From 2cb0651b046438cc444c9947a8cee95982e1e22f Mon Sep 17 00:00:00 2001
From: John Preston <johnprestonmail@gmail.com>
Date: Tue, 7 May 2024 13:18:58 +0400
Subject: [PATCH] Redirect IME to search on Windows.

---
 .../SourceFiles/dialogs/dialogs_widget.cpp    | 27 +++++++++++++++----
 Telegram/SourceFiles/dialogs/dialogs_widget.h |  2 ++
 .../platform/win/main_window_win.cpp          | 15 +++++++++++
 .../platform/win/main_window_win.h            |  5 ++++
 Telegram/SourceFiles/window/main_window.cpp   |  8 ++++++
 Telegram/SourceFiles/window/main_window.h     |  5 +++-
 6 files changed, 56 insertions(+), 6 deletions(-)

diff --git a/Telegram/SourceFiles/dialogs/dialogs_widget.cpp b/Telegram/SourceFiles/dialogs/dialogs_widget.cpp
index 2f1763964..575516ffa 100644
--- a/Telegram/SourceFiles/dialogs/dialogs_widget.cpp
+++ b/Telegram/SourceFiles/dialogs/dialogs_widget.cpp
@@ -356,6 +356,14 @@ Widget::Widget(
 		Ui::PostponeCall(this, [=] { listScrollUpdated(); });
 	}, lifetime());
 
+	setAttribute(Qt::WA_InputMethodEnabled);
+	controller->widget()->imeCompositionStarts(
+	) | rpl::filter([=] {
+		return redirectImeToSearch();
+	}) | rpl::start_with_next([=] {
+		_search->setFocusFast();
+	}, lifetime());
+
 	_search->changes(
 	) | rpl::start_with_next([=] {
 		applySearchUpdate();
@@ -3290,12 +3298,17 @@ void Widget::keyPressEvent(QKeyEvent *e) {
 	}
 }
 
+bool Widget::redirectToSearchPossible() const {
+	return !_openedFolder
+		&& !_openedForum
+		&& !_childList
+		&& _search->isVisible()
+		&& !_search->hasFocus()
+		&& hasFocus();
+}
+
 bool Widget::redirectKeyToSearch(QKeyEvent *e) const {
-	if (_openedFolder
-		|| _openedForum
-		|| _childList
-		|| !_search->isVisible()
-		|| _search->hasFocus()) {
+	if (!redirectToSearchPossible()) {
 		return false;
 	}
 	const auto character = !(e->modifiers() & ~Qt::ShiftModifier)
@@ -3316,6 +3329,10 @@ bool Widget::redirectKeyToSearch(QKeyEvent *e) const {
 	return data && data->hasText();
 }
 
+bool Widget::redirectImeToSearch() const {
+	return redirectToSearchPossible();
+}
+
 void Widget::paintEvent(QPaintEvent *e) {
 	if (controller()->contentOverlapped(this, e)) {
 		return;
diff --git a/Telegram/SourceFiles/dialogs/dialogs_widget.h b/Telegram/SourceFiles/dialogs/dialogs_widget.h
index ecd2f3608..5ff9828d5 100644
--- a/Telegram/SourceFiles/dialogs/dialogs_widget.h
+++ b/Telegram/SourceFiles/dialogs/dialogs_widget.h
@@ -250,7 +250,9 @@ private:
 	void updateSuggestions(anim::type animated);
 	void processSearchFocusChange();
 
+	[[nodiscard]] bool redirectToSearchPossible() const;
 	[[nodiscard]] bool redirectKeyToSearch(QKeyEvent *e) const;
+	[[nodiscard]] bool redirectImeToSearch() const;
 
 	MTP::Sender _api;
 
diff --git a/Telegram/SourceFiles/platform/win/main_window_win.cpp b/Telegram/SourceFiles/platform/win/main_window_win.cpp
index 8c852b837..dd2f3dafe 100644
--- a/Telegram/SourceFiles/platform/win/main_window_win.cpp
+++ b/Telegram/SourceFiles/platform/win/main_window_win.cpp
@@ -480,6 +480,21 @@ bool MainWindow::initGeometryFromSystem() {
 	return true;
 }
 
+bool MainWindow::nativeEvent(
+		const QByteArray &eventType,
+		void *message,
+		long *result) {
+	if (message) {
+		const auto msg = static_cast<MSG*>(message);
+		if (msg->message == WM_IME_STARTCOMPOSITION) {
+			Core::Sandbox::Instance().customEnterFromEventLoop([&] {
+				imeCompositionStartReceived();
+			});
+		}
+	}
+	return false;
+}
+
 void MainWindow::updateWindowIcon() {
 	updateTaskbarAndIconCounters();
 }
diff --git a/Telegram/SourceFiles/platform/win/main_window_win.h b/Telegram/SourceFiles/platform/win/main_window_win.h
index 856bee773..63dc6ba17 100644
--- a/Telegram/SourceFiles/platform/win/main_window_win.h
+++ b/Telegram/SourceFiles/platform/win/main_window_win.h
@@ -48,6 +48,11 @@ protected:
 
 	bool initGeometryFromSystem() override;
 
+	bool nativeEvent(
+		const QByteArray &eventType,
+		void *message,
+		long *result) override;
+
 private:
 	struct Private;
 
diff --git a/Telegram/SourceFiles/window/main_window.cpp b/Telegram/SourceFiles/window/main_window.cpp
index 3f8c9b5ba..1c5de5967 100644
--- a/Telegram/SourceFiles/window/main_window.cpp
+++ b/Telegram/SourceFiles/window/main_window.cpp
@@ -795,10 +795,18 @@ void MainWindow::setPositionInited() {
 	_positionInited = true;
 }
 
+void MainWindow::imeCompositionStartReceived() {
+	_imeCompositionStartReceived.fire({});
+}
+
 rpl::producer<> MainWindow::leaveEvents() const {
 	return _leaveEvents.events();
 }
 
+rpl::producer<> MainWindow::imeCompositionStarts() const {
+	return _imeCompositionStartReceived.events();
+}
+
 void MainWindow::leaveEventHook(QEvent *e) {
 	_leaveEvents.fire({});
 }
diff --git a/Telegram/SourceFiles/window/main_window.h b/Telegram/SourceFiles/window/main_window.h
index 8feb329a9..79dc3c6fe 100644
--- a/Telegram/SourceFiles/window/main_window.h
+++ b/Telegram/SourceFiles/window/main_window.h
@@ -119,7 +119,8 @@ public:
 
 	void launchDrag(std::unique_ptr<QMimeData> data, Fn<void()> &&callback);
 
-	rpl::producer<> leaveEvents() const;
+	[[nodiscard]] rpl::producer<> leaveEvents() const;
+	[[nodiscard]] rpl::producer<> imeCompositionStarts() const;
 
 	virtual void updateWindowIcon() = 0;
 	void updateTitle();
@@ -185,6 +186,7 @@ protected:
 		return false;
 	}
 
+	void imeCompositionStartReceived();
 	void setPositionInited();
 
 	virtual QRect computeDesktopRect() const;
@@ -214,6 +216,7 @@ private:
 	bool _isActive = false;
 
 	rpl::event_stream<> _leaveEvents;
+	rpl::event_stream<> _imeCompositionStartReceived;
 
 	bool _maximizedBeforeHide = false;