Java tutorial
/******************************************************************************* * Copyright 2012 momock.com * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. ******************************************************************************/ package com.momock.binder.container; import java.lang.ref.WeakReference; import java.util.concurrent.BlockingQueue; import java.util.concurrent.LinkedBlockingQueue; import android.support.v4.view.PagerAdapter; import android.support.v4.view.ViewPager; import android.view.GestureDetector; import android.view.MotionEvent; import android.view.View; import android.view.ViewGroup; import com.momock.binder.ContainerBinder; import com.momock.binder.IItemBinder; import com.momock.data.DataChangedEventArgs; import com.momock.data.IDataList; import com.momock.event.EventArgs; import com.momock.event.IEventHandler; import com.momock.event.ItemEventArgs; import com.momock.util.Logger; import com.momock.widget.IIndexIndicator; import com.momock.widget.IRoundAdapter; import com.momock.widget.RoundPagerAdapter; public class ViewPagerBinder extends ContainerBinder<ViewPager> { int viewPagerState = ViewPager.SCROLL_STATE_IDLE; public boolean isDragging() { return viewPagerState != ViewPager.SCROLL_STATE_IDLE; } public ViewPagerBinder(IItemBinder binder) { super(binder); } PagerAdapter adapter = null; public PagerAdapter getAdapter() { return adapter; } public void onBind(final ViewPager view, final IDataList<?> dataSource) { if (view != null) { if (refIndicator != null && refIndicator.get() != null) { refIndicator.get().setCount(dataSource.getItemCount()); } view.setOnPageChangeListener(new ViewPager.OnPageChangeListener() { @Override public void onPageSelected(int position) { position = adapter instanceof IRoundAdapter ? ((IRoundAdapter) adapter).getRealPosition(position) : position; Object item = dataSource.getItem(position); ItemEventArgs args = new ItemEventArgs(view, position, item); itemSelectedEvent.fireEvent(view, args); if (refIndicator != null && refIndicator.get() != null) { refIndicator.get().setCurrentIndex(position); } } @Override public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) { } @Override public void onPageScrollStateChanged(int state) { viewPagerState = state; } }); view.setOnTouchListener(new View.OnTouchListener() { GestureDetector detector = null; @Override public boolean onTouch(View v, MotionEvent event) { view.getParent().requestDisallowInterceptTouchEvent(true); if (detector == null) { detector = new GestureDetector(v.getContext(), new GestureDetector.SimpleOnGestureListener() { @Override public boolean onSingleTapConfirmed(MotionEvent e) { Object item = dataSource.getItem(adapter instanceof IRoundAdapter ? ((IRoundAdapter) adapter).getRealPosition(view.getCurrentItem()) : view.getCurrentItem()); ItemEventArgs args = new ItemEventArgs(view, view.getCurrentItem(), item); itemClickedEvent.fireEvent(view, args); return true; } }); } return detector.onTouchEvent(event); } }); adapter = new PagerAdapter() { BlockingQueue<View> savedViews = new LinkedBlockingQueue<View>(); @Override public int getCount() { return dataSource.getItemCount(); } @Override public boolean isViewFromObject(View view, Object object) { return view == ((View) object); } @Override public Object instantiateItem(ViewGroup container, int position) { View convertView = null; if (savedViews.size() > 0) { convertView = savedViews.poll(); } Object item = dataSource.getItem(position); if (convertView != null) convertView.setTag(null); convertView = itemBinder.onCreateItemView(convertView, item, ViewPagerBinder.this); convertView.setTag(item); container.addView(convertView, 0); return convertView; } @Override public void destroyItem(ViewGroup container, int position, Object object) { savedViews.add((View) object); container.removeView((View) object); } long lastDataSetChangedTick = 0; @Override public void notifyDataSetChanged() { lastDataSetChangedTick = System.nanoTime(); getDataChangedEvent().fireEvent(this, new EventArgs()); if (refIndicator != null && refIndicator.get() != null) { refIndicator.get().setCount(dataSource.getItemCount()); } super.notifyDataSetChanged(); Logger.debug("ViewPagerBinder.PagerAdapter.notifyDataSetChanged"); } long updateTick = 0; @Override public void startUpdate(ViewGroup container) { updateTick = System.nanoTime(); super.startUpdate(container); } @Override public void setPrimaryItem(ViewGroup container, int position, Object object) { super.setPrimaryItem(container, position, object); } @Override public void finishUpdate(ViewGroup container) { super.finishUpdate(container); if (lastDataSetChangedTick < updateTick) lastDataSetChangedTick = 0; } @Override public int getItemPosition(Object object) { return lastDataSetChangedTick == 0 ? PagerAdapter.POSITION_UNCHANGED : PagerAdapter.POSITION_NONE; } }; if (round) adapter = new RoundPagerAdapter(adapter); view.setAdapter(adapter); dataSource.addDataChangedHandler(new IEventHandler<DataChangedEventArgs>() { @Override public void process(Object sender, DataChangedEventArgs args) { adapter.notifyDataSetChanged(); } }); if (round) view.setCurrentItem(Math.max(100, dataSource.getItemCount() * 100), false); } } WeakReference<IIndexIndicator> refIndicator = null; boolean round = false; public void bind(final ViewPager view, final IDataList<?> list, final IIndexIndicator indicator, boolean round) { this.refIndicator = new WeakReference<IIndexIndicator>(indicator); this.round = round; super.bind(view, list); } }