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Hamid Palo
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Add ViewObservables.listViewScroll(AbsListView).
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+259
-19
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5 files changed

+259
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‎rxandroid/src/main/java/rx/android/events/OnListViewScrollEvent.java

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/**
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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package rx.android.events;
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import android.widget.AbsListView;
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public class OnListViewScrollEvent {
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public final AbsListView listView;
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public final int scrollState;
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public final int firstVisibleItem;
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public final int visibleItemCount;
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public final int totalItemCount;
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public OnListViewScrollEvent(
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AbsListView listView, int scrollState, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
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this.listView = listView;
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this.scrollState = scrollState;
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this.firstVisibleItem = firstVisibleItem;
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this.visibleItemCount = visibleItemCount;
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this.totalItemCount = totalItemCount;
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}
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@Override
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public boolean equals(Object o) {
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if (this == o) {
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return true;
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}
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if (o == null || getClass() != o.getClass()) {
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return false;
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}
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OnListViewScrollEvent that = (OnListViewScrollEvent) o;
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if (firstVisibleItem != that.firstVisibleItem) {
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return false;
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}
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if (scrollState != that.scrollState) {
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return false;
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}
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if (totalItemCount != that.totalItemCount) {
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return false;
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}
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if (visibleItemCount != that.visibleItemCount) {
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return false;
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}
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if (!listView.equals(that.listView)) {
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return false;
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}
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return true;
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}
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@Override
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public int hashCode() {
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int result = listView.hashCode();
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result = 31 * result + scrollState;
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result = 31 * result + firstVisibleItem;
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result = 31 * result + visibleItemCount;
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result = 31 * result + totalItemCount;
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return result;
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}
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@Override
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public String toString() {
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return "OnListViewScrollEvent{" +
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"listView=" + listView +
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", scrollState=" + scrollState +
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", firstVisibleItem=" + firstVisibleItem +
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", visibleItemCount=" + visibleItemCount +
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", totalItemCount=" + totalItemCount +
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'}';
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}
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}

‎rxandroid/src/main/java/rx/android/observables/ViewObservable.java

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@@ -14,6 +14,7 @@
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package rx.android.observables;
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import android.view.View;
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import android.widget.AbsListView;
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import android.widget.AdapterView;
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import android.widget.CompoundButton;
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import android.widget.TextView;
@@ -22,9 +23,11 @@
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import rx.android.events.OnCheckedChangeEvent;
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import rx.android.events.OnClickEvent;
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import rx.android.events.OnItemClickEvent;
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import rx.android.events.OnListViewScrollEvent;
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import rx.android.events.OnTextChangeEvent;
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import rx.android.operators.OperatorAdapterViewOnItemClick;
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import rx.android.operators.OperatorCompoundButtonInput;
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import rx.android.operators.OnSubscribeListViewScroll;
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import rx.android.operators.OperatorTextViewInput;
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import rx.android.operators.OperatorViewClick;
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@@ -58,4 +61,13 @@ public static Observable<OnItemClickEvent> itemClicks(final AdapterView<?> adapt
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return Observable.create(new OperatorAdapterViewOnItemClick(adapterView));
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}
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/**
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* Returns an observable that emits all the scroll events from the provided ListView.
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* Note that this will replace any listeners previously set through
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* {@link android.widget.AbsListView#setOnScrollListener(android.widget.AbsListView.OnScrollListener)} unless those
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* were set by this method or {@link rx.android.operators.OnSubscribeListViewScroll}.
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*/
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public static Observable<OnListViewScrollEvent> listScrollEvents(final AbsListView listView) {
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return Observable.create(new OnSubscribeListViewScroll(listView));
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}
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}

‎rxandroid/src/main/java/rx/android/operators/OnSubscribeListViewScroll.java

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/**
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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package rx.android.operators;
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import android.widget.AbsListView;
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import android.widget.AdapterView;
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import rx.Observable;
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import rx.Subscriber;
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import rx.android.events.OnListViewScrollEvent;
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import rx.android.observables.Assertions;
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import rx.android.subscriptions.AndroidSubscriptions;
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import rx.functions.Action0;
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import java.util.ArrayList;
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import java.util.List;
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import java.util.Map;
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import java.util.WeakHashMap;
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public class OnSubscribeListViewScroll implements Observable.OnSubscribe<OnListViewScrollEvent> {
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private final AbsListView listView;
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public OnSubscribeListViewScroll(AbsListView listView) {
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this.listView = listView;
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}
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@Override
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public void call(final Subscriber<? super OnListViewScrollEvent> observer) {
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Assertions.assertUiThread();
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final CompositeOnScrollListener composite = CachedListeners.getFromViewOrCreate(listView);
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final AbsListView.OnScrollListener listener = new AbsListView.OnScrollListener() {
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int currentScrollState = SCROLL_STATE_IDLE;
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@Override
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public void onScrollStateChanged(AbsListView view, int scrollState) {
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this.currentScrollState = scrollState;
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}
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@Override
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public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
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OnListViewScrollEvent event = new OnListViewScrollEvent(view, this.currentScrollState, firstVisibleItem,
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visibleItemCount, totalItemCount);
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observer.onNext(event);
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}
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};
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composite.addOnScrollListener(listener);
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observer.add(AndroidSubscriptions.unsubscribeInUiThread(new Action0() {
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@Override
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public void call() {
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composite.removeOnScrollListener(listener);
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}
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}));
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}
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private static class CompositeOnScrollListener implements AbsListView.OnScrollListener {
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private final List<AbsListView.OnScrollListener> listeners = new ArrayList<AbsListView.OnScrollListener>();
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public boolean addOnScrollListener(final AbsListView.OnScrollListener listener) {
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return listeners.add(listener);
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}
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public boolean removeOnScrollListener(final AbsListView.OnScrollListener listener) {
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return listeners.remove(listener);
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}
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@Override
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public void onScrollStateChanged(AbsListView view, int scrollState) {
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for (AbsListView.OnScrollListener listener : listeners) {
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listener.onScrollStateChanged(view, scrollState);
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}
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}
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@Override
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public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
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for (AbsListView.OnScrollListener listener : listeners) {
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listener.onScroll(view, firstVisibleItem, visibleItemCount, totalItemCount);
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}
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}
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}
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private static class CachedListeners {
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private static final Map<AdapterView<?>, CompositeOnScrollListener> sCachedListeners =
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new WeakHashMap<AdapterView<?>, CompositeOnScrollListener>();
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public static CompositeOnScrollListener getFromViewOrCreate(final AbsListView view) {
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final CompositeOnScrollListener cached = sCachedListeners.get(view);
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if (cached != null) {
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return cached;
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}
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final CompositeOnScrollListener listener = new CompositeOnScrollListener();
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sCachedListeners.put(view, listener);
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view.setOnScrollListener(listener);
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return listener;
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}
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}
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}

‎sample-app/src/main/java/rx/android/samples/ListFragmentActivity.java

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package rx.android.samples;
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import android.app.Activity;
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import android.app.ListFragment;
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import android.app.Fragment;
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import android.os.Bundle;
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import android.view.LayoutInflater;
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import android.view.View;
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import android.view.ViewGroup;
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import android.widget.ArrayAdapter;
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import android.widget.ListView;
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import android.widget.ProgressBar;
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import rx.Observable;
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import rx.Subscriber;
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import rx.android.events.OnListViewScrollEvent;
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import rx.android.observables.AndroidObservable;
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import rx.android.observables.ViewObservable;
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import rx.functions.Action1;
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import static rx.android.schedulers.AndroidSchedulers.mainThread;
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}
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@SuppressWarnings("ConstantConditions")
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public static class RetainedListFragment extends ListFragment {
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public static class RetainedListFragment extends Fragment {
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private ArrayAdapter<String> adapter;
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}
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@Override
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public void onCreate(Bundle savedInstanceState) {
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super.onCreate(savedInstanceState);
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public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
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View view = inflater.inflate(R.layout.list_fragment, container, false);
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adapter = new ArrayAdapter<String>(getActivity(), android.R.layout.simple_list_item_1);
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setListAdapter(adapter);
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SampleObservables.numberStrings(1, 20, 250)
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.observeOn(mainThread())
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.lift(new BindAdapter())
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.subscribe();
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ListView listView = (ListView) view.findViewById(android.R.id.list);
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listView.setAdapter(adapter);
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AndroidObservable.bindFragment(this, SampleObservables.numberStrings(1, 500, 100))
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.observeOn(mainThread())
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.lift(new BindAdapter())
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.subscribe();
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final ProgressBar progressBar = (ProgressBar) view.findViewById(android.R.id.progress);
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AndroidObservable.bindFragment(this, ViewObservable.listScrollEvents(listView))
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.subscribe(new Action1<OnListViewScrollEvent>() {
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@Override
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public void call(OnListViewScrollEvent event) {
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if (event.totalItemCount == 0) {
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return;
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}
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int progress =
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(int) ((100.0 * (event.firstVisibleItem + event.visibleItemCount)) / event.totalItemCount);
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progressBar.setProgress(progress);
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}
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});
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return view;
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}
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private final class BindAdapter implements Observable.Operator<String, String> {
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@Override
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public Subscriber<? super String> call(Subscriber<? super String> subscriber) {
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return new Subscriber<String>() {

‎sample-app/src/main/res/layout/list_fragment.xml

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<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
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<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
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android:layout_width="match_parent"
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android:layout_height="match_parent">
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<TextView
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android:id="@android:id/empty"
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<ProgressBar
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android:id="@android:id/progress"
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style="@android:style/Widget.Holo.ProgressBar.Horizontal"
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android:layout_width="match_parent"
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android:layout_height="match_parent"
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android:gravity="center"
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android:text="Loading..."
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android:visibility="gone" />
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android:layout_height="48dp"
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android:indeterminate="false" />
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<ListView
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android:id="@android:id/list"
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android:layout_width="match_parent"
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android:layout_height="match_parent" />
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android:layout_height="match_parent"
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android:layout_marginTop="48dp" />
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</RelativeLayout>
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</FrameLayout>

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