/*

* Copyright (c) 2002-2005 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:  Interface for text viewer

*

*/

#ifndef MCATEXTVIEW_H

#define MCATEXTVIEW_H

#include <frmtlay.h> // TCursorSelection

// CLASS DECLARATION

class TPointerEvent;

/**

*  Interface for text viewer

*

*  @lib chat.app

*  @since Series 60 3.0

*/

class MCATextView

    {

    public: // Enumerations

        enum TPenBehaviour

            {

            EPenForwardToChild = 0,

            EPenForwardToParent,

            EPenProcessEvent,

            EPenIgnoreEvent

            };

    public: // New functions

        /**

         * Handles changed format.

         * @param aChanged Changed section of rich text

         * @param aPreserveFocus ETrue : Keeps focus of text control in place

         *                       EFalse : Focus moves with changes

         */

        virtual void HandleFormatChangedL( TCursorSelection& aChanged,

                                           TBool aPreserveFocus = EFalse ) = 0;

        /**

         * Handles insertion and deletion

         * @param aChanged Changed section of rich text. If this function is

         *                 being used to handle deletion only, this argument

         *                 should be of length zero and its start position

         *                 should be the beginning of the deletion.

         * @param aDeletedChars The number of deleted characters. Specify zero

         *                 if this function is being used to handle insertion

         *                 only.

         */

        virtual void HandleInsertDeleteL( TCursorSelection& aChanged,

                                          TInt aDeletedChars ) = 0;

        /**

         * Handles addition of text

         * @param aFirst Should be set to ETrue if

         *               this is the first addition of text

         * @param aSelection Selection

         * @param aTop If selection doesn't fit to screen, should the top of the

         *        selection be visible. I.e. If ETrue, top of the message is shown.

         *        if EFalse, bottom of the message is shown.

         */

        virtual void HandleAdditionL( TBool aFirst, TCursorSelection& aSelection,

                                      TBool aTop ) = 0;

        /**

         * Scrolls selection to screen and updates scroll bars

         * @param aSelection Selection

         * @param aTop If selection doesn't fit to screen, should the top of the

         *        selection be visible. I.e. If ETrue, top of the message is shown.

         *        if EFalse, bottom of the message is shown.

         */

        virtual void ScrollVisibleL( TCursorSelection& aSelection, TBool aTop ) = 0;

        /**

         * @return Current scroll selection (i.e. the visible part)

         */

        virtual TCursorSelection ScrollSelection() = 0;

        /**

         * Scrolls view up or down

         * @param aAmount Amount of lines to be scrolled

         * Use negative values for scrolling up

         */

        virtual void ScrollLinesL( TInt aAmount ) = 0;

        /**

         * @return ETrue if aPos is visible on screen, EFalse otherwise.

         */

        virtual TBool IsVisible( TInt aPos ) = 0;

        /**

         * @return ETrue if the paragraph in aPos fits to screen

         */

        virtual TBool ParagraphFits( TInt aPos ) = 0;

        /**

         * Redraws the view

         */

        virtual void Redraw() = 0;

        /**

         * Sets the behaviour of this control to pointer events.

         * see TPenBehaviour for more detailed info.

         * @param aPen How this control should react to pointer events

         */

        virtual void SetPenBehaviour( TPenBehaviour aPen ) = 0;

        /**

         * Return current pen behaviour state. Determines how this control

         * reacts to pointer events.

         * @return Current pen behaviour

         */

        virtual TPenBehaviour PenBehaviour() = 0;

        /**

         * Reformats the view after a global change has been made to the layout,

         * but without causing a redraw.

         * @since S60 v3.2

         * @param aYPosQualifier Specifies whether the visible area is to be

         *                       filled and whether the top line should be made

         *                       fully visible if possible.

         */

        virtual void HandleGlobalChangeNoRedrawL(

            TViewYPosQualifier aYPosQualifier = TViewYPosQualifier() ) = 0;

    protected:

        /**

         * This gets called when the pointer event is inside the text message.

         * @param aPointerEvent Pointer event

         */

        virtual void ProcessStylusEventL(

            const TPointerEvent& aPointerEvent ) = 0;

        /**

         * Destructor.

         */

        virtual ~MCATextView() {};

    };

#endif      // MCATEXTVIEW_H

// End of File