From 3a916e466e83253987985a233f6a93f8fc3e92ec Mon Sep 17 00:00:00 2001
From: Henry-Hiles <henry@henryhiles.com>
Date: Thu, 15 Oct 2026 13:40:24 -0400
Subject: [PATCH] allow pasting attachments from keyboard

Closes #55
---
 android/app/src/main/AndroidManifest.xml      | 10 ++
 .../app/src/main/res/xml/provider_paths.xml   |  6 ++
 lib/controllers/attachment.dart               | 37 +++++++
 lib/widgets/composer/composer.dart            | 96 ++++++++++++++++---
 lib/widgets/composer/paste_files_action.dart  | 12 +++
 linux/flutter/generated_plugin_registrant.cc  |  4 +
 linux/flutter/generated_plugins.cmake         |  1 +
 linux/nix/devshell.nix                        |  5 +-
 macos/Flutter/GeneratedPluginRegistrant.swift |  2 +
 pubspec.lock                                  |  8 ++
 pubspec.yaml                                  |  1 +
 .../flutter/generated_plugin_registrant.cc    |  3 +
 windows/flutter/generated_plugins.cmake       |  1 +
 13 files changed, 171 insertions(+), 15 deletions(-)
 create mode 100644 android/app/src/main/res/xml/provider_paths.xml
 create mode 100644 lib/widgets/composer/paste_files_action.dart

diff --git a/android/app/src/main/AndroidManifest.xml b/android/app/src/main/AndroidManifest.xml
index d4dbebe..b471fb4 100644
--- a/android/app/src/main/AndroidManifest.xml
+++ b/android/app/src/main/AndroidManifest.xml
@@ -51,6 +51,16 @@
         <meta-data
             android:name="flutterEmbedding"
             android:value="2" />
+        <!-- Needed by pasteboard, for pasting files from the clipboard -->
+        <provider
+            android:name="androidx.core.content.FileProvider"
+            android:authorities="${applicationId}.provider"
+            android:exported="false"
+            android:grantUriPermissions="true">
+            <meta-data
+                android:name="android.support.FILE_PROVIDER_PATHS"
+                android:resource="@xml/provider_paths" />
+        </provider>
     </application>
     <!-- Required to query activities that can process text, see:
          https://developer.android.com/training/package-visibility and
diff --git a/android/app/src/main/res/xml/provider_paths.xml b/android/app/src/main/res/xml/provider_paths.xml
new file mode 100644
index 0000000..03d4219
--- /dev/null
+++ b/android/app/src/main/res/xml/provider_paths.xml
@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="utf-8"?>
+<paths xmlns:android="http://schemas.android.com/apk/res/android">
+    <external-path
+        name="external_files"
+        path="." />
+</paths>
diff --git a/lib/controllers/attachment.dart b/lib/controllers/attachment.dart
index 2cabbae..10830aa 100644
--- a/lib/controllers/attachment.dart
+++ b/lib/controllers/attachment.dart
@@ -1,3 +1,6 @@
+import "dart:io";
+import "dart:typed_data";
+
 import "package:file_selector/file_selector.dart";
 import "package:flutter_riverpod/flutter_riverpod.dart";
 import "package:nexus/controllers/client.dart";
@@ -5,6 +8,8 @@ import "package:nexus/controllers/rooms.dart";
 import "package:nexus/models/content/content.dart";
 import "package:nexus/models/content/message.dart";
 import "package:path/path.dart";
+import "package:pasteboard/pasteboard.dart";
+import "package:path_provider/path_provider.dart";
 
 class AttachmentController(final String roomId)
     extends Notifier<(String, MessageContent?)?> {
@@ -29,6 +34,38 @@ class AttachmentController(final String roomId)
     state = (filename, content);
   }
 
+  /// Attaches [bytes] as a file called [filename], e.g. for pasted images.
+  Future<void> addBytes(Uint8List bytes, String filename) async {
+    // A new directory each time, so files with the same name don't clash
+    final directory = await (await getTemporaryDirectory()).createTemp(
+      "attachment",
+    );
+    final file = File(join(directory.path, filename));
+    await file.writeAsBytes(bytes);
+
+    await add(XFile(file.path));
+  }
+
+  /// Attaches the first file on the clipboard, or the image on it if there are
+  /// no files. Returns whether there was anything to attach.
+  ///
+  /// Failing to read the clipboard counts as it being empty, so callers can
+  /// still fall back to pasting text.
+  Future<bool> paste() async {
+    final files = await Pasteboard.files().onError((_, _) => const []);
+    if (files.firstOrNull case final path?) {
+      await add(XFile(path));
+      return true;
+    }
+
+    if (await Pasteboard.image.onError((_, _) => null) case final image?) {
+      await addBytes(image, "image.png");
+      return true;
+    }
+
+    return false;
+  }
+
   static final provider = NotifierProvider.family
       .autoDispose<AttachmentController, (String, MessageContent?)?, String>(
         AttachmentController.new,
diff --git a/lib/widgets/composer/composer.dart b/lib/widgets/composer/composer.dart
index 31583be..36c884c 100644
--- a/lib/widgets/composer/composer.dart
+++ b/lib/widgets/composer/composer.dart
@@ -18,6 +18,7 @@ import "package:nexus/controllers/power_level.dart";
 import "package:nexus/models/content/message.dart";
 import "package:nexus/models/relation_type.dart";
 import "package:nexus/widgets/composer/overlays/tagger_overlay.dart";
+import "package:nexus/widgets/composer/paste_files_action.dart";
 import "package:nexus/widgets/composer/relation_preview.dart";
 import "package:nexus/main.dart";
 
@@ -100,6 +101,22 @@ class const Composer(
       }
     }
 
+    /// Attaches a file or image from the clipboard, returning whether there
+    /// was one, so pasting text can be used otherwise.
+    Future<bool> pasteFiles() async {
+      // Only one attachment is supported at a time
+      if (attachment != null) return false;
+
+      return ref
+          .read(AttachmentController.provider(roomId).notifier)
+          .paste()
+          .onError((Object error, StackTrace stackTrace) {
+            showError(error, stackTrace);
+            // It was a file, just failed to upload, so don't paste it as text
+            return true;
+          });
+    }
+
     void send() {
       if (controller.value.text.isEmpty && attachment == null ||
           attachment != null && attachment.$2 == null) {
@@ -257,21 +274,72 @@ class const Composer(
 
                                     return KeyEventResult.ignored;
                                   },
-                                  child: TextField(
-                                    maxLines: 12,
-                                    minLines: 1,
-                                    textCapitalization: .sentences,
-                                    autofocus:
-                                        (Platform.isLinux ||
-                                        Platform.isMacOS ||
-                                        Platform.isWindows),
-                                    decoration: .new(
-                                      hintText: "Your message here...",
-                                      border: .none,
+                                  // Overrides the keyboard shortcut for pasting
+                                  child: Actions(
+                                    actions: {
+                                      PasteTextIntent: PasteFilesAction(
+                                        pasteFiles,
+                                      ),
+                                    },
+                                    child: TextField(
+                                      maxLines: 12,
+                                      minLines: 1,
+                                      textCapitalization: .sentences,
+                                      autofocus:
+                                          (Platform.isLinux ||
+                                          Platform.isMacOS ||
+                                          Platform.isWindows),
+                                      decoration: .new(
+                                        hintText: "Your message here...",
+                                        border: .none,
+                                      ),
+                                      controller: controller,
+                                      key: key,
+                                      focusNode: node,
+                                      // The toolbar's paste button doesn't use the shortcut's action, so replace it too
+                                      contextMenuBuilder: (_, editableText) =>
+                                          AdaptiveTextSelectionToolbar.buttonItems(
+                                            anchors:
+                                                editableText.contextMenuAnchors,
+                                            buttonItems: editableText
+                                                .contextMenuButtonItems
+                                                .map(
+                                                  (item) => item.type == .paste
+                                                      ? item.copyWith(
+                                                          onPressed: () async {
+                                                            editableText
+                                                                .hideToolbar();
+                                                            if (!await pasteFiles()) {
+                                                              item.onPressed
+                                                                  ?.call();
+                                                            }
+                                                          },
+                                                        )
+                                                      : item,
+                                                )
+                                                .toList(),
+                                          ),
+                                      // Images pasted from Android keyboards' clipboards are inserted as content
+                                      contentInsertionConfiguration: .new(
+                                        onContentInserted: (content) {
+                                          if (attachment != null) return;
+
+                                          if (content.data case final data?) {
+                                            ref
+                                                .read(
+                                                  AttachmentController.provider(
+                                                    roomId,
+                                                  ).notifier,
+                                                )
+                                                .addBytes(
+                                                  data,
+                                                  "image.${content.mimeType.split("/").last}",
+                                                )
+                                                .onError(showError);
+                                          }
+                                        },
+                                      ),
                                     ),
-                                    controller: controller,
-                                    key: key,
-                                    focusNode: node,
                                   ),
                                 ),
                               ),
diff --git a/lib/widgets/composer/paste_files_action.dart b/lib/widgets/composer/paste_files_action.dart
new file mode 100644
index 0000000..7ca11b0
--- /dev/null
+++ b/lib/widgets/composer/paste_files_action.dart
@@ -0,0 +1,12 @@
+import "package:material_ui/material_ui.dart";
+
+/// Overrides a text field's paste, to paste files and images with
+/// [pasteFiles], falling back to pasting text if it returns false.
+class PasteFilesAction(final Future<bool> Function() pasteFiles)
+    extends Action<PasteTextIntent> {
+  @override
+  Future<void> invoke(PasteTextIntent intent) async {
+    // callingAction is the text field's own paste action, which this overrides
+    if (!await pasteFiles()) callingAction?.invoke(intent);
+  }
+}
diff --git a/linux/flutter/generated_plugin_registrant.cc b/linux/flutter/generated_plugin_registrant.cc
index c7d5bdb..b2ee366 100644
--- a/linux/flutter/generated_plugin_registrant.cc
+++ b/linux/flutter/generated_plugin_registrant.cc
@@ -11,6 +11,7 @@
 #include <file_selector_linux/file_selector_plugin.h>
 #include <media_kit_libs_linux/media_kit_libs_linux_plugin.h>
 #include <media_kit_video/media_kit_video_plugin.h>
+#include <pasteboard/pasteboard_plugin.h>
 #include <screen_retriever_linux/screen_retriever_linux_plugin.h>
 #include <url_launcher_linux/url_launcher_plugin.h>
 #include <webcrypto/webcrypto_plugin.h>
@@ -32,6 +33,9 @@ void fl_register_plugins(FlPluginRegistry* registry) {
   g_autoptr(FlPluginRegistrar) media_kit_video_registrar =
       fl_plugin_registry_get_registrar_for_plugin(registry, "MediaKitVideoPlugin");
   media_kit_video_plugin_register_with_registrar(media_kit_video_registrar);
+  g_autoptr(FlPluginRegistrar) pasteboard_registrar =
+      fl_plugin_registry_get_registrar_for_plugin(registry, "PasteboardPlugin");
+  pasteboard_plugin_register_with_registrar(pasteboard_registrar);
   g_autoptr(FlPluginRegistrar) screen_retriever_linux_registrar =
       fl_plugin_registry_get_registrar_for_plugin(registry, "ScreenRetrieverLinuxPlugin");
   screen_retriever_linux_plugin_register_with_registrar(screen_retriever_linux_registrar);
diff --git a/linux/flutter/generated_plugins.cmake b/linux/flutter/generated_plugins.cmake
index b8f6a3a..eea220b 100644
--- a/linux/flutter/generated_plugins.cmake
+++ b/linux/flutter/generated_plugins.cmake
@@ -8,6 +8,7 @@ list(APPEND FLUTTER_PLUGIN_LIST
   file_selector_linux
   media_kit_libs_linux
   media_kit_video
+  pasteboard
   screen_retriever_linux
   url_launcher_linux
   webcrypto
diff --git a/linux/nix/devshell.nix b/linux/nix/devshell.nix
index 8bc8641..6b2b94d 100644
--- a/linux/nix/devshell.nix
+++ b/linux/nix/devshell.nix
@@ -8,7 +8,10 @@ let
       "36.0.0"
     ];
     cmakeVersions = [ "3.22.1" ];
-    platformVersions = [ "36" ];
+    platformVersions = [
+      "34"
+      "36"
+    ];
     abiVersions = [
       "armeabi-v7a"
       "arm64-v8a"
diff --git a/macos/Flutter/GeneratedPluginRegistrant.swift b/macos/Flutter/GeneratedPluginRegistrant.swift
index 8b6bbb6..2a15f97 100644
--- a/macos/Flutter/GeneratedPluginRegistrant.swift
+++ b/macos/Flutter/GeneratedPluginRegistrant.swift
@@ -12,6 +12,7 @@ import flutter_local_notifications
 import media_kit_libs_macos_video
 import media_kit_video
 import package_info_plus
+import pasteboard
 import screen_retriever_macos
 import shared_preferences_foundation
 import url_launcher_macos
@@ -27,6 +28,7 @@ func RegisterGeneratedPlugins(registry: FlutterPluginRegistry) {
   MediaKitLibsMacosVideoPlugin.register(with: registry.registrar(forPlugin: "MediaKitLibsMacosVideoPlugin"))
   MediaKitVideoPlugin.register(with: registry.registrar(forPlugin: "MediaKitVideoPlugin"))
   FPPPackageInfoPlusPlugin.register(with: registry.registrar(forPlugin: "FPPPackageInfoPlusPlugin"))
+  PasteboardPlugin.register(with: registry.registrar(forPlugin: "PasteboardPlugin"))
   ScreenRetrieverMacosPlugin.register(with: registry.registrar(forPlugin: "ScreenRetrieverMacosPlugin"))
   SharedPreferencesPlugin.register(with: registry.registrar(forPlugin: "SharedPreferencesPlugin"))
   UrlLauncherPlugin.register(with: registry.registrar(forPlugin: "UrlLauncherPlugin"))
diff --git a/pubspec.lock b/pubspec.lock
index 0f4641a..942ee76 100644
--- a/pubspec.lock
+++ b/pubspec.lock
@@ -1047,6 +1047,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "4.1.0"
+  pasteboard:
+    dependency: "direct main"
+    description:
+      name: pasteboard
+      sha256: fedbe8da188d2f713aa8b01260737342e6e1087534a3ab26e1a719f8d3e8f32f
+      url: "https://pub.dev"
+    source: hosted
+    version: "0.5.0"
   path:
     dependency: "direct main"
     description:
diff --git a/pubspec.yaml b/pubspec.yaml
index ef3d403..77dc064 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -97,6 +97,7 @@ dependencies:
         git:
             url: https://github.com/Henry-Hiles/xdg_desktop_portal.dart
             ref: quad/nexus
+    pasteboard: 0.5.0
 
 dev_dependencies:
     build_runner: 2.16.2
diff --git a/windows/flutter/generated_plugin_registrant.cc b/windows/flutter/generated_plugin_registrant.cc
index 5d2b53e..95357c4 100644
--- a/windows/flutter/generated_plugin_registrant.cc
+++ b/windows/flutter/generated_plugin_registrant.cc
@@ -11,6 +11,7 @@
 #include <file_selector_windows/file_selector_windows.h>
 #include <media_kit_libs_windows_video/media_kit_libs_windows_video_plugin_c_api.h>
 #include <media_kit_video/media_kit_video_plugin_c_api.h>
+#include <pasteboard/pasteboard_plugin.h>
 #include <screen_retriever_windows/screen_retriever_windows_plugin_c_api.h>
 #include <url_launcher_windows/url_launcher_windows.h>
 #include <webcrypto/webcrypto_plugin.h>
@@ -27,6 +28,8 @@ void RegisterPlugins(flutter::PluginRegistry* registry) {
       registry->GetRegistrarForPlugin("MediaKitLibsWindowsVideoPluginCApi"));
   MediaKitVideoPluginCApiRegisterWithRegistrar(
       registry->GetRegistrarForPlugin("MediaKitVideoPluginCApi"));
+  PasteboardPluginRegisterWithRegistrar(
+      registry->GetRegistrarForPlugin("PasteboardPlugin"));
   ScreenRetrieverWindowsPluginCApiRegisterWithRegistrar(
       registry->GetRegistrarForPlugin("ScreenRetrieverWindowsPluginCApi"));
   UrlLauncherWindowsRegisterWithRegistrar(
diff --git a/windows/flutter/generated_plugins.cmake b/windows/flutter/generated_plugins.cmake
index c74b2f5..a7b2473 100644
--- a/windows/flutter/generated_plugins.cmake
+++ b/windows/flutter/generated_plugins.cmake
@@ -8,6 +8,7 @@ list(APPEND FLUTTER_PLUGIN_LIST
   file_selector_windows
   media_kit_libs_windows_video
   media_kit_video
+  pasteboard
   screen_retriever_windows
   url_launcher_windows
   webcrypto