1 /*

     2 * Copyright (c) 2004 Nokia Corporation and/or its subsidiary(-ies).

     3 * All rights reserved.

     4 * This component and the accompanying materials are made available

     5 * under the terms of "Eclipse Public License v1.0"

     6 * which accompanies this distribution, and is available

     7 * at the URL "http://www.eclipse.org/legal/epl-v10.html".

     8 *

     9 * Initial Contributors:

    10 * Nokia Corporation - initial contribution.

    11 *

    12 * Contributors:

    13 *

    14 * Description: 

    15 *   Interface for Series 60 font type, incorporating principles of series 60 layout

    16 *

    17 *

    18 */

    19 

    20    

    21 #ifndef AKNLAYOUTFONT_H

    22 #define AKNLAYOUTFONT_H

    23 

    24 #include <gdi.h>

    25 #include <fbs.h>

    26 #include <AknFontSpecification.h>

    27 #include <AknTextDecorationMetrics.h>

    28 

    29 class CBitmapDevice;

    30 

    31 /**

    32 * This abstract class is a CFbsFont that can update itself (re-bind a font) and has standard

    33 * Series 60 layout API available.

    34 * 

    35 * Concrete classes derived from this implement constructors and Update methods that

    36 * supply the specification required for the initially, and newly bound font, respectively. 

    37 * Derived classes must also implement the CreateFont framework method in order to

    38 * implement the font binding itself.

    39 * 

    40 *  @lib avkon.dll

    41 *  @since 2.8

    42 *

    43 *  @internal

    44 */

    45 NONSHARABLE_CLASS(CAknLayoutFont) : public CFbsFont

    46     {

    47 

    48 public:

    49     /**

    50     * C++ Destructor.

    51     */

    52     virtual ~CAknLayoutFont();

    53 

    54 public: // New functions

    55     /**  

    56     * Update this object's binding to a CFbsFont, using the member data of the derived class.

    57     * This method only needs to be called if the client owns the CAknLayoutFont

    58     * object, and there has been a layout switch that may affect the font. 

    59     * 

    60     * It is functionally equivalent to deleting the CAknLayoutFont object, and 

    61     * reconstructing it with the same parameters.

    62     */

    63     IMPORT_C void Update();

    64 

    65     /**

    66     * Return the maximum extent of any pixel in the font upwards from the baseline

    67     * Measured up, so therefore it is a positive value.

    68     * 

    69     * @return maximum ascent of the font

    70     */ 

    71     IMPORT_C TInt MaxAscent() const;

    72 

    73     /**

    74     * Return the maximum extent of any pixel in the font down the baseline

    75     * Measured down, so therefore it is usually a positive value.

    76     * 

    77     * @return maximum descent of the font

    78     */ 

    79     IMPORT_C TInt MaxDescent() const;

    80 

    81     /*

    82     * Position of the baseline measured down from the Series 60 layout text pane top

    83     *

    84     * @return distance from text pane top to baseline

    85     */

    86     IMPORT_C TInt TextPaneTopToBaseline() const;

    87     

    88     /*

    89     * Position of the text pane bottom measured down from the baseline

    90     *

    91     * @return distance from text pane top to baseline

    92     */

    93     IMPORT_C TInt BaselineToTextPaneBottom() const;

    94 

    95     /*

    96     * Series 60 text pane height. 

    97     * Always equal to TextPaneTopToBaseline() + BaselineToTextPaneBottom()

    98     *

    99     * @return text pane height

   100     */

   101     IMPORT_C TInt TextPaneHeight() const;

   102 

   103     /**

   104     * This provides the baseline relative to the top of the combined font for a specific 

   105     * character code. This value does not include any TopShortfall.

   106     **/

   107     TInt AscentForCharacter( TChar aCharacter ) const; 

   108 

   109     /**

   110     * Returns if a font pointer cast to this type if the actual type conforms to this type. 

   111     * 

   112     * @returns NULL if the font does not conform to CAknLayoutFont.

   113     */

   114     IMPORT_C static const CAknLayoutFont* AsCAknLayoutFontOrNull( const CFont* aFont );

   115 

   116     /**

   117     * Returns an object describing how the text with this font is to be decorated

   118     * 

   119     * @return   text decoration metrics for the font

   120     */

   121     IMPORT_C TAknTextDecorationMetrics TextDecorationMetrics() const;

   122 

   123     /**

   124     * Returns the Avkon font category (EAknFontCategoryPrimary, EAknFontCategorySecondary...)

   125     * that was used to generate this font.

   126     * 

   127     * @return   font category

   128     */

   129     IMPORT_C TAknFontCategory FontCategory() const;

   130 

   131     /**

   132     * This API allows the font to provide the metrics under which the font was requested.

   133     * 

   134     * @return   the font specification for which the font has been supplied

   135     */

   136     IMPORT_C TAknFontSpecification FontSpecification() const;

   137     

   138 public: // Functions from CFont

   139      

   140 public:// Functions from CFbsFont

   141 

   142     TFontSpec DoFontSpecInTwips() const;

   143 

   144 protected:

   145     /**

   146     * C++ Constructor.

   147     */

   148     CAknLayoutFont( CBitmapDevice& aScreenDevice );

   149     CBitmapDevice& BitmapDevice() const;

   150 

   151 protected: // Internal methods

   152 

   153     void SetExcessAscent( TInt aExcessAscent );

   154     void SetExcessDescent( TInt aExcessDescent );

   155     void SetBottomShortfall( TInt aBottomShortfall );

   156     void SetTextPaneHeight( TInt aTextPaneHeight );

   157 

   158 private: // New Framework methods

   159     virtual CFbsFont* SupplyFont() = 0;

   160     virtual TInt DoAscentForCharacter( TChar aCharacter ) const;

   161     virtual TAknTextDecorationMetrics DoTextDecorationMetrics() const = 0;

   162     virtual TAknFontSpecification DoFontSpecification() const = 0;

   163     virtual void CAknLayoutFont_Reserved_1();

   164 

   165 private:

   166     void Register();

   167     void Deregister();

   168 

   169 private:

   170 

   171     CFbsFont* iNonDynamicFont;

   172     CBitmapDevice& iScreenDevice;

   173     TInt iExcessAscent;

   174     TInt iExcessDescent;

   175     TInt iBottomShortfall;

   176     TInt iTextPaneHeight;

   177     TInt iSpare;

   178     };

   179 

   180 

   181 #endif  //AKNLAYOUTFONT_H