android view实现横向滑动选择

 public boolean mAlwaysOverrideTouch = true; protected ListAdapter mAdapter; private int mLeftViewIndex = -1; private int mRightViewIndex = 0; protected int mCurrentX; protected int mNextX; private int mMaxX = Integer.MAX_VALUE; private int mDisplayOffset = 0; protected Scroller mScroller; private GestureDetector mGesture; private Queue mRemovedViewQueue = new LinkedList(); private OnItemSelectedListener mOnItemSelected; private OnItemClickListener mOnItemClicked; private OnItemLongClickListener mOnItemLongClicked; private OnScrollListener mScrollListener; /** * 选中item时图片 */ private Drawable mDrawable; private boolean mDataChanged = false; private Context context; private boolean scrollerFalg1 = false; private boolean scrollerFalg2 = false; private int position = 0x7f020000; public HorizontalScrollSelectView(Context context, AttributeSet attrs) { super(context, attrs); this.context = context; initView(); } private synchronized void initView() { mLeftViewIndex = -1; mRightViewIndex = 0; mDisplayOffset = 0; mCurrentX = 0; mNextX = 0; mMaxX = Integer.MAX_VALUE; mScroller = new Scroller(getContext()); mGesture = new GestureDetector(getContext(), mOnGesture); } public void setMScrollListener(OnScrollListener listener) { mScrollListener = listener; } @Override public void setOnItemSelectedListener(OnItemSelectedListener listener) { mOnItemSelected = listener; } @Override public void setOnItemClickListener(OnItemClickListener listener) { mOnItemClicked = listener; } @Override public void setOnItemLongClickListener(OnItemLongClickListener listener) { mOnItemLongClicked = listener; } /** * 设置选中状态时的图片 * * @param mDrawable */ public void setSelectBitmap(Drawable mDrawable) { this.mDrawable = mDrawable; } private DataSetObserver mDataObserver = new DataSetObserver() { @Override public void onChanged() { synchronized (HorizontalScrollSelectView.this) { mDataChanged = true; } invalidate(); requestLayout(); } @Override public void onInvalidated() { reset(); invalidate(); requestLayout(); } }; @Override public ListAdapter getAdapter() { return mAdapter; } @Override public View getSelectedView() { //TODO: implement return null; } @Override public void setAdapter(ListAdapter adapter) { if (mAdapter != null) { mAdapter.unregisterDataSetObserver(mDataObserver); } mAdapter = adapter; mAdapter.registerDataSetObserver(mDataObserver); reset(); } private synchronized void reset() { initView(); removeAllViewsInLayout(); requestLayout(); } @Override public void setSelection(int position) { //TODO: implement int positionX = position * this.getWidth(); int maxWidth = this.getChildCount() * this.getWidth(); if (positionX <= 0) { positionX = 0; } if (positionX > maxWidth) { positionX = maxWidth; } scrollTo(positionX); } private void addAndMeasureChild(final View child, int viewPos) { LayoutParams params = child.getLayoutParams(); if (params == null) { params = new LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT); } addViewInLayout(child, viewPos, params, true); child.measure(MeasureSpec.makeMeasureSpec(getWidth(), MeasureSpec.AT_MOST), MeasureSpec.makeMeasureSpec(getHeight(), MeasureSpec.AT_MOST)); } @SuppressLint("NewApi") @Override protected synchronized void onLayout(boolean changed, int left, int top, int right, int bottom) { super.onLayout(changed, left, top, right, bottom); if (mAdapter == null) { return; } if (mDataChanged) { int oldCurrentX = mCurrentX; initView(); removeAllViewsInLayout(); mNextX = oldCurrentX; mDataChanged = false; } if (mScroller.computeScrollOffset()) { int scrollx = mScroller.getCurrX(); mNextX = scrollx; } // if(mNextX <= 0){ //  mNextX = 0; //  mScroller.forceFinished(true); // } // if(mNextX >= mMaxX) { //  mNextX = mMaxX; //  mScroller.forceFinished(true); // } int dx = mCurrentX - mNextX; removeNonVisibleItems(dx); fillList(dx); positionItems(dx); // Log.e("onlayout", "mLeftViewIndex"+(mLeftViewIndex+1)); mCurrentX = mNextX; if (!mScroller.isFinished()) { post(new Runnable() { @Override public void run() { requestLayout(); } }); } else { if (scrollerFalg1 || (!scrollerFalg1 && scrollerFalg2)) { View chid = getChildAt(0); if (chid != null) { mDisplayOffset = 0; positionItems(0); if (mDrawable != null) { getChildAt(2).setBackground(mDrawable); } if (mScrollListener != null) { int position = (int) getChildAt(2).getTag(this.position); mScrollListener.onScrollSelectItem(this, position); } } } } } /** * 获取屏幕宽度 * * @param context * @return */ public static int getSecreenWidth(Context context) { DisplayMetrics dm = new DisplayMetrics(); dm = context.getResources().getDisplayMetrics(); int screenWidth = dm.widthPixels; return screenWidth / 5; } private void fillList(final int dx) { int edge = 0; View child = getChildAt(0); if (child != null) { edge = child.getLeft(); } fillListLeft(edge, dx); edge = 0; child = getChildAt(getChildCount() - 1); if (child != null) { edge = child.getRight(); } fillListRight(edge, dx); } private void fillListRight(int rightEdge, final int dx) { //&& mRightViewIndex = mAdapter.getCount()) { mRightViewIndex = 0; } View child = mAdapter.getView(mRightViewIndex, mRemovedViewQueue.poll(), this); child.setTag(position, mRightViewIndex); addAndMeasureChild(child, -1); rightEdge += child.getMeasuredWidth(); //  if(mRightViewIndex == mAdapter.getCount()-1) { //  mMaxX = mCurrentX + rightEdge - getWidth(); //  } // //  if (mMaxX <0) { //  mMaxX = 0; //  } mRightViewIndex++; } } private void fillListLeft(int leftEdge, final int dx) { //&& mLeftViewIndex >= 0 while (leftEdge + dx > 0) { if (mLeftViewIndex <= -1) { mLeftViewIndex = mAdapter.getCount() - 1; } View child = mAdapter.getView(mLeftViewIndex, mRemovedViewQueue.poll(), this); child.setTag(position, mLeftViewIndex); addAndMeasureChild(child, 0); leftEdge -= child.getMeasuredWidth(); mLeftViewIndex--; mDisplayOffset -= child.getMeasuredWidth(); } } private void removeNonVisibleItems(final int dx) { View child = getChildAt(0); while (child != null && child.getRight() + dx <= 0) { mDisplayOffset += child.getMeasuredWidth(); mRemovedViewQueue.offer(child); removeViewInLayout(child); mLeftViewIndex++; if (mLeftViewIndex >= mAdapter.getCount()) { mLeftViewIndex = 0; } child = getChildAt(0); } child = getChildAt(getChildCount() - 1); while (child != null && child.getLeft() + dx >= getWidth()) { mRemovedViewQueue.offer(child); removeViewInLayout(child); mRightViewIndex--; if (mRightViewIndex <= -1) { mRightViewIndex = mAdapter.getCount() - 1; } child = getChildAt(getChildCount() - 1); } } private void positionItems(final int dx) { if (getChildCount() > 0) { mDisplayOffset += dx; int left = mDisplayOffset; for (int i = 0; i