/** * created by jiang, 16/2/28 * Copyright (c) 2016, [email protected] All Rights Reserved. * * # # * # _oo0oo_ # * # o8888888o # * # 88" . "88 # * # (| -_- |) # * # 0\ = /0 # * # ___/`---'\___ # * # .' \\| |# '. # * # / \\||| : |||# \ # * # / _||||| -:- |||||- \ # * # | | \\\ - #/ | | # * # | \_| ''\---/'' |_/ | # * # \ .-\__ '-' ___/-. / # * # ___'. .' /--.--\ `. .'___ # * # ."" '< `.___\_<|>_/___.' >' "". # * # | | : `- \`.;`\ _ /`;.`/ - ` : | | # * # \ \ `_. \_ __\ /__ _/ .-` / / # * # =====`-.____`.___ \_____/___.-`___.-'===== # * # `=---=' # * # ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ # * # # * # 佛祖保佑 永无BUG # * # # */ package com.jiang.android.rxjavaapp.adapter.fragmentadapter; import android.annotation.TargetApi; import android.app.Fragment; import android.app.FragmentManager; import android.app.FragmentTransaction; import android.os.Build; import android.os.Parcelable; import android.util.Log; import android.view.View; import android.view.ViewGroup; /** * Created by jiang on 16/2/28. */ public abstract class FragmentPagerAdapter extends PagerAdapter { private static final String TAG = "FragmentPagerAdapter"; private static final boolean DEBUG = false; private final FragmentManager mFragmentManager; private FragmentTransaction mCurTransaction = null; private Fragment mCurrentPrimaryItem = null; public FragmentPagerAdapter(FragmentManager fm) { mFragmentManager = fm; } /** * Return the Fragment associated with a specified position. */ public abstract Fragment getItem(int position); @Override public void startUpdate(ViewGroup container) { } @TargetApi(Build.VERSION_CODES.ICE_CREAM_SANDWICH_MR1) @Override public Object instantiateItem(ViewGroup container, int position) { if (mCurTransaction == null) { mCurTransaction = mFragmentManager.beginTransaction(); } final long itemId = getItemId(position); // Do we already have this fragment? String name = makeFragmentName(container.getId(), itemId); Fragment fragment = mFragmentManager.findFragmentByTag(name); if (fragment != null) { if (DEBUG) Log.v(TAG, "Attaching item #" + itemId + ": f=" + fragment); mCurTransaction.attach(fragment); } else { fragment = getItem(position); if (DEBUG) Log.v(TAG, "Adding item #" + itemId + ": f=" + fragment); mCurTransaction.add(container.getId(), fragment, makeFragmentName(container.getId(), itemId)); } if (fragment != mCurrentPrimaryItem) { fragment.setMenuVisibility(false); fragment.setUserVisibleHint(false); } return fragment; } @Override public void destroyItem(ViewGroup container, int position, Object object) { if (mCurTransaction == null) { mCurTransaction = mFragmentManager.beginTransaction(); } if (DEBUG) Log.v(TAG, "Detaching item #" + getItemId(position) + ": f=" + object + " v=" + ((Fragment) object).getView()); mCurTransaction.detach((Fragment) object); } @Override public void setPrimaryItem(ViewGroup container, int position, Object object) { Fragment fragment = (Fragment) object; if (fragment != mCurrentPrimaryItem) { if (mCurrentPrimaryItem != null) { mCurrentPrimaryItem.setMenuVisibility(false); mCurrentPrimaryItem.setUserVisibleHint(false); } if (fragment != null) { fragment.setMenuVisibility(true); fragment.setUserVisibleHint(true); } mCurrentPrimaryItem = fragment; } } @Override public void finishUpdate(ViewGroup container) { if (mCurTransaction != null) { mCurTransaction.commitAllowingStateLoss(); mCurTransaction = null; mFragmentManager.executePendingTransactions(); } } @Override public boolean isViewFromObject(View view, Object object) { return ((Fragment) object).getView() == view; } @Override public Parcelable saveState() { return null; } @Override public void restoreState(Parcelable state, ClassLoader loader) { } /** * Return a unique identifier for the item at the given position. * <p> * <p>The default implementation returns the given position. * Subclasses should override this method if the positions of items can change.</p> * * @param position Position within this adapter * @return Unique identifier for the item at position */ public long getItemId(int position) { return position; } private static String makeFragmentName(int viewId, long id) { return "android:switcher:" + viewId + ":" + id; } }