add deco API versioning support

REVIEW: 104978
BUG: 299141
FIXED-IN: 4.9

clients/aurorae/src/aurorae.cpp

@@ -434,6 +434,9 @@ extern "C"
     KDE_EXPORT KDecorationFactory *create_factory() {
         return Aurorae::AuroraeFactory::instance();
     }
+    KWIN_EXPORT int decoration_version() {
+        return KWIN_DECORATION_API_VERSION;
+    }
 }
 
 

clients/b2/b2client.cpp

@@ -119,10 +119,7 @@ static bool drawSmallBorders = false;
 
 // =====================================
 
-extern "C" KDE_EXPORT KDecorationFactory* create_factory()
-{
-    return new B2::B2ClientFactory();
-}
+KWIN_DECORATION(B2::B2ClientFactory)
 
 // =====================================
 

clients/laptop/laptopclient.cpp

@@ -78,10 +78,8 @@ static bool pixmaps_created = false;
 
 // =====================================
 
-extern "C" KDE_EXPORT KDecorationFactory* create_factory()
-{
-    return new Laptop::LaptopClientFactory();
-}
+KWIN_DECORATION(Laptop::LaptopClientFactory)
+
 
 // =====================================
 

clients/oxygen/oxygenfactory.cpp

@@ -35,11 +35,7 @@
 #include <KWindowInfo>
 #include <kdeversion.h>
 
-extern "C"
-{
-    KDE_EXPORT KDecorationFactory* create_factory()
-    { return new Oxygen::Factory(); }
-}
+KWIN_DECORATION(Oxygen::Factory)
 
 namespace Oxygen
 {

clients/plastik/plastik.cpp

@@ -552,6 +552,8 @@ PlastikHandler* Handler()
 // Plugin Stuff                                                             //
 //////////////////////////////////////////////////////////////////////////////
 
+
+// KWIN_DECORATION(KWinPlastik::PlastikHandler)
 extern "C"
 {
     KDE_EXPORT KDecorationFactory *create_factory()
@@ -559,4 +561,8 @@ extern "C"
         KWinPlastik::handler = new KWinPlastik::PlastikHandler();
         return KWinPlastik::handler;
     }
+    KWIN_EXPORT int decoration_version() {
+        return KWIN_DECORATION_API_VERSION;
+    }
 }
+

libkdecorations/kdecoration.h

@@ -34,6 +34,19 @@ DEALINGS IN THE SOFTWARE.
 
 #define KWIN_EXPORT KDE_EXPORT
 
+#define KWIN_DECORATION_API_VERSION 1
+
+/**
+ * Defines the class to be used for decoration factory.
+ * The class must be namespace complete.
+ * E.g.  KWIN_EFFECT( Oxygen::Factory )
+ **/
+#define KWIN_DECORATION( classname ) \
+    extern "C" { \
+        KWIN_EXPORT KDecorationFactory* create_factory() { return new classname(); } \
+        KWIN_EXPORT int decoration_version() { return KWIN_DECORATION_API_VERSION; } \
+    }
+
 class KConfig;
 
 /** @defgroup kdecoration KWin decorations library */

libkdecorations/kdecoration_plugins_p.cpp

@@ -157,6 +157,25 @@ trydefaultlib:
     }
 
     create_ptr = NULL;
+    version_ptr = 0;
+    KLibrary::void_function_ptr version_func = library->resolveFunction("decoration_version");
+    if (version_func) {
+        // TODO for the moment we let unversioned decos through
+        // later on this function shall become mandatory!
+        version_ptr = (int(*)())version_func;
+        const int deco_version = version_ptr();
+        if (deco_version != KWIN_DECORATION_API_VERSION) {
+            if (nameStr != defaultPlugin) {
+                kWarning(1212) << i18n("The library %1 has wrong API version %2", path, deco_version);
+                library->unload();
+                library = NULL;
+                goto trydefaultlib;
+            }
+        }
+    } else {
+        kWarning(1212) << i18n("******\n\nThe library %1 has no API version\nPlease use the KWIN_DECORATION or future versions of kwin will no longer load this decoration!\n*******", path);
+    }
+
     KLibrary::void_function_ptr create_func = library->resolveFunction("create_factory");
     if (create_func)
         create_ptr = (KDecorationFactory * (*)())create_func;

libkdecorations/kdecoration_plugins_p.h

@@ -59,6 +59,7 @@ protected:
     QString defaultPlugin; // FRAME normalne protected?
 private:
     KDecorationFactory*(*create_ptr)();
+    int (*version_ptr)();
     KLibrary *library;
     KDecorationFactory* fact;
     KLibrary *old_library;
@@ -71,6 +72,7 @@ private:
 
  Plugins API:
     KDecorationFactory* create_factory(); - called once after loading
+    int decoration_version(); - called once after loading
 
 */