From 4a10702f6c39279c2d4613f12622046399a3eecd Mon Sep 17 00:00:00 2001
From: Hajime Hoshi <hajimehoshi@gmail.com>
Date: Mon, 16 Sep 2024 18:20:01 +0900
Subject: [PATCH] internal/ui: replace deprecated APIs

[UIScreen mainScreen] is now deprecated.
---
 internal/ui/ui_android.go |  2 +-
 internal/ui/ui_ios.go     | 33 ++++++++++++++++++++++++++++-----
 internal/ui/ui_mobile.go  |  5 ++++-
 3 files changed, 33 insertions(+), 7 deletions(-)

diff --git a/internal/ui/ui_android.go b/internal/ui/ui_android.go
index d688d85fc..ab71b61dd 100644
--- a/internal/ui/ui_android.go
+++ b/internal/ui/ui_android.go
@@ -119,7 +119,7 @@ func (*graphicsDriverCreatorImpl) newPlayStation5() (graphicsdriver.Graphics, er
 	return nil, errors.New("ui: PlayStation 5 is not supported in this environment")
 }
 
-func deviceScaleFactorImpl() float64 {
+func (u *UserInterface) deviceScaleFactor() float64 {
 	var s float64
 	if err := app.RunOnJVM(func(vm, env, ctx uintptr) error {
 		// TODO: This might be crash when this is called from init(). How can we detect this?
diff --git a/internal/ui/ui_ios.go b/internal/ui/ui_ios.go
index 190140df7..64760256e 100644
--- a/internal/ui/ui_ios.go
+++ b/internal/ui/ui_ios.go
@@ -19,8 +19,31 @@ package ui
 //
 // #import <UIKit/UIKit.h>
 //
-// static double devicePixelRatio() {
-//   return [[UIScreen mainScreen] nativeScale];
+// static double devicePixelRatioOnMainThread(UIView* view) {
+//   UIWindow* window = view.window;
+//   if (!window) {
+//     return 1;
+//   }
+//   UIWindowScene* scene = window.windowScene;
+//   if (!scene) {
+//     return 1;
+//   }
+//   return scene.screen.nativeScale;
+// }
+//
+// static double devicePixelRatio(uintptr_t viewPtr) {
+//   if (!viewPtr) {
+//     return 1;
+//   }
+//   UIView* view = (__bridge UIView*)(void*)viewPtr;
+//   if ([NSThread isMainThread]) {
+//     return devicePixelRatioOnMainThread(view);
+//   }
+//   __block double scale;
+//   dispatch_sync(dispatch_get_main_queue(), ^{
+//     scale = devicePixelRatioOnMainThread(view);
+//   });
+//   return scale;
 // }
 import "C"
 
@@ -66,6 +89,7 @@ func (*graphicsDriverCreatorImpl) newPlayStation5() (graphicsdriver.Graphics, er
 }
 
 func (u *UserInterface) SetUIView(uiview uintptr) error {
+	u.uiView.Store(uiview)
 	select {
 	case err := <-u.errCh:
 		return err
@@ -89,9 +113,8 @@ func (u *UserInterface) IsGL() (bool, error) {
 	return u.GraphicsLibrary() == GraphicsLibraryOpenGL, nil
 }
 
-func deviceScaleFactorImpl() float64 {
-	// TODO: Can this be called from non-main threads?
-	return float64(C.devicePixelRatio())
+func (u *UserInterface) deviceScaleFactor() float64 {
+	return float64(C.devicePixelRatio(C.uintptr_t(u.uiView.Load())))
 }
 
 func dipToNativePixels(x float64, scale float64) float64 {
diff --git a/internal/ui/ui_mobile.go b/internal/ui/ui_mobile.go
index d755798e3..fd6a86038 100644
--- a/internal/ui/ui_mobile.go
+++ b/internal/ui/ui_mobile.go
@@ -104,6 +104,9 @@ type userInterfaceImpl struct {
 	strictContextRestoration     atomic.Bool
 	strictContextRestorationOnce sync.Once
 
+	// uiView is used only on iOS.
+	uiView atomic.Uintptr
+
 	m sync.RWMutex
 }
 
@@ -285,7 +288,7 @@ func (m *Monitor) DeviceScaleFactor() float64 {
 	// Initialize this lazily.
 	m.deviceScaleFactorOnce.Do(func() {
 		// Assume that the device scale factor never changes on mobiles.
-		m.deviceScaleFactor = deviceScaleFactorImpl()
+		m.deviceScaleFactor = theUI.deviceScaleFactor()
 	})
 	return m.deviceScaleFactor
 }