mmuifw_plat/alf_widgetmodel_api/inc/alf/ialfgridlayoutpolicy.h
changeset 0 e83bab7cf002
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mmuifw_plat/alf_widgetmodel_api/inc/alf/ialfgridlayoutpolicy.h	Thu Dec 17 08:56:02 2009 +0200
@@ -0,0 +1,219 @@
+/*
+* Copyright (c) 2008 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:  interface for layout policy
+*
+*/
+
+
+#ifndef I_ALFGRIDLAYOUTMANAGER
+#define I_ALFGRIDLAYOUTMANAGER
+
+#include <alf/ialfinterfacebase.h>
+#include <alf/alftypes.h>
+
+class CAlfLayout;
+class CAlfControl;
+
+namespace Alf
+    {
+
+class CAlfWidgetControl;
+
+namespace ialfgridlayoutpolicy
+    {
+     static const IfId Ident =
+        {
+        0, "gridlayoutpolicy"
+        };
+    }
+    
+using Alf::CAlfWidgetControl;
+
+
+
+/**
+ * The interface for grid layout policy
+ *
+ * Provides grid specific layout APIs
+ * 
+ * @code
+ * // Create layout manager interface.
+ * IAlfLayoutManager* layoutManager = IAlfInterfaceBase::makeInterface<IAlfLayoutManager>(control);
+ *
+ * // See if layout policy is supported in the given layout manager.
+ * IAlfGridLayoutPolicy* layoutPolicy = IAlfInterfaceBase::makeInterface<IAlfGridLayoutPolicy>(layoutManager);
+ *
+ * if(layoutPreferences != 0)
+ *     {
+ *     int rows = layoutPolicy->dimensionCount(EAlfGridDimensionRow);
+ *     }
+ * @endcode
+ *
+ * @lib alfwidgetmodel.lib
+ * @since S60 ?S60_version
+ * @status Draft
+ */
+class IAlfGridLayoutPolicy : public IAlfInterfaceBase
+    {
+public:
+       
+    static inline const IfId& type()
+        {       
+        return ialfgridlayoutpolicy::Ident;
+        }
+        
+    virtual inline ~IAlfGridLayoutPolicy() {}
+    
+public:
+    /* Each dimension corresponds to a different axis for the grid blocks */
+    enum gridLayoutDimension
+        {
+        EGridDimensionColumn = 0,
+        EGridDimensionRow
+        };
+
+public:
+    
+    /**
+     * Sets the number and weights of blocks in this grid layout in the direction of the specified
+     * dimension. Each block's weight will be set to equal the supplied value, the result
+     * of which is that all blocks will be equally spaced, whatever the units. 
+     *
+     * @see appendWeight; for more information on how weights are used to calculate layout positions.
+     *
+     * @note This API could be useful if then subsequent calls to @c replaceWeight are made to 
+     * change specific values, depending on how many of the values are different. 
+     * @note Calling this with aCount set to 0 will clear all of the existing weights in the direction
+     * of the specified dimension.
+     * @note this is the same as using metrics with unit type EAlfUnitWeight.
+     *
+     * @param aDim the dimension along which to fill
+     * @param aCount The number of lines of blocks to fill
+     * @param aWeight the weights to be used for all blocks
+     * @throw AlfVisualException
+     */    
+    virtual void fillWeights(gridLayoutDimension aDim, int aCount, const TAlfMetric& aWeight) = 0;
+
+    /**
+     * Add a new line of blocks to this grid layout at the last position in the direction of the 
+     * specified dimension. It will have the supplied weight. Weights can be any metric value, 
+     * hence different units can be used for each block. In particular, EAlfUnitWeight can be used 
+     * to represent weight values in aribtrary proportional units.
+     *
+     * In the case of proportional weights, the effect of this will be to cause the other blocks to 
+     * resize according to the new total weight.
+     *
+     * @note If non-relative coordinates are specified (e.g., real pixels), the combined blocks might not 
+     *      fill the entire layout area. However, weights will always stretch to fill all available space 
+     *      after the fixed units have been determined. Therefore, depending on circumstances it may
+     *      be better to use EAlfUnitWeight
+     * @note For example [2 weights, 1 weight, 2 weights] in a layout of 100 pixels would result 
+     *      in [40 pixels, 20 pixels, 40 pixels]. 
+     * @note For example [10 pixels, 1 weight, 15 pixels] in a layout of 100 pixels would result 
+     *      in [10 pixels, 75 pixels, 15 pixels]. 
+     *
+     * @param aDim the dimension to which the weight corresponds
+     * @param aWeight the weight to be used for the block in the specified dimension, 
+     *          replacing any previously existing weight for that block
+     * @throw AlfVisualException
+     */
+    virtual void appendWeight(gridLayoutDimension aDim, const TAlfMetric& aWeight) = 0;
+
+    /**
+     * Add a new line of blocks to this grid layout at the specified position in the direciton of 
+     * the specified dimension. It will have the supplied weight. In the case of proportional 
+     * weights, the effect of this will be to cause the other blocks to resize according to the new 
+     * total weight. It will also mean that many child visuals will now occupy different blocks within
+     * the grid according to how the blocks wrap.
+     *
+     * @note will leave if the specified position is greater than the number of objects currently in the array, 
+     * so check first by calling @c preferredDimensionCount
+     * @see appendWeight for more information on how weights are used to calculate layout positions.
+     *
+     * @param aDim the dimension to which the weight corresponds
+     * @param aWeight the weight to be used for the block in the specified dimension, 
+     *          replacing any previously existing weight for that block
+     * @param aPos the index of the block
+     * @throw AlfVisualException
+     */
+    virtual void insertWeight(gridLayoutDimension aDim, const TAlfMetric& aWeight, int aPos) = 0;
+    
+    /**
+     * Sets the weight of a specific line of blocks in this grid layout, in the direction of the supplied dimension.
+     * In the case of proportional weights, the effect of this will be to cause the 
+     * other blocks to resize according to the new total weight. 
+     *
+     * @see appendWeight for more information on how weights are used to calculate layout positions.
+     *
+     * @param aDim the dimension to which the weight corresponds
+     * @param aWeight the weight to be used for the block in the specified dimension, 
+     *          replacing any previously existing weight for that cell
+     * @param aPos the index of the cell
+     * @throw AlfVisualException
+     */
+    virtual void replaceWeight(gridLayoutDimension aDim, const TAlfMetric& aWeight, int aPos) = 0;
+
+    /**
+     * Remove a line of blocks from this grid layout at the specified position in the 
+     * specified dimension. In the case of proportional weights, the effect of this will 
+     * be to cause the other blocks to resize according to the new total weight. It will also mean 
+     * that many child visuals will now occupy different blocks within the grid according to how 
+     * the blocks wrap.
+     *
+     * @see appendWeight for more information on how weights are used to calculate layout positions.
+     *
+     * @param aDim the dimension to which the weight corresponds
+     * @param aPos the index of the cell
+     * @throw AlfVisualException
+     */
+    virtual void removeWeight(gridLayoutDimension aDim, int aPos) = 0;
+
+    /**
+     * Returns the weight of a specific line of blocks in this grid layout, in the
+     * specified dimension. 
+     *
+     * @see appendWeight for more information on how weights are used to calculate layout positions.
+     *
+     * @param aDim the dimension to which the weight corresponds
+     * @param aPos the index of the cell
+     * @return the weight being used for the cell in the specified dimension, will be 0 magnitude if not set
+     * @throw AlfVisualException
+     */
+    virtual TAlfMetric weight(gridLayoutDimension aDim, int aPos) const = 0;
+        
+    /**
+     * Return the number of lines of blocks in this grid, along the specified dimension
+     *
+     * @param aDim the dimension along which to count
+     * @return The number of lines of blocks in this grid.
+     */        
+    virtual int count(gridLayoutDimension aDim) const = 0;
+    
+public:
+// from base class IAlfInterfaceBase
+    
+    /**
+     * Interface getter. 
+     * @see IAlfInterfaceBase::MakeInterface
+     *
+     * @param aType The type id of the queried interface.
+     * @return The queried interface, or NULL if the interface is not
+     *         supported or available.
+     */    
+    virtual IAlfInterfaceBase* makeInterface( const IfId& aType ) = 0;
+    };
+
+    } // namespace Alf
+
+#endif // I_ALFGRIDLAYOUTMANAGER