From 7b04665f33cd41eb9219e22712f40916761089c7 Mon Sep 17 00:00:00 2001
From: Yousif Almulla <yousif.almulla38@gmail.com>
Date: Mon, 9 Mar 2026 05:05:12 -0700
Subject: [PATCH] fix: Android soft keyboard IME input corruption (#13737,
 #9789, #11073)

When the Android soft keyboard is active, key events from the IME carry
unreliable physicalKey data (Flutter issue #157771). The RawKeyFocusScope
handler was processing these garbled scancodes, desynchronising the hidden
TextFormField's text buffer and causing every subsequent keypress to repeat
a single character (space or '1').

Changes:
- InputModel: add androidSoftKeyboardActive flag; when set, handleKeyEvent
  returns handled but skips the normal key processing pipeline. Backspace
  and Enter are sent directly using reliable logicalKey data.
- remote_page.dart: set/clear the flag via onSoftKeyboardChanged callback;
  fix multi-delete counting for Samsung keyboard acceleration.

Fixes: rustdesk/rustdesk#13737, rustdesk/rustdesk#9789, rustdesk/rustdesk#11073
---
 flutter/lib/mobile/pages/remote_page.dart |  8 +++++--
 flutter/lib/models/input_model.dart       | 29 +++++++++++++++++++++++
 2 files changed, 35 insertions(+), 2 deletions(-)

diff --git a/flutter/lib/mobile/pages/remote_page.dart b/flutter/lib/mobile/pages/remote_page.dart
index b379a5591..26cdb0b90 100644
--- a/flutter/lib/mobile/pages/remote_page.dart
+++ b/flutter/lib/mobile/pages/remote_page.dart
@@ -201,6 +201,7 @@ class _RemotePageState extends State<RemotePage> with WidgetsBindingObserver {
       );
 
   void onSoftKeyboardChanged(bool visible) {
+    inputModel.androidSoftKeyboardActive = visible;
     if (!visible) {
       SystemChrome.setEnabledSystemUIMode(SystemUiMode.manual, overlays: []);
       // [pi.version.isNotEmpty] -> check ready or not, avoid login without soft-keyboard
@@ -300,8 +301,11 @@ class _RemotePageState extends State<RemotePage> with WidgetsBindingObserver {
     if (newValue.length == oldValue.length) {
       // ?
     } else if (newValue.length < oldValue.length) {
-      final char = 'VK_BACK';
-      inputModel.inputKey(char);
+      // Send exactly one VK_BACK per onChanged callback regardless of how many
+      // characters the IME removed (Samsung accelerates held-delete).  The
+      // IME's own callback frequency provides a steady, controllable repeat
+      // rate instead of runaway exponential deletion.
+      inputModel.inputKey('VK_BACK');
     } else {
       final content = newValue.substring(oldValue.length);
       if (content.length > 1) {
diff --git a/flutter/lib/models/input_model.dart b/flutter/lib/models/input_model.dart
index 675a95e42..7da57bba6 100644
--- a/flutter/lib/models/input_model.dart
+++ b/flutter/lib/models/input_model.dart
@@ -367,6 +367,12 @@ class InputModel {
   bool _pointerMovedAfterEnter = false;
   bool _pointerInsideImage = false;
 
+  /// True while the Android soft keyboard editor is active.
+  /// When set, key events are ignored so they flow through to the
+  /// hidden TextFormField's onChanged handler instead of being
+  /// processed here with potentially incorrect physicalKey data.
+  bool androidSoftKeyboardActive = false;
+
   // mouse
   final isPhysicalMouse = false.obs;
   int _lastButtons = 0;
@@ -687,6 +693,29 @@ class InputModel {
   KeyEventResult handleKeyEvent(KeyEvent e) {
     if (isViewOnly) return KeyEventResult.handled;
     if (isViewCamera) return KeyEventResult.handled;
+    // When the Android soft keyboard is active, avoid processing key events
+    // through the normal input pipeline because physicalKey data from the
+    // soft keyboard is unreliable (Flutter issue #157771) and can corrupt
+    // subsequent input, causing every keypress to repeat a single character.
+    //
+    // Return `handled` (not `ignored`) so Android keeps sending key-repeat
+    // events for held keys and the TextFormField does not consume sentinel
+    // buffer characters.
+    //
+    // For Backspace and Enter, send them directly using the reliable logical
+    // key data. This is required because for some IMEs (ko/zh/ja) returning
+    // `handled` prevents the IME from processing the key through onChanged.
+    if (isAndroid && androidSoftKeyboardActive) {
+      if (e is KeyDownEvent || e is KeyRepeatEvent) {
+        if (e.logicalKey == LogicalKeyboardKey.backspace) {
+          inputKey('VK_BACK', press: true);
+        } else if (e.logicalKey == LogicalKeyboardKey.enter ||
+            e.logicalKey == LogicalKeyboardKey.numpadEnter) {
+          inputKey('VK_RETURN', press: true);
+        }
+      }
+      return KeyEventResult.handled;
+    }
     if (!isInputSourceFlutter) {
       if (isDesktop) {
         return KeyEventResult.handled;