在界面顶部滑动展开的自定义FrameLayout

用法：

translationView.show();translationView.hide();translationView.setShadowColor(ActivityCompat.getColor(MainActivity.this, R.color.blue));//设置背景颜色

源码：

import android.animation.Animator;import android.animation.AnimatorListenerAdapter;import android.animation.ObjectAnimator;import android.content.Context;import android.graphics.Canvas;import android.support.annotation.ColorInt;import android.support.v4.view.MotionEventCompat;import android.util.AttributeSet;import android.util.Log;import android.view.MotionEvent;import android.view.View;import android.widget.FrameLayout;public class TranslationView extends FrameLayout {    private static final String TAG = "TranslationView";    private static final int DEFAULT_COLOR = 0x50000000;    private int mShadowColor = DEFAULT_COLOR;    private boolean mIsShow = false;    private View mTranslationView;    public TranslationView(Context context) {        super(context, null);    }    public TranslationView(Context context, AttributeSet attrs) {        super(context, attrs, 0);    }    public TranslationView(Context context, AttributeSet attrs, int defStyleAttr) {        super(context, attrs, defStyleAttr);    }    @Override    protected void onFinishInflate() {        if (getChildCount() != 2) {            throw new IllegalStateException("only and should contain two child view");        }        mTranslationView = getChildAt(1);    }    @Override    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {        super.onMeasure(widthMeasureSpec, heightMeasureSpec);        Log.d(TAG, "onMeasure");    }    @Override    protected void onLayout(boolean changed, int left, int top, int right, int bottom) {        super.onLayout(changed, left, top, right, bottom);        mTranslationView.layout(0, -mTranslationView.getHeight(), mTranslationView.getWidth(), 0);    }    @Override    protected boolean drawChild(Canvas canvas, View child, long drawingTime) {        if (mIsShow && child == mTranslationView) {            canvas.drawColor(mShadowColor);        }        return super.drawChild(canvas, child, drawingTime);    }    @Override    public boolean onInterceptTouchEvent(MotionEvent ev) {        final int action = MotionEventCompat.getActionMasked(ev);        switch (action){            case MotionEvent.ACTION_DOWN:{                if(mIsShow&&inShadow(ev)){                    hide();                    return true;                }            }        }        return  super.onInterceptTouchEvent(ev);    }    private boolean inShadow(MotionEvent ev) {        float x = ev.getX();        float y = ev.getY();        final float leftEdge = mTranslationView.getX();        final float rightEdge = leftEdge+mTranslationView.getWidth();        final float topEdge =mTranslationView.getHeight();        final float bottomEdge = getHeight()+topEdge;        return x > leftEdge && x < rightEdge && y > topEdge && y < bottomEdge;    }    public void show() {        if (!mIsShow) {            mIsShow = true;            ObjectAnimator objectAnimator = ObjectAnimator.ofFloat(mTranslationView, "translationY", mTranslationView.getTranslationY(), mTranslationView.getHeight());            objectAnimator.addListener(new AnimatorListenerAdapter() {                @Override                public void onAnimationStart(Animator animation) {                    super.onAnimationStart(animation);                    invalidate();                }            });            objectAnimator.start();        }    }    public void hide() {        if (mIsShow) {            mIsShow = false;            ObjectAnimator objectAnimator = ObjectAnimator.ofFloat(mTranslationView, "translationY", mTranslationView.getTranslationY(), -mTranslationView.getHeight());            objectAnimator.addListener(new AnimatorListenerAdapter() {                @Override                public void onAnimationEnd(Animator animation) {                    super.onAnimationEnd(animation);                    invalidate();                }            });            objectAnimator.start();        }    }    public void setShadowColor(@ColorInt int color) {        mShadowColor = color;    }}