Android实现探探图片滑动效果

public class OverLayCardLayoutManager extends RecyclerView.LayoutManager {  private static final String TAG = "swipecard";  public static int MAX_SHOW_COUNT = 4;  public static float SCALE_GAP = 0.05f;  public static int TRANS_Y_GAP;  public OverLayCardLayoutManager(Context context) {    //平移时, 需要用到的参考值    TRANS_Y_GAP = (int) (20 * context.getResources().getDisplayMetrics().density);  }  @Override  public RecyclerView.LayoutParams generateDefaultLayoutParams() {    //必须要实现的方法    return new RecyclerView.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT);  }  @Override  public void onLayoutChildren(RecyclerView.Recycler recycler, RecyclerView.State state) {    //在这个方法中进行View的布局操作.此方法会被调用多次.    detachAndScrapAttachedViews(recycler);    int itemCount = getItemCount();    if (itemCount < 1) {      return;    }    //top-3View的position    int bottomPosition;    //边界处理    if (itemCount < MAX_SHOW_COUNT) {      bottomPosition = 0;    } else {      bottomPosition = itemCount - MAX_SHOW_COUNT;    }    //从可见的最底层View开始layout，依次层叠上去    for (int position = bottomPosition; position < itemCount; position++) {      //1:重recycler的缓存机制中拿到一个View      View view = recycler.getViewForPosition(position);      //2:和自定义ViewGroup一样, 需要先addView      addView(view);      //3:和自定义ViewGroup一样, 也需要测量View的大小      measureChildWithMargins(view, 0, 0);      int widthSpace = getWidth() - getDecoratedMeasuredWidth(view);      int heightSpace = getHeight() - getDecoratedMeasuredHeight(view);      //4:和自定义ViewGroup的onLayout一样, 需要layout View.对View进行布局       //我们在布局时，将childView居中处理，这里也可以改为只水平居中      layoutDecoratedWithMargins(view, widthSpace / 2, heightSpace / 2,          widthSpace / 2 + getDecoratedMeasuredWidth(view),          heightSpace / 2 + getDecoratedMeasuredHeight(view));      /**       * TopView的Scale 为1，translationY 0       * 每一级Scale相差0.05f，translationY相差7dp左右       *       * 观察人人影视的UI，拖动时，topView被拖动，Scale不变，一直为1.       * top-1View 的Scale慢慢变化至1，translation也慢慢恢复0       * top-2View的Scale慢慢变化至 top-1View的Scale，translation 也慢慢变化只top-1View的translation       * top-3View的Scale要变化，translation岿然不动       */      //第几层,举例子，count =7， 最后一个TopView（6）是第0层，      int level = itemCount - position - 1;      //如果不需要缩放平移, 那么下面的代码可以注释掉...      //除了顶层不需要缩小和位移      if (level > 0 /*&& level < mShowCount - 1*/) {        //每一层都需要X方向的缩小        view.setScaleX(1 - SCALE_GAP * level);        //前N层，依次向下位移和Y方向的缩小        if (level < MAX_SHOW_COUNT - 1) {          view.setTranslationY(TRANS_Y_GAP * level);          view.setScaleY(1 - SCALE_GAP * level);        } else {//第N层在 向下位移和Y方向的缩小的成都与 N-1层保持一致          view.setTranslationY(TRANS_Y_GAP * (level - 1));          view.setScaleY(1 - SCALE_GAP * (level - 1));        }      }    }  }}

public class RenRenCallback extends ItemTouchHelper.SimpleCallback {  private static final String TAG = "RenRen";  private static final int MAX_ROTATION = 15;  OnSwipeListener mSwipeListener;  boolean isSwipeAnim = false;  public RenRenCallback() {    //第一个参数决定可以拖动排序的方向, 这里由于不需要拖动排序,所以传0    //第二个参数决定可以支持滑动的方向,这里设置了上下左右都可以滑动.    super(0, ItemTouchHelper.DOWN | ItemTouchHelper.UP | ItemTouchHelper.LEFT | ItemTouchHelper.RIGHT);  }  public void setSwipeListener(OnSwipeListener swipeListener) {    mSwipeListener = swipeListener;  }  //水平方向是否可以被回收掉的阈值  public float getThreshold(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder) {    //2016 12 26 考虑 探探垂直上下方向滑动，不删除卡片，这里参照源码写死0.5f    return recyclerView.getWidth() * /*getSwipeThreshold(viewHolder)*/ 0.5f;  }  @Override  public boolean onMove(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, RecyclerView.ViewHolder target) {    //由于不支持滑动排序, 所以不需要处理此方法    return false;  }  @Override  public void onSwiped(RecyclerView.ViewHolder viewHolder, int direction) {    //当view需要滑动的时候,会回调此方法    //但是这个方法只是告诉你View需要滑动, 并不是对View和Adapter进行额外的操作,    //所以, 如果你需要实现滑动删除, 那么需要在此方法中remove item等.    //我们这里需要对滑动过后的View,进行恢复操作.     viewHolder.itemView.setRotation(0);//恢复最后一次的旋转状态    if (mSwipeListener != null) {      mSwipeListener.onSwipeTo(viewHolder, 0);    }    notifyListener(viewHolder.getAdapterPosition(), direction);  }  private void notifyListener(int position, int direction) {    Log.w(TAG, "onSwiped: " + position + " " + direction);    if (mSwipeListener != null) {      mSwipeListener.onSwiped(position, direction);    }  }  @Override  public float getSwipeThreshold(RecyclerView.ViewHolder viewHolder) {    //滑动的比例达到多少之后, 视为滑动    return 0.3f;  }  @Override  public void onChildDraw(Canvas c, RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, float dX, float dY, int actionState, boolean isCurrentlyActive) {    super.onChildDraw(c, recyclerView, viewHolder, dX, dY, actionState, isCurrentlyActive);    //当你在滑动的过程中, 此方法一直会被回调, 就跟onTouch事件一样...    //先根据滑动的dx dy 算出现在动画的比例系数fraction    float swipeValue = (float) Math.sqrt(dX * dX + dY * dY);    final float threshold = getThreshold(recyclerView, viewHolder);    float fraction = swipeValue / threshold;    //边界修正 最大为1    if (fraction > 1) {      fraction = 1;    } else if (fraction < -1) {      fraction = -1;    }    //对每个ChildView进行缩放 位移    int childCount = recyclerView.getChildCount();    for (int i = 0; i < childCount; i++) {      View child = recyclerView.getChildAt(i);      //第几层,举例子，count =7， 最后一个TopView（6）是第0层，      int level = childCount - i - 1;      if (level > 0) {        child.setScaleX(1 - SCALE_GAP * level + fraction * SCALE_GAP);        if (level < MAX_SHOW_COUNT - 1) {          child.setScaleY(1 - SCALE_GAP * level + fraction * SCALE_GAP);          child.setTranslationY(TRANS_Y_GAP * level - fraction * TRANS_Y_GAP);        } else {          //child.setTranslationY((float) (mTranslationYGap * (level - 1) - fraction * mTranslationYGap));        }      } else {        //最上层        //rotate        if (dX < -50) {          child.setRotation(-fraction * MAX_ROTATION);        } else if (dX > 50) {          child.setRotation(fraction * MAX_ROTATION);        } else {          child.setRotation(0);        }        if (mSwipeListener != null) {          RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child.getLayoutParams();          final int adapterPosition = params.getViewAdapterPosition();          mSwipeListener.onSwipeTo(recyclerView.findViewHolderForAdapterPosition(adapterPosition), dX);        }      }    }  }  //扩展实现:点击按钮实现左滑效果  public void toLeft(RecyclerView recyclerView) {    if (check(recyclerView)) {      animTo(recyclerView, false);    }  }  //扩展实现:点击按钮实现右滑效果  public void toRight(RecyclerView recyclerView) {    if (check(recyclerView)) {      animTo(recyclerView, true);    }  }  private void animTo(final RecyclerView recyclerView, boolean right) {    final int position = recyclerView.getAdapter().getItemCount() - 1;    final View view = recyclerView.findViewHolderForAdapterPosition(position).itemView;    TranslateAnimation translateAnimation = new TranslateAnimation(Animation.RELATIVE_TO_SELF, 0,        Animation.RELATIVE_TO_SELF, right ? 1f : -1f,        Animation.RELATIVE_TO_SELF, 0f, Animation.RELATIVE_TO_SELF, 1.3f);    translateAnimation.setFillAfter(true);    translateAnimation.setDuration(300);    translateAnimation.setInterpolator(new DecelerateInterpolator());    translateAnimation.setAnimationListener(new Animation.AnimationListener() {      @Override      public void onAnimationStart(Animation animation) {      }      @Override      public void onAnimationEnd(Animation animation) {        isSwipeAnim = false;        recyclerView.removeView(view);        notifyListener(position,            x > view.getMeasuredWidth() / 2                ?                ItemTouchHelper.RIGHT : ItemTouchHelper.LEFT);      }      @Override      public void onAnimationRepeat(Animation animation) {      }    });    view.startAnimation(translateAnimation);  }  private boolean check(RecyclerView recyclerView) {    if (isSwipeAnim) {      return false;    }    if (recyclerView == null || recyclerView.getAdapter() == null) {      return false;    }    if (recyclerView.getAdapter().getItemCount() == 0) {      return false;    }    isSwipeAnim = true;    return true;  }  public interface OnSwipeListener {    /**     * @param direction {@link ItemTouchHelper#LEFT} / {@link ItemTouchHelper#RIGHT}     *         {@link ItemTouchHelper#UP} or {@link ItemTouchHelper#DOWN}).     */    void onSwiped(int adapterPosition, int direction);    /**     * 最上层View滑动时回调.     *     * @param viewHolder 最上层的ViewHolder     * @param offset   距离原始位置的偏移量     */    void onSwipeTo(RecyclerView.ViewHolder viewHolder, float offset);  }  public static class SimpleSwipeCallback implements OnSwipeListener {    /**     * {@inheritDoc}     */    @Override    public void onSwiped(int adapterPosition, int direction) {    }    /**     * {@inheritDoc}     */    @Override    public void onSwipeTo(RecyclerView.ViewHolder viewHolder, float offset) {    }  }}

<LinearLayout  xmlns:android="http://schemas.android.com/apk/res/android"  android:layout_width="wrap_content"  android:layout_height="wrap_content"  android:layout_gravity="center_horizontal|bottom"  android:layout_marginBottom="20dp"  android:orientation="horizontal">  <ImageView    android:id="@+id/left"    android:layout_width="wrap_content"    android:layout_height="wrap_content"    android:layout_gravity="center"    android:layout_margin="10dp"    android:background="@drawable/home_buttons_dislike"    android:onClick="left" />  <ImageView    android:id="@+id/info"    android:layout_width="wrap_content"    android:layout_height="wrap_content"    android:layout_gravity="center"    android:layout_margin="10dp"    android:background="@drawable/home_buttons_info" />  <ImageView    android:id="@+id/right"    android:layout_width="wrap_content"    android:layout_height="wrap_content"    android:layout_margin="10dp"    android:background="@drawable/home_buttons_like"    /></LinearLayout>

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"  android:layout_width="wrap_content"  android:layout_height="wrap_content"  android:layout_gravity="center_horizontal|bottom"  android:layout_marginBottom="20dp"  android:orientation="horizontal">  <ImageView    android:id="@+id/left"    android:layout_width="wrap_content"    android:layout_height="wrap_content"    android:layout_gravity="center"    android:layout_margin="10dp"    android:background="@drawable/home_buttons_dislike"    android:onClick="left" />  <ImageView    android:id="@+id/info"    android:layout_width="wrap_content"    android:layout_height="wrap_content"    android:layout_gravity="center"    android:layout_margin="10dp"    android:background="@drawable/home_buttons_info" />  <ImageView    android:id="@+id/right"    android:layout_width="wrap_content"    android:layout_height="wrap_content"    android:layout_margin="10dp"    android:background="@drawable/home_buttons_like"    /></LinearLayout>

    flingContainer = (SwipeFlingAdapterView) findViewById(R.id.frame);   //设置适配器    flingContainer.setAdapter(adapter);    flingContainer.setFlingListener(new SwipeFlingAdapterView.onFlingListener() {      @Override      public void removeFirstObjectInAdapter() {        al.remove(0);        adapter.notifyDataSetChanged();      }      @Override      public void onLeftCardExit(Object dataObject) {        makeToast(MainActivity.this, "不喜欢");      }      @Override      public void onRightCardExit(Object dataObject) {        makeToast(MainActivity.this, "喜欢");      }      @Override      public void onAdapterAboutToEmpty(int itemsInAdapter) {        al.add(new CardMode("循环测试", 18, list.get(itemsInAdapter % imageUrls.length - 1)));        adapter.notifyDataSetChanged();        i++;      }      @Override      public void onScroll(float scrollProgressPercent) {        View view = flingContainer.getSelectedView();        view.findViewById(R.id.item_swipe_right_indicator).setAlpha(scrollProgressPercent < 0 ? -scrollProgressPercent : 0);        view.findViewById(R.id.item_swipe_left_indicator).setAlpha(scrollProgressPercent > 0 ? scrollProgressPercent : 0);      }    });