From 1930b1134675fea101df822be3fc2a4adbbc8268 Mon Sep 17 00:00:00 2001
From: y5nw <37980625+y5nw@users.noreply.github.com>
Date: Thu, 8 Feb 2024 00:36:00 +0100
Subject: [PATCH] [SDL] Avoid unnecessarily "restarting" text input

---
 source/Irrlicht/CIrrDeviceSDL.cpp | 33 +++++++++++++++++++++++--------
 source/Irrlicht/CIrrDeviceSDL.h   |  2 ++
 2 files changed, 27 insertions(+), 8 deletions(-)

diff --git a/source/Irrlicht/CIrrDeviceSDL.cpp b/source/Irrlicht/CIrrDeviceSDL.cpp
index 7b643ce2..0ed8864c 100644
--- a/source/Irrlicht/CIrrDeviceSDL.cpp
+++ b/source/Irrlicht/CIrrDeviceSDL.cpp
@@ -219,17 +219,29 @@ void CIrrDeviceSDL::resetReceiveTextInputEvents() {
 	gui::IGUIElement *elem = GUIEnvironment->getFocus();
 	if (elem && elem->acceptsIME())
 	{
-		core::rect<s32> pos = elem->getAbsolutePosition();
-		SDL_Rect rect;
-		rect.x = pos.UpperLeftCorner.X;
-		rect.y = pos.UpperLeftCorner.Y;
-		rect.w = pos.getWidth();
-		rect.h = pos.getHeight();
-		SDL_SetTextInputRect(&rect);
-		SDL_StartTextInput();
+		core::rect<s32> *pos = new core::rect<s32>(elem->getAbsolutePosition());
+		if (lastElemPos == NULL || *lastElemPos != *pos)
+		{
+			if (lastElemPos != NULL)
+				delete lastElemPos;
+			lastElemPos = pos;
+			SDL_Rect rect;
+			rect.x = pos->UpperLeftCorner.X;
+			rect.y = pos->UpperLeftCorner.Y;
+			rect.w = pos->getWidth();
+			rect.h = pos->getHeight();
+			SDL_SetTextInputRect(&rect);
+			SDL_StartTextInput();
+		}
+		else
+		{
+			delete pos;
+		}
 	}
 	else
 	{
+		delete lastElemPos;
+		lastElemPos = NULL;
 		SDL_StopTextInput();
 	}
 }
@@ -310,6 +322,8 @@ CIrrDeviceSDL::CIrrDeviceSDL(const SIrrlichtCreationParameters& param)
 		createGUIAndScene();
 		VideoDriver->OnResize(core::dimension2d<u32>(Width, Height));
 	}
+
+	lastElemPos = NULL;
 }
 
 
@@ -323,6 +337,9 @@ CIrrDeviceSDL::~CIrrDeviceSDL()
 		for (u32 i=0; i<numJoysticks; ++i)
 			SDL_JoystickClose(Joysticks[i]);
 #endif
+		if (lastElemPos != NULL) {
+			delete lastElemPos;
+		}
 		if (Window)
 		{
 			SDL_GL_MakeCurrent(Window, NULL);
diff --git a/source/Irrlicht/CIrrDeviceSDL.h b/source/Irrlicht/CIrrDeviceSDL.h
index 1713a3b9..2321bd88 100644
--- a/source/Irrlicht/CIrrDeviceSDL.h
+++ b/source/Irrlicht/CIrrDeviceSDL.h
@@ -303,6 +303,8 @@ namespace irr
 
 		bool Resizable;
 
+		core::rect<s32> *lastElemPos;
+
 		struct SKeyMap
 		{
 			SKeyMap() {}