Polish mobile UX downloads and comments

android/app/src/main/AndroidManifest.xml

@@ -2,7 +2,7 @@
     <uses-permission android:name="android.permission.INTERNET"/>
 
     <application
-        android:label="gel_rule_app"
+        android:label="RuleGel"
         android:name="${applicationName}"
         android:icon="@mipmap/ic_launcher">
         <activity

android/app/src/main/kotlin/com/example/gel_rule_app/MainActivity.kt

@@ -1,5 +1,64 @@
 package com.example.gel_rule_app
 
+import android.content.ContentValues
+import android.os.Build
+import android.os.Environment
+import android.provider.MediaStore
 import io.flutter.embedding.android.FlutterActivity
+import io.flutter.embedding.engine.FlutterEngine
+import io.flutter.plugin.common.MethodChannel
+import java.io.File
+import java.io.FileInputStream
+import java.io.FileOutputStream
 
-class MainActivity : FlutterActivity()
+class MainActivity : FlutterActivity() {
+    override fun configureFlutterEngine(flutterEngine: FlutterEngine) {
+        super.configureFlutterEngine(flutterEngine)
+        MethodChannel(flutterEngine.dartExecutor.binaryMessenger, "rulegel/downloads")
+            .setMethodCallHandler { call, result ->
+                if (call.method != "saveToDownloads") {
+                    result.notImplemented()
+                    return@setMethodCallHandler
+                }
+                try {
+                    val path = call.argument<String>("path") ?: error("Missing path")
+                    val fileName = call.argument<String>("fileName") ?: File(path).name
+                    val mimeType = call.argument<String>("mimeType") ?: "application/octet-stream"
+                    result.success(saveToDownloads(path, fileName, mimeType))
+                } catch (error: Throwable) {
+                    result.error("save_failed", error.message, null)
+                }
+            }
+    }
+
+    private fun saveToDownloads(path: String, fileName: String, mimeType: String): String {
+        val source = File(path)
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
+            val values = ContentValues().apply {
+                put(MediaStore.Downloads.DISPLAY_NAME, fileName)
+                put(MediaStore.Downloads.MIME_TYPE, mimeType)
+                put(MediaStore.Downloads.RELATIVE_PATH, Environment.DIRECTORY_DOWNLOADS)
+                put(MediaStore.Downloads.IS_PENDING, 1)
+            }
+            val resolver = applicationContext.contentResolver
+            val uri = resolver.insert(MediaStore.Downloads.EXTERNAL_CONTENT_URI, values)
+                ?: error("Could not create Downloads entry")
+            resolver.openOutputStream(uri)?.use { output ->
+                FileInputStream(source).use { input -> input.copyTo(output) }
+            } ?: error("Could not open Downloads output stream")
+            values.clear()
+            values.put(MediaStore.Downloads.IS_PENDING, 0)
+            resolver.update(uri, values, null, null)
+            return fileName
+        }
+
+        @Suppress("DEPRECATION")
+        val downloads = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS)
+        downloads.mkdirs()
+        val destination = File(downloads, fileName)
+        FileInputStream(source).use { input ->
+            FileOutputStream(destination).use { output -> input.copyTo(output) }
+        }
+        return destination.absolutePath
+    }
+}