Support pinch, double tap and rotation gestures on iOS (#3130)

This is off by default on iOS. Note that pinch delta may be NaN.

Co-authored-by: Mads Marquart <mads@marquart.dk>

examples/touchpad_gestures.rs

@@ -1,50 +0,0 @@
-use simple_logger::SimpleLogger;
-use winit::{
-    event::{Event, WindowEvent},
-    event_loop::EventLoop,
-    window::WindowBuilder,
-};
-
-#[path = "util/fill.rs"]
-mod fill;
-
-fn main() -> Result<(), impl std::error::Error> {
-    SimpleLogger::new().init().unwrap();
-    let event_loop = EventLoop::new().unwrap();
-
-    let window = WindowBuilder::new()
-        .with_title("Touchpad gestures")
-        .build(&event_loop)
-        .unwrap();
-
-    println!("Only supported on macOS at the moment.");
-
-    event_loop.run(move |event, elwt| {
-        if let Event::WindowEvent { event, .. } = event {
-            match event {
-                WindowEvent::CloseRequested => elwt.exit(),
-                WindowEvent::TouchpadMagnify { delta, .. } => {
-                    if delta > 0.0 {
-                        println!("Zoomed in {delta}");
-                    } else {
-                        println!("Zoomed out {delta}");
-                    }
-                }
-                WindowEvent::SmartMagnify { .. } => {
-                    println!("Smart zoom");
-                }
-                WindowEvent::TouchpadRotate { delta, .. } => {
-                    if delta > 0.0 {
-                        println!("Rotated counterclockwise {delta}");
-                    } else {
-                        println!("Rotated clockwise {delta}");
-                    }
-                }
-                WindowEvent::RedrawRequested => {
-                    fill::fill_window(&window);
-                }
-                _ => (),
-            }
-        }
-    })
-}