Java Code Examples for androidx.fragment.app.Fragment#isAdded()

private void showFragment(Fragment fragment, @IdRes int id) {
    if (fragment == null || fragment.isResumed()) {
        return;
    }

    FragmentTransaction transaction = getChildFragmentManager().beginTransaction();
    if (fragment.isAdded()) {
        if (fragment instanceof BaseTriggerFragment && currentTriggerFragment != null) {
            transaction.hide(currentTriggerFragment);
        } else if (fragment instanceof IActuatorCallback && currentActuatorFragment != null) {
            transaction.hide(currentActuatorFragment);
        }
        transaction.show(fragment);
    } else {
        transaction.replace(id, fragment);
    }
    transaction.commit();
}
 

@Override
public void onCheckedChanged(RadioGroup radioGroup, int checkedId) {
	for (int i = 0; i < rgs.getChildCount(); i++) {
		if (rgs.getChildAt(i).getId() == checkedId) {
			Fragment fragment = fragments.get(i);
			FragmentTransaction ft = obtainFragmentTransaction(i);
			getCurrentFragment().onPause(); 
			if (fragment.isAdded()) {
				fragment.onResume(); 
			} else {
				ft.add(fragmentContentId, fragment);
			}
			showTab(i); 
			ft.commit();

			
			if (null != onRgsExtraCheckedChangedListener) {
				onRgsExtraCheckedChangedListener.OnRgsExtraCheckedChanged(
						radioGroup, checkedId, i);
			}

		}
	}

}
 

@Override
public Object instantiateItem(ViewGroup container, int position) {
    Fragment fragment = getItem(position);
    if (fragment.isAdded()) {
        return fragment;
    }

    Fragment instantiatedFragment = (Fragment) super.instantiateItem(container, position);
    Slide slide = data.get(position);
    if (slide instanceof RestorableSlide) {
        //Load old fragment from fragment manager
        ((RestorableSlide) slide).setFragment(instantiatedFragment);
        data.set(position, slide);
        if (instantiatedFragment instanceof SlideFragment && instantiatedFragment.isAdded()) {
            ((SlideFragment) instantiatedFragment).updateNavigation();
        }
    }
    return instantiatedFragment;
}
 

/**
 * 第一次加载的时候调用该方法设置resId
 */
public void addOrReplaceFragment(Fragment fragment, int resId) {
    if (resId != 0) {
        fragmentContainerResId = resId;
    }
    if (fragment == null) {
        return;
    }
    if (currentFragment == null) {
        getSupportFragmentManager().beginTransaction().add(fragmentContainerResId, fragment).show(fragment).commitAllowingStateLoss();
        currentFragment = fragment;
    } else if (currentFragment != fragment) {
        if (fragment.isAdded()) {
            getSupportFragmentManager().beginTransaction().hide(currentFragment).show(fragment).commit();
        } else {
            getSupportFragmentManager().beginTransaction().hide(currentFragment).add(fragmentContainerResId, fragment).show(fragment).commitAllowingStateLoss();
        }
        currentFragment = fragment;
    }
}
 

/**
 * 第一次加载的时候调用该方法设置resId
 *
 * @param fragment
 * @param resId
 */
public void addOrReplaceFragment(Fragment fragment, int resId) {
    if (resId != 0) {
        fragmentContainerResId = resId;
    }
    if (fragment == null) {
        return;
    }
    if (currentFragment == null) {
        getChildFragmentManager().beginTransaction().add(resId, fragment).show(fragment).commitAllowingStateLoss();
        currentFragment = fragment;
        return;
    }
    if (fragment.isAdded()) {
        getChildFragmentManager().beginTransaction().hide(currentFragment).show(fragment).commit();
    } else {
        getChildFragmentManager().beginTransaction().hide(currentFragment).add(fragmentContainerResId, fragment).show(fragment).commitAllowingStateLoss();
    }
    currentFragment = fragment;
}
 

@Override
public void onBackPressed() {
    /** @see BackPressAware */
    for (Fragment fragment : mFragmentManager.getFragments()) {
        if (fragment instanceof BackPressAware && fragment.isAdded()) {
            // Enable a single fragment to intercept the back press.
            ((BackPressAware) fragment).onBackPressed();
            return;
        }
    }
    // Intercept all back press calls until there's no more fragments on the back stack.
    mFragmentManager.popBackStack();
    if (mFragmentManager.getBackStackEntryCount() == 0) {
        super.onBackPressed();
    }
}
 

private void switchFragment(String tag) {
    /* Fragment 切换 */
    FragmentTransaction transaction = mFragmentManager.beginTransaction();
    if (fragmentTags.indexOf(tag) < 0) {
        return;
    }
    Fragment showFragment = fragments.get(fragmentTags.indexOf(tag));
    Fragment currentFragment = mFragmentManager.findFragmentByTag(currentTag);
    if (currentFragment != null) {
        transaction.hide(currentFragment);
    }
    if (showFragment.isAdded()) {
        transaction.show(showFragment);
    }
    else {
        transaction.add(R.id.content_frame, showFragment, tag);
        transaction.show(showFragment);
    }
    transaction.setTransitionStyle(FragmentTransaction.TRANSIT_FRAGMENT_FADE);
    transaction.commitAllowingStateLoss();
    currentTag = tag;
}
 

@Override
public boolean onNavigationItemSelected(@NonNull MenuItem menuItem) {
    int index;
    int itemId = menuItem.getItemId();
    switch (itemId) {
        default:
        case R.id.tab_api:
            index = 0;
            break;
        case R.id.tab_list:
            index = 1;
            break;
        case R.id.tab_extension:
            index = 2;
            break;
        case R.id.tab_pip:
            index = 3;
            break;
    }

    if (mCurrentIndex != index) {
        //切换tab，释放正在播放的播放器
        if (mCurrentIndex == 1) {
            getVideoViewManager().releaseByTag(Tag.LIST);
            getVideoViewManager().releaseByTag(Tag.SEAMLESS, false);//注意不能移除
        }
        FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
        Fragment fragment = mFragments.get(index);
        Fragment curFragment = mFragments.get(mCurrentIndex);
        if (fragment.isAdded()) {
            transaction.hide(curFragment).show(fragment);
        } else {
            transaction.add(R.id.layout_content, fragment).hide(curFragment);
        }
        transaction.commitAllowingStateLoss();
        mCurrentIndex = index;
    }
    return true;
}
 

@Override
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
    super.onCreateOptionsMenu(menu, inflater);
    if (pager == null) return;
    inflater.inflate(R.menu.menu_main, menu);
    if (isPlaylistPage()) {
        menu.add(0, R.id.action_new_playlist, 0, R.string.new_playlist_title);
    }
    Fragment currentFragment = getCurrentFragment();
    if (currentFragment instanceof AbsLibraryPagerRecyclerViewCustomGridSizeFragment && currentFragment.isAdded()) {
        AbsLibraryPagerRecyclerViewCustomGridSizeFragment absLibraryRecyclerViewCustomGridSizeFragment = (AbsLibraryPagerRecyclerViewCustomGridSizeFragment) currentFragment;

        MenuItem gridSizeItem = menu.findItem(R.id.action_grid_size);
        if (Util.isLandscape(getResources())) {
            gridSizeItem.setTitle(R.string.action_grid_size_land);
        }
        setUpGridSizeMenu(absLibraryRecyclerViewCustomGridSizeFragment, gridSizeItem.getSubMenu());

        menu.findItem(R.id.action_colored_footers).setChecked(absLibraryRecyclerViewCustomGridSizeFragment.usePalette());
        menu.findItem(R.id.action_colored_footers).setEnabled(absLibraryRecyclerViewCustomGridSizeFragment.canUsePalette());

        setUpSortOrderMenu(absLibraryRecyclerViewCustomGridSizeFragment, menu.findItem(R.id.action_sort_order).getSubMenu());
    } else {
        menu.removeItem(R.id.action_grid_size);
        menu.removeItem(R.id.action_colored_footers);
        menu.removeItem(R.id.action_sort_order);
    }
    Activity activity = getActivity();
    if (activity == null) return;
    ToolbarContentTintHelper.handleOnCreateOptionsMenu(getActivity(), toolbar, menu, ATHToolbarActivity.getToolbarBackgroundColor(toolbar));
}
 

/**
 * 初始化fragments
 */
private void initFragments() {
    for (Fragment fragment : mFragments) {
        if (fragment.isAdded()) {
            mFragmentManager.beginTransaction().hide(fragment).commit();
        } else {
            mFragmentManager.beginTransaction().add(mContainerViewId, fragment).hide(fragment).commit();
        }
    }
    setFragments(0);
}
 

public void showFragment(@NonNull Fragment fragment) {
    //相当于new一个实例FragmentTransaction
    FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
    if (fragment.isAdded()) {
        ft.show(fragment);
    } else {
        //把该ft加入到栈中进行管理
        ft.addToBackStack(fragment.getClass().getSimpleName());
        ft.add(R.id.container, fragment);
    }
    ft.commitAllowingStateLoss();
    Log.e("Lifecycle", "getBackStackEntryCount: " + getSupportFragmentManager().getBackStackEntryCount());
}
 

/**
 * Method to remove the child {@link Fragment} against the provided tag.
 *
 * @param parentFragment {@link Fragment} that containing the child {@link Fragment}
 * @param tag            string to search the fragment.
 */
public static void removeFragmentByTag(@NonNull Fragment parentFragment, @NonNull String tag) {
    if (parentFragment.isAdded()) {
        final FragmentManager fragmentManager = parentFragment.getChildFragmentManager();
        final Fragment fragment = fragmentManager.findFragmentByTag(tag);
        if (fragment != null) {
            fragmentManager.beginTransaction().remove(fragment)
                    .commitAllowingStateLoss();
        }
    }
}
 

private void removeFragment(Fragment fragment) {
  if (fragment != null && (fragment.isAdded() || fragment.isDetached())) {
    Timber.d("Removing fragment: %s", fragment.getTag());

    ensureTransaction();
    fragmentTransaction.remove(fragment);
  }
}
 

@NonNull
public static List<AwesomeFragment> getFragmentsAtAddedList(@NonNull FragmentManager fragmentManager) {
    List<AwesomeFragment> children = new ArrayList<>();
    List<Fragment> fragments = fragmentManager.getFragments();
    for (int i = 0, size = fragments.size(); i < size; i++) {
        Fragment fragment = fragments.get(i);
        if (fragment instanceof AwesomeFragment && fragment.isAdded()) {
            children.add((AwesomeFragment) fragment);
        }
    }
    return children;
}
 

public static void showMultipaneIfInLandscape(SettingsActivity activity) {
    if (activity.secondFragmentContainer != null) {
        activity.secondFragmentContainer.setVisibility(View.VISIBLE);
        FragmentManager manager = activity.getSupportFragmentManager();
        Fragment secondPane = manager.findFragmentByTag(TAG_PREFERENCE_FRAGMENT_SECOND_PANE);
        if (secondPane == null) {
            secondPane = MaxLockPreferenceFragment.Screen.MAIN.getScreen();
        }
        if (!secondPane.isAdded())
            manager.beginTransaction().replace(R.id.second_fragment_container, secondPane, TAG_PREFERENCE_FRAGMENT_SECOND_PANE).commit();
    }
}
 

@Override
protected void dismissInternal(boolean allowStateLoss, boolean fromOnDismiss) {
    super.dismissInternal(allowStateLoss, fromOnDismiss);
    Fragment target = getTargetFragment();
    if (target instanceof AwesomeFragment && target.isAdded() && fromOnDismiss) {
        FragmentHelper.executePendingTransactionsSafe(requireFragmentManager());
        AwesomeFragment fragment = (AwesomeFragment) target;
        fragment.onFragmentResult(getRequestCode(), getResultCode(), getResultData());
    }
}
 

protected void showDialogInternal(AwesomeFragment dialog, int requestCode) {
    FragmentManager fragmentManager = getSupportFragmentManager();
    if (fragmentManager.getBackStackEntryCount() > 0) {
        Fragment fragment = fragmentManager.findFragmentById(android.R.id.content);
        if (fragment != null && fragment.isAdded()) {
            dialog.setTargetFragment(fragment, requestCode);
        }
    }
    Bundle args = FragmentHelper.getArguments(dialog);
    args.putBoolean(AwesomeFragment.ARGS_SHOW_AS_DIALOG, true);
    dialog.show(fragmentManager, dialog.getSceneId());
    FragmentHelper.executePendingTransactionsSafe(fragmentManager);
}
 

static boolean isFragmentDestroyed(Fragment fragment) {
  return fragment.isRemoving()
      || fragment.getActivity() == null
      || fragment.isDetached()
      || !fragment.isAdded()
      || fragment.getView() == null;
}
 

void showFragment(String tag, Bundle args, boolean addToBackstack) {
    if (isFinishing() || isDestroyed()) {
        return;
    }

    FragmentManager fm = getSupportFragmentManager();

    Fragment fragment = fm.findFragmentByTag(tag);
    if (fragment == null) {
        switch (tag) {
            case FRAGMENT_MESSAGES:
                fragment = new MessagesFragment();
                break;
            case FRAGMENT_INFO:
                fragment = new TopicInfoFragment();
                break;
            case FRAGMENT_PERMISSIONS:
                fragment = new TopicPermissionsFragment();
                break;
            case FRAGMENT_EDIT_MEMBERS:
                fragment = new EditMembersFragment();
                break;
            case FRAGMENT_VIEW_IMAGE:
                fragment = new ImageViewFragment();
                break;
            case FRAGMENT_FILE_PREVIEW:
                fragment = new FilePreviewFragment();
                break;
            case FRAGMENT_INVALID:
                fragment = new InvalidTopicFragment();
                break;
        }
    } else if (args == null) {
        // Retain old arguments.
        args = fragment.getArguments();
    }
    if (fragment == null) {
        throw new NullPointerException();
    }

    args = args != null ? args : new Bundle();
    args.putString("topic", mTopicName);
    args.putString(MessagesFragment.MESSAGE_TO_SEND, mMessageText);
    if (fragment.getArguments() != null) {
        fragment.getArguments().putAll(args);
    } else {
        fragment.setArguments(args);
    }

    FragmentTransaction trx = fm.beginTransaction();
    if (!fragment.isAdded()) {
        trx = trx.replace(R.id.contentFragment, fragment, tag)
                .setTransition(FragmentTransaction.TRANSIT_FRAGMENT_OPEN);
    } else if (!fragment.isVisible()) {
        trx = trx.show(fragment);
    } else {
        addToBackstack = false;
    }

    if (FRAGMENT_MESSAGES.equals(tag)) {
        trx.setPrimaryNavigationFragment(fragment);
    }

    if (addToBackstack) {
        trx.addToBackStack(tag);
    }
    if (!trx.isEmpty()) {
        trx.commit();
    }
}
 

/**
 * Decodes and scales a contact's image from a file pointed to by a Uri in the contact's data,
 * and returns the result as a Bitmap. The column that contains the Uri varies according to the
 * platform version.
 *
 * @param photoData For platforms prior to Android 3.0, provide the Contact._ID column value.
 *                  For Android 3.0 and later, provide the Contact.PHOTO_THUMBNAIL_URI value.
 * @param imageSize The desired target width and height of the output image in pixels.
 * @return A Bitmap containing the contact's image, resized to fit the provided image size. If
 * no thumbnail exists, returns null.
 */
private static Bitmap loadContactPhotoThumbnail(Fragment fragment, String photoData, int imageSize) {

    // Ensures the Fragment is still added to an activity. As this method is called in a
    // background thread, there's the possibility the Fragment is no longer attached and
    // added to an activity. If so, no need to spend resources loading the contact photo.
    if (!fragment.isAdded()) {
        return null;
    }

    Activity activity = fragment.getActivity();
    if (activity == null || activity.isFinishing() || activity.isDestroyed()) {
        return null;
    }

    // Instantiates an AssetFileDescriptor. Given a content Uri pointing to an image file, the
    // ContentResolver can return an AssetFileDescriptor for the file.

    // This "try" block catches an Exception if the file descriptor returned from the Contacts
    // Provider doesn't point to an existing file.
    Uri thumbUri = Uri.parse(photoData);
    try (AssetFileDescriptor afd = activity.getContentResolver().openAssetFileDescriptor(thumbUri, "r")) {

        // Retrieves a file descriptor from the Contacts Provider. To learn more about this
        // feature, read the reference documentation for
        // ContentResolver#openAssetFileDescriptor.

        // Gets a FileDescriptor from the AssetFileDescriptor. A BitmapFactory object can
        // decode the contents of a file pointed to by a FileDescriptor into a Bitmap.
        if (afd != null) {
            // Decodes a Bitmap from the image pointed to by the FileDescriptor, and scales it
            // to the specified width and height
            return ImageLoader.decodeSampledBitmapFromStream(
                    new BufferedInputStream(new FileInputStream(afd.getFileDescriptor())), imageSize, imageSize);
        }
    } catch (IOException e) {
        // If the file pointed to by the thumbnail URI doesn't exist, or the file can't be
        // opened in "read" mode, ContentResolver.openAssetFileDescriptor throws a
        // FileNotFoundException.
        if (BuildConfig.DEBUG) {
            Log.d(TAG, "Contact photo thumbnail not found for contact " + photoData
                    + ": " + e.toString());
        }
    }
    // If an AssetFileDescriptor was returned, try to close it
    // Closing a file descriptor might cause an IOException if the file is
    // already closed. Nothing extra is needed to handle this.

    // If the decoding failed, returns null
    return null;
}