feat(android): add function to dispatch closure to the Android context (

#864)

.changes/dispatch-android-fn.md

@@ -0,0 +1,5 @@
+---
+"wry": patch
+---
+
+Add function to dispatch closure with the Android context.

src/webview/android/main_pipe.rs

@@ -183,8 +183,10 @@ impl MainPipe<'_> {
           }
         }
         WebViewMessage::Jni(f) => {
-          if let Some(webview) = &self.webview {
-            f(env, activity, webview.as_obj());
+          if let Some(w) = &self.webview {
+            f(env, activity, w.as_obj());
+          } else {
+            f(env, activity, JObject::null());
           }
         }
         WebViewMessage::LoadUrl(url, headers) => {

src/webview/android/mod.rs

@@ -367,6 +367,16 @@ pub fn find_class<'a>(
   Ok(my_class.into())
 }
 
+/// Dispatch a closure to run on the Android context.
+///
+/// The closure takes the JNI env, the Android activity instance and the possibly null webview.
+pub fn dispatch<F>(func: F)
+where
+  F: FnOnce(JNIEnv, JObject, JObject) + Send + 'static,
+{
+  MainPipe::send(WebViewMessage::Jni(Box::new(func)));
+}
+
 fn create_headers_map<'a, 'b>(
   env: &'a JNIEnv,
   headers: &http::HeaderMap,

src/webview/mod.rs

@@ -12,7 +12,7 @@ pub use web_context::WebContext;
 pub(crate) mod android;
 #[cfg(target_os = "android")]
 pub mod prelude {
-  pub use super::android::{binding::*, find_class, setup, Context};
+  pub use super::android::{binding::*, dispatch, find_class, setup, Context};
 }
 #[cfg(target_os = "android")]
 pub use android::JniHandle;