Allow sharing files via Android's share sheet

app/src/main/AndroidManifest.xml

@@ -28,6 +28,16 @@
                 <action android:name="android.intent.action.MAIN" />
                 <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
+            <intent-filter>
+                <action android:name="android.intent.action.SEND" />
+                <category android:name="android.intent.category.DEFAULT" />
+                <data android:mimeType="*/*" />
+            </intent-filter>
+            <intent-filter>
+                <action android:name="android.intent.action.SEND_MULTIPLE" />
+                <category android:name="android.intent.category.DEFAULT" />
+                <data android:mimeType="*/*" />
+            </intent-filter>
         </activity>
 
         <service

app/src/main/java/org/onionshare/android/ui/MainActivity.kt

@@ -1,8 +1,12 @@
 package org.onionshare.android.ui
 
 import android.Manifest.permission.POST_NOTIFICATIONS
+import android.content.Intent
+import android.content.Intent.EXTRA_STREAM
+import android.net.Uri
 import android.os.Build.VERSION.SDK_INT
 import android.os.Bundle
+import android.os.Parcelable
 import androidx.activity.ComponentActivity
 import androidx.activity.compose.setContent
 import androidx.activity.result.contract.ActivityResultContracts.RequestPermission
@@ -25,6 +29,33 @@ class MainActivity : ComponentActivity() {
         setContent {
             MainUi(viewModel)
         }
+        onNewIntent(intent)
+    }
+
+    override fun onNewIntent(intent: Intent?) {
+        when (intent?.action) {
+            Intent.ACTION_SEND -> {
+                handleSend(intent.getParcelableExtra<Parcelable>(EXTRA_STREAM) as? Uri)
+            }
+
+            Intent.ACTION_SEND_MULTIPLE -> {
+                handleSendMultiple(intent.getParcelableArrayListExtra(EXTRA_STREAM))
+            }
+
+            else -> super.onNewIntent(intent)
+        }
+    }
+
+    private fun handleSend(uri: Uri?) {
+        if (uri == null) return
+        viewModel.onUrisReceived(listOf(uri), false)
+    }
+
+    private fun handleSendMultiple(parcelables: ArrayList<Parcelable>?) {
+        if (parcelables == null) return
+        val uris = parcelables.mapNotNull { it as? Uri }
+        if (uris.isEmpty()) return
+        viewModel.onUrisReceived(uris, false)
     }
 
     override fun onStart() {

app/src/main/java/org/onionshare/android/ui/MainViewModel.kt

@@ -2,12 +2,15 @@ package org.onionshare.android.ui
 
 import android.app.Application
 import android.net.Uri
+import android.widget.Toast
+import android.widget.Toast.LENGTH_LONG
 import androidx.lifecycle.AndroidViewModel
 import androidx.lifecycle.viewModelScope
 import dagger.hilt.android.lifecycle.HiltViewModel
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.launch
 import org.briarproject.android.dontkillmelib.DozeUtils.needsDozeWhitelisting
+import org.onionshare.android.R
 import org.onionshare.android.ShareManager
 import org.onionshare.android.files.FileManager
 import org.onionshare.android.files.FilesState
@@ -32,8 +35,10 @@ class MainViewModel @Inject constructor(
     fun onUrisReceived(uris: List<Uri>, takePermission: Boolean) {
         require(uris.isNotEmpty()) { "Call this only for non-empty list of Uris" }
 
-        viewModelScope.launch {
+        if (shareState.value.allowsModifyingFiles) viewModelScope.launch {
             fileManager.addFiles(uris, takePermission)
+        } else {
+            Toast.makeText(getApplication(), R.string.share_error_not_allowed, LENGTH_LONG).show()
         }
     }
 

app/src/main/res/values/strings.xml

@@ -53,6 +53,7 @@
     <string name="share_error_snackbar_text">Could not start OnionShare</string>
     <string name="share_error_file_snackbar_text">Could not open %s. Removed.</string>
     <string name="share_error_snackbar_action">Retry</string>
+    <string name="share_error_not_allowed">Sharing new files is only possible when not already sharing.</string>
 
     <string name="about_title">About</string>
     <string name="about_app_version">App Version %s</string>