/*

* Copyright (c) 2007 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:  Base interface for all container widgets

*

*/

#ifndef I_ALFCONTAINERWIDGET_H

#define I_ALFCONTAINERWIDGET_H

#include <alf/ialfwidget.h>

class CAlfLayout;

namespace Alf

    {

class IAlfLayoutManager;

namespace ialfcontainerwidget

    {

static const IfId ident =

    {

    0, "container"

    };

    }

/**

 * The interface for container widget.

 * 

 * Container widget maintains it's own control group. When a widget control is set to container

 * widget throught the IAlfWidget::setControl() - method the control is automatically appended to the 

 * container widget's control group. If the control that is being set to the container widget is 

 * already part of another control group it will be removed from the previous control group and appended

 * to the container widget's control group.

 *

 * @lib alfwidgetmodel.lib

 * @since S60 ?S60_version

 * @status Draft

 */

class IAlfContainerWidget : public IAlfWidget

    {

public:

    static inline const IfId& type()

        {

        return ialfcontainerwidget::ident;

        }

    virtual ~IAlfContainerWidget() {}

    /**

     * Returns total number of widgets contained by this container.

     *

     * @return int Total number of widgets.

     */

    virtual int widgetCount() const = 0;

    /**

     * Adds a child widget to the container.

     *

     * This will throw an osncore::AlfException exception with error code 

     * osncore::EInvalidArgument if the aWidget is the same widget that the container

     * widget itself or if user tries to add a view widget into a container

     * widget.

     *

     * Adding a widget instance that is already added will be silently

     * ignored.

     *

     * @exception osncore::AlfException with error code osncore::EInvalidArgument if the

     *            aWidget is the same widget as the container widget or when

     *            a view widget is attempted to be added to a container.

     *

     * @param  aWidget Child widget to be added to container.

     */

    virtual void addWidget(IAlfWidget& aWidget) = 0;

    /**

     * Returns child widget at given index. If index is not found return null.

     *

     * @param  aIndex Index of widget to be returned.

     * @return Widget at given index or null if the widget is not found.

     */

    virtual IAlfWidget* getWidget(int aIndex) const = 0;

    /**

     * Returns the child index, when given the child widget.

     *

     * @param  aWidget child widget, which index is returned 

     * @return the index of the child widget, or -1, if widget is not child of this container.

     */

    virtual int getWidgetIndex(IAlfWidget& aWidget) const = 0; 

    /**

     * Removes the child widget from given index.

     *

     * If widget for the given index is not found then the call

     * is silently ignored.

     *

     * @param aIndex Index from which widget has to be removed.

     */

    virtual void removeWidget(int aIndex) = 0;

    /**

     * Sets the base layout of container widget. Ownership of the

     * layout manager is transferred to container widget.

     *

     * @param aLayout New base layout of container widget.

     */

    virtual void applyLayout(IAlfLayoutManager& aLayout) = 0;

    };

    } // namespace Alf

#endif // I_ALFCONTAINERWIDGET_H