feat: added SDL_SetWindowHitTest wrapper #268
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revmischa
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revmischa
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Thanks for the contribution!
| let boxed: Box<Box<dyn Fn(crate::rect::Point) -> HitTestResult>> = | ||
| Box::new(Box::new(hit_test)); |
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I wrapped the closure twice to relax the trait bounds when dereferencing the callback from c_void pointer, as only Box'ing it once would yield
expected a `Fn(Point)` closure, found `c_void`
the trait `Fn(Point)` is not implemented for `c_void`
required for the cast from `*mut c_void` to `*mut dyn Fn(Point) -> HitTestResult
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let callback = &*(data as *const dyn Fn(Point) -> HitTestResult); might work
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I tried your solution but it seems the compiler still stops us from casting it into a trait pointer...
expected a `Fn(Point)` closure, found `c_void`
the trait `Fn(Point)` is not implemented for `c_void`
required for the cast from `*mut c_void` to `*const dyn Fn(Point) -> HitTestResult
Casting the void pointer into the trait pointer still requires the void pointer to implement that trait (which c_void doesn't)
I think Box is still needed to relax the trait bounds
src/sdl3/video.rs
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| unsafe { | ||
| let result = | ||
| sys::video::SDL_SetWindowHitTest(self.context.raw, Some(hit_test_sys), userdata); |
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It seems like the hit_test will never be freed, we could store the userdata pointer on the Window struct and free it on Window drop perhaps.
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This PR adds a wrapper function and required enums for the
SDL_SetWindowHitTestfunction in thevideosubmodule.The function is currently implemented with a trampoline function to wrap around bindgen's
extern "C"function pointer type.To replace
SDL_SetWindowHitTest(SDL_Window* win, const SDL_Point* area, void* data)'sdatavoid pointer, I've implemented the closure as animpl Fnto be able to capture variables as needed into the closure instead of passing them as function parameters.