Add better support for keymap update handling

Use the new X11 support API xkb_x11_* released in libxkbcommon version 0.4.0.

From the commit message where this API was introduced:

"These are function to create an xkb_keymap directly from XKB requests
to the X server. This opens up the possibility for X clients to use
xcb + xcb-xkb + xkbcommon as a proper replacement for Xlib + xkbfile for
keyboard support.

Why not just use the RMLVO that the server puts in the _XKB_RULES_NAMES
property? This does not account for custom keymaps, on-the-fly keymap
modifications, remote clients, etc., so is not a proper solution in
practice. Also, some servers don't even set it. Now, the client just
needs to recreate the keymap in response to a change in the server's
keymap (as Xlib clients do with XRefreshKeyboardMapping() and friends)."

This patch moves XKEYBOARD presence decision from compile time to runtime
for a proper remote X client support.

Task-number: QTBUG-31527
Task-number: QTBUG-32760
Change-Id: I4d402668cda2126ef180b27022154f96b1874b1d
Reviewed-by: Uli Schlachter <psychon@znc.in>
Reviewed-by: Lars Knoll <lars.knoll@digia.com>

1 files changed, 87 insertions, 133 deletions

diff --git a/src/plugins/platforms/xcb/qxcbkeyboard.cpp b/src/plugins/platforms/xcb/qxcbkeyboard.cpp
index 0a52640c9a..5de5530124 100644
--- a/src/plugins/platforms/xcb/qxcbkeyboard.cpp
+++ b/src/plugins/platforms/xcb/qxcbkeyboard.cpp
@@ -658,6 +658,7 @@ void QXcbKeyboard::clearXKBConfig()
 void QXcbKeyboard::updateKeymap()
 {
     m_config = true;
+    // set xkb context object
     if (!xkb_context) {
         xkb_context = xkb_context_new((xkb_context_flags)0);
         if (!xkb_context) {
@@ -666,67 +667,50 @@ void QXcbKeyboard::updateKeymap()
             return;
         }
     }
-    readXKBConfig();
-    // Compile a keymap from RMLVO (rules, models, layouts, variants and options) names
-    if (xkb_keymap)
-        xkb_keymap_unref(xkb_keymap);
+    // update xkb keymap object
+    xkb_keymap_unref(xkb_keymap);
+    xkb_keymap = 0;
 
-    xkb_keymap = xkb_keymap_new_from_names(xkb_context, &xkb_names, (xkb_keymap_compile_flags)0);
+    struct xkb_state *new_state = 0;
+#ifndef QT_NO_XKB
+    if (connection()->hasXKB()) {
+        xkb_keymap = xkb_x11_keymap_new_from_device(xkb_context, xcb_connection(), core_device_id, (xkb_keymap_compile_flags)0);
+        if (xkb_keymap) {
+            // Create a new keyboard state object for a keymap
+            new_state = xkb_x11_state_new_from_device(xkb_keymap, xcb_connection(), core_device_id);
+        }
+    }
+#endif
+    if (!xkb_keymap) {
+        // Compile a keymap from RMLVO (rules, models, layouts, variants and options) names
+        readXKBConfig();
+        xkb_keymap = xkb_keymap_new_from_names(xkb_context, &xkb_names, (xkb_keymap_compile_flags)0);
+        if (xkb_keymap)
+            new_state = xkb_state_new(xkb_keymap);
+    }
 
     if (!xkb_keymap) {
         qWarning("Qt: Failed to compile a keymap");
         m_config = false;
-        return;
     }
-    // Create a new keyboard state object for a keymap
-    struct xkb_state *new_state = xkb_state_new(xkb_keymap);
     if (!new_state) {
-        qWarning("Qt: Failed to create a new keyboard state");
+        qWarning("Qt: Failed to create xkb state");
         m_config = false;
-        return;
     }
+    if (!m_config)
+        return;
 
-    if (xkb_state) {
-        xkb_state_unref(xkb_state);
-        xkb_state = new_state;
-    } else {
-        xkb_state = new_state;
-#ifndef QT_NO_XKB
-        // get initial state from the X server (and keep it up-to-date at all times)
-        xcb_xkb_get_state_cookie_t state;
-        xcb_xkb_get_state_reply_t *init_state;
-
-        xcb_connection_t *c = xcb_connection();
-        state = xcb_xkb_get_state(c, XCB_XKB_ID_USE_CORE_KBD);
-        init_state = xcb_xkb_get_state_reply(c, state, 0);
-        if (!init_state) {
-            qWarning("Qt: couldn't retrieve an initial keyboard state");
-            return;
-        }
-        /* The xkb keyboard state is comprised of the state of all keyboard modifiers,
-           the keyboard group, and the state of the pointer buttons */
-        xkb_state_update_mask(xkb_state,
-                              init_state->baseMods,
-                              init_state->latchedMods,
-                              init_state->lockedMods,
-                              init_state->baseGroup,
-                              init_state->latchedGroup,
-                              init_state->lockedGroup);
-        free(init_state);
-#else
+    // update xkb state object
+    xkb_state_unref(xkb_state);
+    xkb_state = new_state;
+    if (!connection()->hasXKB())
         updateXKBMods();
-#endif
-    }
 }
 
 #ifndef QT_NO_XKB
 void QXcbKeyboard::updateXKBState(xcb_xkb_state_notify_event_t *state)
 {
-    if (!m_config)
-        return;
-
-    if (connection()->hasXKB()) {
-
+    if (m_config && connection()->hasXKB()) {
         const xkb_state_component newState
                 = xkb_state_update_mask(xkb_state,
                                   state->baseMods,
@@ -741,35 +725,34 @@ void QXcbKeyboard::updateXKBState(xcb_xkb_state_notify_event_t *state)
         }
     }
 }
+#endif
 
-#else
 void QXcbKeyboard::updateXKBStateFromCore(quint16 state)
 {
-    if (!m_config)
-        return;
+    if (m_config && !connection()->hasXKB()) {
+        const quint32 modsDepressed = xkb_state_serialize_mods(xkb_state, XKB_STATE_MODS_DEPRESSED);
+        const quint32 modsLatched = xkb_state_serialize_mods(xkb_state, XKB_STATE_MODS_LATCHED);
+        const quint32 modsLocked = xkb_state_serialize_mods(xkb_state, XKB_STATE_MODS_LOCKED);
+        const quint32 xkbMask = xkbModMask(state);
+
+        const quint32 latched = modsLatched & xkbMask;
+        const quint32 locked = modsLocked & xkbMask;
+        quint32 depressed = modsDepressed & xkbMask;
+        // set modifiers in depressed if they don't appear in any of the final masks
+        depressed |= ~(depressed | latched | locked) & xkbMask;
+
+        const xkb_state_component newState
+                = xkb_state_update_mask(xkb_state,
+                              depressed,
+                              latched,
+                              locked,
+                              0,
+                              0,
+                              (state >> 13) & 3); // bits 13 and 14 report the state keyboard group
 
-    const quint32 modsDepressed = xkb_state_serialize_mods(xkb_state, XKB_STATE_MODS_DEPRESSED);
-    const quint32 modsLatched = xkb_state_serialize_mods(xkb_state, XKB_STATE_MODS_LATCHED);
-    const quint32 modsLocked = xkb_state_serialize_mods(xkb_state, XKB_STATE_MODS_LOCKED);
-    const quint32 xkbMask = xkbModMask(state);
-
-    const quint32 latched = modsLatched & xkbMask;
-    const quint32 locked = modsLocked & xkbMask;
-    quint32 depressed = modsDepressed & xkbMask;
-    // set modifiers in depressed if they don't appear in any of the final masks
-    depressed |= ~(depressed | latched | locked) & xkbMask;
-
-    const xkb_state_component newState
-            = xkb_state_update_mask(xkb_state,
-                          depressed,
-                          latched,
-                          locked,
-                          0,
-                          0,
-                          (state >> 13) & 3); // bits 13 and 14 report the state keyboard group
-
-    if ((newState & XKB_STATE_LAYOUT_EFFECTIVE) == XKB_STATE_LAYOUT_EFFECTIVE) {
-        //qWarning("TODO: Support KeyboardLayoutChange on QPA (QTBUG-27681)");
+        if ((newState & XKB_STATE_LAYOUT_EFFECTIVE) == XKB_STATE_LAYOUT_EFFECTIVE) {
+            //qWarning("TODO: Support KeyboardLayoutChange on QPA (QTBUG-27681)");
+        }
     }
 }
 
@@ -799,16 +782,15 @@ quint32 QXcbKeyboard::xkbModMask(quint16 state)
 
 void QXcbKeyboard::updateXKBMods()
 {
-    xkb_mods.shift = xkb_map_mod_get_index(xkb_keymap, XKB_MOD_NAME_SHIFT);
-    xkb_mods.lock = xkb_map_mod_get_index(xkb_keymap, XKB_MOD_NAME_CAPS);
-    xkb_mods.control = xkb_map_mod_get_index(xkb_keymap, XKB_MOD_NAME_CTRL);
-    xkb_mods.mod1 = xkb_map_mod_get_index(xkb_keymap, "Mod1");
-    xkb_mods.mod2 = xkb_map_mod_get_index(xkb_keymap, "Mod2");
-    xkb_mods.mod3 = xkb_map_mod_get_index(xkb_keymap, "Mod3");
-    xkb_mods.mod4 = xkb_map_mod_get_index(xkb_keymap, "Mod4");
-    xkb_mods.mod5 = xkb_map_mod_get_index(xkb_keymap, "Mod5");
+    xkb_mods.shift = xkb_keymap_mod_get_index(xkb_keymap, XKB_MOD_NAME_SHIFT);
+    xkb_mods.lock = xkb_keymap_mod_get_index(xkb_keymap, XKB_MOD_NAME_CAPS);
+    xkb_mods.control = xkb_keymap_mod_get_index(xkb_keymap, XKB_MOD_NAME_CTRL);
+    xkb_mods.mod1 = xkb_keymap_mod_get_index(xkb_keymap, "Mod1");
+    xkb_mods.mod2 = xkb_keymap_mod_get_index(xkb_keymap, "Mod2");
+    xkb_mods.mod3 = xkb_keymap_mod_get_index(xkb_keymap, "Mod3");
+    xkb_mods.mod4 = xkb_keymap_mod_get_index(xkb_keymap, "Mod4");
+    xkb_mods.mod5 = xkb_keymap_mod_get_index(xkb_keymap, "Mod5");
 }
-#endif
 
 QList<int> QXcbKeyboard::possibleKeys(const QKeyEvent *event) const
 {
@@ -893,10 +875,8 @@ QList<int> QXcbKeyboard::possibleKeys(const QKeyEvent *event) const
             result += (qtKey + mods);
         }
     }
-    if (kb_state)
-        xkb_state_unref(kb_state);
-    if (fallback_keymap)
-        xkb_keymap_unref(fallback_keymap);
+    xkb_state_unref(kb_state);
+    xkb_keymap_unref(fallback_keymap);
 
     return result;
  }
@@ -963,58 +943,41 @@ QXcbKeyboard::QXcbKeyboard(QXcbConnection *connection)
     , xkb_context(0)
     , xkb_keymap(0)
     , xkb_state(0)
-#ifndef QT_NO_XKB
     , core_device_id(0)
-#endif
 {
     memset(&xkb_names, 0, sizeof(xkb_names));
-    updateKeymap();
 #ifndef QT_NO_XKB
     if (connection->hasXKB()) {
-
         updateVModMapping();
         updateVModToRModMapping();
-
-        // get the core keyboard id
-        xcb_xkb_get_device_info_cookie_t device_id_cookie;
-        xcb_xkb_get_device_info_reply_t *device_id;
-
-        device_id_cookie = xcb_xkb_get_device_info(xcb_connection(),
-                                            XCB_XKB_ID_USE_CORE_KBD,
-                                            0, 0, 0, 0, 0, 0);
-
-        device_id = xcb_xkb_get_device_info_reply(xcb_connection(), device_id_cookie, 0);
-        if (!device_id) {
+        core_device_id = xkb_x11_get_core_keyboard_device_id(xcb_connection());
+        if (core_device_id == -1) {
             qWarning("Qt: couldn't get core keyboard device info");
             return;
         }
-
-        core_device_id = device_id->deviceID;
-        free(device_id);
+    } else {
+#endif
+        m_key_symbols = xcb_key_symbols_alloc(xcb_connection());
+        updateModifiers();
+#ifndef QT_NO_XKB
     }
-#else
-    m_key_symbols = xcb_key_symbols_alloc(xcb_connection());
-    updateModifiers();
 #endif
+    updateKeymap();
 }
 
 QXcbKeyboard::~QXcbKeyboard()
 {
-    if (xkb_state)
-        xkb_state_unref(xkb_state);
-    if (xkb_keymap)
-        xkb_keymap_unref(xkb_keymap);
-    if (xkb_context)
-        xkb_context_unref(xkb_context);
-#ifdef QT_NO_XKB
-    xcb_key_symbols_free(m_key_symbols);
-#endif
+    xkb_state_unref(xkb_state);
+    xkb_keymap_unref(xkb_keymap);
+    xkb_context_unref(xkb_context);
+    if (!connection()->hasXKB())
+        xcb_key_symbols_free(m_key_symbols);
     clearXKBConfig();
 }
 
-#ifndef QT_NO_XKB
 void QXcbKeyboard::updateVModMapping()
 {
+#ifndef QT_NO_XKB
     xcb_xkb_get_names_cookie_t names_cookie;
     xcb_xkb_get_names_reply_t *name_reply;
     xcb_xkb_get_names_value_list_t names_list;
@@ -1078,10 +1041,12 @@ void QXcbKeyboard::updateVModMapping()
     }
 
     free(name_reply);
+#endif
 }
 
 void QXcbKeyboard::updateVModToRModMapping()
 {
+#ifndef QT_NO_XKB
     xcb_xkb_get_map_cookie_t map_cookie;
     xcb_xkb_get_map_reply_t *map_reply;
     xcb_xkb_get_map_map_t map;
@@ -1144,8 +1109,9 @@ void QXcbKeyboard::updateVModToRModMapping()
 
     free(map_reply);
     resolveMaskConflicts();
+#endif
 }
-#else
+
 void QXcbKeyboard::updateModifiers()
 {
     // The core protocol does not provide a convenient way to determine the mapping
@@ -1209,7 +1175,6 @@ void QXcbKeyboard::updateModifiers()
     free(modMapReply);
     resolveMaskConflicts();
 }
-#endif
 
 void QXcbKeyboard::resolveMaskConflicts()
 {
@@ -1292,17 +1257,9 @@ void QXcbKeyboard::handleKeyEvent(QWindow *window, QEvent::Type type, xcb_keycod
 
     if (!m_config)
         return;
-    // It is crucial the order of xkb_state_key_get_one_sym &
-    // xkb_state_update_key operations is not reversed!
+
+    // It is crucial the order of xkb_state_key_get_one_sym & xkb_state_update_key operations is not reversed!
     xcb_keysym_t sym = xkb_state_key_get_one_sym(xkb_state, code);
-#ifdef QT_NO_XKB
-    enum xkb_key_direction direction;
-    if (type == QEvent::KeyPress)
-        direction = XKB_KEY_DOWN;
-    else
-        direction = XKB_KEY_UP;
-    xkb_state_update_key(xkb_state, code, direction);
-#endif
 
     QPlatformInputContext *inputContext = QGuiApplicationPrivate::platformIntegration()->inputContext();
     QMetaMethod method;
@@ -1422,17 +1379,14 @@ void QXcbKeyboard::handleKeyReleaseEvent(QXcbWindowEventListener *eventListener,
 void QXcbKeyboard::handleMappingNotifyEvent(const void *event)
 {
     updateKeymap();
-#ifdef QT_NO_XKB
-    void *ev = const_cast<void *>(event);
-    xcb_refresh_keyboard_mapping(m_key_symbols, static_cast<xcb_mapping_notify_event_t *>(ev));
-    updateModifiers();
-#else
-    Q_UNUSED(event)
     if (connection()->hasXKB()) {
         updateVModMapping();
         updateVModToRModMapping();
+    } else {
+        void *ev = const_cast<void *>(event);
+        xcb_refresh_keyboard_mapping(m_key_symbols, static_cast<xcb_mapping_notify_event_t *>(ev));
+        updateModifiers();
     }
-#endif
 }
 
 QT_END_NAMESPACE