Added KDecorationFactory::checkRequirements(), which allows the decoration

plugin to check what the core supports, i.e. the opposite of supports().
Not used yet, but apparently will be needed e.g. for the new tranparency.

svn path=/trunk/kdebase/kwin/; revision=269291

kcmkwin/kwindecoration/preview.cpp

@@ -398,4 +398,9 @@ unsigned long KDecorationPreviewOptions::updateSettings()
     return changed;
     }
 
+bool KDecorationPreviewPlugins::provides( Requirement )
+    {
+    return false;
+    }
+    
 #include "preview.moc"

kcmkwin/kwindecoration/preview.h

@@ -24,11 +24,11 @@
 
 #include <qwidget.h>
 #include <kdecoration_p.h>
+#include <kdecoration_plugins_p.h>
 
 class QLabel;
 
 class KDecorationPreviewBridge;
-class KDecorationPlugins;
 class KDecorationOptions;
 
 class KDecorationPreview
@@ -118,4 +118,17 @@ class KDecorationPreviewOptions
         virtual unsigned long updateSettings();
     };
 
+class KDecorationPreviewPlugins
+    : public KDecorationPlugins
+    {
+    public:
+        KDecorationPreviewPlugins( KConfig* cfg );
+        virtual bool provides( Requirement );
+    };
+
+inline KDecorationPreviewPlugins::KDecorationPreviewPlugins( KConfig* cfg )
+    : KDecorationPlugins( cfg )
+    {
+    }
+
 #endif

lib/kdecoration.h

@@ -125,8 +125,19 @@ public:
         BorderOversized, ///< Oversized borders
         BordersCount     ///< @internal
         };
+
+    enum Ability { ABILITY_DUMMY = 10000000 };
+
+    enum Requirement { REQUIREMENT_DUMMY = 1000000 };
 };    
 
+class KDecorationProvides
+    : public KDecorationDefines
+    {
+    public:
+        virtual bool provides( Requirement req ) = 0;
+    };
+
 /**
  * This class holds various configuration settings for the decoration.
  * It is accessible from the decorations either as KDecoration::options()

lib/kdecoration_plugins_p.cpp

@@ -161,6 +161,7 @@ bool KDecorationPlugins::loadPlugin( QString nameStr )
         return false;
         }
     fact = create_ptr();
+    fact->checkRequirements( this ); // let it check what is supported
 
     pluginStr = nameStr;
     

lib/kdecoration_plugins_p.h

@@ -34,13 +34,16 @@ DEALINGS IN THE SOFTWARE.
 #include <qstring.h>
 #include <qwidget.h>
 
+#include "kdecoration.h"
+
 class KLibrary;
+class KConfig;
 class KDecoration;
 class KDecorationBridge;
 class KDecorationFactory;
-class KConfig;
 
 class KDecorationPlugins
+    : public KDecorationProvides
     {
     public:
         KDecorationPlugins( KConfig* cfg );

lib/kdecorationfactory.cpp

@@ -47,6 +47,10 @@ bool KDecorationFactory::supports( Ability )
     return false;
     }
 
+void KDecorationFactory::checkRequirements( KDecorationProvides* )
+    {
+    }
+
 QValueList< KDecorationDefines::BorderSize > KDecorationFactory::borderSizes() const
     {
     return QValueList< BorderSize >() << BorderNormal;

lib/kdecorationfactory.h

@@ -35,7 +35,6 @@ class KDecorationFactory
     : public KDecorationDefines
     {
     public:
-        enum Ability { NOTHING_YET }; // FRAME pridat, + pamatovat na 32bitu?
 	/**
 	 * Constructor. Called after loading the decoration plugin. All global
 	 * initialization of the plugin should be done in the factory constructor.
@@ -72,6 +71,8 @@ class KDecorationFactory
         virtual QValueList< BorderSize > borderSizes() const;
 
         virtual bool supports( Ability ability );
+        
+        virtual void checkRequirements( KDecorationProvides* provides );
 	/**
 	 * Returns the KDecorationOptions object, which is used to access
 	 * configuration settings for the decoration.

plugins.cpp

@@ -34,4 +34,9 @@ void PluginMgr::error( const QString &error_msg )
     exit(1);
     }
 
+bool PluginMgr::provides( Requirement )
+    {
+    return false;
+    }
+
 } // namespace

plugins.h

@@ -22,6 +22,7 @@ class PluginMgr
     {
     public:
         PluginMgr();
+        virtual bool provides( Requirement );
     protected:
         virtual void error( const QString& error_msg );
     };