From c29ec46b0eee99670ce7762898fe3a4810db968b Mon Sep 17 00:00:00 2001
From: Nishan Bende <nishanbende@gmail.com>
Date: Mon, 16 Aug 2021 11:24:28 -0700
Subject: [PATCH] fix#29319 - ios dismiss modal (#31500)

Summary:
This PR aims to resolve iOS can't dismiss Modal on swipe gesture.
https://github.com/facebook/react-native/issues/29319

When modal presentationStyle is pageSheet, iOS allows to dismiss the modal using swipe gesture. This PR adds support for that feature
## Changelog

<!-- Help reviewers and the release process by writing your own changelog entry. For an example, see:
https://github.com/facebook/react-native/wiki/Changelog
-->

[iOS] [Added] - Support for onRequestClose for iOS Modal component.

Pull Request resolved: https://github.com/facebook/react-native/pull/31500

Test Plan:
- If onRequestClose updates the visibility state, modal will be closed.

```
<Modal
    visible={visible}
    animationType="slide"
    presentationStyle="pageSheet"
    onRequestClose={dismiss}>
</Modal>
```

https://user-images.githubusercontent.com/23293248/117590263-36cd7f00-b14c-11eb-940c-86e700c0b8e7.mov

## Notes
- In this PR, only support for partial drag is added. i.e. user can't drag the modal up and down completely. I added full user dragging but reverted in this [commit](https://github.com/facebook/react-native/commit/bb65b9a60d54b61652d608661eba876b49be3b17) to support controllable onRequestClose. If someone has any suggestion to have full draggable support + controllable onRequestClose, please let me know.

<!--

 the code is solid. Example: The exact commands you ran and their output, screenshots / videos if the pull request changes the user interface. -->

Reviewed By: p-sun

Differential Revision: D30041625

Pulled By: sammy-SC

fbshipit-source-id: 9675da760bd5c070c4f0e1d30271c8af5c50b998
---
 React/Views/RCTModalHostView.h        |  2 +-
 React/Views/RCTModalHostView.m        | 16 ++++++++++++++++
 React/Views/RCTModalHostViewManager.m |  1 +
 3 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/React/Views/RCTModalHostView.h b/React/Views/RCTModalHostView.h
index 880b24c9a48d46..01d38615400060 100644
--- a/React/Views/RCTModalHostView.h
+++ b/React/Views/RCTModalHostView.h
@@ -16,7 +16,7 @@
 
 @protocol RCTModalHostViewInteractor;
 
-@interface RCTModalHostView : UIView <RCTInvalidating>
+@interface RCTModalHostView : UIView <RCTInvalidating, UIAdaptivePresentationControllerDelegate>
 
 @property (nonatomic, copy) NSString *animationType;
 @property (nonatomic, assign) UIModalPresentationStyle presentationStyle;
diff --git a/React/Views/RCTModalHostView.m b/React/Views/RCTModalHostView.m
index fa9aae7a2c14f0..bea9e08af961b5 100644
--- a/React/Views/RCTModalHostView.m
+++ b/React/Views/RCTModalHostView.m
@@ -24,6 +24,7 @@ @implementation RCTModalHostView {
   RCTTouchHandler *_touchHandler;
   UIView *_reactSubview;
   UIInterfaceOrientation _lastKnownOrientation;
+  RCTDirectEventBlock _onRequestClose;
 }
 
 RCT_NOT_IMPLEMENTED(-(instancetype)initWithFrame : (CGRect)frame)
@@ -57,6 +58,18 @@ - (void)notifyForBoundsChange:(CGRect)newBounds
   }
 }
 
+- (void)setOnRequestClose:(RCTDirectEventBlock)onRequestClose
+{
+  _onRequestClose = onRequestClose;
+}
+
+- (void)presentationControllerDidAttemptToDismiss:(UIPresentationController *)controller
+{
+  if (_onRequestClose != nil) {
+    _onRequestClose(nil);
+  }
+}
+
 - (void)notifyForOrientationChange
 {
   if (!_onOrientationChange) {
@@ -169,6 +182,9 @@ - (void)ensurePresentedOnlyIfNeeded
     if (self.presentationStyle != UIModalPresentationNone) {
       _modalViewController.modalPresentationStyle = self.presentationStyle;
     }
+    if (@available(iOS 13.0, *)) {
+      _modalViewController.presentationController.delegate = self;
+    }
     [_delegate presentModalHostView:self withViewController:_modalViewController animated:[self hasAnimationType]];
     _isPresented = YES;
   }
diff --git a/React/Views/RCTModalHostViewManager.m b/React/Views/RCTModalHostViewManager.m
index 7ca197d5866f7c..80342bac8dd792 100644
--- a/React/Views/RCTModalHostViewManager.m
+++ b/React/Views/RCTModalHostViewManager.m
@@ -121,6 +121,7 @@ - (void)invalidate
 RCT_EXPORT_VIEW_PROPERTY(supportedOrientations, NSArray)
 RCT_EXPORT_VIEW_PROPERTY(onOrientationChange, RCTDirectEventBlock)
 RCT_EXPORT_VIEW_PROPERTY(visible, BOOL)
+RCT_EXPORT_VIEW_PROPERTY(onRequestClose, RCTDirectEventBlock)
 
 // Fabric only
 RCT_EXPORT_VIEW_PROPERTY(onDismiss, RCTDirectEventBlock)