Added support to start specific Android Activity and added possibilit…

README.md

@@ -19,7 +19,7 @@ First, add `flutter_appavailability` as a [dependency in your pubspec.yaml file]
 - `checkAvailability(String uri)`
 - `getInstalledApps()` (only for **Android**)
 - `isAppEnabled(String uri)` (only for **Android**)
-- `launchApp(String uri)`
+- `launchApp(String uri, String activity)`
 
 See the [docs](https://pub.dartlang.org/documentation/flutter_appavailability/latest/).
 
@@ -132,6 +132,13 @@ class _MyAppState extends State<MyApp> {
 
 ```
 
+Example starting specific activity on Android. (this is useful if you want to start a specific activity of the app or the app doesn't have a launch intent and is not visible in a launcher)
+```dart
+
+AppAvailability.launchApp('com.example.helloworld', 'com.example.helloworld.settings.main.SettingsActivity');
+
+```
+
 Android:
 ![screenshot_1536780581](https://user-images.githubusercontent.com/5956938/45448682-48c49e80-b6d3-11e8-8e56-5972b017e233.png)
 

android/src/main/java/com/pichillilorenzo/flutter_appavailability/AppAvailability.java

@@ -14,6 +14,7 @@
 import android.app.Activity;
 import android.content.Context;
 import android.content.Intent;
+import android.content.pm.ActivityInfo;
 import android.content.pm.PackageManager;
 import android.content.pm.PackageInfo;
 import android.content.pm.ApplicationInfo;
@@ -40,6 +41,7 @@ public static void registerWith(Registrar registrar) {
   @Override
   public void onMethodCall(MethodCall call, Result result) {
     String uriSchema;
+    String activityName;
     switch (call.method) {
       case "checkAvailability":
         uriSchema = call.argument("uri").toString();
@@ -54,7 +56,8 @@ public void onMethodCall(MethodCall call, Result result) {
         break;
       case "launchApp":
         uriSchema = call.argument("uri").toString();
-        this.launchApp(uriSchema , result);
+        activityName = call.argument("activity").toString();
+        this.launchApp(uriSchema, activityName, result);
         break;
       default:
         result.notImplemented();
@@ -127,19 +130,54 @@ private void isAppEnabled(String packageName, Result result) {
   }
 
   @TargetApi(Build.VERSION_CODES.CUPCAKE)
-  private void launchApp(String packageName, Result result) {
-    PackageInfo info = getAppPackageInfo(packageName);
+  private void launchApp(String packageName, String activityName, Result result) {
 
-    if(info != null) {
-      Intent launchIntent = registrar.context().getPackageManager().getLaunchIntentForPackage(packageName);
-      if (launchIntent != null) {
-        launchIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
-        registrar.context().startActivity(launchIntent);
+    //Start specific activity of the app
+    if(activityName != null){
+      try {
+        launchActivity(packageName, activityName);
         result.success(null);
-        return;
+      } catch (Exception e) {
+        e.printStackTrace();
+      }
+    } else {
+      PackageInfo info = getAppPackageInfo(packageName);
+
+      if(info != null) {
+        Intent launchIntent = registrar.context().getPackageManager().getLaunchIntentForPackage(packageName);
+        if (launchIntent != null) {
+          launchIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
+          registrar.context().startActivity(launchIntent);
+          result.success(null);
+          return;
+        }
+
+        //this will try to launch any available activity for the app if getLaunchIntentForPackage returns null, useful for launching apps without Launcher intent
+        if(info.activities != null){
+          for (ActivityInfo activityInfo:
+                  info.activities) {
+            try {
+              launchActivity(packageName, activityInfo.name);
+              result.success(null);
+              break;
+            } catch (Exception e) {
+              e.printStackTrace();
+            }
+          }
+          return;
+        }
       }
     }
 
     result.error("", "App not found " + packageName, null);
   }
+
+  @TargetApi(Build.VERSION_CODES.CUPCAKE)
+  private void launchActivity(String packageName, String activityName) {
+    Intent launchIntent = new Intent(Intent.ACTION_MAIN);
+    launchIntent.addCategory(Intent.CATEGORY_LAUNCHER);
+    launchIntent.setClassName(packageName, activityName);
+    launchIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
+    registrar.context().startActivity(launchIntent);
+  }
 }

lib/flutter_appavailability.dart

@@ -85,13 +85,14 @@ class AppAvailability {
     return await _channel.invokeMethod("isAppEnabled", args);
   }
 
-  /// Launch an app with the given [uri] scheme if it exists.
+  /// Launch an app with the given [uri] scheme if it exists or if [activity] name is provided [android only].
   ///
   /// If the app app isn't found, then a [PlatformException] is thrown.
-  static Future<void> launchApp(String uri) async {
+  static Future<void> launchApp(String uri, String activity) async {
     Map<String, dynamic> args = <String, dynamic>{};
     args.putIfAbsent('uri', () => uri);
     if (Platform.isAndroid) {
+      args.putIfAbsent('activity', () => activity);
       await _channel.invokeMethod("launchApp", args);
     }
     else if (Platform.isIOS) {