How to drag window without titlebar.

[fazibear]

Trying to implement a simple dragging for a window without titlebar.

Here is an example:

use winit::{
    application::ApplicationHandler,
    dpi::PhysicalPosition,
    error::EventLoopError,
    event::{ElementState, MouseButton, WindowEvent},
    event_loop::{ActiveEventLoop, ControlFlow, EventLoop},
    window::{Window, WindowId},
};

#[derive(Default)]
pub struct App {
    window: Option<Window>,
    is_dragging: bool,
    last_cursor_position: PhysicalPosition<f64>,
}

impl ApplicationHandler for App {
    fn about_to_wait(&mut self, _event_loop: &ActiveEventLoop) {
        if let Some(window) = self.window.as_ref() {
            window.request_redraw();
        }
    }

    fn resumed(&mut self, event_loop: &ActiveEventLoop) {
        let window_attributes = Window::default_attributes()
            .with_title("Fantastic window number one!")
            .with_resizable(false)
            .with_decorations(false)
            .with_inner_size(winit::dpi::LogicalSize::new(128.0, 128.0));
        let window = event_loop.create_window(window_attributes).unwrap();
        self.window = Some(window);
    }

    fn window_event(
        &mut self,
        _event_loop: &ActiveEventLoop,
        _window_id: WindowId,
        event: WindowEvent,
    ) {
        match event {
            WindowEvent::CursorMoved { position, .. } => {
                if self.is_dragging {
                    let window_position: PhysicalPosition<f64> = self
                        .window
                        .as_ref()
                        .unwrap()
                        .outer_position()
                        .unwrap()
                        .cast();

                    let new_position = PhysicalPosition::new(
                        window_position.x + (position.x - self.last_cursor_position.x),
                        window_position.y + (position.y - self.last_cursor_position.y),
                    );

                    self.window
                        .as_ref()
                        .unwrap()
                        .set_outer_position(new_position)
                }

                self.last_cursor_position = position;
            }

            WindowEvent::MouseInput {
                state,
                button: MouseButton::Left,
                ..
            } => match state {
                ElementState::Pressed => {
                    self.is_dragging = true;
                }
                ElementState::Released => {
                    self.is_dragging = false;
                }
            },
            WindowEvent::CloseRequested => {}
            WindowEvent::RedrawRequested => {}
            _ => (),
        }
    }
}

fn main() -> Result<(), EventLoopError> {
    let event_loop = EventLoop::new().unwrap();
    event_loop.set_control_flow(ControlFlow::Wait);
    let mut app = App::default();
    event_loop.run_app(&mut app)
}

It's not working very well. Window moves slower than cursor or blinks. I'm using Mac OS.

Also tried drag_window() window moves correctly, but jumps to the top left corner.

What am I doing wrong?
Thanks for help

[fazibear]

Nevermind, drag_window() works as expected.