From b4058bb0683ddee853948e40786e7bc958a1701c Mon Sep 17 00:00:00 2001
From: WenJingRui <2539699336@qq.com>
Date: Tue, 23 Nov 2021 07:27:56 +0800
Subject: [PATCH] [iOS] Fix:Keyboard inset is not correct when presenting and
 native ViewController on FlutterViewController (flutter/engine#29862)

---
 .../darwin/ios/framework/Source/FlutterViewController.mm  | 5 +++--
 .../ios/framework/Source/FlutterViewControllerTest.mm     | 8 ++++++++
 2 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/engine/src/flutter/shell/platform/darwin/ios/framework/Source/FlutterViewController.mm b/engine/src/flutter/shell/platform/darwin/ios/framework/Source/FlutterViewController.mm
index 4f7125f8248..7f5ebd1e819 100644
--- a/engine/src/flutter/shell/platform/darwin/ios/framework/Source/FlutterViewController.mm
+++ b/engine/src/flutter/shell/platform/darwin/ios/framework/Source/FlutterViewController.mm
@@ -1200,9 +1200,10 @@ static flutter::PointerData::DeviceKind DeviceKindFromTouchType(UITouch* touch)
       }
       completion:^(BOOL finished) {
         if (self.displayLink == currentDisplayLink) {
+          // Indicates the displaylink captured by this block is the original one,which also
+          // indicates the animation has not been interrupted from its beginning. Moreover,indicates
+          // the animation is over and there is no more animation about to exectute.
           [self invalidateDisplayLink];
-        }
-        if (finished) {
           [self removeKeyboardAnimationView];
           [self ensureViewportMetricsIsCorrect];
         }
diff --git a/engine/src/flutter/shell/platform/darwin/ios/framework/Source/FlutterViewControllerTest.mm b/engine/src/flutter/shell/platform/darwin/ios/framework/Source/FlutterViewControllerTest.mm
index 2c462e479c5..0bb83465728 100644
--- a/engine/src/flutter/shell/platform/darwin/ios/framework/Source/FlutterViewControllerTest.mm
+++ b/engine/src/flutter/shell/platform/darwin/ios/framework/Source/FlutterViewControllerTest.mm
@@ -173,9 +173,17 @@ typedef enum UIAccessibilityContrast : NSInteger {
                     @"UIKeyboardAnimationDurationUserInfoKey" : [NSNumber numberWithDouble:0.25],
                     @"UIKeyboardIsLocalUserInfoKey" : [NSNumber numberWithBool:isLocal]
                   }];
+
+  XCTestExpectation* expectation = [self expectationWithDescription:@"update viewport"];
+  OCMStub([mockEngine updateViewportMetrics:flutter::ViewportMetrics()])
+      .ignoringNonObjectArgs()
+      .andDo(^(NSInvocation* invocation) {
+        [expectation fulfill];
+      });
   id viewControllerMock = OCMPartialMock(viewController);
   [viewControllerMock keyboardWillChangeFrame:notification];
   OCMVerify([viewControllerMock startKeyBoardAnimation:0.25]);
+  [self waitForExpectationsWithTimeout:5.0 handler:nil];
 }
 
 - (void)testEnsureViewportMetricsWillInvokeAndDisplayLinkWillInvalidateInViewDidDisappear {