RedCore/cocos2d/cocos/ui/UIHelper.h

/****************************************************************************
Copyright (c) 2013-2017 Chukong Technologies Inc.

http://www.cocos2d-x.org

Permission is hereby granted, free of charge, to any person obtaining a copy
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THE SOFTWARE.
****************************************************************************/

#ifndef __UIHELPER_H__
#define __UIHELPER_H__

#include <string>
#include "platform/CCPlatformMacros.h"
#include "ui/GUIExport.h"
#include "2d/CCNode.h"

NS_CC_BEGIN

/**
 * @addtogroup ui
 * @{
 */
namespace ui {
    
    class Widget;

/**
 * Helper class for traversing children in widget tree.
 * It also provides some helper functions for layout.
 */
class CC_GUI_DLL Helper
{
public:
    /**
     * Find a widget with a specific tag from root widget.
     * This search will be recursive through all child widgets.
     * @param root      The be searched root widget.
     * @param tag       The widget tag.
     * @return Widget instance pointer.
     */
    static Widget* seekWidgetByTag(Widget* root, int tag);
    
    /**
     * Find a widget with a specific name from root widget.
     * This search will be recursive through all child widgets.
     *
     * @param root      The be searched root widget.
     * @param name      The widget name.
     * @return Widget instance pointer.
     */
    static Widget* seekWidgetByName(Widget* root, const std::string& name);
    
    /**
     * Find a widget with a specific action tag from root widget
     * This search will be recursive through all child widgets.
     *@param root The be searched root widget.
     *@param tag The widget action's tag.
     *@return Widget instance pointer.
     */
    static Widget* seekActionWidgetByActionTag(Widget* root, int tag);
    
    /**
     * @brief Get a UTF8 substring from a std::string with a given start position and length
     *  Sample:  std::string str = "中国中国中国";  substr = getSubStringOfUTF8String(str,0,2) will = "中国"
     *
     * @param str The source string.
     * @param start The start position of the substring.
     * @param length The length of the substring in UTF8 count
     * @return a UTF8 substring
     * @js NA
     */
    static std::string getSubStringOfUTF8String(const std::string& str,
                                   std::string::size_type start,
                                   std::string::size_type length);
    
    /**
     * Refresh object and it's children layout state
     *
     *@param rootNode   A Node* or Node* descendant instance pointer.
     *
     */
    static void doLayout(Node *rootNode);

    /**
     *  Change the active property of Layout's @see `LayoutComponent`
     *@param active A boolean value.
     */
    static void changeLayoutSystemActiveState(bool active);
    
    /**
     *@brief  restrict capInsetSize, when the capInsets's width is larger than the textureSize, it will restrict to 0,
     *        the height goes the same way as width.
     *@param  capInsets A user defined capInsets.
     *@param  textureSize  The size of a scale9enabled texture
     *@return a restricted capInset.
     */
    static Rect restrictCapInsetRect(const Rect& capInsets, const Size& textureSize);

    /**
     *@brief Convert a node's boundingBox rect into screen coordinates.
     *
     * @param node Any node pointer.
     *
     * @return A Rect in screen coordinates.
     */
    static Rect convertBoundingBoxToScreen(Node* node);
};
}

// end of ui group
/// @}
NS_CC_END

#endif /* defined(__CocoGUI__UISystem__) */