put webview with transparent background

jaumard · jaumard · commit c01c5b0237cd · 2019-03-30T09:12:43.000+01:00
fix flutter/flutter#29300
diff --git a/packages/webview_flutter/android/src/main/java/io/flutter/plugins/webviewflutter/FlutterWebView.java b/packages/webview_flutter/android/src/main/java/io/flutter/plugins/webviewflutter/FlutterWebView.java
@@ -6,6 +6,7 @@
 
 import android.annotation.TargetApi;
 import android.content.Context;
+import android.graphics.Color;
 import android.os.Build;
 import android.view.View;
 import android.webkit.WebStorage;
@@ -28,6 +29,7 @@ public class FlutterWebView implements PlatformView, MethodCallHandler {
   @SuppressWarnings("unchecked")
   FlutterWebView(Context context, BinaryMessenger messenger, int id, Map<String, Object> params) {
     webView = new WebView(context);
+    webView.setBackgroundColor(Color.TRANSPARENT);
     // Allow local storage.
     webView.getSettings().setDomStorageEnabled(true);
 
@@ -100,6 +102,7 @@ public void onMethodCall(MethodCall methodCall, Result result) {
 
   private void loadUrl(MethodCall methodCall, Result result) {
     String url = (String) methodCall.arguments;
+    webView.setBackgroundColor(Color.TRANSPARENT);
     webView.loadUrl(url);
     result.success(null);
   }
diff --git a/packages/webview_flutter/android/src/main/java/io/flutter/plugins/webviewflutter/FlutterWebViewClient.java b/packages/webview_flutter/android/src/main/java/io/flutter/plugins/webviewflutter/FlutterWebViewClient.java
@@ -70,6 +70,12 @@ public boolean shouldOverrideUrlLoading(WebView view, String url) {
     return true;
   }
 
+  @Override
+  public void onPageFinished(WebView view, String url)
+  {
+    view.setBackgroundColor(0x00000000);
+  }
+
   private void notifyOnNavigationRequest(
       String url, Map<String, String> headers, WebView webview, boolean isMainFrame) {
     HashMap<String, Object> args = new HashMap<>();
diff --git a/packages/webview_flutter/example/lib/main.dart b/packages/webview_flutter/example/lib/main.dart
@@ -10,11 +10,11 @@ import 'package:webview_flutter/webview_flutter.dart';
 void main() => runApp(MaterialApp(home: WebViewExample()));
 
 const String kNavigationExamplePage = '''
-<!DOCTYPE html><html>
+<!DOCTYPE html><html  style="background-color:transparent;">
 <head><title>Navigation Delegate Example</title></head>
-<body>
+<body style="background-color:transparent;">
 <p>
-The navigation delegate is set to block navigation to the youtube website.
+The navigation delegate is set to block navigation to the youtube website, and as the webview background is transparent, you can see scaffold background.
 </p>
 <ul>
 <ul><a href="https://www.youtube.com/">https://www.youtube.com/</a></ul>
@@ -31,6 +31,7 @@ class WebViewExample extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     return Scaffold(
+      backgroundColor: Colors.green,
       appBar: AppBar(
         title: const Text('Flutter WebView example'),
         // This drop down menu demonstrates that Flutter widgets can be shown over the web view.
diff --git a/packages/webview_flutter/ios/Classes/FlutterWebView.m b/packages/webview_flutter/ios/Classes/FlutterWebView.m
@@ -66,6 +66,10 @@ - (instancetype)initWithFrame:(CGRect)frame
     configuration.userContentController = userContentController;
 
     _webView = [[WKWebView alloc] initWithFrame:frame configuration:configuration];
+    _webView.opaque = NO;
+    _webView.backgroundColor = UIColor.clearColor;
+    _webView.scrollView.backgroundColor = UIColor.clearColor;
+
     _navigationDelegate = [[FLTWKNavigationDelegate alloc] initWithChannel:_channel];
     _webView.navigationDelegate = _navigationDelegate;
     __weak __typeof__(self) weakSelf = self;
