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Commit c98d0e2

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Paul Soucy
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Added an IteratorListView and a SimplePrefsStorage
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2 files changed

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‎devsmartlib/src/com/devsmart/android/SimplePrefsStorage.java

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package com.devsmart.android;
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import org.json.JSONException;
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import org.json.JSONObject;
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import android.content.Context;
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import android.content.SharedPreferences;
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import android.content.SharedPreferences.Editor;
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import android.util.Log;
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public class SimplePrefsStorage {
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public static final String PREFS_NAME = "simpleprefs";
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private static final String KEY_NAME = "jsonprefs";
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private SharedPreferences mPrefs;
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public SimplePrefsStorage(Context context) {
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mPrefs = context.getSharedPreferences(PREFS_NAME, Context.MODE_PRIVATE);
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}
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public void clear() {
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Editor e = mPrefs.edit();
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e.clear();
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e.commit();
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}
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public JSONObject getData() {
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JSONObject retval = new JSONObject();
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String jsonstr = mPrefs.getString(KEY_NAME, null);
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if(jsonstr != null){
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try {
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retval = new JSONObject(jsonstr);
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} catch (JSONException e) {
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Log.e(SimplePrefsStorage.class.getName(), "", e);
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}
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}
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return retval;
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}
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public void save(JSONObject data) {
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Editor e = mPrefs.edit();
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e.putString(KEY_NAME, data.toString());
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e.commit();
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}
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}

‎devsmartlib/src/com/devsmart/android/ui/IteratorListView.java

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package com.devsmart.android.ui;
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import java.util.LinkedList;
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import java.util.ListIterator;
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import java.util.Queue;
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import android.content.Context;
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import android.util.AttributeSet;
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import android.view.GestureDetector;
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import android.view.MotionEvent;
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import android.view.View;
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import android.view.ViewGroup;
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import android.widget.Scroller;
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public class IteratorListView extends ViewGroup {
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public interface ViewAdapter<T extends Object> {
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View getView(T obj, View poll, IteratorListView iteratorListView);
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}
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private Queue<View> mRemovedViewQueue = new LinkedList<View>();
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private Scroller mScroller;
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private GestureDetector mScrollGestureDetector;
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//number of pixes to scroll on the next onLayout
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private int mdY = 0;
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private int mLastY = 0;
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private int mYOffset = 0;
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private boolean mIsFingerDown;
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private int mTopItem = 0;
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private int mBottomItem = 0;
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private int mCurrentItem = 0;
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private ListIterator<?> mIterator;
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private ViewAdapter<Object> mAdapter;
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public IteratorListView(Context context) {
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super(context);
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init();
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}
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public IteratorListView(Context context, AttributeSet attrs) {
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super(context, attrs);
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init();
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}
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private void init() {
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mScroller = new Scroller(getContext());
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mScrollGestureDetector = new GestureDetector(getContext(), mOnGesture);
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}
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public <T> void setIteratorAdapter(ListIterator<T> iterator, ViewAdapter<T> adapter) {
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mIterator = iterator;
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mAdapter = (ViewAdapter<Object>) adapter;
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//seek to the top of the list
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while(mIterator.hasPrevious()){
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mIterator.previous();
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}
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mTopItem = 0;
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mBottomItem = -1;
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mCurrentItem = -1;
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removeAllViews();
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}
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private GestureDetector.SimpleOnGestureListener mOnGesture = new GestureDetector.SimpleOnGestureListener() {
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@Override
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public boolean onDown(MotionEvent e) {
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mIsFingerDown = true;
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mScroller.forceFinished(true);
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return true;
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}
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@Override
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public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
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final int maxScrollDistance = getMeasuredHeight()*1;
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mLastY = 0;
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mScroller.fling(0, mdY, 0, Math.round(velocityY), 0, 0, -maxScrollDistance, maxScrollDistance);
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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 onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {
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mdY -= Math.round(distanceY);
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requestLayout();
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return true;
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}
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};
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@Override
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public boolean onTouchEvent(MotionEvent event) {
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boolean retval = mScrollGestureDetector.onTouchEvent(event);
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if(event.getAction() == MotionEvent.ACTION_UP){
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mIsFingerDown = false;
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if(getChildCount() > 0){
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int topOfFirstChild = getChildAt(0).getTop();
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if(topOfFirstChild + mdY > 0){
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mScroller.forceFinished(true);
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mLastY = 0;
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mScroller.startScroll(0, 0, mdY, -mYOffset);
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requestLayout();
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}
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}
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}
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return retval;
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}
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@Override
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protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
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super.onMeasure(widthMeasureSpec, heightMeasureSpec);
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for(int i = 0;i<getChildCount();i++){
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View child = getChildAt(i);
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int oldHeight = child.getMeasuredHeight();
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child.measure(MeasureSpec.makeMeasureSpec(getWidth(), MeasureSpec.EXACTLY),
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MeasureSpec.makeMeasureSpec(getHeight(), MeasureSpec.UNSPECIFIED));
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int childDiff = child.getMeasuredHeight() - oldHeight;
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if(childDiff > 0 && child.getBottom() < getHeight()/2){
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mYOffset -= childDiff;
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}
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}
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}
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@Override
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protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
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if(mAdapter == null){
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return;
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}
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if(mScroller.computeScrollOffset()){
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int y = mScroller.getCurrY();
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mdY += y - mLastY;
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mLastY = y;
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}
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mYOffset += mdY;
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removeNonVisibleItems();
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fillDown();
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fillUp();
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positionItems();
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mdY = 0;
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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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} else if(mYOffset > 0 && !mIsFingerDown){
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mLastY = 0;
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mScroller.startScroll(0, 0, mdY, -mYOffset);
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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 removeNonVisibleItems(){
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final int height = getHeight();
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View child = getChildAt(0);
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//remove from top
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while(child != null && child.getBottom() + mdY < 0){
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removeViewInLayout(child);
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mRemovedViewQueue.offer(child);
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mYOffset += child.getMeasuredHeight();
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child = getChildAt(0);
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mTopItem++;
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}
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//remove from bottom
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child = getChildAt(getChildCount()-1);
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while(child != null && child.getTop() + mdY > height){
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removeViewInLayout(child);
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mRemovedViewQueue.offer(child);
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child = getChildAt(getChildCount()-1);
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mBottomItem--;
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}
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}
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private void addAndMeasureChild(View child, int index){
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LayoutParams layoutparams = child.getLayoutParams();
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if(layoutparams == null){
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layoutparams = new LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.WRAP_CONTENT);
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}
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addViewInLayout(child, index, layoutparams, true);
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child.measure(MeasureSpec.makeMeasureSpec(getWidth(), MeasureSpec.EXACTLY),
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MeasureSpec.makeMeasureSpec(getHeight(), MeasureSpec.UNSPECIFIED));
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}
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private View getView(Object obj) {
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View child = mAdapter.getView(obj, mRemovedViewQueue.poll(), this);
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return child;
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}
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private void fillDown() {
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if(mAdapter == null){
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return;
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}
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final int windowHeight = getHeight();
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int bottomOfLastChild = 0;
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if(getChildCount() > 0){
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bottomOfLastChild = getChildAt(getChildCount()-1).getBottom();
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}
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while(bottomOfLastChild + mdY < windowHeight && mIterator.hasNext()) {
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Object obj = mIterator.next();
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mCurrentItem++;
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if(mCurrentItem > mBottomItem){
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View child = getView(obj);
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addAndMeasureChild(child, -1);
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bottomOfLastChild += child.getMeasuredHeight();
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mBottomItem = mCurrentItem;
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}
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}
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}
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private void fillUp() {
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if(mAdapter == null){
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return;
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}
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int topOfFirstChild = 0;
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if(getChildCount() > 0){
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topOfFirstChild = getChildAt(0).getTop();
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}
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while(topOfFirstChild + mdY > 0 && mIterator.hasPrevious()) {
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Object obj = mIterator.previous();
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mCurrentItem--;
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if(mCurrentItem < mTopItem){
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View child = getView(obj);
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addAndMeasureChild(child, 0);
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topOfFirstChild -= child.getMeasuredHeight();
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mYOffset -= child.getMeasuredHeight();
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mTopItem = mCurrentItem;
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}
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}
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}
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private void positionItems() {
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int top = mYOffset;
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for(int i=0;i<getChildCount();i++){
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View child = getChildAt(i);
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int childHeight = child.getMeasuredHeight();
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child.layout(0, top, child.getMeasuredWidth(), top + childHeight);
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top += childHeight;
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}
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}
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}

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