suggest the Calendar at opening .ics files from a file manager

app/src/main/AndroidManifest.xml

@@ -27,7 +27,17 @@
             </intent-filter>
         </activity>
 
-        <activity android:name=".activities.MainActivity"/>
+        <activity android:name=".activities.MainActivity">
+            <intent-filter>
+                <action android:name="android.intent.action.VIEW"/>
+                <category android:name="android.intent.category.DEFAULT"/>
+
+                <data android:scheme="content"/>
+                <data android:scheme="file"/>
+                <data android:mimeType="text/x-vcalendar"/>
+                <data android:mimeType="text/calendar"/>
+            </intent-filter>
+        </activity>
 
         <activity
             android:name=".activities.WidgetMonthlyConfigureActivity"

app/src/main/kotlin/com/simplemobiletools/calendar/activities/MainActivity.kt

@@ -72,6 +72,10 @@ class MainActivity : SimpleActivity(), NavigationListener {
         storeStoragePaths()
         if (resources.getBoolean(R.bool.portrait_only))
             requestedOrientation = ActivityInfo.SCREEN_ORIENTATION_PORTRAIT
+
+        if (intent?.action == Intent.ACTION_VIEW && intent.data != null) {
+            importEventsFromFile(intent.data!!.path)
+        }
     }
 
     override fun onResume() {
@@ -238,8 +242,13 @@ class MainActivity : SimpleActivity(), NavigationListener {
 
     private fun importEvents() {
         FilePickerDialog(this) {
-            if (it.toLowerCase().endsWith(".ics")) {
+            importEventsFromFile(it)
-                ImportEventsDialog(this, it) {
+        }
+    }
+
+    private fun importEventsFromFile(path: String) {
+        if (path.toLowerCase().endsWith(".ics")) {
+            ImportEventsDialog(this, path) {
                 if (it) {
                     updateViewPager()
                 }
@@ -248,7 +257,6 @@ class MainActivity : SimpleActivity(), NavigationListener {
             toast(R.string.invalid_file_format)
         }
     }
-    }
 
     private fun tryExportEvents() {
         if (hasReadStoragePermission()) {