[XembedSNIProxy] Redirect and handle structure requests on the embedded window.

Summary:
When the window is embedded, it should not request position change. Sometimes applications are misbehaving and ignore this constrain. We need to capture all structure requests (position or size change) and ignore them. In other words, we must be a window manager for the embedded window.

BUG: 414667

Test Plan:
0. You need multiples screens to test this
1. Configure screens so that (0,0) is not on the primary screen
2. Run any Windows app with tray icon using Wine
3. Left click event should work correctly

Reviewers: #plasma_workspaces, #plasma, davidedmundson

Reviewed By: #plasma_workspaces, #plasma, davidedmundson

Subscribers: plasma-devel

Tags: #plasma

Differential Revision: https://phabricator.kde.org/D26079

xembed-sni-proxy/fdoselectionmanager.cpp

@@ -154,6 +154,13 @@ bool FdoSelectionManager::nativeEventFilter(const QByteArray &eventType, void *m
             sniProxy->update();
             xcb_damage_subtract(QX11Info::connection(), m_damageWatches[damagedWId], XCB_NONE, XCB_NONE);
         }
+    } else if (responseType == XCB_CONFIGURE_REQUEST) {
+        const auto event = reinterpret_cast<xcb_configure_request_event_t *>(ev);
+        const auto sniProxy = m_proxies.value(event->window);
+        if (sniProxy) {
+            // The embedded window tries to move or resize. Ignore this request and send the current configuration.
+            sniProxy->sendConfigureNotification();
+        }
     }
 
     return false;

xembed-sni-proxy/sniproxy.cpp

@@ -49,6 +49,7 @@
 #define SNI_WATCHER_PATH "/StatusNotifierWatcher"
 
 static uint16_t s_embedSize = 32; //max size of window to embed. We no longer resize the embedded window as Chromium acts stupidly.
+static unsigned int XEMBED_VERSION = 0;
 
 int SNIProxy::s_serviceCount = 0;
 
@@ -95,10 +96,12 @@ SNIProxy::SNIProxy(xcb_window_t wid, QObject* parent):
     //create a container window
     auto screen = xcb_setup_roots_iterator (xcb_get_setup (c)).data;
     m_containerWid = xcb_generate_id(c);
-    uint32_t values[2];
-    auto mask = XCB_CW_BACK_PIXEL | XCB_CW_OVERRIDE_REDIRECT;
+    uint32_t values[3];
+    uint32_t mask = XCB_CW_BACK_PIXEL | XCB_CW_OVERRIDE_REDIRECT | XCB_CW_EVENT_MASK;
     values[0] = screen->black_pixel; //draw a solid background so the embedded icon doesn't get garbage in it
     values[1] = true; //bypass wM
+    // Redirect and handle structure (size, position) requests on the embedded window.
+    values[2] = XCB_EVENT_MASK_STRUCTURE_NOTIFY | XCB_EVENT_MASK_SUBSTRUCTURE_NOTIFY | XCB_EVENT_MASK_SUBSTRUCTURE_REDIRECT;
     xcb_create_window (c,                          /* connection    */
                     XCB_COPY_FROM_PARENT,          /* depth         */
                      m_containerWid,               /* window Id     */
@@ -148,7 +151,7 @@ SNIProxy::SNIProxy(xcb_window_t wid, QObject* parent):
     xcb_change_save_set(c, XCB_SET_MODE_INSERT, wid);
 
     //tell client we're embedding it
-    xembed_message_send(wid, XEMBED_EMBEDDED_NOTIFY, m_containerWid, 0, 0);
+    xembed_message_send(wid, XEMBED_EMBEDDED_NOTIFY, 0, m_containerWid, XEMBED_VERSION);
 
     //move window we're embedding
     const uint32_t windowMoveConfigVals[2] = { 0, 0 };
@@ -220,6 +223,22 @@ void SNIProxy::stackContainerWindow(const uint32_t stackMode) const
     xcb_configure_window(c, m_containerWid, XCB_CONFIG_WINDOW_STACK_MODE, stackData);
 }
 
+void SNIProxy::sendConfigureNotification() const
+{
+    xcb_configure_notify_event_t event;
+    memset(&event, 0x00, sizeof(xcb_configure_notify_event_t));
+    event.response_type = XCB_CONFIGURE_NOTIFY;
+    event.event = m_windowId;
+    event.window = m_windowId;
+    event.x = 0;
+    event.y = 0;
+    event.width = s_embedSize;
+    event.height = s_embedSize;
+
+    auto connection = QX11Info::connection();
+    xcb_send_event(connection, false, m_windowId, XCB_EVENT_MASK_STRUCTURE_NOTIFY, reinterpret_cast<char *>(&event));
+}
+
 QSize SNIProxy::calculateClientWindowSize() const
 {
     auto c = QX11Info::connection();
@@ -239,19 +258,12 @@ QSize SNIProxy::calculateClientWindowSize() const
     if (clientWindowSize.isEmpty() || clientWindowSize.width() > s_embedSize || clientWindowSize.height() > s_embedSize) {
         qCDebug(SNIPROXY) << "Resizing window" << m_windowId << Title() << "from w*h" << clientWindowSize;
 
-        xcb_configure_notify_event_t event;
-        memset(&event, 0x00, sizeof(xcb_configure_notify_event_t));
-        event.response_type = XCB_CONFIGURE_NOTIFY;
-        event.event = m_windowId;
-        event.window = m_windowId;
-        event.width = s_embedSize;
-        event.height = s_embedSize;
-        xcb_send_event(c, false, m_windowId, XCB_EVENT_MASK_STRUCTURE_NOTIFY, (char *) &event);
+        sendConfigureNotification();
 
-        const uint32_t windowMoveConfigVals[2] = { s_embedSize, s_embedSize };
+        const uint32_t windowSizeConfigVals[2] = { s_embedSize, s_embedSize };
         xcb_configure_window(c, m_windowId,
                              XCB_CONFIG_WINDOW_WIDTH | XCB_CONFIG_WINDOW_HEIGHT,
-                             windowMoveConfigVals);
+                             windowSizeConfigVals);
 
         clientWindowSize = QSize(s_embedSize, s_embedSize);
     }

xembed-sni-proxy/sniproxy.h

@@ -50,6 +50,7 @@ public:
 
     void update();
     void stackContainerWindow(const uint32_t stackMode) const;
+    void sendConfigureNotification() const;
 
     /**
      * @return the category of the application associated to this item