-- 自动布局的方向
ScreenLayoutDir =
{
	-- 左边
	SL_Left = 1,
	-- 下面
	SL_Bottom = 2,
	-- 右边
	SL_Right = 3,
	-- 上面
	SL_Top = 4,
}


-- 全屏自动把一个控件绕着一个控件水平布局
-- rect 控件的矩形（x,y,width,height）都是屏幕坐标系，锚点在0,0，即xy是这个控件的左下角
-- pos 参考点，被控制的控件始终以这个参考点的轴向为主要参照（屏幕坐标）
-- size 被控制的控件的大小（屏幕坐标）
-- @return 返回被控制的控件的屏幕坐标，假设控件的锚点在0,0，即计算出来是被控制的控件的左下角位置
function screenLayout(rect , pos , size , screenSize, dir)
	screenSize = screenSize or cc.Director:getInstance():getWinSize();
	local targetPos = nil
	if dir then
		-- 左边
		if dir == ScreenLayoutDir.SL_Left then
			targetPos = cc.p(rect.x - size.width, pos.y - size.height / 2);
		elseif dir == ScreenLayoutDir.SL_Bottom then
			targetPos = cc.p(pos.x, rect.y - size.height);
		elseif dir == ScreenLayoutDir.SL_Right then
			targetPos = cc.p(rect.x + rect.width, pos.y - size.height / 2);
		elseif dir == ScreenLayoutDir.SL_Top then
			targetPos = cc.p(pos.x, rect.y + rect.height);
		end
		-- 必须都要限制在定义的区域里面
		targetPos.x = cc.clampf(targetPos.x , 0 , screenSize.width - size.width);
		targetPos.y = cc.clampf(targetPos.y , 0 , screenSize.height - size.height);
		return targetPos
	else
		-- 计算左边位置(历史遗留问题)
		targetPos = cc.p(rect.x - size.width , pos.y - size.height / 2);
		-- 左边没越界，说明放得下
		if targetPos.x >= 0 then
			targetPos.y = cc.clampf(targetPos.y , 0 , screenSize.height - size.height);
			return targetPos;
		-- 左边放不下，放右边吧
		else
			targetPos.x = rect.x + rect.width;
			targetPos.y = cc.clampf(targetPos.y , 0 , screenSize.height - size.height);
			return targetPos;
		end
	end
end

-- 全屏布局函数
-- nodeContainer 布局容器节点
-- nodePoint 布局参考点的节点
-- nodeTarget 被布局的节点
function screenLayoutNode(nodeContainer , nodePoint , nodeTarget , screenSize, dir)
	local rect = nodeContainer:getWorldRect();

	local pos = nodePoint:getParent():convertToWorldSpace2D(cc.p(nodePoint:getLeftInParent() , nodePoint:getBottomInParent()));

	local size = nodeTarget:getContentSize();
	local targetPos = screenLayout(rect , pos , size , screenSize, dir);

	local targetToParentPos = nodeTarget:getParent():convertToNodeSpace2D(targetPos);

	local targetAp = nodeTarget:getAnchorPoint();
	targetToParentPos.x = targetToParentPos.x + targetAp.x * size.width
	targetToParentPos.y = targetToParentPos.y + targetAp.y * size.height
	nodeTarget:setPosition(targetToParentPos);
end

-- 自动执行的全屏布局
-- nodeContainer 布局容器节点
-- nodePoint 布局参考点的节点
-- nodeTarget 被布局的节点
-- dir表示强制放到那个方向（如果放不下就往里面挤挤）
function autoScreenLayoutNode(nodeContainer , nodePoint , nodeTarget, screenSize, dir)
	local function onUpdate()
		screenLayoutNode(nodeContainer , nodePoint , nodeTarget, screenSize, dir);
	end

	-- 每帧更新一次
	schedule(nodeTarget , onUpdate , 0);
	onUpdate();
	return onUpdate;
end

-- 自动执行的全屏布局(当nodeContainer或者nodePoint不存在了则停止布局)
-- nodeContainer 布局容器节点
-- nodePoint 布局参考点的节点
-- nodeTarget 被布局的节点
function autoScreenLayoutNodeEx(nodeContainer , nodePoint , nodeTarget , screenSize)
	local layoutAction = nil
	local function onUpdate()
		if tolua.isnull(nodeContainer) or tolua.isnull(nodePoint) then
			local function stopLayoutAction()
				if not tolua.isnull(nodeTarget) and not tolua.isnull(layoutAction) then
					nodeTarget:stopAction(layoutAction)
					layoutAction = nil
				end
			end
			runInNextFrame(stopLayoutAction)
		else
			-- 更新
			screenLayoutNode(nodeContainer , nodePoint , nodeTarget , screenSize);
		end
	end

	-- 每帧更新一次
	layoutAction = schedule(nodeTarget , onUpdate , 0);
	onUpdate();
	return onUpdate;
end