Java tutorial
/* * Copyright 2016 Victor Albertos * * 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 rx_fcm.internal; import android.app.Activity; import android.support.annotation.Nullable; import android.support.v4.app.Fragment; import android.support.v4.app.FragmentActivity; import android.support.v4.app.FragmentManager; import java.util.ArrayList; import java.util.List; import rx_fcm.FcmReceiverUIForeground; class GetFcmReceiversUIForeground { private List<Fragment> fcmReceiversUIForegroundNotTargetScreen; Wrapper retrieve(String screenName, Activity activity) { Wrapper receiverCandidate = null; if (activity == null) return receiverCandidate; if (activity instanceof FcmReceiverUIForeground) { FcmReceiverUIForeground fcmReceiverUIForeground = (FcmReceiverUIForeground) activity; boolean targetScreen = fcmReceiverUIForeground.matchesTarget(screenName); receiverCandidate = new Wrapper(fcmReceiverUIForeground, targetScreen); if (targetScreen) return receiverCandidate; } if (!(activity instanceof FragmentActivity)) return receiverCandidate; FragmentActivity fragmentActivity = (FragmentActivity) activity; FragmentManager fragmentManager = fragmentActivity.getSupportFragmentManager(); fcmReceiversUIForegroundNotTargetScreen = new ArrayList<>(); Fragment fragment = getFcmReceiverUIForeground(fragmentManager.getFragments(), screenName); fcmReceiversUIForegroundNotTargetScreen.clear(); if (fragment != null) { FcmReceiverUIForeground fcmReceiverUIForeground = (FcmReceiverUIForeground) fragment; boolean isTargetScreen = fcmReceiverUIForeground.matchesTarget(screenName); return new Wrapper(fcmReceiverUIForeground, isTargetScreen); } else { return receiverCandidate; } } @Nullable private Fragment getFcmReceiverUIForeground(List<Fragment> fragments, String screenName) { if (fragments == null) return null; for (Fragment fragment : fragments) { if (fragment != null && isVisible(fragment) && fragment instanceof FcmReceiverUIForeground) { FcmReceiverUIForeground fcmReceiverUIForeground = (FcmReceiverUIForeground) fragment; boolean isTargetScreen = fcmReceiverUIForeground.matchesTarget(screenName); if (isTargetScreen) return fragment; fcmReceiversUIForegroundNotTargetScreen.add(fragment); if (fragment.getChildFragmentManager() != null) { Fragment candidate = getFcmReceiverUIForegroundFromChild(fragment, screenName); if (candidate != null) return candidate; } } else if (fragment != null && isVisible(fragment) && fragment.getChildFragmentManager() != null) { Fragment candidate = getFcmReceiverUIForegroundFromChild(fragment, screenName); if (candidate != null) return candidate; } } if (!fcmReceiversUIForegroundNotTargetScreen.isEmpty()) return fcmReceiversUIForegroundNotTargetScreen.get(0); else return null; } private Fragment getFcmReceiverUIForegroundFromChild(Fragment fragment, String screenName) { List<Fragment> childFragments = fragment.getChildFragmentManager().getFragments(); Fragment candidate = getFcmReceiverUIForeground(childFragments, screenName); if (candidate == null) return null; FcmReceiverUIForeground fcmReceiverUIForeground = (FcmReceiverUIForeground) candidate; boolean isTargetScreen = fcmReceiverUIForeground.matchesTarget(screenName); if (isTargetScreen) return candidate; fcmReceiversUIForegroundNotTargetScreen.add(candidate); return null; } static class Wrapper { private final FcmReceiverUIForeground fcmReceiverUIForeground; private final boolean targetScreen; public Wrapper(FcmReceiverUIForeground fcmReceiverUIForeground, boolean targetScreen) { this.fcmReceiverUIForeground = fcmReceiverUIForeground; this.targetScreen = targetScreen; } public FcmReceiverUIForeground fcmReceiverUIForeground() { return fcmReceiverUIForeground; } public boolean isTargetScreen() { return targetScreen; } } //exists for testing purposes private boolean mock; void mockForTestingPurposes() { mock = true; } //exists for testing purposes boolean isVisible(Fragment fragment) { if (mock) return true; return fragment.getUserVisibleHint(); } }