ReactiveWiFi 
Android library listening available WiFi Access Points and related information with RxJava Observables.
This library is one of the successors of the NetworkEvents library. Its functionality was extracted from ReactiveNetwork project to make it more specialized and reduce number of required permissions required to perform specific task.
If you are searching library for observing network or Internet connectivity check ReactiveNetwork project.
Library is compatible with RxJava 1.+ and RxAndroid 1.+ and uses them under the hood.
JavaDoc is available at: http://pwittchen.github.io/ReactiveWiFi/
Contents
Usage
Library has the following RxJava Observables available in the public API:
Observable<List<ScanResult>> observeWifiAccessPoints(final Context context) Observable<Integer> observeWifiSignalLevel(final Context context, final int numLevels) Observable<WifiSignalLevel> observeWifiSignalLevel(final Context context) Observable<SupplicantState> observeSupplicantState(final Context context) Observable<WifiInfo> observeWifiAccessPointChanges(final Context context) Observable<WifiState> observeWifiStateChange(final Context context)Please note: Due to memory leak in WifiManager reported in issue 43945 in Android issue tracker it's recommended to use Application Context instead of Activity Context.
Observing WiFi Access Points
Please note: If you want to observe WiFi access points on Android M (6.0) or higher, you need to request runtime permission for ACCESS_COARSE_LOCATION or ACCESS_FINE_LOCATION. After that, location services have to be enabled. See sample app in app directory to check how it's done. User needs to enable Location manually. You can suggest him or her to do it via AccessRequester class from this library as follows:
if (!AccessRequester.isLocationEnabled(this)) {
AccessRequester.requestLocationAccess(this);
}
else {
// observe WiFi Access Points
}
If you need more customization (e.g. custom title and message of the dialog window or custom listener), check public API of the AccessRequester class.
We can observe WiFi Access Points with observeWifiAccessPoints(context) method. Subscriber will be called everytime, when strength of the WiFi Access Points signal changes (it usually happens when user is moving around with a mobile device). We can do it in the following way:
ReactiveWifi.observeWifiAccessPoints(context)
.subscribeOn(Schedulers.io())
... // anything else what you can do with RxJava
.observeOn(AndroidSchedulers.mainThread())
.subscribe(new Action1<List<ScanResult>>() {
@Override public void call(List<ScanResult> scanResults) {
// do something with scanResults
}
}
);
Hint: If you want to operate on a single ScanResult instead of List<ScanResult> in a subscribe(...) method, consider using flatMap(...) and Observable.from(...) operators from RxJava for transforming the stream.
Observing WiFi signal level
We can observe WiFi signal level with observeWifiSignalLevel(context, numLevels) method. Subscriber will be called everytime, when signal level of the connected WiFi changes (it usually happens when user is moving around with a mobile device). We can do it in the following way:
ReactiveWifi.observeWifiSignalLevel(context, numLevels)
.subscribeOn(Schedulers.io())
... // anything else what you can do with RxJava
.observeOn(AndroidSchedulers.mainThread())
.subscribe(new Action1<Integer>() {
@Override public void call(Integer level) {
// do something with level
}
}
);
We can also observe WiFi signal level with observeWifiSignalLevel(final Context context) method, which has predefined num levels value, which is equal to 4 and returns Observable<WifiSignalLevel>. WifiSignalLevel is an enum, which contains information about current signal level. We can do it as follows:
ReactiveWifi.observeWifiSignalLevel(context)
.subscribeOn(Schedulers.io())
... // anything else what you can do with RxJava
.observeOn(AndroidSchedulers.mainThread())
.subscribe(new Action1<WifiSignalLevel>() {
@Override public void call(WifiSignalLevel signalLevel) {
// do something with signalLevel
}
}
);
WifiSignalLevel has the following values:
public enum WifiSignalLevel {
NO_SIGNAL(0, "no signal"),
POOR(1, "poor"),
FAIR(2, "fair"),
GOOD(3, "good"),
EXCELLENT(4, "excellent");
...
}
Observing WiFi information changes
We can observe WiFi network information changes with observeWifiAccessPointChanges(context) method. Subscriber will be called every time the WiFi network the device is connected to has changed. We can do it in the following way:
ReactiveWifi.observeWifiAccessPointChanges(context)
.subscribeOn(Schedulers.io())
... // anything else what you can do with RxJava
.observeOn(AndroidSchedulers.mainThread())
.subscribe(new Action1<WifiInfo>() {
@Override public void call(WifiInfo wifiInfo) {
// do something with wifiInfo
}
}
);
Observing WPA Supplicant state changes
We can observe changes in the WPA Supplicant state with observeSupplicantState(context) method. Subscriber will be called every time the WPA Supplicant will change its state, getting information at a lower level than usually available. We can do it in the following way:
ReactiveWifi.observeSupplicantState(context)
.subscribeOn(Schedulers.io())
... // anything else what you can do with RxJava
.observeOn(AndroidSchedulers.mainThread())
.subscribe(new Action1<SupplicantState>() {
@Override public void call(SuppicantState state) {
// do something with state
}
}
);
Observing WiFi state changes
We can observe wifi state change with observeWifiStateChange(context) method. Subscriber will be called every time whenever the wifi state change such like enabling,disabling,enabled and disabled. We can do it in the following way:
ReactiveWifi.observeWifiStateChange(context)
.subscribeOn(Schedulers.io())
... // anything else what you can do with RxJava
.observeOn(AndroidSchedulers.mainThread())
.subscribe(new Action1<WifiState>() {
@Override public void call(WifiState wifiState) {
// do something with state
}
}
);
Examples
Exemplary application is located in app directory of this repository.
If you want to use this library with Kotlin, check app-kotlin directory.
Download
<dependency>
<groupId>com.github.pwittchen</groupId>
<artifactId>reactivewifi</artifactId>
<version>0.2.0</version> </dependency>or through Gradle:
dependencies {
compile 'com.github.pwittchen:reactivewifi:0.2.0'
}
Code style
Code style used in the project is called SquareAndroid from Java Code Styles repository by Square available at: https://github.com/square/java-code-styles.
Static code analysis
Static code analysis runs Checkstyle, FindBugs, PMD and Lint. It can be executed with command:
./gradlew check Reports from analysis are generated in library/build/reports/ directory.
License
Copyright 2016 Piotr Wittchen 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.