CheckableLinearLayout.java

package io.hefuyi.zhihudaily.widget;

import android.content.Context;
import android.graphics.drawable.Drawable;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Checkable;
import android.widget.LinearLayout;

/**
 * Created by hefuyi on 16/8/2.
 */
public class CheckableLinearLayout extends LinearLayout implements Checkable {

    private boolean mChecked;

    private static final int[] CHECKED_STATE_SET = {android.R.attr.state_checked};

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

    public CheckableLinearLayout(Context context, AttributeSet attributeSet) {
        this(context, attributeSet, 0);
    }

    public CheckableLinearLayout(Context context, AttributeSet attributeSet, int defStyleAttr) {
        super(context, attributeSet, defStyleAttr);
    }

    /*handle chicks*/

    @Override
    public boolean performClick() {
        toggle();
        return super.performClick();
    }

    @Override
    public boolean onInterceptTouchEvent(MotionEvent ev) {
        return onTouchEvent(ev);
    }

    /*checkable*/
    @Override
    public void setChecked(boolean checked) {
        if (mChecked != checked) {
            mChecked = checked;
            refreshDrawableState();
            //使当前viewGroup下的子view设置为checked状态
            setCheckedRecursive(this, checked);
        }
    }

    private void setCheckedRecursive(ViewGroup parent, boolean checked) {
        int count = parent.getChildCount();
        for (int i=0;i<count;i++) {
            View v = parent.getChildAt(i);
            if (v instanceof Checkable) {
                ((Checkable) v).setChecked(checked);
            }
            if (v instanceof ViewGroup) {
                setCheckedRecursive((ViewGroup) v, checked);
            }
        }
    }

    @Override
    public boolean isChecked() {
        return mChecked;
    }

    @Override
    public void toggle() {
        setChecked(!mChecked);
    }

    /*drawable states*/

    @Override
    protected int[] onCreateDrawableState(int extraSpace) {
        final int[] drawableStare = super.onCreateDrawableState(extraSpace + 1);
        if (isChecked()) {
            mergeDrawableStates(drawableStare, CHECKED_STATE_SET);
        }
        return drawableStare;
    }

    @Override
    protected void drawableStateChanged() {
        super.drawableStateChanged();

        Drawable drawable = getBackground();
        if (drawable != null) {
            int[] myDrawableStete = getDrawableState();
            drawable.setState(myDrawableStete);
            invalidate();
        }
    }
}