Advertisement
Not a member of Pastebin yet?
Sign Up,
it unlocks many cool features!
- /*
- Edited FragmentPageAdapter.java by Ivan Seidel | github.com/ivanseidel
- This was made to add the method 'clear', allowing it to force a clear on the caching of fragments.
- More can be found on my StackOverflow Thread:
- http://stackoverflow.com/questions/16601048/viewpager-skip-views-on-return-leaving-blank/16603264
- */
- /*
- * Copyright (C) 2011 The Android Open Source Project
- *
- * 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.
- */
- import android.os.Parcelable;
- import android.support.v4.app.Fragment;
- import android.support.v4.app.FragmentManager;
- import android.support.v4.app.FragmentStatePagerAdapter;
- import android.support.v4.app.FragmentTransaction;
- import android.support.v4.view.PagerAdapter;
- import android.util.Log;
- import android.view.View;
- import android.view.ViewGroup;
- /**
- * Implementation of {@link android.support.v4.view.PagerAdapter} that
- * represents each page as a {@link Fragment} that is persistently
- * kept in the fragment manager as long as the user can return to the page.
- *
- * <p>This version of the pager is best for use when there are a handful of
- * typically more static fragments to be paged through, such as a set of tabs.
- * The fragment of each page the user visits will be kept in memory, though its
- * view hierarchy may be destroyed when not visible. This can result in using
- * a significant amount of memory since fragment instances can hold on to an
- * arbitrary amount of state. For larger sets of pages, consider
- * {@link FragmentStatePagerAdapter}.
- *
- * <p>When using FragmentPagerAdapter the host ViewPager must have a
- * valid ID set.</p>
- *
- * <p>Subclasses only need to implement {@link #getItem(int)}
- * and {@link #getCount()} to have a working adapter.
- *
- * <p>Here is an example implementation of a pager containing fragments of
- * lists:
- *
- * {@sample development/samples/Support4Demos/src/com/example/android/supportv4/app/FragmentPagerSupport.java
- * complete}
- *
- * <p>The <code>R.layout.fragment_pager</code> resource of the top-level fragment is:
- *
- * {@sample development/samples/Support4Demos/res/layout/fragment_pager.xml
- * complete}
- *
- * <p>The <code>R.layout.fragment_pager_list</code> resource containing each
- * individual fragment's layout is:
- *
- * {@sample development/samples/Support4Demos/res/layout/fragment_pager_list.xml
- * complete}
- */
- 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;
- }
- public void clear(ViewGroup container){
- if (mCurTransaction == null) {
- mCurTransaction = mFragmentManager.beginTransaction();
- }
- for(int i = 0; i < getCount(); i++){
- final long itemId = getItemId(i);
- // Do we already have this fragment?
- String name = makeFragmentName(container.getId(), itemId);
- Fragment fragment = mFragmentManager.findFragmentByTag(name);
- if(fragment != null){
- mCurTransaction.detach(fragment);
- }
- }
- mCurTransaction.commitAllowingStateLoss();
- mCurTransaction = null;
- }
- /**
- * Return the Fragment associated with a specified position.
- */
- public abstract Fragment getItem(int position);
- @Override
- public void startUpdate(ViewGroup container) {
- }
- @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>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;
- }
- }
Advertisement
Add Comment
Please, Sign In to add comment
Advertisement