1 /*

     2 * Copyright (c) 1999-2009 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 * FORM global parameters; held in thread-local storage.

    16 *

    17 */

    18 

    19 

    20 #ifndef __FRMPARAM_H__

    21 #define __FRMPARAM_H__

    22 

    23 #include <gdi.h>

    24 

    25 

    26 /** 

    27 Specifies the protocol for getting system colours for use in text views. A

    28 class which implements this protocol allows an application (or a thread,

    29 because a pointer to the object is held in thread-local storage) to use system

    30 colours in text views.

    31 

    32 You should create an object of an MFormParam-derived class which implements the

    33 SystemColor() function. Then, pass a pointer to the object to the static

    34 function MFormParam::Set(). The MFormParam-derived object is owned by the

    35 caller of Set(). When system colours are no longer needed, you should cancel

    36 them by calling MFormParam::Set(NULL). It is the caller's responsibility to

    37 cause the text view to be redrawn after system colours are changed.

    38 

    39 CTextLayout uses the colour translation function SystemColor() (if an

    40 MFormParam-derived object is present) to set the pen and brush colours for

    41 drawing components of the text view. It calls MFormParam::Get() before each

    42 draw. This enables an application to introduce system colours, change the

    43 parameter object, or abolish system colours, and redraw everything correctly;

    44 no information is left over from the last draw.

    45 @publishedAll

    46 @released

    47 */

    48 class MFormParam

    49 

    50 	{

    51 	public:

    52 

    53 	/** Translates 8-bit logical colour indices to physical colours pure

    54 	virtual function.

    55 

    56 	The colour index is stored in a TLogicalRgb object and is returned by

    57 	TLogicalRgb::SystemColorIndex().

    58 

    59 	There are three reserved index values:

    60 

    61 	Zero means the logical colour does not map to a system colour: the logical

    62 	colour is in fact an ordinary TRgb. This function should not normally be

    63 	called with this value.

    64 

    65 	254 and 255 are default foreground and background colours respectively, and

    66 	should be converted to the GUI's standard foreground and background colours

    67 

    68 	The values 1-253 are reserved for the use of the GUI and can be interpreted

    69 	as convenient. These can be interpreted as

    70 	TLogicalColor::EColorWindowBackground upward; this mapping can be done by

    71 	subtracting one from the index number aColorIndex.

    72 

    73 	@param aColorIndex Logical colour index. Between 1 and 255 inclusive.

    74 	@param aDefaultColor The default colour. This is the colour to be used if

    75 	no translation is performed. This allows translation to change certain

    76 	indices but not others, (by passing the default colour back unchanged).

    77 	@return The physical colour which maps to the logical colour index. */

    78 	virtual TRgb SystemColor(TUint aColorIndex,TRgb aDefaultColor) const = 0;

    79 	IMPORT_C virtual void Reserved();

    80 	IMPORT_C static void Set(const MFormParam* aParam);

    81 	IMPORT_C static const MFormParam* Get();

    82 	};

    83 

    84 #endif // __FRMPARAM_H__