Android imitiert den seitlich verschiebbaren Löscheffekt von QQ WeChat

public class DragDelListView extends ListView {
 
  private boolean moveable=false;
  private boolean closed=true;
  private float mDownX,mDownY;
  private int mTouchPosition,oldPosition=-1;
  private DragDelItem mTouchView,oldView;
  private Context context;
  public DragDelListView(Context context) {
    super(context);
    init(context);
  }
  public DragDelListView(Context context, AttributeSet attrs, int defStyle) {
    super(context, attrs, defStyle);
    init(context);
  }
  public DragDelListView(Context context, AttributeSet attrs) {
    super(context, attrs);
    init(context);
  }
  private void init(Context context) {
    this.context=context;
  }
 
 
  @Override
  public boolean onTouchEvent(MotionEvent ev) {
    switch (ev.getAction()) {
    case MotionEvent.ACTION_DOWN:
      mTouchPosition = pointToPosition((int) ev.getX(), (int) ev.getY());
      mTouchView=(DragDelItem)getChildAt(mTouchPosition - getFirstVisiblePosition());
      mDownX = ev.getX();
      mDownY=ev.getY();
      if(oldPosition==mTouchPosition ||closed)
      {
        moveable=true;
        mTouchView.mDownX =(int)mDownX;
      }else
      {
        moveable=false;
        if(oldView!=null)
        {
          oldView.smoothCloseMenu();
        }
      }
      oldPosition=mTouchPosition;
      oldView=mTouchView;
      break;
    case MotionEvent.ACTION_MOVE:
      if (Math.abs(mDownX-ev.getX()) < Math.abs(mDownY-ev.getY()) * dp2px(2)) {
        break; 
      } 
      if (moveable) 
      {
        int dis = (int) (mTouchView.mDownX -ev.getX());
        if(mTouchView.state==mTouchView.STATE_OPEN)
          dis+=mTouchView.mMenuView.getWidth();
        mTouchView.swipe(dis);
        ev.setAction(MotionEvent.ACTION_CANCEL);
      }
 
      break;
    case MotionEvent.ACTION_UP:
 
      if (moveable) 
      {
        if ((mTouchView.mDownX -ev.getX()) > (mTouchView.mMenuView.getWidth()/2)) {
          // open
          mTouchView.smoothOpenMenu();
          closed=false;
        } else {
          // close
          mTouchView.smoothCloseMenu();
          closed=true;
        }
        ev.setAction(MotionEvent.ACTION_CANCEL);
      }
      break;
    }
    return super.onTouchEvent(ev);
  }
 
  private int dp2px(int dp) {
    return (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, dp,
        getContext().getResources().getDisplayMetrics());
  }
 
 
}

public class DragDelItem extends LinearLayout {
 
  public static final int STATE_CLOSE = 0;
  public static final int STATE_OPEN = 1;
  private View mContentView;
  public View mMenuView;
  public int mDownX;
  public int state = STATE_CLOSE;
  public boolean isFling;
  private int mBaseX;
  private Scroller scroll;
 
  public DragDelItem(View contentView, View menuView) {
    super(contentView.getContext());
    scroll=new Scroller(getContext());
    mContentView = contentView;
    mMenuView = menuView;
    init();
  }
 
  private DragDelItem(Context context, AttributeSet attrs) {
    super(context, attrs);
  }
 
  private DragDelItem(Context context) {
    super(context);
  }
 
 
  private void init() {
    setLayoutParams(new AbsListView.LayoutParams(LayoutParams.MATCH_PARENT,
        LayoutParams.WRAP_CONTENT));
    LayoutParams contentParams = new LayoutParams(
        LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
    mContentView.setLayoutParams(contentParams);
 
    mMenuView.setLayoutParams(new LayoutParams(LayoutParams.WRAP_CONTENT,
        LayoutParams.WRAP_CONTENT));
 
    addView(mContentView);
    addView(mMenuView);
 
  }
 
 
  public void swipe(int dis) {
    if (dis > mMenuView.getWidth()) {
      dis = mMenuView.getWidth();
    }
    if (dis < 0) {
      dis = 0;
    }
    mContentView.layout(-dis, mContentView.getTop(),
        mContentView.getWidth() - dis, getMeasuredHeight());
    mMenuView.layout(mContentView.getWidth() - dis, mMenuView.getTop(),
        mContentView.getWidth() + mMenuView.getWidth() - dis,
        mMenuView.getBottom());
  }
 
  @Override
  public void computeScroll() {
    if (state == STATE_OPEN) {
      if (scroll.computeScrollOffset()) {
        swipe(scroll.getCurrX());
        postInvalidate();
      }
    } else {
      if (scroll.computeScrollOffset()) {
        swipe(mBaseX - scroll.getCurrX());
        postInvalidate();
      }
    }
  }
 
  public void smoothCloseMenu() {
    state = STATE_CLOSE;
    mBaseX = -mContentView.getLeft();
    scroll.startScroll(0, 0, mBaseX, 0, 350);
    postInvalidate();
  }
 
  public void smoothOpenMenu() {
 
    state = STATE_OPEN;
    scroll.startScroll(-mContentView.getLeft(), 0,
        mMenuView.getWidth()/2, 0, 350);
    postInvalidate();
  }
 
  @Override
  protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    super.onMeasure(widthMeasureSpec, heightMeasureSpec);
 
    mMenuView.measure(MeasureSpec.makeMeasureSpec(0,
        MeasureSpec.UNSPECIFIED), MeasureSpec.makeMeasureSpec(
        getMeasuredHeight(), MeasureSpec.EXACTLY));
    mContentView.measure(MeasureSpec.makeMeasureSpec(0,
        MeasureSpec.UNSPECIFIED), MeasureSpec.makeMeasureSpec(
        getMeasuredHeight(), MeasureSpec.EXACTLY));
 
  }
 
  @Override
  protected void onLayout(boolean changed, int l, int t, int r, int b) {
    mContentView.layout(0, 0, getMeasuredWidth(),
        mContentView.getMeasuredHeight());
    mMenuView.layout(getMeasuredWidth(), 0,
        getMeasuredWidth() + mMenuView.getMeasuredWidth(),
        mContentView.getMeasuredHeight());
 
  }
 
}

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
  android:id="@+id/rl_layout"
  android:layout_width="match_parent"
  android:layout_height="wrap_content"
  android:background="#999999"
  android:padding="8dp" >
    <ImageView
      android:id="@+id/iv_icon"
      android:layout_width="50dp"
      android:layout_height="50dp"
      android:src="@drawable/ic_launcher" />
 
    <TextView
      android:id="@+id/tv_name"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_centerVertical="true"
      android:layout_marginLeft="10dp"
      android:layout_toRightOf="@+id/iv_icon"
      android:text="name"
      android:textColor="@android:color/black"
      android:textSize="18sp" />
</RelativeLayout>
 
—swipemenu.xml代码
 
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
  android:layout_width="wrap_content"
  android:layout_height="match_parent"
  android:orientation="horizontal"
  >
 
  <TextView
    android:id="@+id/tv_open"
    android:layout_width="90dp"
    android:layout_height="match_parent"
    android:gravity="center"
    android:background="#C2C2C2"
    android:text="置顶"
    android:textColor="@android:color/white"
    android:textSize="18sp" />
  <TextView
    android:id="@+id/tv_del"
    android:layout_width="90dp"
    android:layout_height="match_parent"
    android:gravity="center"
    android:background="#FF0000"
    android:text="删除"
    android:textColor="@android:color/white"
    android:textSize="18sp" />
 
</LinearLayout>

public class MainActivity extends Activity {
  private List<ApplicationInfo> mAppList;
  private DragDelListView mListView;
  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_list);
 
    mAppList = getPackageManager().getInstalledApplications(0);
    mListView = (DragDelListView) findViewById(R.id.listView);
    mListView.setAdapter(new AppAdapter(mAppList));
  }
  class AppAdapter extends BaseAdapter {
    private List<ApplicationInfo> mAppList;
    public AppAdapter(List<ApplicationInfo> appList)
    {
      mAppList=appList;
    }
    @Override
    public int getCount() {
      return mAppList.size();
    }
 
    @Override
    public ApplicationInfo getItem(int position) {
      return mAppList.get(position);
    }
 
    @Override
    public long getItemId(int position) {
      return position;
    }
 
    @Override
    public View getView(final int position, View convertView, ViewGroup parent) {
 
      ViewHolder holder=null;
      View menuView=null;
      if (convertView == null) {
        convertView = View.inflate(getApplicationContext(),
            R.layout.swipecontent, null);
        menuView = View.inflate(getApplicationContext(),
            R.layout.swipemenu, null);
        convertView = new DragDelItem(convertView,menuView);
        holder=new ViewHolder(convertView);
      } else {
        holder = (ViewHolder) convertView.getTag();
      }
        ApplicationInfo item = getItem(position);
        holder.iv_icon.setImageDrawable(item.loadIcon(getPackageManager()));
        holder.tv_name.setText(item.loadLabel(getPackageManager()));
        holder.tv_open.setOnClickListener(new View.OnClickListener() {
          @Override
          public void onClick(View arg0) {
            Toast.makeText(MainActivity.this, "置顶:"+position, Toast.LENGTH_SHORT).show();
          }
        });
        holder.tv_del.setOnClickListener(new View.OnClickListener() {
 
          @Override
          public void onClick(View arg0) {
            Toast.makeText(MainActivity.this, "删除:"+position, Toast.LENGTH_SHORT).show();
          }
        });
      return convertView;
    }
 
    class ViewHolder {
      ImageView iv_icon;
      TextView tv_name;
      TextView tv_open,tv_del;
      RelativeLayout relativeLayout;
      public ViewHolder(View view) {
        iv_icon = (ImageView) view.findViewById(R.id.iv_icon);
        tv_name = (TextView) view.findViewById(R.id.tv_name);
        tv_open=(TextView)view.findViewById(R.id.tv_open);
        tv_del=(TextView)view.findViewById(R.id.tv_del);
        relativeLayout = (RelativeLayout) view.findViewById(R.id.rl_layout);
        //改变relativeLayout宽度
        WindowManager wm = (WindowManager) getApplicationContext().getSystemService(Context.WINDOW_SERVICE);
        int width = wm.getDefaultDisplay().getWidth();
        relativeLayout.setMinimumWidth(width-60);
        view.setTag(this);
      }
    }
  }
}

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  >
 
    <com.draglistview.DragDelListView
      android:id="@+id/listView"
      android:layout_width="match_parent"
      android:layout_height="match_parent" />
 
</RelativeLayout>