Implement basic desktop app with chromium embeded framework (#2874)

* Remove tauri based desktop app

* Allow bzip-1.0.6 license

* Implement basic cef based desktop app

* Cleanup build setup

* Use wait until and execute cef loop more frequently

* Remove custom do browser work event

* Move WinitApp into its own module

* Cleanup event handling

* Cleanup + Scheudule cef message loop work

* Fix cpu overheating on idle: https://xkcd.com/1172/

* Use tracing crate for logging instead of println

* Rebase to main

---------

Co-authored-by: Dennis Kobert <dennis@kobert.dev>

desktop/src/cef/internal/render_handler.rs

@@ -0,0 +1,84 @@
+use cef::rc::{Rc, RcImpl};
+use cef::sys::{_cef_render_handler_t, cef_base_ref_counted_t};
+use cef::{Browser, ImplBrowser, ImplBrowserHost, ImplRenderHandler, PaintElementType, Rect, WrapRenderHandler};
+
+use crate::FrameBuffer;
+use crate::cef::CefEventHandler;
+
+pub(crate) struct RenderHandlerImpl<H: CefEventHandler> {
+	object: *mut RcImpl<_cef_render_handler_t, Self>,
+	event_handler: H,
+}
+impl<H: CefEventHandler> RenderHandlerImpl<H> {
+	pub(crate) fn new(event_handler: H) -> Self {
+		Self {
+			object: std::ptr::null_mut(),
+			event_handler,
+		}
+	}
+}
+impl<H: CefEventHandler> ImplRenderHandler for RenderHandlerImpl<H> {
+	fn view_rect(&self, _browser: Option<&mut Browser>, rect: Option<&mut Rect>) {
+		if let Some(rect) = rect {
+			let view = self.event_handler.window_size();
+			*rect = Rect {
+				x: 0,
+				y: 0,
+				width: view.width as i32,
+				height: view.height as i32,
+			};
+		}
+	}
+
+	fn on_paint(
+		&self,
+		browser: Option<&mut Browser>,
+		_type_: PaintElementType,
+		_dirty_rect_count: usize,
+		_dirty_rects: Option<&Rect>,
+		buffer: *const u8,
+		width: ::std::os::raw::c_int,
+		height: ::std::os::raw::c_int,
+	) {
+		let buffer_size = (width * height * 4) as usize;
+		let buffer_slice = unsafe { std::slice::from_raw_parts(buffer, buffer_size) };
+		let frame_buffer = FrameBuffer::new(buffer_slice.to_vec(), width as usize, height as usize).expect("Failed to create frame buffer");
+
+		let draw_successful = self.event_handler.draw(frame_buffer);
+		if !draw_successful {
+			if let Some(browser) = browser {
+				browser.host().unwrap().was_resized();
+			}
+		}
+	}
+
+	fn get_raw(&self) -> *mut _cef_render_handler_t {
+		self.object.cast()
+	}
+}
+
+impl<H: CefEventHandler> Clone for RenderHandlerImpl<H> {
+	fn clone(&self) -> Self {
+		unsafe {
+			let rc_impl = &mut *self.object;
+			rc_impl.interface.add_ref();
+		}
+		Self {
+			object: self.object,
+			event_handler: self.event_handler.clone(),
+		}
+	}
+}
+impl<H: CefEventHandler> Rc for RenderHandlerImpl<H> {
+	fn as_base(&self) -> &cef_base_ref_counted_t {
+		unsafe {
+			let base = &*self.object;
+			std::mem::transmute(&base.cef_object)
+		}
+	}
+}
+impl<H: CefEventHandler> WrapRenderHandler for RenderHandlerImpl<H> {
+	fn wrap_rc(&mut self, object: *mut RcImpl<_cef_render_handler_t, Self>) {
+		self.object = object;
+	}
+}