package com.itheima.googleplay_8.views;

import com.itheima.googleplay_8.R;

import android.content.Context;
import android.content.res.TypedArray;
import android.util.AttributeSet;
import android.widget.FrameLayout;

/**
 * @author  Administrator
 * @time     2015-7-18 下午2:10:54
 * @des    TODO
 *
 * @version $Rev: 33 $
 * @updateAuthor $Author: admin $
 * @updateDate $Date: 2015-07-18 15:13:26 +0800 (星期六, 18 七月 2015) $
 * @updateDes TODO
 */
public class RatioLayout extends FrameLayout {
    private float                mPicRatio        = 0f;                // 图片的宽高比 2.43
    private static final int    RELATIVE_WIDTH    = 0;                // 控件宽度固定,已知图片的宽高比,求控件的高度
    private static final int    RELATIVE_HEIGHT    = 1;                // 控件高度固定,已知图片的宽高比,求控件的宽度
    private int                    mRelative        = RELATIVE_WIDTH;

    public RatioLayout(Context context) {
        this(context, null);
    }

    public RatioLayout(Context context, AttributeSet attrs) {
        super(context, attrs);

        TypedArray typedArray = context.obtainStyledAttributes(attrs, R.styleable.RatioLayout);

        mPicRatio = typedArray.getFloat(R.styleable.RatioLayout_picRatio, 0);

        mRelative = typedArray.getInt(R.styleable.RatioLayout_relative, RELATIVE_WIDTH);

        typedArray.recycle();
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {

        // 控件宽度固定,已知图片的宽高比,求控件的高度
        int parentWidthMode = MeasureSpec.getMode(widthMeasureSpec);

        // 控件高度固定,已知图片的宽高比,求控件的宽度
        int parentHeightMode = MeasureSpec.getMode(heightMeasureSpec);

        if (parentWidthMode == MeasureSpec.EXACTLY && mPicRatio != 0 && mRelative == RELATIVE_WIDTH) {// 控件宽度固定,已知图片的宽高比,求控件的高度
            // 得到父容器的宽度
            int parentWidth = MeasureSpec.getSize(widthMeasureSpec);
            // 得到孩子的宽度
            int childWidth = parentWidth - getPaddingLeft() - getPaddingRight();
            // 控件的宽度/控件的高度 = mPicRatio;

            // 计算孩子的高度
            int childHeight = (int) (childWidth / mPicRatio + .5f);

            // 计算父容器的高度
            int parentHeight = childHeight + getPaddingBottom() + getPaddingTop();

            // 主动测绘孩子.固定孩子的大小
            int childWidthMeasureSpec = MeasureSpec.makeMeasureSpec(childWidth, MeasureSpec.EXACTLY);
            int childHeightMeasureSpec = MeasureSpec.makeMeasureSpec(childHeight, MeasureSpec.EXACTLY);
            measureChildren(childWidthMeasureSpec, childHeightMeasureSpec);

            // 设置自己的测试结果
            setMeasuredDimension(parentWidth, parentHeight);

        } else if (parentHeightMode == MeasureSpec.EXACTLY && mPicRatio != 0 && mRelative == RELATIVE_HEIGHT) {
            // 控件高度固定,已知图片的宽高比,求控件的宽度
            // 得到父亲的高度
            int parentHeight = MeasureSpec.getSize(heightMeasureSpec);

            // 得到孩子的高度
            int childHeight = parentHeight - getPaddingBottom() - getPaddingTop();

            // 控件的宽度/控件的高度 = mPicRatio;
            // 计算控件宽度
            int childWidth = (int) (childHeight * mPicRatio + .5f);

            // 得到父亲的宽度
            int parentWidth = childWidth + getPaddingRight() + getPaddingLeft();

            // 主动测绘孩子.固定孩子的大小
            int childWidthMeasureSpec = MeasureSpec.makeMeasureSpec(childWidth, MeasureSpec.EXACTLY);
            int childHeightMeasureSpec = MeasureSpec.makeMeasureSpec(childHeight, MeasureSpec.EXACTLY);
            measureChildren(childWidthMeasureSpec, childHeightMeasureSpec);

            // 设置自己的测试结果
            setMeasuredDimension(parentWidth, parentHeight);

        } else {
            super.onMeasure(widthMeasureSpec, heightMeasureSpec);

        }

    }
}