DragLayout测试代码（ViewDragHelper）

import android.content.Context;
import android.graphics.Rect;
import android.support.v4.view.ViewCompat;
import android.support.v4.widget.ViewDragHelper;
import android.util.AttributeSet;
import android.view.*;
import android.widget.FrameLayout;

import com.hide.transitionstest.app.R;

public class DragLayout extends FrameLayout {

    public static final int STATE_COLLAPSE = 1;
    public static final int STATE_EXPAND = 2;

    private ViewGroup mDragContent;
    private View mTouchView;


    private IDragListener iDragListener;
    private ViewDragHelper mDragHelper;
    private int mSlideMaxY;
    private int mTopPadding;
    private int mCurState = STATE_EXPAND;


    private ViewDragHelper.Callback mCallback = new ViewDragHelper.Callback() {
        @Override
        public boolean tryCaptureView(View child, int pointerId) {
            return child == mDragContent;
        }

        @Override
        public int clampViewPositionVertical(View child, int top, int dy) {
            return clampHeight(top);
        }

        @Override
        public void onViewPositionChanged(View changedView, int left, int top, int dx, int dy) {
            if (iDragListener != null) {
                iDragListener.onDragChange(dragPercent(top));
            }
        }

        @Override
        public int getViewVerticalDragRange(View child) {
            return mSlideMaxY;
        }

        @Override
        public void onViewReleased(View releasedChild, float xvel, float yvel) {
            super.onViewReleased(releasedChild, xvel, yvel);

            int settleTop = mTopPadding;
            int slideRange = releasedChild.getTop() - mTopPadding;
            switch (mCurState) {
                case STATE_EXPAND:
                    if (yvel >= 0
                            && slideRange > mSlideMaxY / 5) {
                        settleTop = getHeight() - mTouchView.getMeasuredHeight();
                    }
                    break;
                case STATE_COLLAPSE:
                    slideRange = getHeight() - releasedChild.getTop() - mTouchView.getMeasuredHeight();
                    if (yvel > 0
                            || slideRange 

import android.app.Activity;
import android.graphics.Color;
import android.os.Bundle;
import android.transitions.everywhere.TransitionManager;
import android.view.View;
import android.view.ViewGroup;
import android.view.ViewTreeObserver;
import android.widget.FrameLayout;
import android.widget.ImageView;

import com.hide.transitionplayer.lib.TransitionPlayer;
import com.hide.transitionstest.app.widget.DragLayout;

/**
 * * * * * * * * * * * * * * * * * * * * * * *
 * Created by zhaoyiding
 * Date: 15/10/12
 * * * * * * * * * * * * * * * * * * * * * * *
 **/
public class DragTransitionActivity extends Activity
        implements DragLayout.IDragListener {

    private View mDimView;
    private ViewGroup mSceneRoot;
    private TransitionPlayer mTransitionPlayer = new TransitionPlayer();
    private ImageView mHeadImg;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_drag_transition);

//        mDimView = findViewById(R.id.dimView);
//        mSceneRoot = (ViewGroup) findViewById(R.id.scene_root);
//        mHeadImg = (ImageView) findViewById(R.id.headimg);
//
//        initImg();

        final DragLayout mDragLayout = (DragLayout) findViewById(R.id.drag_layout);
        mDragLayout.setOnDragListener(this);
//        mDragLayout.getViewTreeObserver().addOnPreDrawListener(new ViewTreeObserver.OnPreDrawListener() {
//            @Override
//            public boolean onPreDraw() {
//                mDragLayout.getViewTreeObserver().removeOnPreDrawListener(this);
//                TransitionManager.beginDelayedTransition(mSceneRoot, mTransitionPlayer);
//                ViewGroup.MarginLayoutParams marginParams = (ViewGroup.MarginLayoutParams) mHeadImg.getLayoutParams();
//                marginParams.topMargin = 0;
//                mHeadImg.setLayoutParams(marginParams);
//                mHeadImg.setAlpha(1.0f);
//
//                mHeadImg.post(new Runnable() {
//                    @Override
//                    public void run() {
//                        mTransitionPlayer.setCurrentFraction(1.0f);
//
//                    }
//                });
//                return false;
//            }
//        });

    }

//    private void initImg() {
//        int height = getResources().getDisplayMetrics().heightPixels / 3 - IndexActivity.sStatusBarHeight;
//        FrameLayout.LayoutParams params = new FrameLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, height);
//        params.topMargin = -height * 2 / 3;
//        mHeadImg.setLayoutParams(params);
//        mHeadImg.setAlpha(0f);
//    }
//
//    private void setDimViewAlpha(float fraction) {
//        mDimView.setBackgroundColor(Color.argb((int) (255 * fraction), 0, 0, 0));
//        mTransitionPlayer.setCurrentFraction(fraction);
//    }

    @Override
    public void onDragChange(float fraction) {
//        setDimViewAlpha(fraction);
    }
}