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<View  mRemovedViewQueue = new LinkedList<View ();
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()
while (rightEdge + dx < getWidth()) {
if (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 < getChildCount(); i++) {
View child = getChildAt(i);
getChildAt(2).setBackground(null);
int childWidth = child.getMeasuredWidth();
child.layout(left, 0, left + childWidth, child.getMeasuredHeight());
left += childWidth + child.getPaddingRight();
}
}
}
public synchronized void scrollTo(int x) {
mScroller.startScroll(mNextX, 0, x - mNextX, 0);
requestLayout();
}
@Override
public boolean dispatchTouchEvent(MotionEvent ev) {
boolean handled = super.dispatchTouchEvent(ev);
handled |= mGesture.onTouchEvent(ev);
switch (ev.getAction()) {
case MotionEvent.ACTION_UP:
scrollerFalg2 = true;
requestLayout();
break;
default:
break;
}
return handled;
}
protected boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,
float velocityY) {
synchronized (HorizontalScrollSelectView.this) {
//mNextX
mScroller.fling(mNextX, 0, (int) -velocityX, 0, Integer.MIN_VALUE, mMaxX, 0, 0);
}
requestLayout();
scrollerFalg1 = true;
return true;
}
protected boolean onDown(MotionEvent e) {
mScroller.forceFinished(true);
return true;
}
public interface OnScrollListener {
/**
* 互动过程中选中的item
*
* @param position
*/
public void onScrollSelectItem(ViewGroup viewGroup, int position);
}
private OnGestureListener mOnGesture = new GestureDetector.SimpleOnGestureListener() {
@Override
public boolean onDown(MotionEvent e) {
return HorizontalScrollSelectView.this.onDown(e);
}
@Override
public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,
float velocityY) {
return HorizontalScrollSelectView.this.onFling(e1, e2, velocityX, velocityY);
}
@Override
public boolean onScroll(MotionEvent e1, MotionEvent e2,
float distanceX, float distanceY) {
synchronized (HorizontalScrollSelectView.this) {
mNextX += (int) distanceX;
}
requestLayout();
scrollerFalg1 = false;
scrollerFalg2 = false;
return true;
}
@Override
public void onShowPress(MotionEvent e) {
super.onShowPress(e);
}
@Override
public boolean onSingleTapUp(MotionEvent e) {
Log.e("onSingleTapUp", "mLeftViewIndex" + (mLeftViewIndex + 1));
//  scrollerFalg=true;
return super.onSingleTapUp(e);
}
@Override
public boolean onSingleTapConfirmed(MotionEvent e) {
for (int i = 0; i < getChildCount(); i++) {
View child = getChildAt(i);
if (isEventWithinView(e, child)) {
if (mOnItemClicked != null) {
mOnItemClicked.onItemClick(HorizontalScrollSelectView.this, child, mLeftViewIndex + 1 + i, mAdapter.getItemId(mLeftViewIndex + 1 + i));
}
if (mOnItemSelected != null) {
mOnItemSelected.onItemSelected(HorizontalScrollSelectView.this, child, mLeftViewIndex + 1 + i, mAdapter.getItemId(mLeftViewIndex + 1 + i));
}
break;
}
}
return true;
}
@Override
public void onLongPress(MotionEvent e) {
int childCount = getChildCount();
for (int i = 0; i < childCount; i++) {
View child = getChildAt(i);
if (isEventWithinView(e, child)) {
if (mOnItemLongClicked != null) {
mOnItemLongClicked.onItemLongClick(HorizontalScrollSelectView.this, child, mLeftViewIndex + 1 + i, mAdapter.getItemId(mLeftViewIndex + 1 + i));
}
break;
}
}
}
private boolean isEventWithinView(MotionEvent e, View child) {
Rect viewRect = new Rect();
int[] childPosition = new int[2];
child.getLocationOnScreen(childPosition);
int left = childPosition[0];
int right = left + child.getWidth();
int top = childPosition[1];
int bottom = top + child.getHeight();
viewRect.set(left, top, right, bottom);
return viewRect.contains((int) e.getRawX(), (int) e.getRawY());
}
};