利用ViewDragHelper打造悬浮球效果

来源：互联网发布：linux 链接文件夹编辑：程序博客网时间：2024/04/28 11:53

效果图
这里写图片描述

自定义布局

import android.content.Context;import android.graphics.Point;import android.support.v4.widget.ViewDragHelper;import android.util.AttributeSet;import android.view.MotionEvent;import android.view.View;import android.widget.RelativeLayout;/** * Created by yebin on 2016/12/8. */public class VDHLayout extends RelativeLayout{    private View autoBackView;    private ViewDragHelper mDragger;    private Point mAutoBackOriginPos=new Point();    private int mWidth;    private int mHeight;    public VDHLayout(Context context, AttributeSet attrs) {        super(context, attrs);    }    public void addBackView(View view){        this.autoBackView=view;        if(autoBackView!=null){            addView(autoBackView);            inintViewDragHelper();        }    }    private void inintViewDragHelper() {        mDragger=ViewDragHelper.create(this, 1.0f, new ViewDragHelper.Callback() {            @Override            public boolean tryCaptureView(View child, int pointerId) {                return child==autoBackView;            }            @Override            public int clampViewPositionHorizontal(View child, int left, int dx) {                int leftBound=getPaddingLeft();                int rightBound=getWidth()-child.getWidth()-leftBound;                int newLeft=Math.min(Math.max(left,leftBound),rightBound);                return newLeft;            }            @Override            public int clampViewPositionVertical(View child, int top, int dy) {                int topBound=getPaddingTop();                int bottomBound=getHeight()-child.getHeight()-topBound;                int newTop=Math.min(Math.max(top,topBound),bottomBound);                return newTop;            }            @Override            public void onViewPositionChanged(View changedView, int left, int top, int dx, int dy) {                super.onViewPositionChanged(changedView, left, top, dx, dy);                if(changedView==autoBackView){                    mAutoBackOriginPos.y=top;                    if(left<mWidth/2){                        mAutoBackOriginPos.x=0;                    }else{                        mAutoBackOriginPos.x=mWidth-autoBackView.getWidth();                    }                }            }            @Override            public int getViewHorizontalDragRange(View child) {                return getMeasuredWidth()-child.getMeasuredWidth();            }            @Override            public int getViewVerticalDragRange(View child) {                return getMeasuredHeight()-child.getMeasuredHeight();            }            @Override            public void onViewReleased(View releasedChild, float xvel, float yvel) {                if(releasedChild==autoBackView){                    mDragger.settleCapturedViewAt(mAutoBackOriginPos.x,mAutoBackOriginPos.y);                    invalidate();                }            }        });    }    @Override    public void computeScroll() {      //  super.computeScroll();        if(mDragger!=null){            if(mDragger.continueSettling(true)){                invalidate();            }        }    }    @Override    public boolean onTouchEvent(MotionEvent event) {        if(mDragger!=null){            mDragger.processTouchEvent(event);        }        return true;    }    @Override    public boolean onInterceptTouchEvent(MotionEvent ev) {        return mDragger!=null?mDragger.shouldInterceptTouchEvent(ev):super.onInterceptTouchEvent(ev);    }    @Override    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {        super.onMeasure(widthMeasureSpec, heightMeasureSpec);    }    @Override    protected void onLayout(boolean changed, int l, int t, int r, int b) {        super.onLayout(changed, l, t, r, b);        mWidth=getWidth();        mHeight=getHeight();    }}

XML布局文件

<?xml version="1.0" encoding="utf-8"?><com.example.xunfuqiu.VDHLayout    xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:id="@+id/rl_content"    >    <TextView        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:gravity="center"        android:text="Hello World!" />    <ImageView        android:layout_width="200dp"        android:layout_height="200dp"        android:src="@mipmap/ic_launcher"        android:layout_centerInParent="true"        />    <EditText        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:hint="请输入文字。。。"        android:textSize="16sp"        android:layout_alignParentBottom="true"        android:layout_marginBottom="20dp"        /></com.example.xunfuqiu.VDHLayout>

MainActivty使用

import android.support.v7.app.AppCompatActivity;import android.os.Bundle;import android.util.Log;import android.view.View;import android.view.ViewGroup;import android.view.WindowManager;import android.widget.ImageView;import android.widget.RelativeLayout;import android.widget.Toast;public class MainActivity extends AppCompatActivity {    private VDHLayout layout;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        layout = ((VDHLayout) this.findViewById(R.id.rl_content));        ImageView iv=new ImageView(this);        RelativeLayout.LayoutParams params=new RelativeLayout.LayoutParams(             RelativeLayout.LayoutParams.WRAP_CONTENT,             RelativeLayout.LayoutParams.WRAP_CONTENT);        iv.setImageResource(R.mipmap.ic_launcher);        params.addRule(RelativeLayout.ALIGN_PARENT_RIGHT);        params.addRule(RelativeLayout.CENTER_VERTICAL);        iv.setLayoutParams(params);        iv.bringToFront();        layout.addBackView(iv);        iv.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                Toast.makeText(MainActivity.this, "00000000000000", Toast.LENGTH_SHORT).show();            }        });    }}

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