GUACAMOLE-352: Type using dead keys when necessary and possible.

src/protocols/rdp/Makefile.am

@@ -28,6 +28,7 @@ nodist_libguac_client_rdp_la_SOURCES = \
 libguac_client_rdp_la_SOURCES = \
     audio_input.c               \
     client.c                    \
+    decompose.c                 \
     dvc.c                       \
     error.c                     \
     input.c                     \
@@ -98,6 +99,7 @@ noinst_HEADERS =                             \
     guac_svc/svc_service.h                   \
     audio_input.h                            \
     client.h                                 \
+    decompose.h                              \
     dvc.h                                    \
     error.h                                  \
     input.h                                  \

src/protocols/rdp/decompose.c

@@ -0,0 +1,177 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+#include "config.h"
+#include "keyboard.h"
+
+/**
+ * The X11 keysym for the dead key which types a grave (`).
+ */
+#define DEAD_GRAVE 0xFE50
+
+/**
+ * The X11 keysym for the dead key which types an acute (´). Note that this is
+ * NOT equivalent to an apostrophe or single quote.
+ */
+#define DEAD_ACUTE 0xFE51
+
+/**
+ * The X11 keysym for the dead key which types a circumflex/caret (^).
+ */
+#define DEAD_CIRCUMFLEX 0xFE52
+
+/**
+ * The X11 keysym for the dead key which types a tilde (~).
+ */
+#define DEAD_TILDE 0xFE53
+
+/**
+ * The X11 keysym for the dead key which types a dieresis/umlaut (¨).
+ */
+#define DEAD_DIERESIS 0xFE57
+
+/**
+ * The X11 keysym for the dead key which types an abovering (˚). Note that this
+ * is NOT equivalent to the degree symbol.
+ */
+#define DEAD_ABOVERING 0xFE58
+
+/**
+ * The decomposed form of a key that can be typed using two keypresses: a dead
+ * key followed by a base key. For example, on a keyboard which lacks a single
+ * dedicated key for doing the same, "ó" would be typed using the dead acute
+ * key followed by the "o" key. The dead key and base key are pressed and
+ * released in sequence; they are not held down.
+ */
+typedef struct guac_rdp_decomposed_key {
+
+    /**
+     * The keysym of the dead key which must first be pressed and released to
+     * begin typing the desired character. The dead key defines the diacritic
+     * which will be applied to the character typed by the base key.
+     */
+    int dead_keysym;
+
+    /**
+     * The keysym of the base key which must be pressed and released to finish
+     * typing the desired character. The base key defines the normal form of
+     * the character (the form which lacks any diacritic) to which the
+     * diacritic defined by the previously-pressed dead key will be applied.
+     */
+    int base_keysym;
+
+} guac_rdp_decomposed_key;
+
+/**
+ * A lookup table of all known decomposed forms of various keysyms. Keysyms map
+ * directly to entries within this table. A keysym which has no entry within
+ * this table does not have a defined decomposed form (or at least does not
+ * have a decomposed form relevant to RDP).
+ */
+guac_rdp_decomposed_key guac_rdp_decomposed_keys[256] = {
+
+    /* ^ */ [0x005E] = { DEAD_CIRCUMFLEX, ' ' },
+    /* ` */ [0x0060] = { DEAD_GRAVE,      ' ' },
+    /* ~ */ [0x007E] = { DEAD_TILDE,      ' ' },
+    /* ¨ */ [0x00A8] = { DEAD_DIERESIS,   ' ' },
+    /* ´ */ [0x00B4] = { DEAD_ACUTE,      ' ' },
+    /* À */ [0x00C0] = { DEAD_GRAVE,      'A' },
+    /* Á */ [0x00C1] = { DEAD_ACUTE,      'A' },
+    /* Â */ [0x00C2] = { DEAD_CIRCUMFLEX, 'A' },
+    /* Ã */ [0x00C3] = { DEAD_TILDE,      'A' },
+    /* Ä */ [0x00C4] = { DEAD_DIERESIS,   'A' },
+    /* Å */ [0x00C5] = { DEAD_ABOVERING,  'A' },
+    /* È */ [0x00C8] = { DEAD_GRAVE,      'E' },
+    /* É */ [0x00C9] = { DEAD_ACUTE,      'E' },
+    /* Ê */ [0x00CA] = { DEAD_CIRCUMFLEX, 'E' },
+    /* Ë */ [0x00CB] = { DEAD_DIERESIS,   'E' },
+    /* Ì */ [0x00CC] = { DEAD_GRAVE,      'I' },
+    /* Í */ [0x00CD] = { DEAD_ACUTE,      'I' },
+    /* Î */ [0x00CE] = { DEAD_CIRCUMFLEX, 'I' },
+    /* Ï */ [0x00CF] = { DEAD_DIERESIS,   'I' },
+    /* Ñ */ [0x00D1] = { DEAD_TILDE,      'N' },
+    /* Ò */ [0x00D2] = { DEAD_GRAVE,      'O' },
+    /* Ó */ [0x00D3] = { DEAD_ACUTE,      'O' },
+    /* Ô */ [0x00D4] = { DEAD_CIRCUMFLEX, 'O' },
+    /* Õ */ [0x00D5] = { DEAD_TILDE,      'O' },
+    /* Ö */ [0x00D6] = { DEAD_DIERESIS,   'O' },
+    /* Ù */ [0x00D9] = { DEAD_GRAVE,      'U' },
+    /* Ú */ [0x00DA] = { DEAD_ACUTE,      'U' },
+    /* Û */ [0x00DB] = { DEAD_CIRCUMFLEX, 'U' },
+    /* Ü */ [0x00DC] = { DEAD_DIERESIS,   'U' },
+    /* Ý */ [0x00DD] = { DEAD_ACUTE,      'Y' },
+    /* à */ [0x00E0] = { DEAD_GRAVE,      'a' },
+    /* á */ [0x00E1] = { DEAD_ACUTE,      'a' },
+    /* â */ [0x00E2] = { DEAD_CIRCUMFLEX, 'a' },
+    /* ã */ [0x00E3] = { DEAD_TILDE,      'a' },
+    /* ä */ [0x00E4] = { DEAD_DIERESIS,   'a' },
+    /* å */ [0x00E5] = { DEAD_ABOVERING,  'a' },
+    /* è */ [0x00E8] = { DEAD_GRAVE,      'e' },
+    /* é */ [0x00E9] = { DEAD_ACUTE,      'e' },
+    /* ê */ [0x00EA] = { DEAD_CIRCUMFLEX, 'e' },
+    /* ë */ [0x00EB] = { DEAD_DIERESIS,   'e' },
+    /* ì */ [0x00EC] = { DEAD_GRAVE,      'i' },
+    /* í */ [0x00ED] = { DEAD_ACUTE,      'i' },
+    /* î */ [0x00EE] = { DEAD_CIRCUMFLEX, 'i' },
+    /* ï */ [0x00EF] = { DEAD_DIERESIS,   'i' },
+    /* ñ */ [0x00F1] = { DEAD_TILDE,      'n' },
+    /* ò */ [0x00F2] = { DEAD_GRAVE,      'o' },
+    /* ó */ [0x00F3] = { DEAD_ACUTE,      'o' },
+    /* ô */ [0x00F4] = { DEAD_CIRCUMFLEX, 'o' },
+    /* õ */ [0x00F5] = { DEAD_TILDE,      'o' },
+    /* ö */ [0x00F6] = { DEAD_DIERESIS,   'o' },
+    /* ù */ [0x00F9] = { DEAD_GRAVE,      'u' },
+    /* ú */ [0x00FA] = { DEAD_ACUTE,      'u' },
+    /* û */ [0x00FB] = { DEAD_CIRCUMFLEX, 'u' },
+    /* ü */ [0x00FC] = { DEAD_DIERESIS,   'u' },
+    /* ý */ [0x00FD] = { DEAD_ACUTE,      'y' },
+    /* ÿ */ [0x00FF] = { DEAD_DIERESIS,   'y' } 
+
+};
+
+int guac_rdp_decompose_keysym(guac_rdp_keyboard* keyboard, int keysym) {
+
+    /* Verify keysym is within range of lookup table */
+    if (keysym < 0x00 || keysym > 0xFF)
+        return 1;
+
+    /* Verify keysym is actually defined within lookup table */
+    guac_rdp_decomposed_key* key = &guac_rdp_decomposed_keys[keysym];
+    if (!key->dead_keysym)
+        return 1;
+
+    /* Cannot type using decomposed keys if those keys are not defined within
+     * the current layout */
+    if (!guac_rdp_keyboard_is_defined(keyboard, key->dead_keysym)
+            || !guac_rdp_keyboard_is_defined(keyboard, key->base_keysym))
+        return 1;
+
+    /* Press dead key */
+    guac_rdp_keyboard_send_event(keyboard, key->dead_keysym, 1);
+    guac_rdp_keyboard_send_event(keyboard, key->dead_keysym, 0);
+
+    /* Press base key */
+    guac_rdp_keyboard_send_event(keyboard, key->base_keysym, 1);
+    guac_rdp_keyboard_send_event(keyboard, key->base_keysym, 0);
+
+    /* Decomposed key successfully typed */
+    return 0;
+
+}
+

src/protocols/rdp/decompose.h

@@ -0,0 +1,50 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+#ifndef GUAC_RDP_DECOMPOSE_H
+#define GUAC_RDP_DECOMPOSE_H
+
+#include "config.h"
+#include "keyboard.h"
+
+/**
+ * Attempts to type the given keysym by decomposing the associated character
+ * into the dead key and base key pair which would be used to type that
+ * character on a keyboard which lacks the necessary dedicated key. The key
+ * events for the dead key and base key are sent only if the keyboard layout of
+ * the given keyboard defines those keys.
+ *
+ * For example, the keysym for "ò" (0x00F2) would decompose into a dead grave
+ * (`) and the base key "o". May it rest in peace.
+ *
+ * @param keyboard
+ *     The guac_rdp_keyboard associated with the current RDP session.
+ *
+ * @param keysym
+ *     The keysym being pressed.
+ *
+ * @return
+ *     Zero if the keysym was successfully decomposed and sent to the RDP
+ *     server as a pair of key events (the dead key and base key), non-zero
+ *     otherwise.
+ */
+int guac_rdp_decompose_keysym(guac_rdp_keyboard* keyboard, int keysym);
+
+#endif
+

src/protocols/rdp/keyboard.c

@@ -20,6 +20,7 @@
 #include "config.h"
 
 #include "client.h"
+#include "decompose.h"
 #include "keyboard.h"
 #include "rdp.h"
 #include "rdp_keymap.h"
@@ -309,12 +310,15 @@ int guac_rdp_keyboard_send_event(guac_rdp_keyboard* keyboard,
         }
     }
 
-    /* Fall back to unicode events if undefined inside current keymap */
+    /* Fall back to dead keys or Unicode events if otherwise undefined inside
-
+     * current keymap (note that we only handle "pressed" here, as neither
-    /* Only send when key pressed - Unicode events do not have
+     * Unicode events nor dead keys can have a pressed/released state) */
-     * DOWN/RELEASE flags */
     if (pressed) {
 
+        /* Attempt to type using dead keys */
+        if (!guac_rdp_decompose_keysym(keyboard, keysym))
+            return 0;
+
         guac_client_log(client, GUAC_LOG_DEBUG,
                 "Sending keysym 0x%x as Unicode", keysym);