/*

* 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: 

*  Internal implementations of Avkon Layout Utilities

* 

*

*/

#ifndef __AKNLAYOUTUTILSHELPERS_H__

#define __AKNLAYOUTUTILSHELPERS_H__

#include <e32std.h>

#include <AknsConstants.h> // For TAknsQsnTextColorsIndex

class CEikEdwin;

class TAknTextLineLayout;

class CAknLayoutFont;

class TAknTextDecorationMetrics;

class CFont;

/**

* This class contains non-exported internal implementations of some of the functionality within

* AknLayoutUtils.

*

*/

class AknLayoutUtilsHelpers 

    {

public:               

/**

* This layout routine performs the core of the edwin layout.  All layout structures and fonts

* are to be processed to basic parameters by this point.  A font is passed in, and not font id.

* Baselines are defined in terms of the distance from the parent to the baseline of the font, 

* where both a parent boundary and baseline are inifinitely thin lines. (This differs from the 

* baseline definition used elsewhere in the layout system where a value smaller by 1 pixel is used.)*

*

* This routine may be used within Avkon by those writing editor layout routines

* 

* @param aEdwin                 a constructed edwin pointer 

* @param aEdwinParent           rectangle in which to position editor

* @param aFont                  constructed layout font pointer

* @param aColor                 color index

* @param aLeftMargin            space between editor and parent on the left       

* @param aRightMargin           space between editor and parent on the right

* @param aFirstBaseline         distance from parent top to 1st baseline. 

* @param aWidth                 Width of the text pane (For debug checking only)

* @param aJustification         text justification

* @param aNumberOfLinesShown    number of lines of editor to format

* @param aSecondLineBaseline    distance from parent top to 2nd baseline. 0 if not required

* @param aOverrideColor         a Skins color index if required

* @param decorationMetrics      Metrics for the highlights and cursor

* @param aEnsureEditorIsContainedByParent   Boolean to say whether the editor is allowed to

*                                           extend below the parent's bottom.

* @param aNumberOfVisibleLines  Outputs the number of lines formatted in the editor

*/

static void LayoutEdwinScalableWithCorrectedParametersAndDecorationMetrics(

                                 CEikEdwin *aEdwin, 

                                 const TRect &aEdwinParent, 

                                 const CAknLayoutFont *aFont, 

                                 TInt aColor, 

                                 TInt aLeftMargin, 

                                 TInt aRightMargin, 

                                 TInt aFirstBaseline, // naturally defined

                                 TInt aWidth,

                                 TInt aJustification, 

                                 TInt aNumberOfLinesShown, 

                                 TInt aSecondLineBaseline, //naturally defined

                                 TAknsQsnTextColorsIndex aOverrideColor,

                                 TAknTextDecorationMetrics& decorationMetrics,

                                 TBool aEnsureEditorIsContainedByParent,

                                 TInt& aNumberOfVisibleLines);

/**

* Layout helper routine used by majority of LayoutEdwin implementations

*  

* @param aEdwin                 a constructed edwin pointer 

* @param aEdwinParent           rectangle in which to position editor

* @param aFontId                An Avkon font id

* @param aColor                 color index

* @param aLeftMargin            space between editor and parent on the left       

* @param aRightMargin           space between editor and parent on the right

* @param aBaseline              distance from parent top to the top of the pixel row sitting on the baseline 

*                               of the glyphs. 

* @param aWidth                 width of editor

* @param aJustification         text justification

* @param aNumberOfLinesShown    number of lines of editor to format

* @param aSecondLineBaseline    distance from parent top to the top of the pixel row sitting on the baseline 

*                               of the glyphs in the 2nd line. 

* @param aOverrideColor         a Skins color index if required

* @param aCustomFont            font to be used if the layout has a font id = EFontCustom

* @param aMinimizeEdwinView     Editor view size is to be minimised (not used)

*/

static void LayoutEdwinScalable(CEikEdwin *aEdwin, 

                                 const TRect &aEdwinParent, 

                                 TInt aFontId, 

                                 TInt aColor, 

                                 TInt aLeftMargin, 

                                 TInt aRightMargin, 

                                 TInt aBaseline, 

                                 TInt aWidth, 

                                 TInt aJustification, 

                                 TInt aNumberOfLinesShown, 

                                 TInt aSecondLineBaseline, 

                                 TAknsQsnTextColorsIndex aOverrideColor,

                                 const CAknLayoutFont *aCustomFont, 

                                 TBool aMinimizeEdwinView);

/**

* Routine to determine the height required for an editor.  The position of the editor

* relative to parent is also returned via the parameter aVerticalPositionOfEdwin.

* This gap between parent and editor is not included in the returned height.

*/

static TInt EdwinHeightFromLines(

        TInt aParentHeight,

        const TAknTextLineLayout& aLayout,

        TInt aBaselineSeparationOverRide,

        TInt aNumberOfLinesToShowOverRide,

        TInt& aVerticalPositionOfEdwin

        );

/**

* Routine to tell how many lines of laid out editor can fit into an edwin of a given 

* height.

*/

static TInt EdwinLinesWithinHeight (

        const TAknTextLineLayout& aLayout,

        TInt aBaselineSeparationOverRide,

        TInt aMaxHeight,

        TInt& aUsedHeight

        );

private:

/**

* Corrects the baseline back to pre-aknlayout2 conventions. 

*

* If the font is encoded, then the legacy baseline value definition is returned

* If not, then the passed-in value is returned.

*/

static TInt CorrectBaseline( TInt aParentHeight, TInt aBaseline, TInt aFontId);

/** 

* This routine emulates what the Symbian Form/Tagma component is doing 

* internally to get font height and depth.

*/

static void GetFontMaxHeightAndDepth( 

        const CFont* aFont, TInt& aMaxHeight, TInt& aMaxDepth); 

static TInt EdwinHeightFromLines (

        TInt aTextPaneHeight,

        TAknTextDecorationMetrics& aDecorationMetrics,

        TInt aBaselineSeparation,

        TInt aNumberOfLinesToShow

        );

 static TInt EdwinLinesWithinHeight (

        TInt aTextPaneHeight,

        TAknTextDecorationMetrics& aDecorationMetrics,

        TInt aBaselineSeparation,

        TInt aMaxHeight,

        TInt& aUsedHeight

        );

/**

* Routine to obtain the position of an editor's top relative to the parent.

* Because of the way baseline is specified in scalable layout, parent height is 

* required.

*/ 

static void GetEditorVerticalPositionWithinParent(

    TInt aParentHeight, 

    const TAknTextLineLayout& aLayout, 

    TInt& aRelativeVerticalPositionOfEditor );

static TInt EditorVerticalPositionWithinParent(

    const CAknLayoutFont* aLayoutFont,

    TInt aFirstBaseline,

    TInt aTopMargin );

    };

#endif //  __AKNLAYOUTUTILSHELPERS_H__

// End of file