Add code to remove keyboard input accessory view that was causing lay…

…out errors

ios/Classes/FlutterWebviewPlugin.m

@@ -1,7 +1,20 @@
 #import "FlutterWebviewPlugin.h"
+#import <objc/runtime.h>
 
 static NSString *const CHANNEL_NAME = @"flutter_webview_plugin";
 
+@interface _NoInputAccessoryView : NSObject
+
+@end
+
+@implementation _NoInputAccessoryView
+
+- (id)inputAccessoryView {
+  return nil;
+}
+
+@end
+
 // UIWebViewDelegate
 @interface FlutterWebviewPlugin() <WKNavigationDelegate, UIScrollViewDelegate, WKUIDelegate> {
     BOOL _enableAppScheme;
@@ -114,6 +127,7 @@ - (void)initWebview:(FlutterMethodCall*)call {
     self.webview.hidden = [hidden boolValue];
     self.webview.scrollView.showsHorizontalScrollIndicator = [scrollBar boolValue];
     self.webview.scrollView.showsVerticalScrollIndicator = [scrollBar boolValue];
+    [self removeInputAccessoryViewFromWKWebView:self.webview];
 
     [self.webview addObserver:self forKeyPath:@"estimatedProgress" options:NSKeyValueObservingOptionNew context:NULL];
 
@@ -345,4 +359,37 @@ - (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView {
     }
 }
 
+#pragma mark - remove input accessory view
+- (void)removeInputAccessoryViewFromWKWebView:(WKWebView *)webView {
+  UIView *targetView;
+
+  for (UIView *view in webView.scrollView.subviews) {
+    if([[view.class description] hasPrefix:@"WKContent"]) {
+      targetView = view;
+    }
+  }
+
+  if (!targetView) {
+    return;
+  }
+
+  NSString *noInputAccessoryViewClassName = [NSString stringWithFormat:@"%@_NoInputAccessoryView", targetView.class.superclass];
+  Class newClass = NSClassFromString(noInputAccessoryViewClassName);
+
+  if(newClass == nil) {
+    newClass = objc_allocateClassPair(targetView.class, [noInputAccessoryViewClassName cStringUsingEncoding:NSASCIIStringEncoding], 0);
+    if(!newClass) {
+      return;
+    }
+
+    Method method = class_getInstanceMethod([_NoInputAccessoryView class], @selector(inputAccessoryView));
+
+    class_addMethod(newClass, @selector(inputAccessoryView), method_getImplementation(method), method_getTypeEncoding(method));
+
+    objc_registerClassPair(newClass);
+  }
+
+  object_setClass(targetView, newClass);
+}
+
 @end