williamr@4: /*
williamr@4: * Copyright (c) 1999-2009 Nokia Corporation and/or its subsidiary(-ies).
williamr@4: * All rights reserved.
williamr@4: * This component and the accompanying materials are made available
williamr@4: * under the terms of "Eclipse Public License v1.0"
williamr@4: * which accompanies this distribution, and is available
williamr@4: * at the URL "http://www.eclipse.org/legal/epl-v10.html".
williamr@4: *
williamr@4: * Initial Contributors:
williamr@4: * Nokia Corporation - initial contribution.
williamr@4: *
williamr@4: * Contributors:
williamr@4: *
williamr@4: * Description: 
williamr@4: * FORM global parameters; held in thread-local storage.
williamr@4: *
williamr@4: */
williamr@4: 
williamr@2: 
williamr@2: #ifndef __FRMPARAM_H__
williamr@2: #define __FRMPARAM_H__
williamr@2: 
williamr@2: #include <gdi.h>
williamr@2: 
williamr@2: 
williamr@2: /** 
williamr@2: Specifies the protocol for getting system colours for use in text views. A
williamr@2: class which implements this protocol allows an application (or a thread,
williamr@2: because a pointer to the object is held in thread-local storage) to use system
williamr@2: colours in text views.
williamr@2: 
williamr@2: You should create an object of an MFormParam-derived class which implements the
williamr@2: SystemColor() function. Then, pass a pointer to the object to the static
williamr@2: function MFormParam::Set(). The MFormParam-derived object is owned by the
williamr@2: caller of Set(). When system colours are no longer needed, you should cancel
williamr@2: them by calling MFormParam::Set(NULL). It is the caller's responsibility to
williamr@2: cause the text view to be redrawn after system colours are changed.
williamr@2: 
williamr@2: CTextLayout uses the colour translation function SystemColor() (if an
williamr@2: MFormParam-derived object is present) to set the pen and brush colours for
williamr@2: drawing components of the text view. It calls MFormParam::Get() before each
williamr@2: draw. This enables an application to introduce system colours, change the
williamr@2: parameter object, or abolish system colours, and redraw everything correctly;
williamr@2: no information is left over from the last draw.
williamr@2: @publishedAll
williamr@2: @released
williamr@2: */
williamr@2: class MFormParam
williamr@2: 
williamr@2: 	{
williamr@2: 	public:
williamr@2: 
williamr@2: 	/** Translates 8-bit logical colour indices to physical colours pure
williamr@2: 	virtual function.
williamr@2: 
williamr@2: 	The colour index is stored in a TLogicalRgb object and is returned by
williamr@2: 	TLogicalRgb::SystemColorIndex().
williamr@2: 
williamr@2: 	There are three reserved index values:
williamr@2: 
williamr@2: 	Zero means the logical colour does not map to a system colour: the logical
williamr@2: 	colour is in fact an ordinary TRgb. This function should not normally be
williamr@2: 	called with this value.
williamr@2: 
williamr@2: 	254 and 255 are default foreground and background colours respectively, and
williamr@2: 	should be converted to the GUI's standard foreground and background colours
williamr@2: 
williamr@2: 	The values 1-253 are reserved for the use of the GUI and can be interpreted
williamr@2: 	as convenient. These can be interpreted as
williamr@2: 	TLogicalColor::EColorWindowBackground upward; this mapping can be done by
williamr@2: 	subtracting one from the index number aColorIndex.
williamr@2: 
williamr@2: 	@param aColorIndex Logical colour index. Between 1 and 255 inclusive.
williamr@2: 	@param aDefaultColor The default colour. This is the colour to be used if
williamr@2: 	no translation is performed. This allows translation to change certain
williamr@2: 	indices but not others, (by passing the default colour back unchanged).
williamr@2: 	@return The physical colour which maps to the logical colour index. */
williamr@2: 	virtual TRgb SystemColor(TUint aColorIndex,TRgb aDefaultColor) const = 0;
williamr@2: 	IMPORT_C virtual void Reserved();
williamr@2: 	IMPORT_C static void Set(const MFormParam* aParam);
williamr@2: 	IMPORT_C static const MFormParam* Get();
williamr@2: 	};
williamr@2: 
williamr@2: #endif // __FRMPARAM_H__