uiaccelerator_plat/alf_visual_api/inc/alf/alftexturegroup.h
changeset 0 15bf7259bb7c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/uiaccelerator_plat/alf_visual_api/inc/alf/alftexturegroup.h	Tue Feb 02 07:56:43 2010 +0200
@@ -0,0 +1,228 @@
+/*
+* Copyright (c) 2006 Nokia Corporation and/or its subsidiary(-ies). 
+* All rights reserved.
+* This component and the accompanying materials are made available
+* under the terms of "Eclipse Public License v1.0"
+* which accompanies this distribution, and is available
+* at the URL "http://www.eclipse.org/legal/epl-v10.html".
+*
+* Initial Contributors:
+* Nokia Corporation - initial contribution.
+*
+* Contributors:
+*
+* Description:   Group of textures.
+*
+*/
+
+
+
+#ifndef C_ALFTEXTUREGROUP_H
+#define C_ALFTEXTUREGROUP_H
+
+#include <coemain.h>
+#include <alf/alftexturemanager.h>
+
+class CAlfEnv;
+class CAlfTexture;
+class CAlfTextureGroup;
+
+/**
+ * Provides callback methods for getting notifications when texture manager
+ * finishes asynchronous texture loads for a group of textures.
+ *
+ * The class willing to receive these events must implement the methods
+ * of this interface and register itself as an observer to a texture group.
+ *
+ */
+class MAlfTextureGroupLoadingCompletedObserver
+    {
+public:
+    /**
+     * Called to notify the observer that loading of a texture group has
+     * been completed.
+     * @param aTextureGroup Group of textures that has been loaded.
+     * @param aErrorCode KErrNone if the loading of all textures was successful, 
+     * otherwise one of the system-wide error codes indicating reason why the first failed 
+     * texture loading failed.
+     * @note One should not commence loading of a new texture in this callback method. Also
+     * one should not make any changes to a texture group e.g. add or remove textures
+     * in this method.
+     */
+    virtual void TextureGroupLoadingCompleted(CAlfTextureGroup& aTextureGroup, TInt aErrorCode) = 0;
+
+    };
+
+
+/**
+ * This class is a utility class that can be used to group textures into logical group and
+ * then performing operations for the whole group at once.
+ *
+ * Example of utilizing texture group load observer service.  
+ * @code
+ * CMyObserver::InitL()
+ *    {
+ *    // Precondition is that textures has been created at this point but are still possibly 
+ *    // being loaded in the background... 
+ *
+ *    // Create a texturegroup and add textures into it
+ *    iTextureGroup = CAlfTextureGroup::NewL(iEnv);
+ *    iTextureGroup.AddTextureL(texture1);
+ *    iTextureGroup.AddTextureL(texture2);
+ *    iTextureGroup.AddTextureL(texture3);
+ *
+ *    if (iTextureGroup.IsLoadingCompleted())
+ *        {
+ *        // Already all textures have content. We are done, no need to observe.
+ *        TextureGroupLoadingCompleted(iTextureGroup, KErrNone);
+ *        }
+ *    else
+ *        {
+ *        // Not all textures have their content ready, we start observing and get notification later.
+ *        iTextureGroup->AddLoadObserverL(*this);
+ *        }   
+ *     ...
+ *     ...
+ *    }
+ *
+ * CMyObserver::TextureGroupLoadingCompleted(CAlfTextureGroup& aTextureGroup, TInt aErrorCode)
+ *     {
+ *     if (&aTextureGroup = iTextureGroup)
+ *         { 
+ *         // Do needed things here, e.g. show all visuals that use grouped textures   
+ *         iLayout->SetOpacity(TAlfTimedValue(1.f, 300));     
+ *         }
+ *     }
+ *  @endcode
+ *  @lib alfclient.lib
+ *  @since S60 v3.2
+ *
+ */
+NONSHARABLE_CLASS( CAlfTextureGroup ) : public CBase
+    {
+public:
+
+    /**
+     * Static factory method. 
+     * @param aEnv Environment
+     */
+    IMPORT_C static CAlfTextureGroup* NewL(CAlfEnv& aEnv);
+
+    /**
+     * Static factory method. 
+     * @param aEnv Environment
+     */
+    IMPORT_C static CAlfTextureGroup* NewLC(CAlfEnv& aEnv);
+
+   /**
+     * Destructor
+     */
+    IMPORT_C virtual ~CAlfTextureGroup();
+
+   /**
+     * Adds a texture into group. Ownership is not transferred.
+     * If added texture is deleted, it should be removed from the group 
+     * before deletion happens.
+     * @param aTexture Texture to be added into group. 
+     */
+    IMPORT_C void AddTextureL(CAlfTexture& aTexture);
+
+   /**
+     * Removes a texture from group.
+     * @param aTexture Texture to be removed from group. 
+     */
+    IMPORT_C void RemoveTexture(CAlfTexture& aTexture);
+
+    /**
+     * Checks if all textures in the group have content.
+     * @return ETrue if group contains textures, all textures have content
+     * and are bigger than zero size.
+     * otherwise returns EFalse. 
+     *
+     */
+    IMPORT_C TBool IsLoadingCompleted() const;
+
+    /**
+     * Returns the number of textures in the group.
+     *
+     * @return Texture count.
+     */
+    IMPORT_C TInt Count() const;
+    
+    /**
+     * Returns a texture.
+     *
+     * @param aIndex  Index of the texture.
+     *
+     * @return  Reference to a texture.
+     */
+     IMPORT_C CAlfTexture& Texture( TInt aIndex ) const;
+
+    /**
+     * Adds texture group observer.
+     * @param aObserver Observer to be added.
+     */
+    IMPORT_C void AddLoadObserverL(MAlfTextureGroupLoadingCompletedObserver& aObserver);
+
+    /**
+     * Removes texture group observer, this must be done at latest when observer is being deleted.
+     * @param aObserver Observer to be removed.
+     */
+    IMPORT_C void RemoveLoadObserver(MAlfTextureGroupLoadingCompletedObserver& aObserver);
+
+    /**
+     * This method can be used to temporarely enable/disable notifications to observers
+     * when e.g. texture group content is being modified. By default notifications are
+     * enabaled.
+     * @param aEnable If ETrue notifications are delivered normally, otherwise notifications
+     * are not delivered.
+     */
+    IMPORT_C void EnableLoadObservers(TBool aEnable = ETrue);
+
+public:  
+    
+    /**
+     * Called by the toolkit when one texture has been loaded
+     */
+    void NotifyTextureAvailability(CAlfTexture& aTexture, TInt aErrorCode);    
+    
+private:
+
+   /**
+     * Constructor.
+     */
+    CAlfTextureGroup();
+    
+   /**
+     * Constructor.
+     */
+    void ConstructL(CAlfEnv& aEnv);
+    
+   /**
+     * Checks if given texture is part of the group. 
+     */
+    TBool IsTextureInGroup(CAlfTexture& aTexture) const;
+
+   /**
+     * Notifies observers.
+     */
+    void NotifyObservers();
+
+   /**
+     * Registers this object as loading observer to the given texturemanager.
+     */
+    void RegisterAsTextureLoadObserverL(CAlfTextureManager* aManager);
+
+   /**
+     * Unregisters this object as loading observer from the given texturemanager.
+     */
+    void UnRegisterAsTextureLoadObserver(CAlfTextureManager* aManager);
+
+private:
+
+	/* Private data. Owned */
+    struct TPrivateData;    
+    TPrivateData* iData;
+    };
+
+#endif
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