PinnedSectionListView有阴影效果，类似淘点点点餐

import android.content.Context;import android.database.DataSetObserver;import android.graphics.Canvas;import android.graphics.Color;import android.graphics.PointF;import android.graphics.Rect;import android.graphics.drawable.GradientDrawable;import android.graphics.drawable.GradientDrawable.Orientation;import android.os.Parcelable;import android.util.AttributeSet;import android.view.MotionEvent;import android.view.SoundEffectConstants;import android.view.View;import android.view.ViewConfiguration;import android.view.accessibility.AccessibilityEvent;import android.widget.AbsListView;import android.widget.HeaderViewListAdapter;import android.widget.ListAdapter;import android.widget.ListView;import android.widget.SectionIndexer;/** * ListView, which is capable to pin section views at its top while the rest is still scrolled. */public class PinnedSectionListView extends ListView {    //-- inner classes    /** List adapter to be implemented for being used with PinnedSectionListView adapter. */    public static interface PinnedSectionListAdapter extends ListAdapter {        /** This method shall return 'true' if views of given type has to be pinned. */        boolean isItemViewTypePinned(int viewType);        //这里向外提供回调接口        void getShadowPosition(int position);    }    /** Wrapper class for pinned section view and its position in the list. */    static class PinnedSection {        public View view;        public int position;        public long id;    }    //-- class fields    // fields used for handling touch events    private final Rect mTouchRect = new Rect();    private final PointF mTouchPoint = new PointF();    private int mTouchSlop;    private View mTouchTarget;    private MotionEvent mDownEvent;    // fields used for drawing shadow under a pinned section    private GradientDrawable mShadowDrawable;    private int mSectionsDistanceY;    private int mShadowHeight;    /** Delegating listener, can be null. */    OnScrollListener mDelegateOnScrollListener;    /** Shadow for being recycled, can be null. */    PinnedSection mRecycleSection;    /** shadow instance with a pinned view, can be null. */    PinnedSection mPinnedSection;    /** Pinned view Y-translation. We use it to stick pinned view to the next section. */    int mTranslateY;    /** Scroll listener which does the magic */    private final OnScrollListener mOnScrollListener = new OnScrollListener() {        @Override public void onScrollStateChanged(AbsListView view, int scrollState) {            if (mDelegateOnScrollListener != null) { // delegate                mDelegateOnScrollListener.onScrollStateChanged(view, scrollState);            }        }        @Override        public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {            if (mDelegateOnScrollListener != null) { // delegate                mDelegateOnScrollListener.onScroll(view, firstVisibleItem, visibleItemCount, totalItemCount);            }            // get expected adapter or fail fast            ListAdapter adapter = getAdapter();            if (adapter == null || visibleItemCount == 0) return; // nothing to do            final boolean isFirstVisibleItemSection =                    isItemViewTypePinned(adapter, adapter.getItemViewType(firstVisibleItem));            if (isFirstVisibleItemSection) {                View sectionView = getChildAt(0);                if (sectionView.getTop() == getPaddingTop()) { // view sticks to the top, no need for pinned shadow                    destroyPinnedShadow();                } else { // section doesn't stick to the top, make sure we have a pinned shadow                    ensureShadowForPosition(firstVisibleItem, firstVisibleItem, visibleItemCount);                }            } else { // section is not at the first visible position                int sectionPosition = findCurrentSectionPosition(firstVisibleItem);                if (sectionPosition > -1) { // we have section position                    ensureShadowForPosition(sectionPosition, firstVisibleItem, visibleItemCount);                } else { // there is no section for the first visible item, destroy shadow                    destroyPinnedShadow();                }            }        };    };    /** Default change observer. */    private final DataSetObserver mDataSetObserver = new DataSetObserver() {        @Override public void onChanged() {            recreatePinnedShadow();        };        @Override public void onInvalidated() {            recreatePinnedShadow();        }    };    //-- constructors    public PinnedSectionListView(Context context, AttributeSet attrs) {        super(context, attrs);        initView();    }    public PinnedSectionListView(Context context, AttributeSet attrs, int defStyle) {        super(context, attrs, defStyle);        initView();    }    private void initView() {        setOnScrollListener(mOnScrollListener);        mTouchSlop = ViewConfiguration.get(getContext()).getScaledTouchSlop();        initShadow(true);    }    //-- public API methods    public void setShadowVisible(boolean visible) {        initShadow(visible);        if (mPinnedSection != null) {            View v = mPinnedSection.view;            invalidate(v.getLeft(), v.getTop(), v.getRight(), v.getBottom() + mShadowHeight);        }    }    //-- pinned section drawing methods    public void initShadow(boolean visible) {        if (visible) {            if (mShadowDrawable == null) {                mShadowDrawable = new GradientDrawable(Orientation.TOP_BOTTOM,                        new int[] { Color.parseColor("#ffa0a0a0"), Color.parseColor("#50a0a0a0"), Color.parseColor("#00a0a0a0")});                mShadowHeight = (int) (8 * getResources().getDisplayMetrics().density);            }        } else {            if (mShadowDrawable != null) {                mShadowDrawable = null;                mShadowHeight = 0;            }        }    }    /** Create shadow wrapper with a pinned view for a view at given position */    void createPinnedShadow(int position) {//滑动的时候产生pinnedshadow，替换产生，或者新产生        // try to recycle shadow//((PinnedSectionListAdapter) getAdapter())获得对外回调接口对象，提供第几个位置产生数据        ((PinnedSectionListAdapter) getAdapter()).getShadowPosition(position);        PinnedSection pinnedShadow = mRecycleSection;        mRecycleSection = null;        // create new shadow, if needed        if (pinnedShadow == null) pinnedShadow = new PinnedSection();        // request new view using recycled view, if such        View pinnedView = getAdapter().getView(position, pinnedShadow.view, PinnedSectionListView.this);        // read layout parameters        LayoutParams layoutParams = (LayoutParams) pinnedView.getLayoutParams();        if (layoutParams == null) { // create default layout params            layoutParams = new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT);        }        int heightMode = MeasureSpec.getMode(layoutParams.height);        int heightSize = MeasureSpec.getSize(layoutParams.height);        if (heightMode == MeasureSpec.UNSPECIFIED) heightMode = MeasureSpec.EXACTLY;        int maxHeight = getHeight() - getListPaddingTop() - getListPaddingBottom();        if (heightSize > maxHeight) heightSize = maxHeight;        // measure & layout        int ws = MeasureSpec.makeMeasureSpec(getWidth() - getListPaddingLeft() - getListPaddingRight(), MeasureSpec.EXACTLY);        int hs = MeasureSpec.makeMeasureSpec(heightSize, heightMode);        pinnedView.measure(ws, hs);        pinnedView.layout(0, 0, pinnedView.getMeasuredWidth(), pinnedView.getMeasuredHeight());        mTranslateY = 0;        // initialize pinned shadow        pinnedShadow.view = pinnedView;        pinnedShadow.position = position;        pinnedShadow.id = getAdapter().getItemId(position);        // store pinned shadow        mPinnedSection = pinnedShadow;    }    /** Destroy shadow wrapper for currently pinned view */    void destroyPinnedShadow() {        if (mPinnedSection != null) {            // keep shadow for being recycled later            mRecycleSection = mPinnedSection;            mPinnedSection = null;        }    }    /** Makes sure we have an actual pinned shadow for given position. */    void ensureShadowForPosition(int sectionPosition, int firstVisibleItem, int visibleItemCount) {        if (visibleItemCount < 2) { // no need for creating shadow at all, we have a single visible item            destroyPinnedShadow();            return;        }        if (mPinnedSection != null                && mPinnedSection.position != sectionPosition) { // invalidate shadow, if required            destroyPinnedShadow();        }        if (mPinnedSection == null) { // create shadow, if empty            createPinnedShadow(sectionPosition);        }        // align shadow according to next section position, if needed        int nextPosition = sectionPosition + 1;        if (nextPosition < getCount()) {            int nextSectionPosition = findFirstVisibleSectionPosition(nextPosition,                    visibleItemCount - (nextPosition - firstVisibleItem));            if (nextSectionPosition > -1) {                View nextSectionView = getChildAt(nextSectionPosition - firstVisibleItem);                final int bottom = mPinnedSection.view.getBottom() + getPaddingTop();                mSectionsDistanceY = nextSectionView.getTop() - bottom;                if (mSectionsDistanceY < 0) {                    // next section overlaps pinned shadow, move it up                    mTranslateY = mSectionsDistanceY;                } else {                    // next section does not overlap with pinned, stick to top                    mTranslateY = 0;                }            } else {                // no other sections are visible, stick to top                mTranslateY = 0;                mSectionsDistanceY = Integer.MAX_VALUE;            }        }    }    int findFirstVisibleSectionPosition(int firstVisibleItem, int visibleItemCount) {        ListAdapter adapter = getAdapter();        for (int childIndex = 0; childIndex < visibleItemCount; childIndex++) {            int position = firstVisibleItem + childIndex;            int viewType = adapter.getItemViewType(position);            if (isItemViewTypePinned(adapter, viewType)) return position;        }        return -1;    }    int findCurrentSectionPosition(int fromPosition) {        ListAdapter adapter = getAdapter();        if (adapter instanceof SectionIndexer) {            // try fast way by asking section indexer            SectionIndexer indexer = (SectionIndexer) adapter;            int sectionPosition = indexer.getSectionForPosition(fromPosition);            int itemPosition = indexer.getPositionForSection(sectionPosition);            int typeView = adapter.getItemViewType(itemPosition);            if (isItemViewTypePinned(adapter, typeView)) {                return itemPosition;            } // else, no luck        }        // try slow way by looking through to the next section item above        for (int position=fromPosition; position>=0; position--) {            int viewType = adapter.getItemViewType(position);            if (isItemViewTypePinned(adapter, viewType)) return position;        }        return -1; // no candidate found    }    void recreatePinnedShadow() {        destroyPinnedShadow();        ListAdapter adapter = getAdapter();        if (adapter != null && adapter.getCount() > 0) {            int firstVisiblePosition = getFirstVisiblePosition();            int sectionPosition = findCurrentSectionPosition(firstVisiblePosition);            if (sectionPosition == -1) return; // no views to pin, exit            ensureShadowForPosition(sectionPosition,                    firstVisiblePosition, getLastVisiblePosition() - firstVisiblePosition);        }    }    @Override    public void setOnScrollListener(OnScrollListener listener) {        if (listener == mOnScrollListener) {            super.setOnScrollListener(listener);        } else {            mDelegateOnScrollListener = listener;        }    }    @Override    public void onRestoreInstanceState(Parcelable state) {        super.onRestoreInstanceState(state);        post(new Runnable() {            @Override public void run() { // restore pinned view after configuration change                recreatePinnedShadow();            }        });    }    @Override    public void setAdapter(ListAdapter adapter) {        // assert adapter in debug mode//      if (BuildConfig.DEBUG && adapter != null) {        if (adapter != null) {            if (!(adapter instanceof PinnedSectionListAdapter))                throw new IllegalArgumentException("Does your adapter implement PinnedSectionListAdapter?");            if (adapter.getViewTypeCount() < 2)                throw new IllegalArgumentException("Does your adapter handle at least two types" +                        " of views in getViewTypeCount() method: items and sections?");        }        // unregister observer at old adapter and register on new one        ListAdapter oldAdapter = getAdapter();        if (oldAdapter != null) oldAdapter.unregisterDataSetObserver(mDataSetObserver);        if (adapter != null) adapter.registerDataSetObserver(mDataSetObserver);        // destroy pinned shadow, if new adapter is not same as old one        if (oldAdapter != adapter) destroyPinnedShadow();        super.setAdapter(adapter);    }    @Override    protected void onLayout(boolean changed, int l, int t, int r, int b) {        super.onLayout(changed, l, t, r, b);        if (mPinnedSection != null) {            int parentWidth = r - l - getPaddingLeft() - getPaddingRight();            int shadowWidth = mPinnedSection.view.getWidth();            if (parentWidth != shadowWidth) {                recreatePinnedShadow();            }        }    }    @Override    protected void dispatchDraw(Canvas canvas) {        super.dispatchDraw(canvas);        if (mPinnedSection != null) {            // prepare variables            int pLeft = getListPaddingLeft();            int pTop = getListPaddingTop();            View view = mPinnedSection.view;            // draw child            canvas.save();            int clipHeight = view.getHeight() +                    (mShadowDrawable == null ? 0 : Math.min(mShadowHeight, mSectionsDistanceY));            canvas.clipRect(pLeft, pTop, pLeft + view.getWidth(), pTop + clipHeight);            canvas.translate(pLeft, pTop + mTranslateY);            drawChild(canvas, mPinnedSection.view, getDrawingTime());            if (mShadowDrawable != null && mSectionsDistanceY > 0) {                mShadowDrawable.setBounds(mPinnedSection.view.getLeft(),                        mPinnedSection.view.getBottom(),                        mPinnedSection.view.getRight(),                        mPinnedSection.view.getBottom() + mShadowHeight);                mShadowDrawable.draw(canvas);            }            canvas.restore();        }    }    //-- touch handling methods    @Override    public boolean dispatchTouchEvent(MotionEvent ev) {        final float x = ev.getX();        final float y = ev.getY();        final int action = ev.getAction();        if (action == MotionEvent.ACTION_DOWN                && mTouchTarget == null                && mPinnedSection != null                && isPinnedViewTouched(mPinnedSection.view, x, y)) { // create touch target            // user touched pinned view            mTouchTarget = mPinnedSection.view;            mTouchPoint.x = x;            mTouchPoint.y = y;            // copy down event for eventually be used later            mDownEvent = MotionEvent.obtain(ev);        }        if (mTouchTarget != null) {            if (isPinnedViewTouched(mTouchTarget, x, y)) { // forward event to pinned view                mTouchTarget.dispatchTouchEvent(ev);            }            if (action == MotionEvent.ACTION_UP) { // perform onClick on pinned view                super.dispatchTouchEvent(ev);                performPinnedItemClick();                clearTouchTarget();            } else if (action == MotionEvent.ACTION_CANCEL) { // cancel                clearTouchTarget();            } else if (action == MotionEvent.ACTION_MOVE) {                if (Math.abs(y - mTouchPoint.y) > mTouchSlop) {                    // cancel sequence on touch target                    MotionEvent event = MotionEvent.obtain(ev);                    event.setAction(MotionEvent.ACTION_CANCEL);                    mTouchTarget.dispatchTouchEvent(event);                    event.recycle();                    // provide correct sequence to super class for further handling                    super.dispatchTouchEvent(mDownEvent);                    super.dispatchTouchEvent(ev);                    clearTouchTarget();                }            }            return true;        }        // call super if this was not our pinned view        return super.dispatchTouchEvent(ev);    }    private boolean isPinnedViewTouched(View view, float x, float y) {        view.getHitRect(mTouchRect);        // by taping top or bottom padding, the list performs on click on a border item.        // we don't add top padding here to keep behavior consistent.        mTouchRect.top += mTranslateY;        mTouchRect.bottom += mTranslateY + getPaddingTop();        mTouchRect.left += getPaddingLeft();        mTouchRect.right -= getPaddingRight();        return mTouchRect.contains((int)x, (int)y);    }    private void clearTouchTarget() {        mTouchTarget = null;        if (mDownEvent != null) {            mDownEvent.recycle();            mDownEvent = null;        }    }    private boolean performPinnedItemClick() {        if (mPinnedSection == null) return false;        OnItemClickListener listener = getOnItemClickListener();        if (listener != null) {            View view =  mPinnedSection.view;            playSoundEffect(SoundEffectConstants.CLICK);            if (view != null) {                view.sendAccessibilityEvent(AccessibilityEvent.TYPE_VIEW_CLICKED);            }            listener.onItemClick(this, view, mPinnedSection.position, mPinnedSection.id);            return true;        }        return false;    }    public static boolean isItemViewTypePinned(ListAdapter adapter, int viewType) {        if (adapter instanceof HeaderViewListAdapter) {            adapter = ((HeaderViewListAdapter)adapter).getWrappedAdapter();        }        return ((PinnedSectionListAdapter) adapter).isItemViewTypePinned(viewType);    }}

mContentAdapter = new AutoOrderingAdapter(AutoOrderingActivity.this,mArrProduct ,mHandler , new LeftAdapter() {        @Override        public void refreshLeftAdapter(int position) {            // TODO Auto-generated method stub            for(int i = 0 ; i < mArrType.size() ; i++){                if(mArrType.get(i).pos == position){                    mTitleAdapter.refresh(mArrType, i);                }            }        }    });

import java.util.ArrayList;import android.view.View;import android.view.ViewGroup;import android.widget.BaseAdapter;import com.pupuwang.ycyl.R;import com.pupuwang.ycyl.main.home.shops.model.ShopProduct;import com.pupuwang.ycyl.ordering.AutoOrderingAdapter.ViewHolder;import com.pupuwang.ycyl.view.PinnedSectionListView.PinnedSectionListAdapter;public class AutoOrderingAdapter extends BaseAdapter implements PinnedSectionListAdapter{    public void refresh(ArrayList arr){        setArr(arr);        notifyDataSetChanged();    }    @Override    public int getCount() {        // TODO Auto-generated method stub        return arr.size();    }    @Override    public Object getItem(int position) {        // TODO Auto-generated method stub        return arr.get(position);    }    @Override    public long getItemId(int position) {        // TODO Auto-generated method stub        return position;    }    @Override    public View getView(int position, View convertView, ViewGroup parent) {        // TODO Auto-generated method stub        ViewHolder holder = null;        if (convertView == null ||null == (ViewHolder) convertView.getTag(R.id.idkey0 + (position+1)*1000)) {            holder = new ViewHolder();            convertView = mInflater.inflate(R.layout.auto_ordering_child_item, null);            initHolder(convertView, holder);            convertView.setTag(R.id.idkey0 + (position+1)*1000, holder);        }else{            holder = (ViewHolder) convertView.getTag(R.id.idkey0 + (position+1)*1000);        }    }                          @Override    public boolean isItemViewTypePinned(int viewType) {        // TODO Auto-generated method stub        return viewType == 0;//0是标题，1是内容    }                            @Override      public int getViewTypeCount() {          return 2;//2种view的类型 baseAdapter中得方法      }      @Override      public int getItemViewType(int position) {          return ((ShopProduct)getItem(position)).getTitleType();      }                      @Override    public void getShadowPosition(int position) {        // TODO Auto-generated method stub        Log.e("tag", "--------------position: "+ position);        left.refreshLeftAdapter(position);    }

BaseAdapter中不仅仅只有常用必重写得4个方法，还有写方法特殊情况下需要用得getViewTypeCount()

其中主要代码效果在github中找的自己研究下，关于淘点点得效果，还需要另外一个listview相互控制，希望大家能贡献更多得源码，大家不在苦逼。