/*

* Copyright (c) 2006-2007 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:   Layout base class

*

*/

#ifndef C_ALFGRIDLAYOUT_H

#define C_ALFGRIDLAYOUT_H

#include <alf/alflayout.h>

/* Each dimension corresponds to a different axis for the grid blocks */

enum TAlfGridDimension 

    {

    EAlfGridColumn,

    EAlfGridRow

    };

/**

 * These flags specify where pixel error is distributed in grid layout calculations.

 * 

 * If none of these flags are set, then the pixel positions of all children are calculated

 * using reals, then floored to the nearest pixel. If, however, the children must all be

 * the same pixel size, then the following flags can be set. They place extra pixels into

 * the layout's paddings to make up the difference.

 * The flags for increasing and decreasing paddings are

 * mutually exclusive, but you can apply inner and outer padding flags at the same time. This

 * will result in the error being distributed between inner and outer paddings in the same

 * proportion as inner to outer padding. Eg: if inner padding is 10 and outer padding is 20, twice

 * as many error pixels will be distributed to the outer padding.

 * @see SetLayoutModeFlags

 */

enum TAlfGridLayoutModeFlags

    {

    /** Automatically increases innerpaddings if needed. Clears EAlfGridDecreaseInnerPadding if set.*/

    EAlfGridIncreaseInnerPadding = 0x1,

    /** Automatically decreases innerpaddings if needed. Clears EAlfGridIncreaseInnerPadding if set.*/

    EAlfGridDecreaseInnerPadding = 0x2,

    /** Automatically increases outerpaddings if needed. Clears EAlfGridDecreaseOuterPadding if set.*/    

    EAlfGridIncreaseOuterPadding = 0x4,

    /** Automatically decreases outerpaddings if needed. Clears EAlfGridIncreaseOuterPadding if set.*/    

    EAlfGridDecreaseOuterPadding = 0x8,

    EAlfGridFlagAll = 0xF

    };

/**

 * Grid layout class.

 *

 * To use this class, a grid layout is created of a desired width and height.

 * Then, when visuals are added to grid layout, they will populate the grid.

 * By default, all slots in a grid layout are of a uniform size, but the weighting

 * of individual rows and columns can be modified, and can be specified using

 * metric units.

 * Slots will resize automatically as the grid layout size changes.

 *

 * The standard application grid is one example of a grid layout.

 * 

 * Usage:

 *

 * @code

 * // Create a new 3x4 grid layout visual.

 * CAlfGridLayout* grid = CAlfGridLayout::AddNewL( control, 3, 4 );

 * 

 * // Add a single text visual into the grid.

 * CAlfTextVisual* text = CAlfTextVisual::AddNewL( control, grid );

 * 

 * // Make the text visual visible; if no text is specified, nothing is drawn.

 * text->SetTextL(_L("T"));

 * 

 * //Setting grid dimentions with weight

 * RArry<TInt> col;

 * col.AppendL( 1 );

 * col.AppendL( 2 );

 * 

 * //sets no of columns to 2 and width of second column

 * //is double of that of first

 * grid->SetColumns( col );

 * 

 * @endcode

 * @lib alfclient.lib

 * @since S60 v3.2

 */

class CAlfGridLayout : public CAlfLayout

    {

public:

	/* Constructors and destructor. */

    /**

     * Construct a new grid layout and give its ownership to a control.

     *

     * @note the columns and rows will be initialized with equal unit weights, so that blocks will all share 

     * even proportions of the available area to start with.

     * @note in order to use a mixture of metric weights, or to set different weights, set rows 

     * and columns to zero when calling this method, then use e.g. @c AppendWeightL to 

     * subsequently populate the weights.

     * 

     * @param aOwnerControl  Owner control.

     * @param aColumns       Number of columns in the grid.

     * @param aRows          Number of rows in the grid.

     * @param aParentLayout  Parent layout for the new grid layout.

     */

    IMPORT_C static CAlfGridLayout* AddNewL(CAlfControl& aOwnerControl, 

                                            TInt aColumns, TInt aRows,

                                            CAlfLayout* aParentLayout = 0);

	/**

	 * Constructor.

	 */

	IMPORT_C CAlfGridLayout();

	/**

	 * From CAlfLayout. Second-phase constructor.

	 */

	IMPORT_C void ConstructL(CAlfControl& aOwner);

	/**

	 * Virtual destructor.

	 */

	IMPORT_C ~CAlfGridLayout();

	/* Methods. */    

    /**

     * Sets amount of columns.

     *

     * @param aColumnCount Amount of columns.

     */

    IMPORT_C void SetColumnsL(TInt aColumnCount);

    /**

     * Sets amount of rows.

     *

     * @param aRowCount Amount of rows.

     */

    IMPORT_C void SetRowsL(TInt aRowCount);

    /**

     * Sets the number and weights of columns in this grid layout.

     * The caller specifies an array of relative weights to use for each

     * column.

     * Weights can be any integer, ie a column of weight 30 would

     * be twice the width of a column of weight 15.

     *

     * @note this is equivalent to using metrics with unit type EAlfUnitWeight.

     *

     * @param aWeights An array containing weights for each column.

     */    

    IMPORT_C void SetColumnsL(const RArray<TInt>& aWeights);

    /**

     * Sets the number and weights of rows in this grid layout.

     * The caller specifies an array of relative weights to use for each

     * row.

     * Weights can be any integer, ie a row of weight 30 would

     * be twice the height of a row of weight 15.

     *

     * @note this is the same as using metrics with unit type EAlfUnitWeight.

     *

     * @param aWeights An array containing weights for each row.

     */    

    IMPORT_C void SetRowsL(const RArray<TInt>& aWeights);

    /**

     * 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. 

     *

     * @since S60 3.2

     *

     * @see @c AppendWeightL for more information on how weights are used to calculate layout positions.

     *

     * @note This API could be useful if then subsequent calls to @c ReplaceWeightL 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

     */    

    IMPORT_C void FillWeightsL(TAlfGridDimension aDim, TInt aCount, const TAlfMetric& aWeight);

    /**

     * 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.

     *

     * @since S60 3.2

     *

     * @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

     */

    IMPORT_C void AppendWeightL(TAlfGridDimension aDim, const TAlfMetric& aWeight);

    /**

     * 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.

     *

     * @since S60 3.2

     *

     * @see @c AppendWeightL 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

     */

    IMPORT_C void InsertWeightL(TAlfGridDimension aDim, const TAlfMetric& aWeight, TInt aPos);

    /**

     * 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. 

     *

     * @since S60 3.2

     *

     * @see @c AppendWeightL 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

     */

    IMPORT_C void ReplaceWeightL(TAlfGridDimension aDim, const TAlfMetric& aWeight, TInt aPos);

    /**

     * 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.

     *

     * @since S60 3.2

     *

     * @see @c AppendWeightL 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

     */

    IMPORT_C void RemoveWeightL(TAlfGridDimension aDim, TInt aPos);

    /**

     * Returns the weight of a specific line of blocks in this grid layout, in the

     * specified dimension. 

     *

     * @since S60 3.2

     *

     * @see @c AppendWeightL 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

     */

    IMPORT_C TAlfMetric Weight(TAlfGridDimension aDim, TInt aPos) const;

    /**

     * Return the number of lines of blocks in this grid, along the specified dimension.

     *

     * @since S60 3.2

     *

     * @param aDim the dimension along which to count

     * @return The number of lines of blocks in this grid.

     */        

    IMPORT_C TInt DimensionCount(TAlfGridDimension aDim) const;

    /**

     * ! Deprecated, use leaving method instead

     */

    void SetColumns(TInt aColumnCount)

        {

        TRAP_IGNORE(SetColumnsL(aColumnCount))

        }

    /**

     * ! Deprecated, use leaving method instead

     */

    void SetRows(TInt aRowCount)

        {

        TRAP_IGNORE(SetRowsL(aRowCount))

        }

    /**

     * ! Deprecated, use leaving method instead

     */

    void SetColumns(const RArray<TInt>& aWeights)

        {

        TRAP_IGNORE(SetColumnsL(aWeights))

        }

    /**

     * ! Deprecated, use leaving method instead

     */

    void SetRows(const RArray<TInt>& aWeights)

        {

        TRAP_IGNORE(SetRowsL(aWeights))

        }

    /**

     * Sets flags to control expanding behaviour.

     *

     * @param aFlags Flags

     */

    IMPORT_C void SetExpanding(TInt aFlags);

    /**

     * Gets amount of rows.

     *

     * @return Amount of rows.

     */

    IMPORT_C TInt RowCount() const;

    /**

     * Gets amount of columns.

     *

     * @return Amount of columns.

     */

    IMPORT_C TInt ColumnCount() const;

    /**

     * Calculates the position of a child in the grid. Returns the block

     * position, where block (0, 0) is in the top left corner.

     *

     * @param aOrdinal  Ordinal of a child.

     *

     * @return  Block position of the child.

     */    

    IMPORT_C TPoint OrdinalToBlock(TInt aOrdinal) const;

    /**

     * Sets flag(s) which alter the children's pixel error distribution within the grid layout.

     *

     * This method allows the client to force all items in the grid layout to be the same

     * pixel size. The floating point error that this introduces is distributed between the various

     * paddings of the layout.

     * 

     * Example of use that allows outer paddings to be automatically adjusted:

     * \code

     * iGridLayout->SetLayoutModeFlags(EHuiGridRow, EHuiGridAdjustOuterPadding); 

     * \endcode

     *

     * Note that some flags are mutually exclusive, and will clear some existing flags if set.

     *

     * @param aDim the dimension to which the given flag(s) affect.

     * @param aGridLayoutModeFlags Flags to be set or cleared

     * @see TAlfGridLayoutModeFlags, ClearLayoutModeFlags

     */        

    IMPORT_C void SetLayoutModeFlags(TAlfGridDimension aDim, TUint aGridLayoutModeFlags);

    /**

     * Clears flag(s) which alter the children's pixel error distribution within the grid layout.

     *

     * @param aDim the dimension to which the given flag(s) affect.

     * @param aGridLayoutModeFlags Flags to be cleared

     * @see TAlfGridLayoutModeFlags, SetLayoutModeFlags

     */        

    IMPORT_C void ClearLayoutModeFlags(TAlfGridDimension aDim, TUint aGridLayoutModeFlags);    

    /**

     * Return flag(s) which alter the children's pixel error distribution within the grid layout.

     *

     * @param aDim the dimension to return the flags for.

     */

    IMPORT_C TInt LayoutModeFlags(TAlfGridDimension aDim);

    /**

     * From CAlfVisual

     * @see CAlfVisual

     */

    IMPORT_C void RemoveAndDestroyAllD();

    IMPORT_C void UpdateChildrenLayout(TInt aTransitionTime = 0);

    IMPORT_C CAlfVisual* FindTag(const TDesC8& aTag);

    /**

     * From CAlfLayout

     * @see CAlfLayout

     */

    IMPORT_C TAlfXYMetric BaseUnit() const;

protected:

    /**

     * From CAlfVisual

     * @see CAlfVisual

     */

    IMPORT_C void DoRemoveAndDestroyAllD();

    IMPORT_C void PropertyOwnerExtension(const TUid& aExtensionUid, TAny** aExtensionParams);

private:

    // Private structure. Owned.

    struct TGridLayoutPrivateData;

    TGridLayoutPrivateData* iGridLayoutData;

    };

#endif // C_ALFGRIDLAYOUT_H