js: add navbar set center api

doric-js/lib/src/native/navbar.d.ts

@@ -8,4 +8,5 @@ export declare function navbar(context: BridgeContext): {
     setBgColor: (color: Color) => Promise<any>;
     setLeft: (view: View) => Promise<any>;
     setRight: (view: View) => Promise<any>;
+    setCenter: (view: View) => Promise<any>;
 };

doric-js/lib/src/native/navbar.js

@@ -31,6 +31,13 @@ export function navbar(context) {
                 panel.addHeadView("navbar_right", view);
             }
             return context.callNative('navbar', 'setRight', view.toModel());
-        }
+        },
+        setCenter: (view) => {
+            if (panel) {
+                panel.clearHeadViews("navbar_center");
+                panel.addHeadView("navbar_center", view);
+            }
+            return context.callNative('navbar', 'setCenter', view.toModel());
+        },
     };
 }