Java tutorial
/** * Copyright (C) 2015 ogaclejapan * * 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.inno.wang.view.smartlayout.v4; import android.support.v4.util.SparseArrayCompat; import android.support.v4.view.PagerAdapter; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import java.lang.ref.WeakReference; public abstract class ViewPagerItemAdapter extends PagerAdapter { private final ViewPagerItems pages; private final SparseArrayCompat<WeakReference<View>> holder; private final LayoutInflater inflater; public ViewPagerItemAdapter(ViewPagerItems pages) { this.pages = pages; this.holder = new SparseArrayCompat<>(pages.size()); this.inflater = LayoutInflater.from(pages.getContext()); } @Override public int getCount() { return pages.size(); } @Override public Object instantiateItem(ViewGroup container, int position) { View view = getPagerItem(position).initiate(inflater, container); setBitmap(view, position); container.addView(view); holder.put(position, new WeakReference<View>(view)); return view; } public abstract void setBitmap(View view, int position); @Override public void destroyItem(ViewGroup container, int position, Object object) { holder.remove(position); container.removeView((View) object); } @Override public boolean isViewFromObject(View view, Object object) { return object == view; } @Override public CharSequence getPageTitle(int position) { return getPagerItem(position).getTitle(); } @Override public float getPageWidth(int position) { return getPagerItem(position).getWidth(); } public View getPage(int position) { final WeakReference<View> weakRefItem = holder.get(position); return (weakRefItem != null) ? weakRefItem.get() : null; } protected ViewPagerItem getPagerItem(int position) { return pages.get(position); } }