Added enableDropDownWorkaroud webview option for Android to enable a temporary...

Added enableDropDownWorkaroud webview option for Android to enable a temporary workaround for html dropdowns (issue #182)

CHANGELOG.md

@@ -9,6 +9,8 @@
 - Added `regexToCancelSubFramesLoading` webview option for Android to cancel subframe requests on `shouldOverrideUrlLoading` event based on a Regular Expression
 - Updated default value for `domStorageEnabled` option to `true` for Android
 - Fix for Android `InAppBrowser` for some controller methods not exposed.
+- Merge "Fixes null error when calling getOptions for InAppBrowser class" [#214](https://github.com/pichillilorenzo/flutter_inappwebview/pull/214) (thanks to [panndoraBoo](https://github.com/panndoraBoo))
+- Added `enableDropDownWorkaroud` webview option for Android to enable a temporary workaround for html dropdowns (issue [#182](https://github.com/pichillilorenzo/flutter_inappwebview/issues/182))
 
 ### BREAKING CHANGES
 

README.md

@@ -409,6 +409,7 @@ Instead, on the `onLoadStop` WebView event, you can use `callHandler` directly:
 * `thirdPartyCookiesEnabled`: Boolean value to enable third party cookies in the WebView.
 * `hardwareAcceleration`: Boolean value to enable Hardware Acceleration in the WebView.
 * `supportMultipleWindows`: Sets whether the WebView whether supports multiple windows.
+* `regexToCancelSubFramesLoading`: Regular expression used by `shouldOverrideUrlLoading` event to cancel navigation for frames that are not the main frame. If the url request of a subframe matches the regular expression, then the request of that subframe is canceled.
 
 ##### `InAppWebView` iOS-specific options
 

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

 package com.pichillilorenzo.flutter_inappwebview.InAppWebView;
 
-import android.annotation.SuppressLint;
 import android.annotation.TargetApi;
 import android.graphics.Bitmap;
 import android.net.http.SslCertificate;
@@ -227,6 +226,10 @@ public class InAppWebViewClient extends WebViewClient {
 
     String js = InAppWebView.platformReadyJS.replaceAll("[\r\n]+", "");
 
+    if (webView.options.dropDownWorkaroudEnabled) {
+      js += InAppWebView.dropDownWorkaroundJS.replaceAll("[\r\n]+", "");
+    }
+
     if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
       webView.evaluateJavascript(js, (ValueCallback<String>) null);
     } else {

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

@@ -83,6 +83,7 @@ public class InAppWebViewOptions extends Options {
   public Boolean hardwareAcceleration = true;
   public Boolean supportMultipleWindows = false;
   public String regexToCancelSubFramesLoading;
+  public Boolean dropDownWorkaroudEnabled = false;
 
   @Override
   public Object onParse(Map.Entry<String, Object> pair) {

android/src/main/java/com/pichillilorenzo/flutter_inappwebview/JavaScriptBridgeInterface.java

@@ -9,7 +9,13 @@ import android.webkit.ValueCallback;
 
 import com.pichillilorenzo.flutter_inappwebview.InAppWebView.InAppWebView;
 
+import org.json.JSONArray;
+import org.json.JSONException;
+import org.json.JSONObject;
+
+import java.util.ArrayList;
 import java.util.HashMap;
+import java.util.List;
 import java.util.Map;
 
 import io.flutter.plugin.common.MethodChannel;
@@ -251,7 +257,7 @@ public class JavaScriptBridgeInterface {
   }
 
   @JavascriptInterface
-  public void _callHandler(final String handlerName, final String _callHandlerID, String args) {
+  public void _callHandler(final String handlerName, final String _callHandlerID, final String args) {
     final InAppWebView webView = (inAppBrowserActivity != null) ? inAppBrowserActivity.webView : flutterWebView.webView;
 
     final Map<String, Object> obj = new HashMap<>();
@@ -266,6 +272,53 @@ public class JavaScriptBridgeInterface {
     handler.post(new Runnable() {
       @Override
       public void run() {
+
+        // workaround for https://github.com/pichillilorenzo/flutter_inappwebview/issues/182
+        if (handlerName.equals("flutterInAppWebViewDropDownWorkaroud")) {
+          try {
+            JSONArray jsonArray = new JSONArray(args);
+
+            List<Integer> selectedValues = new ArrayList<>();
+            JSONArray jsonSelectedValues = jsonArray.getJSONArray(0);
+            for(int i = 0; i < jsonSelectedValues.length(); i++) {
+              Integer selectedValue = jsonSelectedValues.getInt(i);
+              selectedValues.add(selectedValue);
+            }
+
+            boolean isMultiSelect = jsonArray.getBoolean(1);
+
+            List<List<String>> values = new ArrayList<>();
+            JSONArray options = jsonArray.getJSONArray(2);
+
+            Log.d(LOG_TAG, options.toString());
+            for(int i = 0; i < options.length(); i++) {
+              JSONObject option = options.getJSONObject(i);
+
+              List<String> value = new ArrayList<>();
+              value.add(option.getString("key"));
+              value.add(option.getString("value"));
+
+              values.add(value);
+            }
+
+            webView.showDropDownWorkaroud(selectedValues, values, isMultiSelect, new InAppWebView.DropDownWorkaroudCallback() {
+              @Override
+              public void result(List<String> values) {
+                String value = "{values: " + (new JSONArray(values)) + "}";
+                if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
+                  webView.evaluateJavascript("if(window." + name + "[" + _callHandlerID + "] != null) {window." + name + "[" + _callHandlerID + "](" + value + "); delete window." + name + "[" + _callHandlerID + "];}", (ValueCallback<String>) null);
+                }
+                else {
+                  webView.loadUrl("javascript:if(window." + name + "[" + _callHandlerID + "] != null) {window." + name + "[" + _callHandlerID + "](" + value + "); delete window." + name + "[" + _callHandlerID + "];}");
+                }
+              }
+            });
+          } catch (JSONException e) {
+            e.printStackTrace();
+          }
+          return;
+        }
+
         if (handlerName.equals("onPrint") && Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
           webView.printCurrentPage();
         }

lib/src/in_app_webview.dart

@@ -24,6 +24,7 @@ const javaScriptHandlerForbiddenNames = [
   "onAjaxProgress",
   "shouldInterceptFetchRequest",
   "onPrint",
+  "flutterInAppWebViewDropDownWorkaroud"
 ];
 
 ///InAppWebView Widget class.

lib/src/webview_options.dart

@@ -404,9 +404,17 @@ class AndroidInAppWebViewOptions
   ///If set to `true`, [onCreateWindow] event must be implemented by the host application. The default value is `false`.
   bool supportMultipleWindows;
 
-  ///Regular expression used by [shouldOverrideUrlLoading] event to cancel navigation for frames that are not the main frame.
+  ///Regular expression used by [shouldOverrideUrlLoading] event to cancel navigation requests for frames that are not the main frame.
+  ///If the url request of a subframe matches the regular expression, then the request of that subframe is canceled.
   String regexToCancelSubFramesLoading;
 
+  ///Enable a temporary workaround for html dropdowns (`<select>` tags). It requires **JavaScript enabled**.
+  ///It attempts to block click events for the dropdowns creating a custom `<div>` layer over the dropdown to intercept user's clicks.
+  ///The default value is `false`.
+  ///
+  ///**NOTE**: available on Android 19+.
+  bool dropDownWorkaroudEnabled;
+
   AndroidInAppWebViewOptions(
       {this.textZoom = 100,
       this.clearSessionCache = false,
@@ -449,7 +457,8 @@ class AndroidInAppWebViewOptions
       this.hardwareAcceleration = true,
       this.initialScale = 0,
       this.supportMultipleWindows = false,
-      this.regexToCancelSubFramesLoading});
+      this.regexToCancelSubFramesLoading,
+      this.dropDownWorkaroudEnabled = false});
 
   @override
   Map<String, dynamic> toMap() {
@@ -495,7 +504,8 @@ class AndroidInAppWebViewOptions
       "thirdPartyCookiesEnabled": thirdPartyCookiesEnabled,
       "hardwareAcceleration": hardwareAcceleration,
       "supportMultipleWindows": supportMultipleWindows,
-      "regexToCancelSubFramesLoading": regexToCancelSubFramesLoading
+      "regexToCancelSubFramesLoading": regexToCancelSubFramesLoading,
+      "dropDownWorkaroudEnabled": dropDownWorkaroudEnabled
     };
   }
 
@@ -550,6 +560,7 @@ class AndroidInAppWebViewOptions
     options.hardwareAcceleration = map["hardwareAcceleration"];
     options.supportMultipleWindows = map["supportMultipleWindows"];
     options.regexToCancelSubFramesLoading = map["regexToCancelSubFramesLoading"];
+    options.dropDownWorkaroudEnabled = map["dropDownWorkaroudEnabled"];
     return options;
   }
 }