feat(android): Implement sharing internal files and text

android/src/main/AndroidManifest.xml

@@ -4,7 +4,7 @@
     <application>
         <provider
             android:name="org.moxxy.moxxy_native.content.MoxxyFileProvider"
-            android:authorities="org.moxxy.moxxyv2.fileprovider"
+            android:authorities="org.moxxy.moxxyv2.fileprovider2"
             android:exported="false"
             android:grantUriPermissions="true">
             <meta-data

android/src/main/kotlin/org/moxxy/moxxy_native/Constants.kt

@@ -24,7 +24,7 @@ const val NOTIFICATION_EXTRA_ID_KEY = "notification_id"
 const val NOTIFICATION_MESSAGE_EXTRA_MIME = "mime"
 const val NOTIFICATION_MESSAGE_EXTRA_PATH = "path"
 
-const val MOXXY_FILEPROVIDER_ID = "org.moxxy.moxxyv2.fileprovider"
+const val MOXXY_FILEPROVIDER_ID = "org.moxxy.moxxyv2.fileprovider2"
 
 // Shared preferences keys
 const val SHARED_PREFERENCES_KEY = "org.moxxy.moxxyv2"

android/src/main/kotlin/org/moxxy/moxxy_native/content/MoxxyFileProvider.kt

@@ -1,6 +1,24 @@
 package org.moxxy.moxxy_native.content
 
+import android.content.Context
+import android.net.Uri
 import androidx.core.content.FileProvider
+import org.moxxy.moxxy_native.MOXXY_FILEPROVIDER_ID
 import org.moxxy.moxxy_native.R
+import java.io.File
 
-class MoxxyFileProvider : FileProvider(R.xml.file_paths)
+class MoxxyFileProvider : FileProvider(R.xml.file_paths) {
+    companion object {
+        /*
+         * Convert a path @path inside a sharable storage directory into a content URI, given
+         * the application's context @context.
+         * */
+        fun getUriForPath(context: Context, path: String): Uri {
+            return getUriForFile(
+                context,
+                MOXXY_FILEPROVIDER_ID,
+                File(path),
+            )
+        }
+    }
+}

android/src/main/kotlin/org/moxxy/moxxy_native/notifications/NotificationsImplementation.kt

@@ -14,10 +14,8 @@ import androidx.core.app.NotificationManagerCompat
 import androidx.core.app.Person
 import androidx.core.app.RemoteInput
 import androidx.core.app.TaskStackBuilder
-import androidx.core.content.FileProvider
 import androidx.core.graphics.drawable.IconCompat
 import org.moxxy.moxxy_native.MARK_AS_READ_ACTION
-import org.moxxy.moxxy_native.MOXXY_FILEPROVIDER_ID
 import org.moxxy.moxxy_native.NOTIFICATION_EXTRA_ID_KEY
 import org.moxxy.moxxy_native.NOTIFICATION_EXTRA_JID_KEY
 import org.moxxy.moxxy_native.NOTIFICATION_MESSAGE_EXTRA_MIME
@@ -27,7 +25,7 @@ import org.moxxy.moxxy_native.REPLY_ACTION
 import org.moxxy.moxxy_native.REPLY_TEXT_KEY
 import org.moxxy.moxxy_native.TAG
 import org.moxxy.moxxy_native.TAP_ACTION
-import java.io.File
+import org.moxxy.moxxy_native.content.MoxxyFileProvider
 
 class NotificationsImplementation(private val context: Context) : MoxxyNotificationsApi {
     override fun createNotificationGroups(groups: List<NotificationGroup>) {
@@ -207,11 +205,7 @@ class NotificationsImplementation(private val context: Context) : MoxxyNotificat
             )
             // If we got an image, turn it into a content URI and set it
             if (message.content.mime != null && message.content.path != null) {
-                val fileUri = FileProvider.getUriForFile(
-                    context,
-                    MOXXY_FILEPROVIDER_ID,
-                    File(message.content.path),
-                )
+                val fileUri = MoxxyFileProvider.getUriForPath(context, message.content.path)
                 msg.apply {
                     setData(message.content.mime, fileUri)
 

android/src/main/kotlin/org/moxxy/moxxy_native/platform/PlatformApi.kt

@@ -8,6 +8,8 @@ import io.flutter.plugin.common.BasicMessageChannel
 import io.flutter.plugin.common.BinaryMessenger
 import io.flutter.plugin.common.MessageCodec
 import io.flutter.plugin.common.StandardMessageCodec
+import java.io.ByteArrayOutputStream
+import java.nio.ByteBuffer
 
 private fun wrapResult(result: Any?): List<Any?> {
     return listOf(result)
@@ -41,17 +43,66 @@ class FlutterError(
     val details: Any? = null,
 ) : Throwable()
 
+/** Generated class from Pigeon that represents data sent in messages. */
+data class ShareItem(
+    val path: String? = null,
+    val mime: String,
+    val text: String? = null,
+
+) {
+    companion object {
+        @Suppress("UNCHECKED_CAST")
+        fun fromList(list: List<Any?>): ShareItem {
+            val path = list[0] as String?
+            val mime = list[1] as String
+            val text = list[2] as String?
+            return ShareItem(path, mime, text)
+        }
+    }
+    fun toList(): List<Any?> {
+        return listOf<Any?>(
+            path,
+            mime,
+            text,
+        )
+    }
+}
+
+@Suppress("UNCHECKED_CAST")
+private object MoxxyPlatformApiCodec : StandardMessageCodec() {
+    override fun readValueOfType(type: Byte, buffer: ByteBuffer): Any? {
+        return when (type) {
+            128.toByte() -> {
+                return (readValue(buffer) as? List<Any?>)?.let {
+                    ShareItem.fromList(it)
+                }
+            }
+            else -> super.readValueOfType(type, buffer)
+        }
+    }
+    override fun writeValue(stream: ByteArrayOutputStream, value: Any?) {
+        when (value) {
+            is ShareItem -> {
+                stream.write(128)
+                writeValue(stream, value.toList())
+            }
+            else -> super.writeValue(stream, value)
+        }
+    }
+}
+
 /** Generated interface from Pigeon that represents a handler of messages from Flutter. */
 interface MoxxyPlatformApi {
     fun getPersistentDataPath(): String
     fun getCacheDataPath(): String
     fun openBatteryOptimisationSettings()
     fun isIgnoringBatteryOptimizations(): Boolean
+    fun shareItems(items: List<ShareItem>, genericMimeType: String)
 
     companion object {
         /** The codec used by MoxxyPlatformApi. */
         val codec: MessageCodec<Any?> by lazy {
-            StandardMessageCodec()
+            MoxxyPlatformApiCodec
         }
 
         /** Sets up an instance of `MoxxyPlatformApi` to handle messages through the `binaryMessenger`. */
@@ -122,6 +173,26 @@ interface MoxxyPlatformApi {
                     channel.setMessageHandler(null)
                 }
             }
+            run {
+                val channel = BasicMessageChannel<Any?>(binaryMessenger, "dev.flutter.pigeon.moxxy_native.MoxxyPlatformApi.shareItems", codec)
+                if (api != null) {
+                    channel.setMessageHandler { message, reply ->
+                        val args = message as List<Any?>
+                        val itemsArg = args[0] as List<ShareItem>
+                        val genericMimeTypeArg = args[1] as String
+                        var wrapped: List<Any?>
+                        try {
+                            api.shareItems(itemsArg, genericMimeTypeArg)
+                            wrapped = listOf<Any?>(null)
+                        } catch (exception: Throwable) {
+                            wrapped = wrapError(exception)
+                        }
+                        reply.reply(wrapped)
+                    }
+                } else {
+                    channel.setMessageHandler(null)
+                }
+            }
         }
     }
 }

android/src/main/kotlin/org/moxxy/moxxy_native/platform/PlatformImplementation.kt

@@ -5,6 +5,8 @@ import android.content.Intent
 import android.net.Uri
 import android.os.PowerManager
 import android.provider.Settings
+import androidx.core.app.ShareCompat
+import org.moxxy.moxxy_native.content.MoxxyFileProvider
 
 class PlatformImplementation(private val context: Context) : MoxxyPlatformApi {
     override fun getPersistentDataPath(): String {
@@ -27,4 +29,28 @@ class PlatformImplementation(private val context: Context) : MoxxyPlatformApi {
         val pm = context.getSystemService(PowerManager::class.java)
         return pm.isIgnoringBatteryOptimizations(context.packageName)
     }
+
+    override fun shareItems(items: List<ShareItem>, genericMimeType: String) {
+        // Empty lists make no sense
+        assert(items.isNotEmpty())
+
+        // Convert the paths to content URIs
+        val builder = ShareCompat.IntentBuilder(context).setType(genericMimeType)
+        for (item in items) {
+            assert(item.text == null && item.path != null || item.text != null && item.path == null)
+
+            if (item.text != null) {
+                builder.setText(item.text)
+            } else if (item.path != null) {
+                builder.addStream(MoxxyFileProvider.getUriForPath(context, item.path))
+            }
+        }
+
+        // We cannot just use startChooser() because then Android complains that we're not attached
+        // to an Activity. So, we just ask it to start a new one.
+        val intent = builder.createChooserIntent().apply {
+            addFlags(Intent.FLAG_ACTIVITY_NEW_TASK)
+        }
+        context.startActivity(intent)
+    }
 }