From 8e5492b6e88f2dc7a69b5534541b42d669640dcf Mon Sep 17 00:00:00 2001
From: rustbasic <127506429+rustbasic@users.noreply.github.com>
Date: Wed, 28 Aug 2024 16:40:04 +0900
Subject: [PATCH] Fix: Ensures correct IME behavior when the text input area
 gains or loses focus. (#4896)

Fix: Ensures correct IME behavior when the text input area gains or
loses focus.

Fix: Handling `state.ime_enabled` in multiple `TextEdit`.
Fix: A symptom of characters being copied when there are multiple
TextEdits.

* Related #4137
* Related #4358
* Closes #4374
* Related #4436
* Related #4794
* Related #4908

* Related #5008

Fix Issues: When focus is moved elsewhere, you must set
`state.ime_enabled = false`, otherwise the IME will have problems when
focus returns.

Fix Issues: A symptom of characters being copied when there are multiple
TextEdits.
Deletes all current `IME events`, preventing them from being copied to
`other TextEdits`, without saving the `TextEdit ID`,

( Related Issues: Some `LINUX` seem to trigger an IME enable event on
startup. So, when we gained focus, we do `state.ime_enabled = false`. )
---
 crates/egui/src/widgets/text_edit/builder.rs | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/crates/egui/src/widgets/text_edit/builder.rs b/crates/egui/src/widgets/text_edit/builder.rs
index 8763bd1a3ae..00d7d6e3eff 100644
--- a/crates/egui/src/widgets/text_edit/builder.rs
+++ b/crates/egui/src/widgets/text_edit/builder.rs
@@ -745,6 +745,16 @@ impl<'t> TextEdit<'t> {
             }
         }
 
+        // Ensures correct IME behavior when the text input area gains or loses focus.
+        if state.ime_enabled && (response.gained_focus() || response.lost_focus()) {
+            state.ime_enabled = false;
+            if let Some(mut ccursor_range) = state.cursor.char_range() {
+                ccursor_range.secondary.index = ccursor_range.primary.index;
+                state.cursor.set_char_range(Some(ccursor_range));
+            }
+            ui.input_mut(|i| i.events.retain(|e| !matches!(e, Event::Ime(_))));
+        }
+
         state.clone().store(ui.ctx(), id);
 
         if response.changed {