#runMacro(String)}.
+     *
+     * @param discarded a consumer receiving discarded characters
+     * @return <code>null</code> if cursor position reporting
+     *                  is not supported or a valid cursor position
+     */
+    Cursor getCursorPosition(IntConsumer discarded);
+
 }

src/main/java/org/jline/terminal/impl/AbstractPosixTerminal.java

@@ -1,10 +1,20 @@
+/*
+ * Copyright (c) 2002-2016, the original author or authors.
+ *
+ * This software is distributable under the BSD license. See the terms of the
+ * BSD license in the documentation provided with this software.
+ *
+ * http://www.opensource.org/licenses/bsd-license.php
+ */
 package org.jline.terminal.impl;
 
 import java.io.IOError;
 import java.io.IOException;
 import java.util.Objects;
+import java.util.function.IntConsumer;
 
 import org.jline.terminal.Attributes;
+import org.jline.terminal.Cursor;
 import org.jline.terminal.Size;
 
 public abstract class AbstractPosixTerminal extends AbstractTerminal {
@@ -63,4 +73,10 @@ public void close() throws IOException {
         pty.setAttr(originalAttributes);
         pty.close();
     }
+
+    @Override
+    public Cursor getCursorPosition(IntConsumer discarded) {
+        return CursorSupport.getCursorPosition(this, discarded);
+    }
+
 }

src/main/java/org/jline/terminal/impl/AbstractTerminal.java

@@ -16,11 +16,13 @@
 import java.util.Map;
 import java.util.Objects;
 import java.util.Set;
+import java.util.function.IntConsumer;
 
 import org.jline.terminal.Attributes;
 import org.jline.terminal.Attributes.ControlChar;
 import org.jline.terminal.Attributes.InputFlag;
 import org.jline.terminal.Attributes.LocalFlag;
+import org.jline.terminal.Cursor;
 import org.jline.terminal.Terminal;
 import org.jline.utils.Curses;
 import org.jline.utils.InfoCmp;
@@ -165,4 +167,9 @@ protected void parseInfoCmp() {
         InfoCmp.parseInfoCmp(capabilities, bools, ints, strings);
     }
 
+    @Override
+    public Cursor getCursorPosition(IntConsumer discarded) {
+        return null;
+    }
+
 }

src/main/java/org/jline/terminal/impl/CursorSupport.java

@@ -0,0 +1,109 @@
+/*
+ * Copyright (c) 2002-2016, the original author or authors.
+ *
+ * This software is distributable under the BSD license. See the terms of the
+ * BSD license in the documentation provided with this software.
+ *
+ * http://www.opensource.org/licenses/bsd-license.php
+ */
+package org.jline.terminal.impl;
+
+import org.jline.terminal.Cursor;
+import org.jline.terminal.Terminal;
+import org.jline.utils.Curses;
+import org.jline.utils.InfoCmp;
+
+import java.io.IOError;
+import java.io.IOException;
+import java.util.function.IntConsumer;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+public class CursorSupport {
+
+    public static Cursor getCursorPosition(Terminal terminal, IntConsumer discarded) {
+        try {
+            String u6 = terminal.getStringCapability(InfoCmp.Capability.user6);
+            String u7 = terminal.getStringCapability(InfoCmp.Capability.user7);
+            if (u6 == null || u7 == null) {
+                return null;
+            }
+            // Prepare parser
+            boolean inc1 = false;
+            StringBuilder patb = new StringBuilder();
+            int index = 0;
+            while (index < u6.length()) {
+                char ch;
+                switch (ch = u6.charAt(index++)) {
+                    case '\\':
+                        switch (u6.charAt(index++)) {
+                            case 'e':
+                            case 'E':
+                                patb.append("\\x1b");
+                                break;
+                            default:
+                                throw new IllegalArgumentException();
+                        }
+                        break;
+                    case '%':
+                        ch = u6.charAt(index++);
+                        switch (ch) {
+                            case '%':
+                                patb.append('%');
+                                break;
+                            case 'i':
+                                inc1 = true;
+                                break;
+                            case 'd':
+                                patb.append("([0-9]+)");
+                                break;
+                            default:
+                                throw new IllegalArgumentException();
+                        }
+                        break;
+                    default:
+                        switch (ch) {
+                            case '[':
+                                patb.append('\\');
+                                break;
+                        }
+                        patb.append(ch);
+                        break;
+                }
+            }
+            Pattern pattern = Pattern.compile(patb.toString());
+            // Output cursor position request
+            Curses.tputs(terminal.writer(), u7);
+            terminal.flush();
+            StringBuilder sb = new StringBuilder();
+            int start = 0;
+            while (true) {
+                int c = terminal.reader().read();
+                if (c < 0) {
+                    return null;
+                }
+                sb.append((char) c);
+                Matcher matcher = pattern.matcher(sb.substring(start));
+                if (matcher.matches()) {
+                    int y = Integer.parseInt(matcher.group(1));
+                    int x = Integer.parseInt(matcher.group(2));
+                    if (inc1) {
+                        x--;
+                        y--;
+                    }
+                    if (discarded != null) {
+                        for (int i = 0; i < start; i++) {
+                            discarded.accept(sb.charAt(i));
+                        }
+                    }
+                    return new Cursor(x, y);
+                } else if (!matcher.hitEnd()) {
+                    start++;
+                }
+            }
+        } catch (IOException e) {
+            throw new IOError(e);
+        }
+    }
+
+}

src/main/java/org/jline/terminal/impl/ExternalTerminal.java

@@ -8,10 +8,13 @@
  */
 package org.jline.terminal.impl;
 
+import org.jline.terminal.Cursor;
+
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
 import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.function.IntConsumer;
 
 /**
  * Console implementation with embedded line disciplined.
@@ -74,4 +77,9 @@ public void pump() {
         }
     }
 
+    @Override
+    public Cursor getCursorPosition(IntConsumer discarded) {
+        return CursorSupport.getCursorPosition(this, discarded);
+    }
+
 }

src/main/java/org/jline/terminal/impl/jansi/JansiWinSysTerminal.java

@@ -10,18 +10,26 @@
 
 import java.io.FileDescriptor;
 import java.io.FileOutputStream;
+import java.io.IOError;
 import java.io.IOException;
+import java.util.function.IntConsumer;
 
 import org.fusesource.jansi.WindowsAnsiOutputStream;
 import org.fusesource.jansi.internal.Kernel32;
+import org.fusesource.jansi.internal.Kernel32.CONSOLE_SCREEN_BUFFER_INFO;
 import org.fusesource.jansi.internal.Kernel32.INPUT_RECORD;
 import org.fusesource.jansi.internal.Kernel32.KEY_EVENT_RECORD;
 import org.fusesource.jansi.internal.WindowsSupport;
+import org.jline.terminal.Cursor;
 import org.jline.terminal.Size;
 import org.jline.terminal.impl.AbstractWindowsTerminal;
 import org.jline.utils.InfoCmp;
 import org.jline.utils.Log;
 
+import static org.fusesource.jansi.internal.Kernel32.GetConsoleScreenBufferInfo;
+import static org.fusesource.jansi.internal.Kernel32.GetStdHandle;
+import static org.fusesource.jansi.internal.Kernel32.STD_OUTPUT_HANDLE;
+
 public class JansiWinSysTerminal extends AbstractWindowsTerminal {
 
     public JansiWinSysTerminal(String name, boolean nativeSignals) throws IOException {
@@ -114,4 +122,14 @@ protected byte[] readConsoleInput() {
         return sb.toString().getBytes();
     }
 
+    @Override
+    public Cursor getCursorPosition(IntConsumer discarded) {
+        CONSOLE_SCREEN_BUFFER_INFO info = new CONSOLE_SCREEN_BUFFER_INFO();
+        long console = GetStdHandle(STD_OUTPUT_HANDLE);
+        if (GetConsoleScreenBufferInfo(console, info) == 0) {
+            throw new IOError(new IOException("Could not get the cursor position: " + WindowsSupport.getLastErrorMessage()));
+        }
+        return new Cursor(info.cursorPosition.x, info.cursorPosition.y);
+    }
+
 }

src/main/java/org/jline/terminal/impl/jna/win/JnaWinSysTerminal.java

@@ -11,9 +11,11 @@
 import java.io.FileDescriptor;
 import java.io.FileOutputStream;
 import java.io.IOException;
+import java.util.function.IntConsumer;
 
 import com.sun.jna.Pointer;
 import com.sun.jna.ptr.IntByReference;
+import org.jline.terminal.Cursor;
 import org.jline.terminal.Size;
 import org.jline.terminal.impl.AbstractWindowsTerminal;
 import org.jline.utils.InfoCmp;
@@ -132,4 +134,11 @@ private Kernel32.INPUT_RECORD[] doReadConsoleInput() throws IOException {
         return null;
     }
 
+    @Override
+    public Cursor getCursorPosition(IntConsumer discarded) {
+        Kernel32.CONSOLE_SCREEN_BUFFER_INFO info = new Kernel32.CONSOLE_SCREEN_BUFFER_INFO();
+        Kernel32.INSTANCE.GetConsoleScreenBufferInfo(consoleOut, info);
+        return new Cursor(info.dwCursorPosition.X, info.dwCursorPosition.Y);
+    }
+
 }

src/test/java/org/jline/terminal/impl/ExternalTerminalTest.java

@@ -22,6 +22,7 @@
 import org.jline.terminal.Attributes.InputFlag;
 import org.jline.terminal.Attributes.LocalFlag;
 import org.jline.terminal.Attributes.OutputFlag;
+import org.jline.terminal.Cursor;
 import org.jline.terminal.Terminal;
 import org.junit.Test;
 
@@ -109,5 +110,23 @@ public void run() {
         th.join();
     }
 
+    @Test
+    public void testCursorPosition() throws IOException  {
+        PipedInputStream in = new PipedInputStream();
+        final PipedOutputStream outIn = new PipedOutputStream(in);
+        ByteArrayOutputStream out = new ByteArrayOutputStream();
+        ExternalTerminal console = new ExternalTerminal("foo", "ansi", in, out, "UTF-8");
+
+        outIn.write(new byte[] { 'a', '\033', 'b', '\033', '[', '2', ';', '3', 'R', 'f'});
+        outIn.flush();
+
+        StringBuilder sb = new StringBuilder();
+        Cursor cursor = console.getCursorPosition(c -> sb.append((char) c));
+        assertNotNull(cursor);
+        assertEquals(1, cursor.getX());
+        assertEquals(2, cursor.getY());
+        assertEquals("a\033b", sb.toString());
+        assertEquals('f', console.reader().read());
+    }
 
 }