feat: add feature to zoom webview contents, closes #388 (#564)

* feat: add feature to zoom webview contents, closes #388

* Update src/webview/wkwebview/mod.rs

Co-authored-by: Amr Bashir <amr.bashir2015@gmail.com>

* Update src/webview/mod.rs

Co-authored-by: Amr Bashir <amr.bashir2015@gmail.com>

Co-authored-by: Amr Bashir <amr.bashir2015@gmail.com>

.changes/impl-zoom-feature.md

@@ -0,0 +1,5 @@
+---
+"wry": minor
+---
+
+Add `WebView::zoom` method.

src/webview/android/mod.rs

@@ -118,6 +118,8 @@ impl InnerWebView {
       }
     }
   }
+
+  pub fn zoom(&self, scale_factor: f64) {}
 }
 
 pub struct UnsafeIpc(*mut c_void);

src/webview/mod.rs

@@ -489,6 +489,17 @@ impl WebView {
     self.window.inner_size()
   }
 
+  /// Set the webview zoom level
+  ///
+  /// ## Platform-specific:
+  ///
+  /// - **Android**: Not supported.
+  /// - **macOS**: available on macOS 11+ only.
+  /// - **iOS**: available on iOS 14+ only.
+  pub fn zoom(&self, scale_factor: f64) {
+    self.webview.zoom(scale_factor);
+  }
+
   #[cfg(target_os = "android")]
   pub fn run(self, env: JNIEnv, jclass: JClass, jobject: JObject) -> jobject {
     self.webview.run(env, jclass, jobject).unwrap()

src/webview/webkitgtk/mod.rs

@@ -386,6 +386,10 @@ impl InnerWebView {
   pub fn is_devtools_open(&self) -> bool {
     self.is_inspector_open.load(Ordering::Relaxed)
   }
+
+  pub fn zoom(&self, scale_factor: f64) {
+    WebViewExt::set_zoom_level(&*self.webview, scale_factor);
+  }
 }
 
 pub fn platform_webview_version() -> Result<String> {

src/webview/webview2/mod.rs

@@ -614,6 +614,10 @@ window.addEventListener('mousemove', (e) => window.chrome.webview.postMessage('_
   pub fn is_devtools_open(&self) -> bool {
     false
   }
+
+  pub fn zoom(&self, scale_factor: f64) {
+    let _ = unsafe { self.controller.SetZoomFactor(scale_factor) };
+  }
 }
 
 pub fn platform_webview_version() -> Result<String> {

src/webview/wkwebview/mod.rs

@@ -590,6 +590,12 @@ r#"Object.defineProperty(window, 'ipc', {
       (view_frame.size.width as f64, view_frame.size.height as f64).into();
     logical.to_physical(scale_factor)
   }
+
+  pub fn zoom(&self, scale_factor: f64) {
+    unsafe {
+      let _: () = msg_send![self.webview, setPageZoom: scale_factor];
+    }
+  }
 }
 
 pub fn platform_webview_version() -> Result<String> {