package com.gy.measureandlayout;

import android.content.Context;
import android.util.AttributeSet;
import android.view.View;
import android.view.ViewGroup;

import java.util.Map;

public class CustomLayout extends ViewGroup {

    public CustomLayout(Context context) {
        super(context);
    }

    public CustomLayout(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public CustomLayout(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }


    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        
        int selfWidthSpecModel = MeasureSpec.getMode(widthMeasureSpec);
        int selfHeightSpecModel = MeasureSpec.getMode(heightMeasureSpec);
        int selfWidthSize = MeasureSpec.getSize(widthMeasureSpec);
        int selfHeightSize = MeasureSpec.getSize(heightMeasureSpec);

        for(int i=0;i<getChildCount();i++){
            View childView = getChildAt(i);

            /*获取childView的 布局参数*/
            LayoutParams lp = childView.getLayoutParams();
            int width = lp.width;/*可以matchParent wrapContent 或者设置的实际值*/
            int height= lp.height;/*可以matchParent wrapContent 或者设置的实际值*/

            int childWidthSpec ;
            switch (lp.width){
                case LayoutParams.MATCH_PARENT:
                    if(selfWidthSpecModel == MeasureSpec.EXACTLY || selfWidthSpecModel == MeasureSpec.AT_MOST){
                        /*如果父view 的model 为EXACTLY 或者 AT_MOST */
                        /*因为childView 的model 是MATCH_PARENT 则把父view 的宽度设置给 child 并设置模式为EXACTLY*/
                        childWidthSpec = MeasureSpec.makeMeasureSpec(selfWidthSize,MeasureSpec.EXACTLY);
                    }else{
                        /*如果父view 的model是 UNSPECIFIED 因为没办法确定父view 的宽度 所以直接放弃设置 也给child UNSPECIFIED*/
                        /*size 随便设置 */
                        childWidthSpec = MeasureSpec.makeMeasureSpec(0,MeasureSpec.UNSPECIFIED);
                    }
                    break;
                case LayoutParams.WRAP_CONTENT:
                    if(selfWidthSpecModel == MeasureSpec.EXACTLY || selfWidthSpecModel == MeasureSpec.AT_MOST){
                        /*如果child 的model 是WRAP_CONTENT 那么child需要自己测量尺寸 这里 设置model为AT_MOST*/
                        childWidthSpec = MeasureSpec.makeMeasureSpec(selfWidthSize,MeasureSpec.AT_MOST);
                    }else{
                        /*无限大  就传递无限大 下去*/
                        childWidthSpec = MeasureSpec.makeMeasureSpec(0,MeasureSpec.UNSPECIFIED);
                    }
                    break;
                default:
                    /*设置的是具体的值*/
                    childWidthSpec = MeasureSpec.makeMeasureSpec(lp.width,widthMeasureSpec);
                    break;
            }

            int childHeightSpec ;
            switch (lp.height){
                case LayoutParams.MATCH_PARENT:
                    if(selfHeightSpecModel == MeasureSpec.EXACTLY || selfHeightSpecModel == MeasureSpec.AT_MOST){
                        /*如果父view 的model 为EXACTLY 或者 AT_MOST */
                        /*因为childView 的model 是MATCH_PARENT 则把父view 的宽度设置给 child 并设置模式为EXACTLY*/
                        childHeightSpec = MeasureSpec.makeMeasureSpec(selfHeightSize,MeasureSpec.EXACTLY);
                    }else{
                        /*如果父view 的model是 UNSPECIFIED 因为没办法确定父view 的宽度 所以直接放弃设置 也给child UNSPECIFIED*/
                        /*size 随便设置 */
                        childHeightSpec = MeasureSpec.makeMeasureSpec(0,MeasureSpec.UNSPECIFIED);
                    }
                    break;
                case LayoutParams.WRAP_CONTENT:
                    if(selfHeightSpecModel == MeasureSpec.EXACTLY || selfHeightSpecModel == MeasureSpec.AT_MOST){
                        /*如果child 的model 是WRAP_CONTENT 那么child需要自己测量尺寸 这里 设置model为AT_MOST*/
                        childHeightSpec = MeasureSpec.makeMeasureSpec(selfHeightSize,MeasureSpec.AT_MOST);
                    }else{
                        /*如果父view 的model是 UNSPECIFIED 因为没办法确定父view 的宽度 所以直接放弃设置 也给child UNSPECIFIED*/
                        /*size 随便设置 */
                        childHeightSpec = MeasureSpec.makeMeasureSpec(0,MeasureSpec.UNSPECIFIED);
                    }
                    break;
                default:
                    /*设置的是具体的值*/
                    childHeightSpec = MeasureSpec.makeMeasureSpec(lp.height,widthMeasureSpec);
                    break;
            }

            childView.measure(childWidthSpec,childHeightSpec);

        }
    }


    @Override
    protected void onLayout(boolean changed, int l, int t, int r, int b) {
        int totalHeight = 0;
      for(int i=0;i<getChildCount();i++){
          View view = getChildAt(i);
          int width = view.getMeasuredWidth();
          int height = view.getMeasuredHeight();
          /*这里设置的位置是相对于 父view 的设置值*/
          view.layout(l,t+totalHeight,l+width,t+totalHeight+height);
          totalHeight+=height;
      }
    }
}