Allow applications to dispatch from the main thread.

Author: e3ndr

src/main/java/dev/webview/Webview.java

@@ -155,31 +155,46 @@ public void eval(@NonNull String script) {
     }
 
     public void bind(@NonNull String name, @NonNull ConsumingProducer<JsonArray, JsonElement> handler) {
-        N.webview_bind($pointer, name, new BindCallback() {
-            @Override
-            public void callback(long seq, String req, long arg) {
-                try {
-                    JsonArray arguments = Rson.DEFAULT.fromJson(req, JsonArray.class);
-
+        N.webview_bind(
+            $pointer,
+            name,
+            new BindCallback() {
+                @Override
+                public void callback(long seq, String req, long arg) {
                     try {
-                        @Nullable
-                        JsonElement result = handler.produce(arguments);
-
-                        N.webview_return($pointer, seq, false, Rson.DEFAULT.toJsonString(result));
-                    } catch (Exception e) {
-                        N.webview_return($pointer, seq, true, e.getMessage());
+                        JsonArray arguments = Rson.DEFAULT.fromJson(req, JsonArray.class);
+
+                        try {
+                            @Nullable
+                            JsonElement result = handler.produce(arguments);
+
+                            N.webview_return($pointer, seq, false, Rson.DEFAULT.toJsonString(result));
+                        } catch (Exception e) {
+                            N.webview_return($pointer, seq, true, e.getMessage());
+                        }
+                    } catch (JsonParseException e) {
+                        e.printStackTrace();
                     }
-                } catch (JsonParseException e) {
-                    e.printStackTrace();
                 }
-            }
-        }, 0);
+            },
+            0
+        );
     }
 
     public void unbind(@NonNull String name) {
         N.webview_unbind($pointer, name);
     }
 
+    public void dispatch(@NonNull Runnable handler) {
+        N.webview_dispatch(
+            $pointer,
+            ($pointer, arg) -> {
+                handler.run();
+            },
+            0
+        );
+    }
+
     @Override
     public void run() {
         N.webview_run($pointer);

src/main/java/dev/webview/WebviewNative.java

@@ -74,6 +74,19 @@ static interface BindCallback extends Callback {
 
     }
 
+    /**
+     * Used in {@link webview_dispatch}
+     */
+    static interface DispatchCallback extends Callback {
+
+        /**
+         * @param $pointer The pointer of the webview
+         * @param arg      Unused
+         */
+        void callback(long $pointer, long arg);
+
+    }
+
     /**
      * Creates a new webview instance. If debug is true - developer tools will be
      * enabled (if the platform supports them). Window parameter can be a pointer to
@@ -173,7 +186,7 @@ static interface BindCallback extends Callback {
      * @param callback The callback to be called
      * @param arg      Unused
      */
-    void webview_bind(long $pointer, @NonNull String name, BindCallback callback, long arg);
+    void webview_bind(long $pointer, @NonNull String name, @NonNull BindCallback callback, long arg);
 
     /**
      * Remove the native callback specified.
@@ -194,4 +207,14 @@ static interface BindCallback extends Callback {
      */
     void webview_return(long $pointer, long seq, boolean isError, String result);
 
+    /**
+     * Dispatches the callback on the UI thread, only effective while
+     * {@link #webview_run(long)} is blocking.
+     * 
+     * @param $pointer The instance pointer of the webview
+     * @param callback The callback to be called
+     * @param arg      Unused
+     */
+    void webview_dispatch(long $pointer, @NonNull DispatchCallback callback, long arg);
+
 }