fix(ios): hide the presenter's keyboard under a custom-dimmed sheet

CHANGELOG.md

@@ -18,7 +18,7 @@
 - Added `detentBackgrounds` with color strings or color/blur objects, native iOS transitions, and cross-fades elsewhere. ([#876](https://github.com/lodev09/react-native-true-sheet/pull/876) by [@lodev09](https://github.com/lodev09))
 - Added `dismissThreshold` on Android and Web. Set it to `'short'` to dismiss on a short drag or fling, like Compose Material3's sheet. ([#880](https://github.com/lodev09/react-native-true-sheet/pull/880) by [@lodev09](https://github.com/lodev09))
 - Support Expo SDK 58 and React Native 0.88. The Expo Router `Sheet` navigator works on Router 58, and reopening a sheet on iOS no longer shows a blank screen. ([#896](https://github.com/lodev09/react-native-true-sheet/pull/896) by [@lodev09](https://github.com/lodev09))
-- Added `dimColor` and `dimOpacity` to customize the color and opacity of the dim behind the sheet. ([#911](https://github.com/lodev09/react-native-true-sheet/pull/911), [#919](https://github.com/lodev09/react-native-true-sheet/pull/919) by [@IjzerenHein](https://github.com/IjzerenHein), [@nickcernera](https://github.com/nickcernera) and [@lodev09](https://github.com/lodev09))
+- Added `dimColor` and `dimOpacity` to customize the color and opacity of the dim behind the sheet. ([#911](https://github.com/lodev09/react-native-true-sheet/pull/911), [#919](https://github.com/lodev09/react-native-true-sheet/pull/919), [#925](https://github.com/lodev09/react-native-true-sheet/pull/925) by [@IjzerenHein](https://github.com/IjzerenHein), [@nickcernera](https://github.com/nickcernera) and [@lodev09](https://github.com/lodev09))
 
 ### 🐛 Bug fixes
 

ios/TrueSheetViewController.mm

@@ -16,6 +16,7 @@
 #import "utils/BlurUtil.h"
 #import "utils/GestureUtil.h"
 #import "utils/PlatformUtil.h"
+#import "utils/UIView+FirstResponder.h"
 #import "utils/WindowUtil.h"
 
 #import <React/RCTLog.h>
@@ -103,6 +104,7 @@ @implementation TrueSheetViewController {
   CADisplayLink *_interactivePositionLink;
 
   __weak TrueSheetViewController *_parentSheetController;
+  __weak UIView *_presenterFirstResponder;
 
   UIView *_anchorView;
 
@@ -451,6 +453,10 @@ - (BOOL)useCustomDimming {
   return self.dimmed && (self.dimColor != nil || self.dimOpacity != nil);
 }
 
+- (BOOL)isDimmedAtEveryDetent {
+  return self.dimmed && [self.dimmedDetentIndex integerValue] == 0;
+}
+
 // Like the system dim, fades in between the detent below `dimmedDetentIndex` and the dimmed detent.
 - (CGFloat)dimAlphaForIndex:(CGFloat)index {
   if (![self useCustomDimming]) {
@@ -515,6 +521,15 @@ - (void)viewWillAppear:(BOOL)animated {
 
     [self setupDimView];
 
+    // UIKit hides the presenter's keyboard under a sheet dimmed at every detent and
+    // brings it back on dismiss, but custom dimming leaves the native sheet undimmed.
+    if ([self useCustomDimming] && [self isDimmedAtEveryDetent]) {
+      UIView *firstResponder = [presenter.view findFirstResponder];
+      if ([firstResponder resignFirstResponder]) {
+        _presenterFirstResponder = firstResponder;
+      }
+    }
+
     dispatch_async(dispatch_get_main_queue(), ^{
       NSInteger index = self.currentDetentIndex;
       CGFloat position = self.currentPosition;
@@ -758,6 +773,13 @@ - (void)emitWillDismissEvents {
     [self.delegate viewControllerWillBlur];
     [self.delegate viewControllerWillDismiss];
     [_parentSheetController.delegate viewControllerWillFocus];
+
+    // Restored once the dismiss commits, like UIKit's own keyboard preservation.
+    UIView *firstResponder = _presenterFirstResponder;
+    _presenterFirstResponder = nil;
+    if (!self.presentingViewController.isBeingDismissed) {
+      [firstResponder becomeFirstResponder];
+    }
   }
 }
 
@@ -1388,7 +1410,7 @@ - (void)setupSheetDetents {
 
   if ([self useCustomDimming]) {
     sheet.largestUndimmedDetentIdentifier = sheet.detents.lastObject.identifier;
-  } else if (self.dimmed && [self.dimmedDetentIndex integerValue] == 0) {
+  } else if ([self isDimmedAtEveryDetent]) {
     sheet.largestUndimmedDetentIdentifier = nil;
   } else {
     sheet.largestUndimmedDetentIdentifier = UISheetPresentationControllerDetentIdentifierLarge;