Initial iOS implementation for webview_flutter. (#890)

Author: amirh

packages/webview_flutter/example/ios/Runner/Info.plist

@@ -39,6 +39,8 @@
 		<string>UIInterfaceOrientationLandscapeLeft</string>
 		<string>UIInterfaceOrientationLandscapeRight</string>
 	</array>
+	<key>io.flutter.embedded_views_preview</key>
+	<true/>
 	<key>UIViewControllerBasedStatusBarAppearance</key>
 	<false/>
 </dict>

packages/webview_flutter/ios/Classes/FlutterWebView.h

@@ -0,0 +1,20 @@
+#import <Flutter/Flutter.h>
+#import <WebKit/WebKit.h>
+
+NS_ASSUME_NONNULL_BEGIN
+
+@interface FLTWebViewController : NSObject<FlutterPlatformView>
+
+- (instancetype)initWithWithFrame:(CGRect)frame
+                   viewIdentifier:(int64_t)viewId
+                        arguments:(id _Nullable)args
+                  binaryMessenger:(NSObject<FlutterBinaryMessenger>*)messenger;
+
+- (UIView*)view;
+@end
+
+@interface FLTWebViewFactory : NSObject<FlutterPlatformViewFactory>
+- (instancetype)initWithMessenger:(NSObject<FlutterBinaryMessenger>*)messenger;
+@end
+
+NS_ASSUME_NONNULL_END

packages/webview_flutter/ios/Classes/FlutterWebView.m

@@ -0,0 +1,126 @@
+#import "FlutterWebView.h"
+
+@implementation FLTWebViewFactory {
+  NSObject<FlutterBinaryMessenger>* _messenger;
+}
+
+- (instancetype)initWithMessenger:(NSObject<FlutterBinaryMessenger>*)messenger {
+  self = [super init];
+  if (self) {
+    _messenger = messenger;
+  }
+  return self;
+}
+
+- (NSObject<FlutterMessageCodec>*)createArgsCodec {
+  return [FlutterStandardMessageCodec sharedInstance];
+}
+
+- (NSObject<FlutterPlatformView>*)createWithFrame:(CGRect)frame
+                                   viewIdentifier:(int64_t)viewId
+                                        arguments:(id _Nullable)args {
+  FLTWebViewController* webviewController =
+      [[FLTWebViewController alloc] initWithWithFrame:frame
+                                       viewIdentifier:viewId
+                                            arguments:args
+                                      binaryMessenger:_messenger];
+  return webviewController;
+}
+
+@end
+
+@implementation FLTWebViewController {
+  WKWebView* _webView;
+  int64_t _viewId;
+  FlutterMethodChannel* _channel;
+}
+
+- (instancetype)initWithWithFrame:(CGRect)frame
+                   viewIdentifier:(int64_t)viewId
+                        arguments:(id _Nullable)args
+                  binaryMessenger:(NSObject<FlutterBinaryMessenger>*)messenger {
+  if ([super init]) {
+    _viewId = viewId;
+    _webView = [[WKWebView alloc] initWithFrame:frame];
+    NSString* channelName = [NSString stringWithFormat:@"plugins.flutter.io/webview_%lld", viewId];
+    _channel = [FlutterMethodChannel methodChannelWithName:channelName binaryMessenger:messenger];
+    __weak __typeof__(self) weakSelf = self;
+    [_channel setMethodCallHandler:^(FlutterMethodCall* call, FlutterResult result) {
+      [weakSelf onMethodCall:call result:result];
+    }];
+    NSDictionary<NSString*, id>* settings = args[@"settings"];
+    [self applySettings:settings];
+    NSString* initialUrl = args[@"initialUrl"];
+    if (initialUrl) {
+      [self loadUrl:initialUrl];
+    }
+  }
+  return self;
+}
+
+- (UIView*)view {
+  return _webView;
+}
+
+- (void)onMethodCall:(FlutterMethodCall*)call result:(FlutterResult)result {
+  if ([[call method] isEqualToString:@"updateSettings"]) {
+    [self onUpdateSettings:call result:result];
+  } else if ([[call method] isEqualToString:@"loadUrl"]) {
+    [self onLoadUrl:call result:result];
+  } else {
+    result(FlutterMethodNotImplemented);
+  }
+}
+
+- (void)onUpdateSettings:(FlutterMethodCall*)call result:(FlutterResult)result {
+  [self applySettings:[call arguments]];
+  result(nil);
+}
+
+- (void)onLoadUrl:(FlutterMethodCall*)call result:(FlutterResult)result {
+  NSString* url = [call arguments];
+  if (![self loadUrl:url]) {
+    result([FlutterError errorWithCode:@"loadUrl_failed"
+                               message:@"Failed parsing the URL"
+                               details:[NSString stringWithFormat:@"URL was: '%@'", url]]);
+  } else {
+    result(nil);
+  }
+}
+
+- (void)applySettings:(NSDictionary<NSString*, id>*)settings {
+  for (NSString* key in settings) {
+    if ([key isEqualToString:@"jsMode"]) {
+      NSNumber* mode = settings[key];
+      [self updateJsMode:mode];
+    } else {
+      NSLog(@"webview_flutter: unknown setting key: %@", key);
+    }
+  }
+}
+
+- (void)updateJsMode:(NSNumber*)mode {
+  WKPreferences* preferences = [[_webView configuration] preferences];
+  switch ([mode integerValue]) {
+    case 0:  // disabled
+      [preferences setJavaScriptEnabled:NO];
+      break;
+    case 1:  // unrestricted
+      [preferences setJavaScriptEnabled:YES];
+      break;
+    default:
+      NSLog(@"webview_flutter: unknown javascript mode: %@", mode);
+  }
+}
+
+- (bool)loadUrl:(NSString*)url {
+  NSURL* nsUrl = [NSURL URLWithString:url];
+  if (!nsUrl) {
+    return false;
+  }
+  NSURLRequest* req = [NSURLRequest requestWithURL:nsUrl];
+  [_webView loadRequest:req];
+  return true;
+}
+
+@end

packages/webview_flutter/ios/Classes/WebviewFlutterPlugin.h renamed to packages/webview_flutter/ios/Classes/WebViewFlutterPlugin.h

@@ -0,0 +1,12 @@
+#import "WebViewFlutterPlugin.h"
+#import "FlutterWebView.h"
+
+@implementation FLTWebviewFlutterPlugin
+
++ (void)registerWithRegistrar:(NSObject<FlutterPluginRegistrar>*)registrar {
+  FLTWebViewFactory* webviewFactory =
+      [[FLTWebViewFactory alloc] initWithMessenger:registrar.messenger];
+  [registrar registerViewFactory:webviewFactory withId:@"plugins.flutter.io/webview"];
+}
+
+@end

packages/webview_flutter/ios/Classes/WebViewFlutterPlugin.m

@@ -88,6 +88,14 @@ class _WebViewState extends State<WebView> {
           creationParamsCodec: const StandardMessageCodec(),
         ),
       );
+    } else if (defaultTargetPlatform == TargetPlatform.iOS) {
+      return UiKitView(
+        viewType: 'plugins.flutter.io/webview',
+        onPlatformViewCreated: _onPlatformViewCreated,
+        gestureRecognizers: widget.gestureRecognizers,
+        creationParams: _CreationParams.fromWidget(widget).toMap(),
+        creationParamsCodec: const StandardMessageCodec(),
+      );
     }
     return Text(
         '$defaultTargetPlatform is not yet supported by the webview_flutter plugin');