Improve DOCX open handling on Android and clarify external-viewer behavior

README.md

@@ -8,6 +8,9 @@ Used to create a folder on the user's mobile phone and Desktop;
 
 ---
 ## Opening pdf, xlsx, docs, ppt and zip files
+
+> On Android and Windows this plugin uses apps installed on the device/system to open files.
+> For `.docx` and other formats, make sure a compatible viewer is installed.
 ---
 
 ## Getting Started

android/src/main/kotlin/com/fsconceicao/open_document/OpenDocument.kt

@@ -12,6 +12,7 @@ import androidx.core.content.FileProvider
 import io.flutter.embedding.android.FlutterActivity
 import io.flutter.plugin.common.MethodChannel
 import java.io.File
+import java.util.Locale
 
 
 class OpenDocument(context: Context, activity: FlutterActivity?) {
@@ -25,14 +26,15 @@ class OpenDocument(context: Context, activity: FlutterActivity?) {
 
     @RequiresApi(Build.VERSION_CODES.KITKAT)
     internal fun openDocument(url: String, result: MethodChannel.Result) {
-        try {
-
-            val type = getFileType(name(url).split(".")[1])
-            val intent = Intent(Intent.ACTION_VIEW)
-            intent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION)
-            intent.addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP)
-            intent.addCategory("android.intent.category.DEFAULT")
+        val fileName = name(url)
+        val extension = fileName.substringAfterLast('.', "").lowercase(Locale.ROOT)
+        val type = if (extension.isNotEmpty()) getFileType(extension) else "*/*"
+        val intent = Intent(Intent.ACTION_VIEW)
+        intent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION)
+        intent.addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP)
+        intent.addCategory("android.intent.category.DEFAULT")
 
+        try {
             if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
                 val uri = FileProvider.getUriForFile(
                     applicationContext,
@@ -42,12 +44,33 @@ class OpenDocument(context: Context, activity: FlutterActivity?) {
             } else {
                 intent.setDataAndType(Uri.fromFile(File(url)), type)
             }
-
-            this.activity?.startActivity(intent)
-        } catch (e: ActivityNotFoundException) {
+        } catch (e: Exception) {
             e.printStackTrace()
-            result.error("Error", e.localizedMessage, "Open document failure")
-            // Instruct the user to install a PDF reader here, or something
+            result.error("Error", e.localizedMessage, "Failed to prepare document for opening")
+            return
+        }
+
+        val currentActivity = this.activity
+        if (currentActivity == null) {
+            result.error("Error", "Activity is null", "Open document failure")
+            return
+        }
+
+        currentActivity.runOnUiThread {
+            try {
+                currentActivity.startActivity(intent)
+                result.success(null)
+            } catch (e: ActivityNotFoundException) {
+                e.printStackTrace()
+                result.error(
+                    "Error",
+                    "No app found to open this file type. Install a compatible viewer.",
+                    "Open document failure"
+                )
+            } catch (e: Exception) {
+                e.printStackTrace()
+                result.error("Error", e.localizedMessage, "Open document failure")
+            }
         }
     }
 

lib/open_document.dart

@@ -6,7 +6,8 @@ import 'open_document_platform_interface.dart';
 ///- It has the power to open the zip creating a new folder with
 /// the name of the file using the plugin [Archive]
 class OpenDocument {
-  /// - Open the document by the indicated path [filePath],
+  /// - Open the document by the indicated path [filePath].
+  /// - On Android and Windows, this dispatches the file to a compatible installed app.
   static Future<void> openDocument({required String filePath}) async {
     return await OpenDocumentPlatform.instance.openDocument(filePath: filePath);
   }