feat(windows): allow setting window class name, closes #769 (#770)

.changes/windows-window-class-name.md

@@ -0,0 +1,5 @@
+---
+"tao": "patch"
+---
+
+Add `WindowBuilderExtWindows::with_window_classname` to set the name of the window class created/used to create windows.

src/platform/windows.rs

@@ -231,6 +231,9 @@ pub trait WindowBuilderExtWindows {
   /// Whether to create the window icon with the taskbar icon or not.
   fn with_skip_taskbar(self, skip: bool) -> WindowBuilder;
 
+  /// Customize the window class name.
+  fn with_window_classname<S: Into<String>>(self, classname: S) -> WindowBuilder;
+
   /// Shows or hides the background drop shadow for undecorated windows.
   ///
   /// The shadow is hidden by default.
@@ -284,6 +287,12 @@ impl WindowBuilderExtWindows for WindowBuilder {
     self
   }
 
+  #[inline]
+  fn with_window_classname<S: Into<String>>(mut self, classname: S) -> WindowBuilder {
+    self.platform_specific.window_classname = classname.into();
+    self
+  }
+
   #[inline]
   fn with_undecorated_shadow(mut self, shadow: bool) -> WindowBuilder {
     self.platform_specific.decoration_shadow = shadow;

src/platform_impl/windows/mod.rs

@@ -47,6 +47,7 @@ pub struct PlatformSpecificWindowBuilderAttributes {
   pub menu: Option<HMENU>,
   pub taskbar_icon: Option<Icon>,
   pub skip_taskbar: bool,
+  pub window_classname: String,
   pub no_redirection_bitmap: bool,
   pub drag_and_drop: bool,
   pub preferred_theme: Option<Theme>,
@@ -64,6 +65,7 @@ impl Default for PlatformSpecificWindowBuilderAttributes {
       drag_and_drop: true,
       preferred_theme: None,
       skip_taskbar: false,
+      window_classname: "Window Class".to_string(),
       decoration_shadow: true,
       rtl: false,
     }

src/platform_impl/windows/window.rs

@@ -996,7 +996,7 @@ unsafe fn init<T: 'static>(
   event_loop: &EventLoopWindowTarget<T>,
 ) -> Result<Window, RootOsError> {
   // registering the window class
-  let class_name = register_window_class();
+  let class_name = register_window_class(&pl_attribs.window_classname);
 
   let mut window_flags = WindowFlags::empty();
   window_flags.set(WindowFlags::MARKER_DECORATIONS, attributes.decorations);
@@ -1180,8 +1180,8 @@ unsafe fn init<T: 'static>(
   Ok(win)
 }
 
-unsafe fn register_window_class() -> Vec<u16> {
-  let class_name = util::encode_wide("Window Class");
+unsafe fn register_window_class(window_classname: &str) -> Vec<u16> {
+  let class_name = util::encode_wide(window_classname);
 
   let class = WNDCLASSEXW {
     cbSize: mem::size_of::<WNDCLASSEXW>() as u32,