expose contentdisposition and contentlength from android

Author: ashank96

android/src/main/java/com/pichillilorenzo/flutter_inappwebview/in_app_webview/InAppWebView.java

@@ -1184,6 +1184,10 @@ class DownloadStartListener implements DownloadListener {
     public void onDownloadStart(String url, String userAgent, String contentDisposition, String mimetype, long contentLength) {
       Map<String, Object> obj = new HashMap<>();
       obj.put("url", url);
+      obj.put("userAgent", userAgent);
+      obj.put("contentDisposition", contentDisposition);
+      obj.put("mimetype", mimetype);
+      obj.put("contentLength", contentLength);
       channel.invokeMethod("onDownloadStart", obj);
     }
   }

example/integration_test/webview_flutter_test.dart

@@ -2739,7 +2739,7 @@ void main() {
             onWebViewCreated: (controller) {
               controllerCompleter.complete(controller);
             },
-            onDownloadStart: (controller, url) {
+            onDownloadStart:(controller, url, userAgent, contentDisposition, mimeType, contentLength) {
               onDownloadStartCompleter.complete(url.toString());
             },
           ),

lib/src/in_app_browser/in_app_browser.dart

@@ -377,7 +377,7 @@ class InAppBrowser {
   ///**Official Android API**: https://developer.android.com/reference/android/webkit/WebView#setDownloadListener(android.webkit.DownloadListener)
   ///
   ///**Official iOS API**: https://developer.apple.com/documentation/webkit/wknavigationdelegate/1455643-webview
-  void onDownloadStart(Uri url) {}
+  void onDownloadStart(Uri url, String userAgent, String contentDisposition, String mimeType, int contentLength) {}
 
   ///Event fired when the [InAppBrowser] webview finds the `custom-scheme` while loading a resource. Here you can handle the url request and return a [CustomSchemeResponse] to load a specific resource encoded to `base64`.
   ///

lib/src/in_app_webview/headless_in_app_webview.dart

@@ -299,7 +299,13 @@ class HeadlessInAppWebView implements WebView {
   void Function(InAppWebViewController controller)? onWindowBlur;
 
   @override
-  void Function(InAppWebViewController controller, Uri url)? onDownloadStart;
+  void Function(
+      InAppWebViewController controller,
+      Uri url,
+      String userAgent,
+      String contentDisposition,
+      String mimeType,
+      int contentLength)? onDownloadStart;
 
   @override
   void Function(InAppWebViewController controller, int activeMatchOrdinal,

lib/src/in_app_webview/in_app_webview.dart

@@ -208,7 +208,7 @@ class InAppWebView extends StatefulWidget implements WebView {
       androidOnReceivedTouchIconUrl;
 
   @override
-  final void Function(InAppWebViewController controller, Uri url)?
+  final void Function(InAppWebViewController controller, Uri url, String userAgent, String contentDisposition, String mimeType, int contentLength)?
       onDownloadStart;
 
   @override

lib/src/in_app_webview/in_app_webview_controller.dart

@@ -205,11 +205,16 @@ class InAppWebViewController {
         if ((_webview != null && _webview!.onDownloadStart != null) ||
             _inAppBrowser != null) {
           String url = call.arguments["url"];
+          String userAgent = call.arguments["userAgent"];
+          String contentDisposition = call.arguments["contentDisposition"];
+          String mimeType = call.arguments["mimetype"];
+          int contentLength = call.arguments["contentLength"] as int;
           Uri uri = Uri.parse(url);
+
           if (_webview != null && _webview!.onDownloadStart != null)
-            _webview!.onDownloadStart!(this, uri);
+            _webview!.onDownloadStart!(this, uri, userAgent, contentDisposition, mimeType, contentLength);
           else
-            _inAppBrowser!.onDownloadStart(uri);
+            _inAppBrowser!.onDownloadStart(uri, userAgent, contentDisposition, mimeType, contentLength);
         }
         break;
       case "onLoadResourceCustomScheme":

lib/src/in_app_webview/webview.dart

@@ -120,7 +120,7 @@ abstract class WebView {
   ///**Official Android API**: https://developer.android.com/reference/android/webkit/WebView#setDownloadListener(android.webkit.DownloadListener)
   ///
   ///**Official iOS API**: https://developer.apple.com/documentation/webkit/wknavigationdelegate/1455643-webview
-  final void Function(InAppWebViewController controller, Uri url)?
+  final void Function(InAppWebViewController controller, Uri url, String userAgent, String contentDisposition, String mimeType, int contentLength)?
       onDownloadStart;
 
   ///Event fired when the [WebView] finds the `custom-scheme` while loading a resource. Here you can handle the url request and return a [CustomSchemeResponse] to load a specific resource encoded to `base64`.