From ebbcdc7478423e97d3058c4775117955453d8f5b Mon Sep 17 00:00:00 2001
From: Benoit Marty <benoit@matrix.org>
Date: Mon, 8 Sep 2025 11:11:00 +0200
Subject: [PATCH] Detect mime type when picking a file

The file picker will now try to detect the mime type of the selected file.
If it cannot be detected, it will fallback to `application/octet-stream`.
---
 .../impl/messagecomposer/MessageComposerPresenter.kt     | 4 ++--
 .../android/libraries/mediapickers/api/PickerProvider.kt | 2 +-
 .../libraries/mediapickers/impl/DefaultPickerProvider.kt | 9 ++++++---
 .../libraries/mediapickers/test/FakePickerProvider.kt    | 4 ++--
 4 files changed, 11 insertions(+), 8 deletions(-)

diff --git a/features/messages/impl/src/main/kotlin/io/element/android/features/messages/impl/messagecomposer/MessageComposerPresenter.kt b/features/messages/impl/src/main/kotlin/io/element/android/features/messages/impl/messagecomposer/MessageComposerPresenter.kt
index 70a79938b3..3d32bea1e0 100644
--- a/features/messages/impl/src/main/kotlin/io/element/android/features/messages/impl/messagecomposer/MessageComposerPresenter.kt
+++ b/features/messages/impl/src/main/kotlin/io/element/android/features/messages/impl/messagecomposer/MessageComposerPresenter.kt
@@ -165,8 +165,8 @@ class MessageComposerPresenter(
         val galleryMediaPicker = mediaPickerProvider.registerGalleryPicker { uri, mimeType ->
             handlePickedMedia(uri, mimeType)
         }
-        val filesPicker = mediaPickerProvider.registerFilePicker(AnyMimeTypes) { uri ->
-            handlePickedMedia(uri, MimeTypes.OctetStream)
+        val filesPicker = mediaPickerProvider.registerFilePicker(AnyMimeTypes) { uri, mimeType ->
+            handlePickedMedia(uri, mimeType ?: MimeTypes.OctetStream)
         }
         val cameraPhotoPicker = mediaPickerProvider.registerCameraPhotoPicker { uri ->
             handlePickedMedia(uri, MimeTypes.Jpeg)
diff --git a/libraries/mediapickers/api/src/main/kotlin/io/element/android/libraries/mediapickers/api/PickerProvider.kt b/libraries/mediapickers/api/src/main/kotlin/io/element/android/libraries/mediapickers/api/PickerProvider.kt
index 961f486322..4a2f26a4b3 100644
--- a/libraries/mediapickers/api/src/main/kotlin/io/element/android/libraries/mediapickers/api/PickerProvider.kt
+++ b/libraries/mediapickers/api/src/main/kotlin/io/element/android/libraries/mediapickers/api/PickerProvider.kt
@@ -25,7 +25,7 @@ interface PickerProvider {
     @Composable
     fun registerFilePicker(
         mimeType: String,
-        onResult: (Uri?) -> Unit
+        onResult: (uri: Uri?, mimeType: String?) -> Unit,
     ): PickerLauncher<String, Uri?>
 
     @Composable
diff --git a/libraries/mediapickers/impl/src/main/kotlin/io/element/android/libraries/mediapickers/impl/DefaultPickerProvider.kt b/libraries/mediapickers/impl/src/main/kotlin/io/element/android/libraries/mediapickers/impl/DefaultPickerProvider.kt
index b93820b97d..878c9ea865 100644
--- a/libraries/mediapickers/impl/src/main/kotlin/io/element/android/libraries/mediapickers/impl/DefaultPickerProvider.kt
+++ b/libraries/mediapickers/impl/src/main/kotlin/io/element/android/libraries/mediapickers/impl/DefaultPickerProvider.kt
@@ -88,13 +88,16 @@ class DefaultPickerProvider(
     @Composable
     override fun registerFilePicker(
         mimeType: String,
-        onResult: (Uri?) -> Unit,
+        onResult: (uri: Uri?, mimeType: String?) -> Unit,
     ): PickerLauncher<String, Uri?> {
         // Tests and UI preview can't handle Context or FileProviders, so we might as well disable the whole picker
         return if (LocalInspectionMode.current) {
-            NoOpPickerLauncher { onResult(null) }
+            NoOpPickerLauncher { onResult(null, null) }
         } else {
-            rememberPickerLauncher(type = PickerType.File(mimeType)) { uri -> onResult(uri) }
+            rememberPickerLauncher(type = PickerType.File(mimeType)) { uri ->
+                val pickedMimeType = uri?.let { context.contentResolver.getType(it) }
+                onResult(uri, pickedMimeType)
+            }
         }
     }
 
diff --git a/libraries/mediapickers/test/src/main/kotlin/io/element/android/libraries/mediapickers/test/FakePickerProvider.kt b/libraries/mediapickers/test/src/main/kotlin/io/element/android/libraries/mediapickers/test/FakePickerProvider.kt
index 8dfd88dcd6..3a279868bf 100644
--- a/libraries/mediapickers/test/src/main/kotlin/io/element/android/libraries/mediapickers/test/FakePickerProvider.kt
+++ b/libraries/mediapickers/test/src/main/kotlin/io/element/android/libraries/mediapickers/test/FakePickerProvider.kt
@@ -30,8 +30,8 @@ class FakePickerProvider : PickerProvider {
     }
 
     @Composable
-    override fun registerFilePicker(mimeType: String, onResult: (Uri?) -> Unit): PickerLauncher<String, Uri?> {
-        return NoOpPickerLauncher { onResult(result) }
+    override fun registerFilePicker(mimeType: String, onResult: (Uri?, String?) -> Unit): PickerLauncher<String, Uri?> {
+        return NoOpPickerLauncher { onResult(result, this.mimeType) }
     }
 
     @Composable