通信录分组并且分组标签悬停划入划出（包含错误信息及修改）--第三方开源--PinnedSectionListView...

PinnedSectionListView在github上的链接地址是：https://github.com/beworker/pinned-section-listview 。

下载下来后直接将PinnedSectionListView.java（在一些SDK版本拉动的时候会异常崩溃，异常信息和修改后的文档在后面）复制粘贴在要用的包中：

activity_main.xml：

 1 <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
 2     xmlns:tools="http://schemas.android.com/tools"
 3     android:layout_width="match_parent"
 4     android:layout_height="match_parent"
 5     tools:context="com.zzw.testpinnedsectionlistview.MainActivity" >
 6 
 7     <com.zzw.testpinnedsectionlistview.PinnedSectionListView
 8         android:id="@+id/listView"
 9         android:layout_width="match_parent"
10         android:layout_height="match_parent" />
11 
12 RelativeLayout>

item.xml:

 1 xml version="1.0" encoding="utf-8"?>
 2 <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
 3     android:layout_width="match_parent"
 4     android:layout_height="match_parent"
 5     android:orientation="vertical" >
 6 
 7     <ImageView
 8         android:id="@+id/imageView"
 9         android:layout_width="wrap_content"
10         android:layout_height="wrap_content"
11         android:layout_alignParentLeft="true"
12         android:layout_centerVertical="true"
13         android:src="@drawable/ic_launcher" />
14 
15     <TextView
16         android:id="@+id/textView"
17         android:layout_width="wrap_content"
18         android:layout_height="wrap_content"
19         android:layout_alignBottom="@+id/imageView1"
20         android:layout_alignParentRight="true"
21         android:gravity="center"
22         android:textSize="20sp"
23         android:layout_alignTop="@+id/imageView1"
24         android:layout_toRightOf="@+id/imageView1"
25         android:text="TextView" />
26 
27 RelativeLayout>

item.xml

MainActivity.java：

  1 package com.zzw.testpinnedsectionlistview;
  2 
  3 import java.util.ArrayList;
  4 
  5 import com.zzw.testpinnedsectionlistview.PinnedSectionListView.PinnedSectionListAdapter;
  6 
  7 import android.app.Activity;
  8 import android.content.Context;
  9 import android.graphics.Color;
 10 import android.os.Bundle;
 11 import android.view.LayoutInflater;
 12 import android.view.View;
 13 import android.view.ViewGroup;
 14 import android.widget.ArrayAdapter;
 15 import android.widget.TextView;
 16 
 17 public class MainActivity extends Activity {
 18 
 19     private ArrayList items = null;
 20 
 21     private final int VIEW_TYPE_COUNT = 2;
 22 
 23     @Override
 24     protected void onCreate(Bundle savedInstanceState) {
 25         super.onCreate(savedInstanceState);
 26         setContentView(R.layout.activity_main);
 27 
 28         items =new ArrayList();
 29         // 假设我们演示以A,B,C,,,F这样的字符串作为分组的标签。
 30         // 每一组装载5个子数据。
 31         String[] groups = { "A", "B", "C", "D", "E" };
 32         for (int i = 0; i < groups.length; i++) {
 33             String s = groups[i];
 34 
 35             Item group = new Item();
 36             group.type = Item.GROUP;
 37             group.text = s;
 38             items.add(group);
 39 
 40             for (int j = 0; j < 10; j++) {
 41                 Item child = new Item();
 42                 child.type = Item.CHILD;
 43                 child.text = s + "组数据：" + j;
 44                 items.add(child);
 45             }
 46         }
 47 
 48         PinnedSectionListView listView = (PinnedSectionListView) findViewById(R.id.listView);
 49         listView.setAdapter(new MyAdapter(this, -1));
 50 
 51     }
 52 
 53     private class Item {
 54         public static final int GROUP = 0;
 55         public static final int CHILD = 1;
 56 
 57         public int type;
 58         public String text;
 59     }
 60 
 61     private class MyAdapter extends ArrayAdapter implements PinnedSectionListAdapter {
 62 
 63         private LayoutInflater inflater;
 64 
 65         public MyAdapter(Context context, int resource) {
 66             super(context, resource);
 67 
 68             inflater = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
 69         }
 70 
 71         @Override
 72         public int getItemViewType(int position) {
 73 
 74             return items.get(position).type;
 75         }
 76 
 77         @Override
 78         public int getCount() {
 79 
 80             return items.size();
 81         }
 82 
 83         @Override
 84         public int getViewTypeCount() {
 85 
 86             return VIEW_TYPE_COUNT;
 87         }
 88 
 89         @Override
 90         public Item getItem(int position) {
 91 
 92             return items.get(position);
 93         }
 94 
 95         @Override
 96         public View getView(int position, View convertView, ViewGroup parent) {
 97             switch (getItemViewType(position)) {
 98             case Item.GROUP:
 99 
100                 if (convertView == null) {
101                     convertView = inflater.inflate(android.R.layout.simple_list_item_1, null);
102                 }
103 
104                 TextView textView_group = (TextView) convertView.findViewById(android.R.id.text1);
105                 textView_group.setText(getItem(position).text);
106                 textView_group.setTextColor(Color.BLUE);
107                 textView_group.setTextSize(30);
108                 textView_group.setBackgroundColor(Color.GRAY);
109 
110                 break;
111 
112             case Item.CHILD:
113                 if (convertView == null) {
114                     convertView = inflater.inflate(R.layout.item, null);
115                 }
116 
117                 TextView textView_child = (TextView) convertView.findViewById(R.id.textView);
118                 textView_child.setText(getItem(position).text);
119                 textView_child.setBackgroundColor(Color.YELLOW);
120 
121                 break;
122             }
123             return convertView;
124         }
125 
126         /*
127          * 假设此方法返回皆为false。那么PinnedSectionListView将退化成为一个基础的ListView.
128          * 只不过退化后的ListView只是一个拥有两个View Type的ListView。
129          * 
130          * 从某种角度上讲，此方法对于PinnedSectionListView至关重要
131          * 返回值true或false，将直接导致PinnedSectionListView是一个PinnedSectionListView，
132          * 还是一个普通的ListView
133          * 
134          */
135         @Override
136         public boolean isItemViewTypePinned(int viewType) {
137             boolean type = false;
138             switch (viewType) {
139             case Item.GROUP:
140                 type = true;
141                 break;
142 
143             case Item.CHILD:
144                 type = false;
145                 break;
146 
147             default:
148                 type = false;
149                 break;
150             }
151             return type;
152         }
153     }
154 }

程序运行拉动的时候有的sdk版本会出现程序崩溃，LogCat是这样情况：

 

报错的是原代码PinnedSectionListView.java中的（200行左右）：

// read layout parameters
        LayoutParams layoutParams = (LayoutParams) pinnedView.getLayoutParams();
        if (layoutParams == null) {
            layoutParams = (LayoutParams) generateDefaultLayoutParams();
            pinnedView.setLayoutParams(layoutParams);
        }

主要是这句话：

layoutParams = (LayoutParams) generateDefaultLayoutParams();

经由研究发现，此原因是在调用Android系统的generateDefaultLayoutParams()方法时候，发生异常，致使代码运行获得的结果layoutParams不正常，进而导致PinnedSectionListView崩溃。

解决方案：
自己动手重写Android系统的generateDefaultLayoutParams()方法，返回自己定制的LayoutParams值。

具体实现：
在PinnedSectionListView.java中增加自己重写的generateDefaultLayoutParams()方法：

1 @Override  
2    protected ViewGroup.LayoutParams generateDefaultLayoutParams() {  
3       
4     LayoutParams mLayoutParams=new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT);  
5       
6     return mLayoutParams;  
7    }  

最终修复bug，改进后的PinnedSectionListView.java全部源代码为如下（可直接复制粘贴使用）：

  1 /*
  2  * Copyright (C) 2013 Sergej Shafarenka, halfbit.de
  3  *
  4  * Licensed under the Apache License, Version 2.0 (the "License");
  5  * you may not use this file kt in compliance with the License.
  6  * You may obtain a copy of the License at
  7  *
  8  * http://www.apache.org/licenses/LICENSE-2.0
  9  *
 10  * Unless required by applicable law or agreed to in writing, software
 11  * distributed under the License is distributed on an "AS IS" BASIS,
 12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 13  * See the License for the specific language governing permissions and
 14  * limitations under the License.
 15  */
 16 
 17 package com.zzw.testpinnedsectionlistview;
 18 
 19 
 20 import android.content.Context;
 21 import android.database.DataSetObserver;
 22 import android.graphics.Canvas;
 23 import android.graphics.Color;
 24 import android.graphics.PointF;
 25 import android.graphics.Rect;
 26 import android.graphics.drawable.GradientDrawable;
 27 import android.graphics.drawable.GradientDrawable.Orientation;
 28 import android.os.Parcelable;
 29 import android.util.AttributeSet;
 30 import android.view.MotionEvent;
 31 import android.view.SoundEffectConstants;
 32 import android.view.View;
 33 import android.view.ViewConfiguration;
 34 import android.view.ViewGroup;
 35 import android.view.accessibility.AccessibilityEvent;
 36 import android.widget.AbsListView;
 37 import android.widget.HeaderViewListAdapter;
 38 import android.widget.ListAdapter;
 39 import android.widget.ListView;
 40 import android.widget.SectionIndexer;
 41 
 42 
 43 /**
 44  * ListView, which is capable to pin section views at its top while the rest is still scrolled.
 45  */
 46 public class PinnedSectionListView extends ListView {
 47 
 48     //-- inner classes
 49 
 50     /** List adapter to be implemented for being used with PinnedSectionListView adapter. */
 51     public static interface PinnedSectionListAdapter extends ListAdapter {
 52         /** This method shall return 'true' if views of given type has to be pinned. */
 53         boolean isItemViewTypePinned(int viewType);
 54     }
 55 
 56     /** Wrapper class for pinned section view and its position in the list. */
 57     static class PinnedSection {
 58         public View view;
 59         public int position;
 60         public long id;
 61     }
 62 
 63     //-- class fields
 64 
 65     // fields used for handling touch events
 66     private final Rect mTouchRect = new Rect();
 67     private final PointF mTouchPoint = new PointF();
 68     private int mTouchSlop;
 69     private View mTouchTarget;
 70     private MotionEvent mDownEvent;
 71 
 72     // fields used for drawing shadow under a pinned section
 73     private GradientDrawable mShadowDrawable;
 74     private int mSectionsDistanceY;
 75     private int mShadowHeight;
 76 
 77     /** Delegating listener, can be null. */
 78     OnScrollListener mDelegateOnScrollListener;
 79 
 80     /** Shadow for being recycled, can be null. */
 81     PinnedSection mRecycleSection;
 82 
 83     /** shadow instance with a pinned view, can be null. */
 84     PinnedSection mPinnedSection;
 85 
 86     /** Pinned view Y-translation. We use it to stick pinned view to the next section. */
 87     int mTranslateY;
 88 
 89     /** Scroll listener which does the magic */
 90     private final OnScrollListener mOnScrollListener = new OnScrollListener() {
 91 
 92         @Override public void onScrollStateChanged(AbsListView view, int scrollState) {
 93             if (mDelegateOnScrollListener != null) { // delegate
 94                 mDelegateOnScrollListener.onScrollStateChanged(view, scrollState);
 95             }
 96         }
 97 
 98         @Override
 99         public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
100 
101             if (mDelegateOnScrollListener != null) { // delegate
102                 mDelegateOnScrollListener.onScroll(view, firstVisibleItem, visibleItemCount, totalItemCount);
103             }
104 
105             // get expected adapter or fail fast
106             ListAdapter adapter = getAdapter();
107             if (adapter == null || visibleItemCount == 0) return; // nothing to do
108 
109             final boolean isFirstVisibleItemSection =
110                     isItemViewTypePinned(adapter, adapter.getItemViewType(firstVisibleItem));
111 
112             if (isFirstVisibleItemSection) {
113                 View sectionView = getChildAt(0);
114                 if (sectionView.getTop() == getPaddingTop()) { // view sticks to the top, no need for pinned shadow
115                     destroyPinnedShadow();
116                 } else { // section doesn't stick to the top, make sure we have a pinned shadow
117                     ensureShadowForPosition(firstVisibleItem, firstVisibleItem, visibleItemCount);
118                 }
119 
120             } else { // section is not at the first visible position
121                 int sectionPosition = findCurrentSectionPosition(firstVisibleItem);
122                 if (sectionPosition > -1) { // we have section position
123                     ensureShadowForPosition(sectionPosition, firstVisibleItem, visibleItemCount);
124                 } else { // there is no section for the first visible item, destroy shadow
125                     destroyPinnedShadow();
126                 }
127             }
128         };
129 
130     };
131 
132     /** Default change observer. */
133     private final DataSetObserver mDataSetObserver = new DataSetObserver() {
134         @Override public void onChanged() {
135             recreatePinnedShadow();
136         };
137         @Override public void onInvalidated() {
138             recreatePinnedShadow();
139         }
140     };
141 
142     //-- constructors
143 
144     public PinnedSectionListView(Context context, AttributeSet attrs) {
145         super(context, attrs);
146         initView();
147     }
148 
149     public PinnedSectionListView(Context context, AttributeSet attrs, int defStyle) {
150         super(context, attrs, defStyle);
151         initView();
152     }
153 
154     private void initView() {
155         setOnScrollListener(mOnScrollListener);
156         mTouchSlop = ViewConfiguration.get(getContext()).getScaledTouchSlop();
157         initShadow(true);
158     }
159 
160     //-- public API methods
161 
162     public void setShadowVisible(boolean visible) {
163         initShadow(visible);
164         if (mPinnedSection != null) {
165             View v = mPinnedSection.view;
166             invalidate(v.getLeft(), v.getTop(), v.getRight(), v.getBottom() + mShadowHeight);
167         }
168     }
169 
170     //-- pinned section drawing methods
171 
172     public void initShadow(boolean visible) {
173         if (visible) {
174             if (mShadowDrawable == null) {
175                 mShadowDrawable = new GradientDrawable(Orientation.TOP_BOTTOM,
176                         new int[] { Color.parseColor("#ffa0a0a0"), Color.parseColor("#50a0a0a0"), Color.parseColor("#00a0a0a0")});
177                 mShadowHeight = (int) (8 * getResources().getDisplayMetrics().density);
178             }
179         } else {
180             if (mShadowDrawable != null) {
181                 mShadowDrawable = null;
182                 mShadowHeight = 0;
183             }
184         }
185     }
186 
187     //*****添加*****//
188     @Override
189     protected ViewGroup.LayoutParams generateDefaultLayoutParams() {
190         LayoutParams mLayoutParams=new LayoutParams(LayoutParams.MATCH_PARENT,LayoutParams.WRAP_CONTENT);    
191         return mLayoutParams;
192     }
193     //*****添加*****//
194     
195     /** Create shadow wrapper with a pinned view for a view at given position */
196     void createPinnedShadow(int position) {
197 
198         // try to recycle shadow
199         PinnedSection pinnedShadow = mRecycleSection;
200         mRecycleSection = null;
201 
202         // create new shadow, if needed
203         if (pinnedShadow == null) pinnedShadow = new PinnedSection();
204         // request new view using recycled view, if such
205         View pinnedView = getAdapter().getView(position, pinnedShadow.view, PinnedSectionListView.this);
206 
207         // read layout parameters
208         LayoutParams layoutParams = (LayoutParams) pinnedView.getLayoutParams();
209         if (layoutParams == null) {
210             layoutParams = (LayoutParams) generateDefaultLayoutParams();
211             pinnedView.setLayoutParams(layoutParams);
212         }
213 
214         int heightMode = MeasureSpec.getMode(layoutParams.height);
215         int heightSize = MeasureSpec.getSize(layoutParams.height);
216 
217         if (heightMode == MeasureSpec.UNSPECIFIED) heightMode = MeasureSpec.EXACTLY;
218 
219         int maxHeight = getHeight() - getListPaddingTop() - getListPaddingBottom();
220         if (heightSize > maxHeight) heightSize = maxHeight;
221 
222         // measure & layout
223         int ws = MeasureSpec.makeMeasureSpec(getWidth() - getListPaddingLeft() - getListPaddingRight(), MeasureSpec.EXACTLY);
224         int hs = MeasureSpec.makeMeasureSpec(heightSize, heightMode);
225         pinnedView.measure(ws, hs);
226         pinnedView.layout(0, 0, pinnedView.getMeasuredWidth(), pinnedView.getMeasuredHeight());
227         mTranslateY = 0;
228 
229         // initialize pinned shadow
230         pinnedShadow.view = pinnedView;
231         pinnedShadow.position = position;
232         pinnedShadow.id = getAdapter().getItemId(position);
233 
234         // store pinned shadow
235         mPinnedSection = pinnedShadow;
236     }
237 
238     /** Destroy shadow wrapper for currently pinned view */
239     void destroyPinnedShadow() {
240         if (mPinnedSection != null) {
241             // keep shadow for being recycled later
242             mRecycleSection = mPinnedSection;
243             mPinnedSection = null;
244         }
245     }
246 
247     /** Makes sure we have an actual pinned shadow for given position. */
248     void ensureShadowForPosition(int sectionPosition, int firstVisibleItem, int visibleItemCount) {
249         if (visibleItemCount < 2) { // no need for creating shadow at all, we have a single visible item
250             destroyPinnedShadow();
251             return;
252         }
253 
254         if (mPinnedSection != null
255                 && mPinnedSection.position != sectionPosition) { // invalidate shadow, if required
256             destroyPinnedShadow();
257         }
258 
259         if (mPinnedSection == null) { // create shadow, if empty
260             createPinnedShadow(sectionPosition);
261         }
262 
263         // align shadow according to next section position, if needed
264         int nextPosition = sectionPosition + 1;
265         if (nextPosition < getCount()) {
266             int nextSectionPosition = findFirstVisibleSectionPosition(nextPosition,
267                     visibleItemCount - (nextPosition - firstVisibleItem));
268             if (nextSectionPosition > -1) {
269                 View nextSectionView = getChildAt(nextSectionPosition - firstVisibleItem);
270                 final int bottom = mPinnedSection.view.getBottom() + getPaddingTop();
271                 mSectionsDistanceY = nextSectionView.getTop() - bottom;
272                 if (mSectionsDistanceY < 0) {
273                     // next section overlaps pinned shadow, move it up
274                     mTranslateY = mSectionsDistanceY;
275                 } else {
276                     // next section does not overlap with pinned, stick to top
277                     mTranslateY = 0;
278                 }
279             } else {
280                 // no other sections are visible, stick to top
281                 mTranslateY = 0;
282                 mSectionsDistanceY = Integer.MAX_VALUE;
283             }
284         }
285 
286     }
287 
288     int findFirstVisibleSectionPosition(int firstVisibleItem, int visibleItemCount) {
289         ListAdapter adapter = getAdapter();
290 
291         int adapterDataCount = adapter.getCount();
292         if (getLastVisiblePosition() >= adapterDataCount) return -1; // dataset has changed, no candidate
293 
294         if (firstVisibleItem+visibleItemCount >= adapterDataCount){//added to prevent index Outofbound (in case)
295             visibleItemCount = adapterDataCount-firstVisibleItem;
296         }
297 
298         for (int childIndex = 0; childIndex < visibleItemCount; childIndex++) {
299             int position = firstVisibleItem + childIndex;
300             int viewType = adapter.getItemViewType(position);
301             if (isItemViewTypePinned(adapter, viewType)) return position;
302         }
303         return -1;
304     }
305 
306     int findCurrentSectionPosition(int fromPosition) {
307         ListAdapter adapter = getAdapter();
308 
309         if (fromPosition >= adapter.getCount()) return -1; // dataset has changed, no candidate
310         
311         if (adapter instanceof SectionIndexer) {
312             // try fast way by asking section indexer
313             SectionIndexer indexer = (SectionIndexer) adapter;
314             int sectionPosition = indexer.getSectionForPosition(fromPosition);
315             int itemPosition = indexer.getPositionForSection(sectionPosition);
316             int typeView = adapter.getItemViewType(itemPosition);
317             if (isItemViewTypePinned(adapter, typeView)) {
318                 return itemPosition;
319             } // else, no luck
320         }
321 
322         // try slow way by looking through to the next section item above
323         for (int position=fromPosition; position>=0; position--) {
324             int viewType = adapter.getItemViewType(position);
325             if (isItemViewTypePinned(adapter, viewType)) return position;
326         }
327         return -1; // no candidate found
328     }
329 
330     void recreatePinnedShadow() {
331         destroyPinnedShadow();
332         ListAdapter adapter = getAdapter();
333         if (adapter != null && adapter.getCount() > 0) {
334             int firstVisiblePosition = getFirstVisiblePosition();
335             int sectionPosition = findCurrentSectionPosition(firstVisiblePosition);
336             if (sectionPosition == -1) return; // no views to pin, exit
337             ensureShadowForPosition(sectionPosition,
338                     firstVisiblePosition, getLastVisiblePosition() - firstVisiblePosition);
339         }
340     }
341 
342     @Override
343     public void setOnScrollListener(OnScrollListener listener) {
344         if (listener == mOnScrollListener) {
345             super.setOnScrollListener(listener);
346         } else {
347             mDelegateOnScrollListener = listener;
348         }
349     }
350 
351     @Override
352     public void onRestoreInstanceState(Parcelable state) {
353         super.onRestoreInstanceState(state);
354         post(new Runnable() {
355             @Override public void run() { // restore pinned view after configuration change
356                 recreatePinnedShadow();
357             }
358         });
359     }
360 
361     @Override
362     public void setAdapter(ListAdapter adapter) {
363 
364         // assert adapter in debug mode
365         if (BuildConfig.DEBUG && adapter != null) {
366             if (!(adapter instanceof PinnedSectionListAdapter))
367                 throw new IllegalArgumentException("Does your adapter implement PinnedSectionListAdapter?");
368             if (adapter.getViewTypeCount() < 2)
369                 throw new IllegalArgumentException("Does your adapter handle at least two types" +
370                         " of views in getViewTypeCount() method: items and sections?");
371         }
372 
373         // unregister observer at old adapter and register on new one
374         ListAdapter oldAdapter = getAdapter();
375         if (oldAdapter != null) oldAdapter.unregisterDataSetObserver(mDataSetObserver);
376         if (adapter != null) adapter.registerDataSetObserver(mDataSetObserver);
377 
378         // destroy pinned shadow, if new adapter is not same as old one
379         if (oldAdapter != adapter) destroyPinnedShadow();
380 
381         super.setAdapter(adapter);
382     }
383 
384     @Override
385     protected void onLayout(boolean changed, int l, int t, int r, int b) {
386         super.onLayout(changed, l, t, r, b);
387         if (mPinnedSection != null) {
388             int parentWidth = r - l - getPaddingLeft() - getPaddingRight();
389             int shadowWidth = mPinnedSection.view.getWidth();
390             if (parentWidth != shadowWidth) {
391                 recreatePinnedShadow();
392             }
393         }
394     }
395 
396     @Override
397     protected void dispatchDraw(Canvas canvas) {
398         super.dispatchDraw(canvas);
399 
400         if (mPinnedSection != null) {
401 
402             // prepare variables
403             int pLeft = getListPaddingLeft();
404             int pTop = getListPaddingTop();
405             View view = mPinnedSection.view;
406 
407             // draw child
408             canvas.save();
409 
410             int clipHeight = view.getHeight() +
411                     (mShadowDrawable == null ? 0 : Math.min(mShadowHeight, mSectionsDistanceY));
412             canvas.clipRect(pLeft, pTop, pLeft + view.getWidth(), pTop + clipHeight);
413 
414             canvas.translate(pLeft, pTop + mTranslateY);
415             drawChild(canvas, mPinnedSection.view, getDrawingTime());
416 
417             if (mShadowDrawable != null && mSectionsDistanceY > 0) {
418                 mShadowDrawable.setBounds(mPinnedSection.view.getLeft(),
419                         mPinnedSection.view.getBottom(),
420                         mPinnedSection.view.getRight(),
421                         mPinnedSection.view.getBottom() + mShadowHeight);
422                 mShadowDrawable.draw(canvas);
423             }
424 
425             canvas.restore();
426         }
427     }
428 
429     //-- touch handling methods
430 
431     @Override
432     public boolean dispatchTouchEvent(MotionEvent ev) {
433 
434         final float x = ev.getX();
435         final float y = ev.getY();
436         final int action = ev.getAction();
437 
438         if (action == MotionEvent.ACTION_DOWN
439                 && mTouchTarget == null
440                 && mPinnedSection != null
441                 && isPinnedViewTouched(mPinnedSection.view, x, y)) { // create touch target
442 
443             // user touched pinned view
444             mTouchTarget = mPinnedSection.view;
445             mTouchPoint.x = x;
446             mTouchPoint.y = y;
447 
448             // copy down event for eventually be used later
449             mDownEvent = MotionEvent.obtain(ev);
450         }
451 
452         if (mTouchTarget != null) {
453             if (isPinnedViewTouched(mTouchTarget, x, y)) { // forward event to pinned view
454                 mTouchTarget.dispatchTouchEvent(ev);
455             }
456 
457             if (action == MotionEvent.ACTION_UP) { // perform onClick on pinned view
458                 super.dispatchTouchEvent(ev);
459                 performPinnedItemClick();
460                 clearTouchTarget();
461 
462             } else if (action == MotionEvent.ACTION_CANCEL) { // cancel
463                 clearTouchTarget();
464 
465             } else if (action == MotionEvent.ACTION_MOVE) {
466                 if (Math.abs(y - mTouchPoint.y) > mTouchSlop) {
467 
468                     // cancel sequence on touch target
469                     MotionEvent event = MotionEvent.obtain(ev);
470                     event.setAction(MotionEvent.ACTION_CANCEL);
471                     mTouchTarget.dispatchTouchEvent(event);
472                     event.recycle();
473 
474                     // provide correct sequence to super class for further handling
475                     super.dispatchTouchEvent(mDownEvent);
476                     super.dispatchTouchEvent(ev);
477                     clearTouchTarget();
478 
479                 }
480             }
481 
482             return true;
483         }
484 
485         // call super if this was not our pinned view
486         return super.dispatchTouchEvent(ev);
487     }
488 
489     private boolean isPinnedViewTouched(View view, float x, float y) {
490         view.getHitRect(mTouchRect);
491 
492         // by taping top or bottom padding, the list performs on click on a border item.
493         // we don't add top padding here to keep behavior consistent.
494         mTouchRect.top += mTranslateY;
495 
496         mTouchRect.bottom += mTranslateY + getPaddingTop();
497         mTouchRect.left += getPaddingLeft();
498         mTouchRect.right -= getPaddingRight();
499         return mTouchRect.contains((int)x, (int)y);
500     }
501 
502     private void clearTouchTarget() {
503         mTouchTarget = null;
504         if (mDownEvent != null) {
505             mDownEvent.recycle();
506             mDownEvent = null;
507         }
508     }
509 
510     private boolean performPinnedItemClick() {
511         if (mPinnedSection == null) return false;
512 
513         OnItemClickListener listener = getOnItemClickListener();
514         if (listener != null && getAdapter().isEnabled(mPinnedSection.position)) {
515             View view =  mPinnedSection.view;
516             playSoundEffect(SoundEffectConstants.CLICK);
517             if (view != null) {
518                 view.sendAccessibilityEvent(AccessibilityEvent.TYPE_VIEW_CLICKED);
519             }
520             listener.onItemClick(this, view, mPinnedSection.position, mPinnedSection.id);
521             return true;
522         }
523         return false;
524     }
525 
526     public static boolean isItemViewTypePinned(ListAdapter adapter, int viewType) {
527         if (adapter instanceof HeaderViewListAdapter) {
528             adapter = ((HeaderViewListAdapter)adapter).getWrappedAdapter();
529         }
530         return ((PinnedSectionListAdapter) adapter).isItemViewTypePinned(viewType);
531     }
532 
533 }

PinnedSectionListView.java

 

转载于:https://www.cnblogs.com/zzw1994/p/4997601.html