Get Toplevel::resourceName() and ::resourceClass() from NETWinInfo

It's provided by the NETWinInfo, no need to keep an own implementation.
To keep compatibility with existing KWin code using the window class or
resource it's always converted to lower.

In addition a notify signal Toplevel::windowClassChanged is added and
emitted from the event handler whenever the WM2WindowClass property is
set.

REVIEW: 117496

events.cpp

@@ -523,6 +523,9 @@ bool Client::windowEvent(xcb_generic_event_t *e)
         if (dirtyProperties2.testFlag(NET::WM2WindowRole)) {
             emit windowRoleChanged();
         }
+        if (dirtyProperties2.testFlag(NET::WM2WindowClass)) {
+            getResourceClass();
+        }
     }
 
     const uint8_t eventType = e->response_type & ~0x80;
@@ -1508,6 +1511,9 @@ bool Unmanaged::windowEvent(xcb_generic_event_t *e)
     if (dirtyProperties2.testFlag(NET::WM2WindowRole)) {
         emit windowRoleChanged();
     }
+    if (dirtyProperties2.testFlag(NET::WM2WindowClass)) {
+        getResourceClass();
+    }
     const uint8_t eventType = e->response_type & ~0x80;
     switch (eventType) {
     case XCB_UNMAP_NOTIFY:

manage.cpp

@@ -91,6 +91,7 @@ bool Client::manage(xcb_window_t w, bool isMapped)
         NET::WMPid |
         NET::WMIconName;
     const NET::Properties2 properties2 =
+        NET::WM2WindowClass |
         NET::WM2WindowRole |
         NET::WM2UserTime |
         NET::WM2StartupId |

toplevel.cpp

@@ -224,17 +224,9 @@ Window Toplevel::wmClientLeader() const
 
 void Toplevel::getResourceClass()
 {
-    XClassHint classHint;
-    if (XGetClassHint(display(), window(), &classHint)) {
-        // Qt3.2 and older had this all lowercase, Qt3.3 capitalized resource class.
-        // Force lowercase, so that workarounds listing resource classes still work.
-        resource_name = QByteArray(classHint.res_name).toLower();
-        resource_class = QByteArray(classHint.res_class).toLower();
-        XFree(classHint.res_name);
-        XFree(classHint.res_class);
-    } else {
-        resource_name = resource_class = QByteArray();
-    }
+    resource_name  = QByteArray(info->windowClassName()).toLower();
+    resource_class = QByteArray(info->windowClassClass()).toLower();
+    emit windowClassChanged();
 }
 
 double Toplevel::opacity() const

toplevel.h

@@ -73,8 +73,8 @@ class Toplevel
     Q_PROPERTY(QRect rect READ rect)
     Q_PROPERTY(QPoint clientPos READ clientPos)
     Q_PROPERTY(QSize clientSize READ clientSize)
-    Q_PROPERTY(QByteArray resourceName READ resourceName)
-    Q_PROPERTY(QByteArray resourceClass READ resourceClass)
+    Q_PROPERTY(QByteArray resourceName READ resourceName NOTIFY windowClassChanged)
+    Q_PROPERTY(QByteArray resourceClass READ resourceClass NOTIFY windowClassChanged)
     Q_PROPERTY(QByteArray windowRole READ windowRole NOTIFY windowRoleChanged)
     /**
      * Returns whether the window is a desktop background window (the one with wallpaper).
@@ -372,6 +372,11 @@ Q_SIGNALS:
      * @since 5.0
      **/
     void windowRoleChanged();
+    /**
+     * Emitted whenever the window class name or resource name of the window changes.
+     * @since 5.0
+     **/
+    void windowClassChanged();
 
 protected Q_SLOTS:
     /**

unmanaged.cpp

@@ -65,7 +65,10 @@ bool Unmanaged::track(Window w)
     vis = attr.visual;
     bit_depth = attr.depth;
     info = new NETWinInfo(connection(), w, rootWindow(),
-                          NET::WMWindowType | NET::WMPid, NET::WM2Opacity | NET::WM2WindowRole);
+                          NET::WMWindowType | NET::WMPid,
+                          NET::WM2Opacity |
+                          NET::WM2WindowRole |
+                          NET::WM2WindowClass);
     getResourceClass();
     getWmClientLeader();
     getWmClientMachine();