package com.tejia.lijin.app.ui.subview;
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import android.content.Context;
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import android.database.DataSetObserver;
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import android.graphics.Rect;
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import android.util.AttributeSet;
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import android.view.GestureDetector;
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import android.view.GestureDetector.OnGestureListener;
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import android.view.MotionEvent;
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import android.view.View;
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import android.widget.AdapterView;
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import android.widget.ListAdapter;
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import android.widget.Scroller;
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import java.util.LinkedList;
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import java.util.Queue;
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public class HorizontalListView extends AdapterView<ListAdapter> {
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public boolean mAlwaysOverrideTouch = true;
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protected ListAdapter mAdapter;
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private int mLeftViewIndex = -1;
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private int mRightViewIndex = 0;
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protected int mCurrentX;
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protected int mNextX;
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private int mMaxX = Integer.MAX_VALUE;
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private int mDisplayOffset = 0;
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protected Scroller mScroller;
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private GestureDetector mGesture;
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private Queue<View> mRemovedViewQueue = new LinkedList<>();
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private OnItemSelectedListener mOnItemSelected;
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private OnItemClickListener mOnItemClicked;
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private OnItemLongClickListener mOnItemLongClicked;
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private boolean mDataChanged = false;
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public HorizontalListView(Context context, AttributeSet attrs) {
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super(context, attrs);
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initView();
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}
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private synchronized void initView() {
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mLeftViewIndex = -1;
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mRightViewIndex = 0;
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mDisplayOffset = 0;
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mCurrentX = 0;
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mNextX = 0;
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mMaxX = Integer.MAX_VALUE;
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mScroller = new Scroller(getContext());
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mGesture = new GestureDetector(getContext(), mOnGesture);
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}
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@Override
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public void setOnItemSelectedListener(OnItemSelectedListener listener) {
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mOnItemSelected = listener;
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}
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@Override
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public void setOnItemClickListener(OnItemClickListener listener) {
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mOnItemClicked = listener;
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}
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@Override
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public void setOnItemLongClickListener(OnItemLongClickListener listener) {
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mOnItemLongClicked = listener;
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}
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private DataSetObserver mDataObserver = new DataSetObserver() {
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@Override
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public void onChanged() {
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synchronized (HorizontalListView.this) {
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mDataChanged = true;
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}
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invalidate();
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requestLayout();
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}
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@Override
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public void onInvalidated() {
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reset();
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invalidate();
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requestLayout();
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}
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};
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public boolean onInterceptTouchEvent(MotionEvent ev) {
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getParent().requestDisallowInterceptTouchEvent(true);
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return mGesture.onTouchEvent(ev);
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}
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;
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@Override
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public ListAdapter getAdapter() {
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return mAdapter;
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}
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@Override
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public View getSelectedView() {
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return null;
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}
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@Override
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public void setAdapter(ListAdapter adapter) {
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if (mAdapter != null) {
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mAdapter.unregisterDataSetObserver(mDataObserver);
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}
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mAdapter = adapter;
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mAdapter.registerDataSetObserver(mDataObserver);
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reset();
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}
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private synchronized void reset() {
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initView();
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removeAllViewsInLayout();
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requestLayout();
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}
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@Override
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public void setSelection(int position) {
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}
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private void addAndMeasureChild(final View child, int viewPos) {
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LayoutParams params = child.getLayoutParams();
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if (params == null) {
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params = new LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT);
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}
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addViewInLayout(child, viewPos, params, true);
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child.measure(MeasureSpec.makeMeasureSpec(getWidth(), MeasureSpec.AT_MOST),
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MeasureSpec.makeMeasureSpec(getHeight(), MeasureSpec.AT_MOST));
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}
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@Override
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protected synchronized void onLayout(boolean changed, int left, int top, int right, int bottom) {
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super.onLayout(changed, left, top, right, bottom);
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if (mAdapter == null) {
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return;
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}
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if (mDataChanged) {
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int oldCurrentX = mCurrentX;
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initView();
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removeAllViewsInLayout();
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mNextX = oldCurrentX;
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mDataChanged = false;
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}
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if (mScroller.computeScrollOffset()) {
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int scrollx = mScroller.getCurrX();
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mNextX = scrollx;
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}
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if (mNextX <= 0) {
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mNextX = 0;
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mScroller.forceFinished(true);
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}
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if (mNextX >= mMaxX) {
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mNextX = mMaxX;
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mScroller.forceFinished(true);
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}
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int dx = mCurrentX - mNextX;
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removeNonVisibleItems(dx);
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fillList(dx);
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positionItems(dx);
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mCurrentX = mNextX;
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if (!mScroller.isFinished()) {
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post(new Runnable() {
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@Override
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public void run() {
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requestLayout();
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}
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});
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}
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}
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private void fillList(final int dx) {
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int edge = 0;
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View child = getChildAt(getChildCount() - 1);
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if (child != null) {
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edge = child.getRight();
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}
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fillListRight(edge, dx);
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edge = 0;
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child = getChildAt(0);
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if (child != null) {
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edge = child.getLeft();
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}
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fillListLeft(edge, dx);
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}
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private void fillListRight(int rightEdge, final int dx) {
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while (rightEdge + dx < getWidth() && mRightViewIndex < mAdapter.getCount()) {
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View child = mAdapter.getView(mRightViewIndex, mRemovedViewQueue.poll(), this);
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addAndMeasureChild(child, -1);
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rightEdge += child.getMeasuredWidth();
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if (mRightViewIndex == mAdapter.getCount() - 1) {
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mMaxX = mCurrentX + rightEdge - getWidth();
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}
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if (mMaxX < 0) {
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mMaxX = 0;
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}
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mRightViewIndex++;
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}
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}
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private void fillListLeft(int leftEdge, final int dx) {
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while (leftEdge + dx > 0 && mLeftViewIndex >= 0) {
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View child = mAdapter.getView(mLeftViewIndex, mRemovedViewQueue.poll(), this);
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addAndMeasureChild(child, 0);
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leftEdge -= child.getMeasuredWidth();
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mLeftViewIndex--;
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mDisplayOffset -= child.getMeasuredWidth();
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}
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}
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private void removeNonVisibleItems(final int dx) {
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View child = getChildAt(0);
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while (child != null && child.getRight() + dx <= 0) {
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mDisplayOffset += child.getMeasuredWidth();
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mRemovedViewQueue.offer(child);
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removeViewInLayout(child);
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mLeftViewIndex++;
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child = getChildAt(0);
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}
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child = getChildAt(getChildCount() - 1);
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while (child != null && child.getLeft() + dx >= getWidth()) {
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mRemovedViewQueue.offer(child);
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removeViewInLayout(child);
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mRightViewIndex--;
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child = getChildAt(getChildCount() - 1);
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}
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}
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private void positionItems(final int dx) {
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if (getChildCount() > 0) {
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mDisplayOffset += dx;
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int left = mDisplayOffset;
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for (int i = 0; i < getChildCount(); i++) {
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View child = getChildAt(i);
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int childWidth = child.getMeasuredWidth();
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child.layout(left, 0, left + childWidth, child.getMeasuredHeight());
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left += childWidth + child.getPaddingRight();
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}
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}
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}
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public synchronized void scrollTo(int x) {
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mScroller.startScroll(mNextX, 0, x - mNextX, 0);
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requestLayout();
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}
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@Override
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public boolean dispatchTouchEvent(MotionEvent ev) {
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boolean handled = super.dispatchTouchEvent(ev);
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handled |= mGesture.onTouchEvent(ev);
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return handled;
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}
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protected boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,
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float velocityY) {
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synchronized (HorizontalListView.this) {
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mScroller.fling(mNextX, 0, (int) -velocityX, 0, 0, mMaxX, 0, 0);
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}
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requestLayout();
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return true;
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}
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protected boolean onDown(MotionEvent e) {
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mScroller.forceFinished(true);
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return true;
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}
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private OnGestureListener mOnGesture = new GestureDetector.SimpleOnGestureListener() {
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@Override
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public boolean onDown(MotionEvent e) {
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return HorizontalListView.this.onDown(e);
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}
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@Override
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public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,
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float velocityY) {
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return HorizontalListView.this.onFling(e1, e2, velocityX, velocityY);
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}
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@Override
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public boolean onScroll(MotionEvent e1, MotionEvent e2,
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float distanceX, float distanceY) {
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synchronized (HorizontalListView.this) {
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mNextX += (int) distanceX;
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}
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requestLayout();
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return true;
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}
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@Override
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public boolean onSingleTapConfirmed(MotionEvent e) {
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for (int i = 0; i < getChildCount(); i++) {
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View child = getChildAt(i);
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if (isEventWithinView(e, child)) {
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if (mOnItemClicked != null) {
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mOnItemClicked.onItemClick(HorizontalListView.this, child, mLeftViewIndex + 1 + i, mAdapter.getItemId(mLeftViewIndex + 1 + i));
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}
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if (mOnItemSelected != null) {
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mOnItemSelected.onItemSelected(HorizontalListView.this, child, mLeftViewIndex + 1 + i, mAdapter.getItemId(mLeftViewIndex + 1 + i));
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}
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break;
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}
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}
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return true;
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}
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@Override
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public void onLongPress(MotionEvent e) {
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int childCount = getChildCount();
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for (int i = 0; i < childCount; i++) {
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View child = getChildAt(i);
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if (isEventWithinView(e, child)) {
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if (mOnItemLongClicked != null) {
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mOnItemLongClicked.onItemLongClick(HorizontalListView.this, child, mLeftViewIndex + 1 + i, mAdapter.getItemId(mLeftViewIndex + 1 + i));
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}
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break;
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}
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}
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}
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private boolean isEventWithinView(MotionEvent e, View child) {
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Rect viewRect = new Rect();
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int[] childPosition = new int[2];
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child.getLocationOnScreen(childPosition);
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int left = childPosition[0];
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int right = left + child.getWidth();
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int top = childPosition[1];
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int bottom = top + child.getHeight();
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viewRect.set(left, top, right, bottom);
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return viewRect.contains((int) e.getRawX(), (int) e.getRawY());
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}
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};
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}
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