Trait Renderer 

pub trait Renderer {
    // Required methods
    fn init(&mut self) -> Result<()>;
    fn create_window(&mut self, config: &WindowConfig) -> Result<WindowHandle>;
    fn load_url(&self, window: WindowHandle, url: &str) -> Result<()>;
    fn load_html(&self, window: WindowHandle, html: &str) -> Result<()>;
    fn eval_script(&self, window: WindowHandle, script: &str) -> Result<()>;
    fn set_ipc_handler(&mut self, handler: Box<dyn IpcHandler>);
    fn send_to_frontend(
        &self,
        window: WindowHandle,
        message: &str,
    ) -> Result<()>;
    fn set_title(&self, window: WindowHandle, title: &str) -> Result<()>;
    fn set_size(
        &self,
        window: WindowHandle,
        width: u32,
        height: u32,
    ) -> Result<()>;
    fn set_resizable(&self, window: WindowHandle, resizable: bool) -> Result<()>;
    fn set_visible(&self, window: WindowHandle, visible: bool) -> Result<()>;
    fn close_window(&mut self, window: WindowHandle) -> Result<()>;
    fn minimize_window(&self, window: WindowHandle) -> Result<()>;
    fn maximize_window(&self, window: WindowHandle) -> Result<()>;
    fn is_maximized(&self, window: WindowHandle) -> Result<bool>;
    fn set_fullscreen(
        &self,
        window: WindowHandle,
        fullscreen: bool,
    ) -> Result<()>;
    fn is_fullscreen(&self, window: WindowHandle) -> Result<bool>;
    fn start_drag(&self, window: WindowHandle) -> Result<()>;
    fn start_resize(&self, window: WindowHandle, edge: ResizeEdge) -> Result<()>;
    fn set_decorations(
        &self,
        window: WindowHandle,
        decorations: bool,
    ) -> Result<()>;
    fn set_always_on_top(
        &self,
        window: WindowHandle,
        always: bool,
    ) -> Result<()>;
    fn run(self: Box<Self>) -> Result<()>;
    fn kind(&self) -> RendererKind;

    // Provided methods
    fn load_html_with_base_url(
        &self,
        window: WindowHandle,
        html: &str,
        base_url: &str,
    ) -> Result<()> { ... }
    fn set_click_through(
        &self,
        _window: WindowHandle,
        _enabled: bool,
    ) -> Result<()> { ... }
}

Core trait that both WebView and Chrome backends must implement.

This provides a unified API for creating windows, loading content, executing JavaScript, and handling IPC regardless of the underlying rendering engine.

Required Methods

fn init(&mut self) -> Result<()>

Initialize the renderer.

fn create_window(&mut self, config: &WindowConfig) -> Result<WindowHandle>

Create a new window with the given configuration.

fn load_url(&self, window: WindowHandle, url: &str) -> Result<()>

Load a URL in the specified window.

fn load_html(&self, window: WindowHandle, html: &str) -> Result<()>

Load HTML content directly.

fn eval_script(&self, window: WindowHandle, script: &str) -> Result<()>

Execute JavaScript in the specified window.

fn set_ipc_handler(&mut self, handler: Box<dyn IpcHandler>)

Set the IPC handler for messages from the frontend.

fn send_to_frontend(&self, window: WindowHandle, message: &str) -> Result<()>

Send a message to the frontend JavaScript.

fn set_title(&self, window: WindowHandle, title: &str) -> Result<()>

Set the window title.

fn set_size(&self, window: WindowHandle, width: u32, height: u32) -> Result<()>

Set the window size.

fn set_resizable(&self, window: WindowHandle, resizable: bool) -> Result<()>

Set whether the window is resizable.

fn set_visible(&self, window: WindowHandle, visible: bool) -> Result<()>

Show or hide the window.

fn close_window(&mut self, window: WindowHandle) -> Result<()>

Close a window.

fn minimize_window(&self, window: WindowHandle) -> Result<()>

Minimize the window.

fn maximize_window(&self, window: WindowHandle) -> Result<()>

Toggle maximize/restore.

fn is_maximized(&self, window: WindowHandle) -> Result<bool>

Check whether the window is currently maximized.

fn set_fullscreen(&self, window: WindowHandle, fullscreen: bool) -> Result<()>

Toggle fullscreen mode.

fn is_fullscreen(&self, window: WindowHandle) -> Result<bool>

Check whether the window is currently fullscreen.

fn start_drag(&self, window: WindowHandle) -> Result<()>

Begin an interactive window drag.

Call this from a mousedown handler on a custom title bar element to allow the user to drag the window from any region.

fn start_resize(&self, window: WindowHandle, edge: ResizeEdge) -> Result<()>

Begin an interactive window resize.

edge specifies which edge/corner to resize from.

fn set_decorations(&self, window: WindowHandle, decorations: bool) -> Result<()>

Set whether the window has OS decorations (title bar + borders).

fn set_always_on_top(&self, window: WindowHandle, always: bool) -> Result<()>

Set the window’s always-on-top state.

fn run(self: Box<Self>) -> Result<()>

Run the main event loop. This blocks until the application exits.

fn kind(&self) -> RendererKind

Get the renderer kind.

Provided Methods

fn load_html_with_base_url( &self, window: WindowHandle, html: &str, base_url: &str, ) -> Result<()>

Load HTML content with a document base URL for relative assets.

WebView backends commonly implement load_html with an in-memory document (NavigateToString on WebView2). Such documents do not have a useful filesystem base, so relative Vite assets like ./assets/index.js fail to load. This helper injects a <base> tag before delegating to the backend and keeps local-first renderers portable across WebView2, WKWebView, and WebKitGTK.

fn set_click_through(&self, _window: WindowHandle, _enabled: bool) -> Result<()>

Enable or disable click-through: when enabled, pointer events fall through the window to whatever is behind it (used by wallpaper and click-through overlays). Applied at window creation by default; this method allows toggling it at runtime where the platform supports it.

Default implementation is a no-op; backends override it to call the platform-specific window API.

Dyn Compatibility

This trait is dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors