ProportionLinearLayout.java

package com.ywwxhz.widget;

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

import com.ywwxhz.cnbetareader.R;


/**
 * Created by ywwxhz on 2014/10/9.
 */
public class ProportionLinearLayout extends LinearLayout {

    private boolean reversal = false;
    private float proportion = 1;

    public ProportionLinearLayout(Context context) {
        super(context);
        initView(context, null);
    }

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

    public ProportionLinearLayout(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        initView(context, attrs);
    }

    private void initView(Context context, AttributeSet attrs) {
        if (attrs != null) {
            TypedArray a = context.obtainStyledAttributes(attrs,
                    R.styleable.ProportionLinearLayout);
            reversal = a.getBoolean(
                    R.styleable.ProportionLinearLayout_pl_Reversal, false);
            proportion = a.getFloat(R.styleable.ProportionLinearLayout_pl_proportion, 1);
            a.recycle();
        }
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        setMeasuredDimension(getDefaultSize(0,
                widthMeasureSpec), getDefaultSize(0,
                heightMeasureSpec));

        // Children are just made to fill our space.

        int childWidthSize = getMeasuredWidth();

        int childHeightSize = getMeasuredHeight();

        //高度和宽度一样
        if (reversal) {
            widthMeasureSpec = MeasureSpec.makeMeasureSpec((int) (childHeightSize * proportion), MeasureSpec.EXACTLY);
            heightMeasureSpec = MeasureSpec.makeMeasureSpec(childHeightSize, MeasureSpec.EXACTLY);
        } else {
            widthMeasureSpec = MeasureSpec.makeMeasureSpec(childWidthSize, MeasureSpec.EXACTLY);
            heightMeasureSpec = MeasureSpec.makeMeasureSpec((int) (childWidthSize * proportion), MeasureSpec.EXACTLY);
        }

        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
    }

    public boolean isReversal() {
        return reversal;
    }

    public void setReversal(boolean reversal) {
        this.reversal = reversal;
    }

    public float getProportion() {
        return proportion;
    }

    public void setProportion(float proportion) {
        this.proportion = proportion;
    }
}