android 可拖拽自定义listview;

其他 2020-08-10 11:12:04 阅读次数: 0

在开发systemUi过程中，要求像小米的开关排序进行拖拽添加，对控制中心的每个按钮添加更新；经过不停的探索，最终实现出结果；
下面我们来看实现；
我们先看values下的xml的实现：
colors.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
   ...
    <color name="itemColorNormal">#FFFFFF</color>
    <color name="itemColorPressed">#F5F5F5</color>
</resources>

strings.xml

<resources>
....
    <string name="app_name">MyDragListView</string>
    <string name="drag_tag_text">上方%1$d个开关会出现在通知栏中</string>
</resources>

styles.xml

<resources>
    <!-- Base application theme. -->
    <style name="AppTheme" parent="@android:style/Theme.Holo.Light">
        <!-- Customize your theme here. -->
        <!--<item name="colorPrimary">@color/colorPrimary</item>-->
        <!--<item name="colorPrimaryDark">@color/colorPrimaryDark</item>-->
        <!--<item name="colorAccent">@color/colorAccent</item>-->
    </style>

</resources>

在工程目录下创建一个widget包，创建java文件；
LDragItemClass．java:

package application.com.drag.widget;
public class LDragItemClass {
    public String name;

}

LDragListView.java


import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BlurMaskFilter;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.util.AttributeSet;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewConfiguration;
import android.view.ViewGroup;
import android.view.animation.AlphaAnimation;
import android.view.animation.TranslateAnimation;
import android.widget.ListView;

public class LDragListView extends ListView {


    private LDragAdapter adapter;

    private boolean isDragStatus;

    private View mItemView;

    private Bitmap mBitmap = null;

    private int mCurrentPosition;
    private int mLastPosition;

    private int mDragViewOffset=0; // 触摸点在itemView中的高度

    private int mLastX=0, mLastY=0;
    private int mDownX=0, mDownY=0;

    Paint mPaint;
    BlurMaskFilter bf;
    int radius = 10;

    public LDragListView(Context context) {
        this(context,null);
    }

    public LDragListView(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
    }

    public LDragListView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        init(context);


    }

    void init(Context context){
        // 实例化画笔
        mPaint = new Paint(Paint.ANTI_ALIAS_FLAG | Paint.DITHER_FLAG);
        mPaint.setColor(Color.DKGRAY);
        //outer solid normal 都可以  但是inner不行
        bf = new BlurMaskFilter(radius, BlurMaskFilter.Blur.OUTER);
        mPaint.setMaskFilter(bf);
        mPaint.setAlpha(120);

        mTouchSlop = ViewConfiguration.get(getContext()).getScaledTouchSlop();
    }

    @Override
    public boolean dispatchTouchEvent(MotionEvent ev) {

        int action = ev.getAction();
        switch (action){

            case MotionEvent.ACTION_DOWN:

                stopDrag();
                mLastX = mDownX = (int) ev.getX();
                mLastY = mDownY = (int) ev.getY();

                if(startDrag(false, mDownX, mDownY)){
                    return true;
                }

                break;

            case MotionEvent.ACTION_MOVE:
                if(isDragStatus) {
                    mLastX = (int) ev.getX();
                    mLastY = (int) ev.getY();
                    onDrag(mLastY);
                    invalidate();
                    return true;
                }
                break;
            case MotionEvent.ACTION_UP:
            case MotionEvent.ACTION_OUTSIDE:
            case MotionEvent.ACTION_CANCEL:
                isDragStatus = false;
                if (mBitmap != null) {
                    mLastX = (int) ev.getX();
                    mLastY = (int) ev.getY();
                    onDrop(mLastY);
                    invalidate();
                    return true;
                }
                break;

            default:
                break;
        }

        return super.dispatchTouchEvent(ev);
    }

    @Override
    protected void dispatchDraw(Canvas canvas) {
        super.dispatchDraw(canvas);

        if (mBitmap!=null&&!mBitmap.isRecycled()){
            // 先绘制阴影
            Bitmap bitmap = mBitmap.extractAlpha(mPaint, null);
            mPaint.setAlpha(180);
            canvas.drawBitmap(bitmap, 0, mLastY - mDragViewOffset-radius, mPaint);
            // 再绘制位图
            Paint paint = new Paint();
            paint.setAlpha(180);
            canvas.drawBitmap(mBitmap, 0, mLastY - mDragViewOffset, paint);

        }

    }


    public boolean startDragOnLong(){
        return startDrag(true, 0, mLastY);
    }

    public boolean startDrag(boolean isLong, int x, int y){

        int tempPos = pointToPosition(0, y);
        if(tempPos==INVALID_POSITION){
            return false;
        }

        mLastPosition = mCurrentPosition = tempPos;
        ViewGroup downView = (ViewGroup) getChildAt(mCurrentPosition - getFirstVisiblePosition());
        if (downView != null) {
            if(adapter==null){
                adapter = (LDragAdapter) getAdapter();
            }
            if(isLong){
                if (adapter==null || adapter.isTag(tempPos)){
                    return false;
                }
            }else {
                if (adapter==null || !adapter.canDrag(tempPos, downView, x, y)){
                    return false;
                }
            }

            // 触摸点在item项中的高度
            mDragViewOffset = mDownY - downView.getTop();

            downView.setDrawingCacheEnabled(true);
            mBitmap = Bitmap.createBitmap(downView.getDrawingCache());
            downView.setDrawingCacheEnabled(false);

            mLastY = mDownY;
            mLastX = mDownX;
            mItemView = downView;
            if (mItemView!=null){
                mItemView.setVisibility(INVISIBLE);
            }
            isDragStatus = true;
            return true;

        }
        return false;
    }

    public void onDrag(int moveY){

        Log.e("dfafda", "movePos="+moveY);

        if (moveY < 0) { // 限制触摸范围在ＬｉｓｔＶｉｅｗ中
            moveY = 0;
        } else if (moveY > getHeight()) {
            moveY = getHeight();
        }
        int movePos = pointToPosition(0,moveY);
        if(movePos==INVALID_POSITION){
            checkScroller(moveY); // listview移动.
            return;
        }

        mLastY = moveY;

        int dirCell = movePos > mLastPosition? 1 : -1; //1从上往下移动, -1反之

        for (int i=mLastPosition;(dirCell>0)?i<=movePos:i>=movePos;  i+=dirCell){

            int index = i-getFirstVisiblePosition();
            if(index>getChildCount() || index<0){
                continue;
            }

            int y = getChildAt(index).getTop();
            int temPos = pointToPosition(0, y);
            if(temPos!=INVALID_POSITION){
                mCurrentPosition = temPos;
            }
            // 数据交换
            if (mCurrentPosition != mLastPosition) {

                if (adapter==null){
                    adapter = (LDragAdapter) getAdapter();
                }
                if (adapter!=null){
                    if(adapter.exchange(mLastPosition, mCurrentPosition)){
                        View lastView = mItemView;
                        mItemView = getChildAt(mCurrentPosition - getFirstVisiblePosition());
                        //动画
                        exchangeAnimal(mLastPosition, mCurrentPosition, lastView, mItemView);
                        mLastPosition = mCurrentPosition;
                    }
                }
            }

        }

        checkScroller(moveY); // listview移动.

    }

    private int mAutoScrollUpY; // 拖动的时候，开始向上滚动的边界
    private int mAutoScrollDownY; // 拖动的时候，开始向下滚动的边界
    private int mTouchSlop;

    /***
     * 移动到底部或顶部时自动滚动列表
     * 当移动到底部时，ListView向上滑动，当移动到顶部时，ListVidew要向下滑动
     */
    public void checkScroller(final int y) {

        int offset = 0;
        if (y < mAutoScrollUpY) { // 拖动到顶部，ListView需要下滑
            if (y <= mDownY - mTouchSlop) {
                offset = dp2px(getContext(), 3); // 滑动的距离
            }
        } else if (y > mAutoScrollDownY) { // 拖动到底部，ListView需要上滑
            if (y >= mDownY + mTouchSlop) {
                offset = -dp2px(getContext(), 3); // 滑动的距离
            }
        }

        Log.e("mLastScrollTime", offset+","+y+","+mAutoScrollDownY+","+mAutoScrollUpY+","+mDownY+","+mTouchSlop);

        if (offset != 0) {
            View view = getChildAt(mCurrentPosition - getFirstVisiblePosition());
            if (view != null) {
                // 滚动列表
                setSelectionFromTop(mCurrentPosition, view.getTop() + offset);
            }
        }
    }

    public int dp2px(Context context, float dp) {
        return (int) (context.getResources().getDisplayMetrics().density * dp + 0.5f);
    }

    @Override
    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
        super.onSizeChanged(w, h, oldw, oldh);

        mAutoScrollUpY = dp2px(getContext(), 80); // 取得向上滚动的边际，大概为该控件的1/3
        mAutoScrollDownY = h - mAutoScrollUpY; // 取得向下滚动的边际，大概为该控件的2/3
    }

    void exchangeAnimal(int srcPosition, int position, View srcItemView, View itemView){
        if (srcItemView!=null) {
            int height = srcPosition > position ? -srcItemView.getHeight() : srcItemView.getHeight();
            TranslateAnimation animation = new TranslateAnimation(0, 0, height, 0);
            animation.setDuration(200);
            srcItemView.clearAnimation();
            srcItemView.startAnimation(animation);
            srcItemView.setVisibility(View.VISIBLE);
        }

        if (itemView != null) {
            itemView.setVisibility(View.INVISIBLE);
        }
    }

    public void onDrop(int y){

        if (mItemView != null) {
            mItemView.setVisibility(View.VISIBLE);
            if(Math.abs(y - mItemView.getTop()) > mItemView.getHeight() / 5 ){
                AlphaAnimation animation = new AlphaAnimation(0.5f, 1);
                animation.setDuration(150);
                mItemView.clearAnimation();
                mItemView.startAnimation(animation);
            }
            mItemView = null;
        }
        stopDrag();
    }

    public void stopDrag(){
        if (mBitmap != null) {
            mBitmap.recycle();
            mBitmap = null;

        }
        if (mItemView != null) {
            mItemView.setVisibility(View.VISIBLE);
            mItemView = null;
        }
    }

}

LDragAdapter.java

package application.com.drag.widget;

import android.content.Context;
import android.graphics.Rect;
import android.os.Build;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.TextView;

import java.util.ArrayList;
import java.util.List;

import application.com.drag.R;
public class LDragAdapter extends BaseAdapter {

    private Context mContext;
    private int finalAdded = 0;
    private List<LDragItemClass> mAddedItems;
    private List<LDragItemClass> mNotAddedItems;

    public static final int TYPE_TAG = 0;
    public static final int TYPE_ITEM = 1;


    private String tag = "";

    public LDragAdapter(Context context, ArrayList<LDragItemClass> added, ArrayList<LDragItemClass> notAdded) {
        this.mContext = context;
        mAddedItems = added;
        mNotAddedItems = notAdded;
        finalAdded = mAddedItems.size();

        tag = String.format(context.getResources().getString(R.string.drag_tag_text), finalAdded);
    }

    @Override
    public int getCount() {
        return 1+finalAdded+mNotAddedItems.size();
    }


    @Override
    public int getViewTypeCount() {
        return 2;
    }

    @Override
    public int getItemViewType(int position) {
        if(position==finalAdded){
            return TYPE_TAG;
        }else {
            return TYPE_ITEM;
        }
    }

    @Override
    public Object getItem(int position) {
        return null;
    }

    @Override
    public long getItemId(int position) {
        return 0;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {

        ViewHolder viewHolder=null;
        if (convertView==null){
            if (getItemViewType(position)==TYPE_ITEM){
                convertView = LayoutInflater.from(mContext).inflate(R.layout.drag_list_item, null);
                viewHolder = new ViewHolder(convertView);
            }else {
                convertView = LayoutInflater.from(mContext).inflate(R.layout.drag_list_item_tag, null);
                viewHolder = new ViewHolder(convertView);
            }
        }else {
            viewHolder = (ViewHolder) convertView.getTag();
        }

        LDragItemClass itemObj = getLDragItem(position);
        if(getItemViewType(position)==TYPE_ITEM){
            viewHolder.nameView.setText(itemObj.name);
        }else {
            viewHolder.nameView.setText(tag);
            viewHolder.nameView.setEnabled(false);
        }

        return convertView;
    }


    class ViewHolder{
        TextView nameView;
        ImageView iconView;
        public ViewHolder(View view){
            nameView = (TextView)view.findViewById(R.id.drag_list_item_text);

            view.setTag(this);
        }
    }


    private LDragItemClass getLDragItem(int position){
        if (position==finalAdded){
            return null;
        }
        else if(position<finalAdded){
            //add
            return mAddedItems.get(position);
        }else{
            //not add
            return mNotAddedItems.get(position-finalAdded-1);
        }
    }


    public boolean isTag(int pos){
        if( getItemViewType(pos)==TYPE_TAG){
            return true;
        }
        return false;
    }

    public boolean canDrag(int pos, View dragView, int x, int y){


        if( getItemViewType(pos)==TYPE_TAG){
            return false;
        }
        else {
            if (dragView == null) {
                return false;
            }
            View dragger = dragView.findViewById(R.id.drag_list_item_drag);
            if (dragger == null || dragger.getVisibility() != View.VISIBLE) {
                return false;
            }

            float tx = x - getViewX(dragView);
            float ty = y - getViewY(dragView);
            Rect mFrame = new Rect();
            dragger.getHitRect(mFrame);
            if (mFrame.contains((int) tx, (int) ty)) { // 当点击拖拽图标才可进行拖拽
                return true;
            }

            return false;
        }
    }


    public boolean exchange(int scrPos, int desPos){
        boolean success = false;
        int count = mAddedItems.size();
        if(scrPos==count || desPos==count){
            return false;
        }

        if(scrPos!=desPos){
            if(scrPos<count){
                LDragItemClass srcObj = mAddedItems.get(scrPos);
                if (desPos<count){
                    //change in add rang
                    LDragItemClass desObj = mAddedItems.get(desPos);
                    mAddedItems.set(scrPos, desObj);
                    mAddedItems.set(desPos, srcObj);
                }else {
                    //change from add to notAdd
                    desPos = desPos-mAddedItems.size()-1;
                    LDragItemClass desObj = mNotAddedItems.get(desPos);
                    mAddedItems.set(scrPos, desObj);
                    mNotAddedItems.set(desPos, srcObj);
                }

            }else {
                scrPos = scrPos-mAddedItems.size()-1;
                LDragItemClass srcObj = mNotAddedItems.get(scrPos);
                if (desPos<count){
                    //change from noTAdd to add
                    LDragItemClass desObj = mAddedItems.get(desPos);
                    mAddedItems.set(desPos, srcObj);
                    mNotAddedItems.set(scrPos, desObj);
                }else {
                    //change in notAdd rang
                    desPos = desPos-mAddedItems.size()-1;
                    LDragItemClass desObj = mNotAddedItems.get(desPos);
                    mNotAddedItems.set(scrPos, desObj);
                    mNotAddedItems.set(desPos, srcObj);
                }
            }
            success = true;
        }

        if (success) {
            notifyDataSetChanged();
        }
        return success;

    }

    public float getViewX(View view) {
        if (Build.VERSION.SDK_INT >= 11) {
            return view.getX();
        } else {
            return view.getLeft() + view.getTranslationX();
        }
    }

    public float getViewY(View view) {
        if (Build.VERSION.SDK_INT >= 11) {
            return view.getY();
        } else {
            return view.getTop() + view.getTranslationY();
        }
    }

}

上面三个文件，我们的自定义listView算是写完了，下面我们来看具体实现

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <application.com.drag.widget.LDragListView
        android:id="@+id/id_list"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:divider="@drawable/list_item_divider"
        android:dividerHeight="1px"
        android:listSelector="@drawable/drag_list_selector"
        >
    </application.com.drag.widget.LDragListView>


</RelativeLayout>

我们在来看定义怎么定义itme和tag；
drag_list_item.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:background="#FFFFFF"
    android:layout_height="wrap_content">
    <TextView
        android:id="@+id/drag_list_item_text"
        android:layout_width="wrap_content"
        android:layout_height="50dp"
        android:paddingLeft="32dip"
        android:layout_alignParentLeft="true"
        android:layout_centerVertical="true"
        android:gravity="center_vertical"
        />
    <ImageView android:id="@+id/drag_list_item_drag"
        android:src="@mipmap/dragicon"
        android:layout_alignParentRight="true"
        android:layout_centerVertical="true"
        android:layout_width="wrap_content"
        android:paddingRight="16dip"
        android:layout_height="50dp" />
</RelativeLayout>

drag_list_item_tag.xml

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:background="#00555555"
    android:padding="5dip"
    android:paddingLeft="10dip">
    <!--文本框的ID保持不变-->
    <TextView
        android:id="@+id/drag_list_item_text"
        android:layout_width="match_parent"
        android:layout_height="20dip"
        android:textColor="@android:color/darker_gray"
        android:gravity="center"
        android:textSize="11sp"
        android:text="@string/drag_tag_text"/>
    <!--去除来右边拖拽图像，分组标签是不能随意拖动的-->
</FrameLayout>

drawable包下定义：
drag_list_selector.xml

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<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <!-- 这个是按下去的时候item显示背景色 -->;
    <item android:drawable="@color/itemColorPressed" android:state_pressed="true"></item>
    <!-- 这个是默认的item背景色，设为了透明 -->
    <item android:drawable="@android:color/transparent" android:state_pressed="false"></item>

</selector>

list_item_divider.xml

<?xml version="1.0" encoding="UTF-8"?>
<inset xmlns:android="http://schemas.android.com/apk/res/android"
    android:insetLeft="30dp"
    android:insetRight="0dp"
    android:drawable="@color/gray">
</inset>

我们来看最终的MainActivity的实现；

package application.com.drag;


import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;

import java.util.ArrayList;

import application.com.drag.widget.LDragAdapter;
import application.com.drag.widget.LDragItemClass;
import application.com.drag.widget.LDragListView;

public class MainActivity extends Activity {

    private String data[] = new String[]{"WLAN","截屏","数据","GPS","静音","飞行模式","蓝牙","方向锁屏","自动亮度","手电筒","省电模式","快传","振动","屏蔽按键","勿扰模式","锁屏","同步","护眼模式"};

    private LDragAdapter adapter = null;
    private LDragListView listView = null;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        //初始化样本数据
        initData();
    }

    void initData(){
        ArrayList<LDragItemClass> addlist = new ArrayList<LDragItemClass>();
        ArrayList<LDragItemClass> notAddlist = new ArrayList<LDragItemClass>();

        for(int i=0; i<data.length; i++){
            LDragItemClass item = new LDragItemClass();
                item.name = data[i];
            if(i>6){
                notAddlist.add(item);
            }else {
                addlist.add(item);
            }
        }

        adapter = new LDragAdapter(this, addlist, notAddlist);
        listView = (LDragListView) findViewById(R.id.id_list);
        listView.setAdapter(adapter);
        listView.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() {
            @Override
            public boolean onItemLongClick(AdapterView<?> parent, View view, int position, long id) {

                Log.e("", "pos="+position);
                listView.startDragOnLong();
                return false;
            }
        });


        listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                Log.e("", "pos="+position);
            }
        });

    }
}

以上就算完成了，我们来张图片：
这里写图片描述

下载demo链接https://download.csdn.net/download/xiao_yuanjl/

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