Android实现跟随手指拖动并自动贴边的View样式的实例

/**

 * 根据手指拖动的当前位置，自动贴边的View

 */

publicclassDragViewextendsImageViewimplementsView.OnTouchListener{

 privateintscreenWidth;

 privateintscreenHeight;

 privateContext mContext;

 privateintlastX, lastY;

 privateintleft ,top;

 privateViewGroup.MarginLayoutParams layoutParams;

 privateintstartX;

 privateintendX;

 privatebooleanisMoved =false;

 privateonDragViewClickListener mLister;

 publicinterfaceonDragViewClickListener{

  voidonDragViewClick();

 }

 publicvoidsetOnDragViewClickListener(onDragViewClickListener listener){

  this.mLister = listener;

 }

 publicDragView(Context context) {

  this(context,null);

 }

 publicDragView(Context context, AttributeSet attrs) {

  super(context, attrs);

  mContext = context;

  DisplayMetrics displayMetrics = getResources().getDisplayMetrics();

  screenWidth = displayMetrics.widthPixels;

  screenHeight = displayMetrics.heightPixels-getStatusBarHeight();

  init();

 }

 publicvoidinit(){

  setOnTouchListener(this);

  post(newRunnable() {

   @Override

   publicvoidrun() {

    layoutParams = (ViewGroup.MarginLayoutParams)getLayoutParams();

    layoutParams.topMargin = screenHeight - getHeight();

    layoutParams.leftMargin = screenWidth - getWidth();

    setLayoutParams(layoutParams);

   }

  });

 }

 @Override

 publicbooleanonTouch(View v, MotionEvent event) {

  switch(event.getAction()) {

   caseMotionEvent.ACTION_DOWN:

    lastX = (int) event.getRawX();

    lastY = (int) event.getRawY();

    startX = lastX;

    break;

   caseMotionEvent.ACTION_MOVE:

    isMoved =true;

    intdx = (int) event.getRawX() - lastX;

    intdy = (int) event.getRawY() - lastY;

    left = v.getLeft() + dx;

    top = v.getTop() + dy;

    intright = v.getRight() + dx;

    intbottom = v.getBottom() + dy;

    // 设置不能出界

    if(left <0) {

     left =0;

     right = left + v.getWidth();

    }

    if(right > screenWidth) {

     right = screenWidth;

     left = right - v.getWidth();

    }

    if(top <0) {

     top =0;

     bottom = top + v.getHeight();

    }

    if(bottom > screenHeight) {

     bottom = screenHeight;

     top = bottom - v.getHeight();

    }

    v.layout(left, top, right, bottom );

    lastX = (int) event.getRawX();

    lastY = (int) event.getRawY();

    break;

   caseMotionEvent.ACTION_UP:

    //只有滑动改变上边距时，抬起才进行设置

    if(isMoved) {

     layoutParams = (ViewGroup.MarginLayoutParams)getLayoutParams();

     layoutParams.topMargin = top;

     setLayoutParams(layoutParams);

    }

    endX = (int) event.getRawX();

    //滑动距离比较小，当作点击事件处理

    if(Math.abs(startX - endX) <6) {

     returnfalse;

    }

    if(left +v.getWidth()/2< screenWidth/2) {

     startScroll(left,screenWidth/2,true);

    }else{

     startScroll(left,screenWidth/2,false);

    }

    break;

  }

  returntrue;

}

 //在此处理点击事件

 @Override

 publicbooleanonTouchEvent(MotionEvent event) {

  mLister.onDragViewClick();

  returnsuper.onTouchEvent(event);

 }

 publicvoidstartScroll(finalintstart,intend,finalbooleanisLeft){

  ValueAnimator valueAnimator = ValueAnimator.ofFloat(start,end).setDuration(800);

  valueAnimator.addUpdateListener(newValueAnimator.AnimatorUpdateListener() {

   @Override

   publicvoidonAnimationUpdate(ValueAnimator animation) {

    if(isLeft) {

     layoutParams.leftMargin = (int) (start*(1-animation.getAnimatedFraction()));

    }else{

     layoutParams.leftMargin = (int) (start + (screenWidth - start - getWidth())*(animation.getAnimatedFraction()));

    }

    setLayoutParams(layoutParams);

   }

  });

  valueAnimator.start();

 }

 /**

  * 获取状态栏的高度

  * @return 状态栏高度

  */

 publicintgetStatusBarHeight() {

  intresult =0;

  intresourceId = getResources().getIdentifier("status_bar_height","dimen","android");

  if(resourceId >0) {

   result = getResources().getDimensionPixelSize(resourceId);

  }

  returnresult;

 }

}

publicstaticintcalculateVolume(byte[] var0,intvar1) {

    int[] var3 =null;

    intvar4 = var0.length;

    intvar2;

    if(var1 ==8) {

      var3 =newint[var4];

      for(var2 =0; var2 < var4; ++var2) {

        var3[var2] = var0[var2];

      }

    }elseif(var1 ==16) {

      var3 =newint[var4 /2];

      for(var2 =0; var2 < var4 /2; ++var2) {

        bytevar5 = var0[var2 *2];

        bytevar6 = var0[var2 *2+1];

        intvar13;

        if(var5<0) {

          var13 = var5 +256;

        }else{

          var13 = var5;

        }

        shortvar7 = (short)(var13 +0);

        if(var6<0) {

          var13 = var6 +256;

        }else{

          var13 = var6;

        }

        var3[var2] = (short)(var7 + (var13 <<8));

      }

    }

    int[] var8 = var3;

    if(var3 !=null&& var3.length !=0) {

      floatvar10 =0.0F;

      for(intvar11 =0; var11 < var8.length; ++var11) {

        var10 += (float)(var8[var11] * var8[var11]);

      }

      var10 /= (float)var8.length;

      floatvar12 =0.0F;

      for(var4 =0; var4 < var8.length; ++var4) {

        var12 += (float)var8[var4];

      }

      var12 /= (float)var8.length;

      var4 = (int)(Math.pow(2.0D, (double)(var1 -1)) -1.0D);

      doublevar14 = Math.sqrt((double)(var10 - var12 * var12));

      intvar9;

      if((var9 = (int)(10.0D * Math.log10(var14 *10.0D * Math.sqrt(2.0D) / (double)var4 +1.0D)))<0) {

        var9 =0;

      }

      if(var9 >10) {

        var9 =10;

      }

      returnvar9;

    }else{

      return0;

    }

}

//activity的xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"

  xmlns:tools="http://schemas.android.com/tools"

  android:id="@+id/activity_main"

  android:layout_width="match_parent"

  android:layout_height="match_parent"

  tools:context="baway.com.cj.myrecyclerview2.MainActivity">

  <android.support.v4.widget.SwipeRefreshLayout

    android:id="@+id/swipeRefreshLayout"

    android:layout_width="match_parent"

    android:layout_above="@+id/progress"

    android:layout_height="match_parent">

    <android.support.v7.widget.RecyclerView

      android:id="@+id/recyclerView"

      android:layout_width="match_parent"

      android:layout_height="match_parent">

  <ProgressBar

    android:id="@+id/progress"

    android:layout_width="wrap_content"

    android:layout_height="wrap_content"

    android:layout_centerHorizontal="true"

    android:visibility="gone"

    android:layout_alignParentBottom="true"/>

item1的xml和item2的xml就一个背景颜色不同

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"

  xmlns:tools="http://schemas.android.com/tools"

  android:id="@+id/activity_main"

  android:layout_width="match_parent"

  android:layout_height="match_parent"

  android:background="#f00000"

  tools:context="baway.com.cj.myrecyclerview2.MainActivity">

  <TextView

    android:id="@+id/name"

    android:layout_width="match_parent"

    android:layout_height="50dp"

    android:textSize="20sp"

    android:gravity="center"

    android:textColor="#00ff00"/>

item2

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"

  xmlns:tools="http://schemas.android.com/tools"

  android:id="@+id/activity_main"

  android:layout_width="match_parent"

  android:layout_height="match_parent"

  android:background="#f000ff"

  tools:context="baway.com.cj.myrecyclerview2.MainActivity">

  <TextView

    android:id="@+id/name"

    android:layout_width="match_parent"

    android:layout_height="50dp"

    android:textSize="20sp"

    android:gravity="center"

    android:textColor="#00ff00"/>

//activity,有上啦下拉，添加分割线，

packagebaway.com.cj.myrecyclerview2;

importandroid.graphics.Color;

importandroid.os.Handler;

importandroid.support.v4.widget.SwipeRefreshLayout;

importandroid.support.v7.app.AppCompatActivity;

importandroid.os.Bundle;

importandroid.support.v7.widget.DefaultItemAnimator;

importandroid.support.v7.widget.LinearLayoutManager;

importandroid.support.v7.widget.RecyclerView;

importandroid.util.Log;

importandroid.view.View;

importandroid.widget.ProgressBar;

importandroid.widget.Toast;

importjava.util.ArrayList;

publicclassMainActivityextendsAppCompatActivity {

  privateRecyclerView recyclerView;

  privateMainAdapter mainAdapter;

  privateSwipeRefreshLayout swipeRefreshLayout;

  privateLinearLayoutManager linearLayoutManager;

  privateProgressBar progress;

  @Override

  protectedvoidonCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);

    setContentView(R.layout.activity_main);

    initView();

    initData();

  }

  privatevoidinitView() {

    recyclerView = (RecyclerView)findViewById(R.id.recyclerView);

    swipeRefreshLayout = (SwipeRefreshLayout) findViewById(R.id.swipeRefreshLayout);

    progress = (ProgressBar)findViewById(R.id.progress);

    linearLayoutManager =newLinearLayoutManager(this);

    recyclerView.setLayoutManager(linearLayoutManager);

    mainAdapter =newMainAdapter(this);

    mainAdapter.setOnClickListener(newMyItemOnClickListener() {

      @Override

      publicvoidonItemClick(View view,intposition) {

        Toast.makeText(MainActivity.this," "+position, Toast.LENGTH_SHORT).show();

      }

    });

    recyclerView.setAdapter(mainAdapter);

    recyclerView.addItemDecoration(newMyItemDecoration());

    recyclerView.setItemAnimator(newDefaultItemAnimator());

    swipeRefreshLayout.setColorSchemeColors(Color.RED,Color.GREEN,Color.BLUE);

    swipeRefreshLayout.setProgressViewOffset(true,0,200);

    swipeRefreshLayout.setOnRefreshListener(newSwipeRefreshLayout.OnRefreshListener() {

      @Override

      publicvoidonRefresh() {

        newHandler().postDelayed(newRunnable() {

          @Override

          publicvoidrun() {

            swipeRefreshLayout.setRefreshing(false);

          }

        },3000);

      }

    });

    recyclerView.addOnScrollListener(newRecyclerView.OnScrollListener() {

      @Override

      publicvoidonScrolled(RecyclerView recyclerView,intdx,intdy) {

        super.onScrolled(recyclerView, dx, dy);

        intlastVisibleItemPosition = linearLayoutManager.findLastVisibleItemPosition();

        intitemCount = linearLayoutManager.getItemCount();

        if(lastVisibleItemPosition +1>= itemCount && dy >0) {

          progress.setVisibility(View.VISIBLE);

          newHandler().postDelayed(newRunnable() {

            @Override

            publicvoidrun() {

              progress.setVisibility(View.GONE);

            }

          },3000);

        }

      }

      @Override

      publicvoidonScrollStateChanged(RecyclerView recyclerView,intnewState) {

        super.onScrollStateChanged(recyclerView, newState);

      }

    });

  }

  privatevoidinitData() {

    ArrayListstrings =newArrayList<>();

    for(inti =0; i<50; i++) {

      strings.add("name "+i);

    }

    mainAdapter.setData(strings);

    mainAdapter.notifyDataSetChanged();

  }

}

//adpter有多条目展示

packagebaway.com.cj.myrecyclerview2;

importandroid.content.Context;

importandroid.support.v7.widget.RecyclerView;

importandroid.view.LayoutInflater;

importandroid.view.View;

importandroid.view.ViewGroup;

importandroid.widget.TextView;

importjava.util.ArrayList;

/**

 * Created by cj on 2017/1/12.

 */

publicclassMainAdapterextendsRecyclerView.Adapter {

  privateContext context;

  privateArrayListdatas =newArrayList<>();

  privateMyItemOnClickListener myItemOnClickListener;

  privatefinalintTYPE_0 =0;

  privatefinalintTYPE_1 =1;

  publicMainAdapter(Context context) {

    this.context = context;

  }

  @Override

  publicintgetItemViewType(intposition) {

    if(position %3==0) {

      returnTYPE_0;

    }else{

      returnTYPE_1;

    }

  }

  publicvoidsetOnClickListener(MyItemOnClickListener onClickListener) {

    this.myItemOnClickListener = onClickListener;

  }

  @Override

  publicRecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent,intviewType) {

    if(viewType == TYPE_0) {

      View inflate = LayoutInflater.from(context).inflate(R.layout.item_main,null);

      returnnewMyViewHolder(inflate);

    }else{

      View inflate = LayoutInflater.from(context).inflate(R.layout.item_main2,null);

      returnnewMyViewHolder2(inflate);

    }

  }

  @Override

  publicvoidonBindViewHolder(RecyclerView.ViewHolder holder,finalintposition) {

    if(getItemViewType(position) == TYPE_0) {

      MyViewHolder myViewHolder = (MyViewHolder)holder;

      myViewHolder.name.setText(datas.get(position));

      myViewHolder.name.setOnClickListener(newView.OnClickListener() {

        @Override

        publicvoidonClick(View v) {

          myItemOnClickListener.onItemClick(v,position);

        }

      });

    }else{

      MyViewHolder2 myViewHolder = (MyViewHolder2)holder;

      myViewHolder.name.setText(datas.get(position));

      myViewHolder.name.setOnClickListener(newView.OnClickListener() {

        @Override

        publicvoidonClick(View v) {

          myItemOnClickListener.onItemClick(v,position);

        }

      });

    }

  }

  @Override

  publicintgetItemCount() {

    returndatas.size();

  }

  publicvoidsetData(ArrayListdata) {

    if(data ==null) {

      return;

    }

    this.datas.addAll(data);

  }

  publicclassMyViewHolderextendsRecyclerView.ViewHolder{

    publicTextView name;

    publicMyViewHolder(View itemView) {

      super(itemView);

      name = (TextView) itemView.findViewById(R.id.name);

    }

  }

  publicclassMyViewHolder2extendsRecyclerView.ViewHolder{

    publicTextView name;

    publicMyViewHolder2(View itemView) {

      super(itemView);

      name = (TextView) itemView.findViewById(R.id.name);

    }

  }

}

//自定义分割线继承系统的 RecyclerView.ItemDecoration

packagebaway.com.cj.myrecyclerview2;

importandroid.graphics.Canvas;

importandroid.graphics.Color;

importandroid.graphics.Paint;

importandroid.graphics.Rect;

importandroid.support.v7.widget.RecyclerView;

importandroid.util.Log;

importandroid.view.View;

/**

 * Created by cj on 2017/1/12.

 */

publicclassMyItemDecorationextendsRecyclerView.ItemDecoration {

  privatePaint paint;

  publicMyItemDecoration() {

    paint =newPaint();

    paint.setColor(Color.BLUE);

  }

  @Override

  publicvoidonDraw(Canvas c, RecyclerView parent, RecyclerView.State state) {

    super.onDraw(c, parent, state);

    //c.drawCircle(300,300,300,paint);

    intchildCount = parent.getChildCount();

    for(inti =0; i < childCount; i++) {

      View childAt = parent.getChildAt(i);

      c.drawRect(childAt.getLeft(),childAt.getBottom(),childAt.getWidth()+childAt.getLeft(),childAt.getBottom()+5,paint);

    }

  }

  @Override

  publicvoidonDrawOver(Canvas c, RecyclerView parent, RecyclerView.State state) {

    super.onDrawOver(c, parent, state);

//    int childCount = parent.getChildCount();

//    for (int i = 0; i < childCount; i++) {

//      View childAt = parent.getChildAt(i);

//      c.drawRect(childAt.getLeft(),childAt.getTop(),childAt.getWidth()+childAt.getLeft(),childAt.getBottom()+5,paint);

//    }

  }

  @Override

  publicvoidgetItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {

    super.getItemOffsets(outRect, view, parent, state);

    outRect.set(20,0,20,5);

  }

}