Initial WIP code

src/x.rs

@@ -0,0 +1,137 @@
+use gdk4_x11::x11::xlib;
+use glib::translate::ToGlibPtr;
+use gtk4::{glib, prelude::*};
+use std::{
+    ffi::{CString, NulError},
+    os::raw::c_int,
+};
+
+pub use std::os::raw::{c_uchar, c_ulong, c_ushort};
+
+pub fn get_window_x11(
+    window: &gtk4::Window,
+) -> Option<(gdk4_x11::X11Display, gdk4_x11::X11Surface)> {
+    let surface = window.surface()?.downcast::<gdk4_x11::X11Surface>().ok()?;
+    let display = surface.display()?.downcast::<gdk4_x11::X11Display>().ok()?;
+    Some((display, surface))
+}
+
+#[repr(transparent)]
+pub struct Atom(xlib::Atom);
+
+impl Atom {
+    pub fn new(display: &gdk4_x11::X11Display, prop: &str) -> Result<Self, NulError> {
+        unsafe {
+            let prop = CString::new(prop)?;
+            Ok(Self(gdk4_x11::ffi::gdk_x11_get_xatom_by_name_for_display(
+                display.to_glib_none().0,
+                prop.as_ptr(),
+            )))
+        }
+    }
+}
+
+pub unsafe trait XElement {
+    const TYPE: xlib::Atom;
+    const SIZE: c_int;
+}
+
+unsafe impl XElement for c_uchar {
+    const TYPE: xlib::Atom = xlib::XA_CARDINAL;
+    const SIZE: c_int = 8;
+}
+
+unsafe impl XElement for c_ushort {
+    const TYPE: xlib::Atom = xlib::XA_CARDINAL;
+    const SIZE: c_int = 16;
+}
+
+unsafe impl XElement for c_ulong {
+    const TYPE: xlib::Atom = xlib::XA_CARDINAL;
+    const SIZE: c_int = 32;
+}
+
+unsafe impl XElement for Atom {
+    const TYPE: xlib::Atom = xlib::XA_ATOM;
+    const SIZE: c_int = 32;
+}
+
+pub unsafe trait XProp {
+    const TYPE: xlib::Atom;
+    const SIZE: c_int;
+
+    fn ptr(&self) -> *const u8;
+
+    fn nelements(&self) -> c_int;
+}
+
+unsafe impl<T: XElement, const LEN: usize> XProp for &[T; LEN] {
+    const TYPE: xlib::Atom = T::TYPE;
+    const SIZE: c_int = T::SIZE;
+
+    fn ptr(&self) -> *const u8 {
+        self.as_ptr() as _
+    }
+
+    fn nelements(&self) -> c_int {
+        LEN as c_int
+    }
+}
+
+unsafe impl<T: XElement> XProp for &[T] {
+    const TYPE: xlib::Atom = T::TYPE;
+    const SIZE: c_int = T::SIZE;
+
+    fn ptr(&self) -> *const u8 {
+        self.as_ptr() as _
+    }
+
+    fn nelements(&self) -> c_int {
+        self.len() as c_int
+    }
+}
+
+unsafe impl XProp for &str {
+    const TYPE: xlib::Atom = xlib::XA_STRING;
+    const SIZE: c_int = 8;
+
+    fn ptr(&self) -> *const u8 {
+        self.as_ptr()
+    }
+
+    fn nelements(&self) -> c_int {
+        self.len() as c_int
+    }
+}
+
+#[allow(dead_code)]
+pub enum PropMode {
+    Replace,
+    Prepend,
+    Append,
+}
+
+pub unsafe fn change_property<T: XProp>(
+    display: &gdk4_x11::X11Display,
+    surface: &gdk4_x11::X11Surface,
+    prop: &str,
+    mode: PropMode,
+    value: T,
+) {
+    // TODO check error return value
+    let mode = match mode {
+        PropMode::Replace => xlib::PropModeReplace,
+        PropMode::Prepend => xlib::PropModePrepend,
+        PropMode::Append => xlib::PropModeAppend,
+    };
+    xlib::XChangeProperty(
+        display.xdisplay(),
+        surface.xid(),
+        Atom::new(display, prop).unwrap().0,
+        T::TYPE,
+        T::SIZE,
+        mode,
+        value.ptr(),
+        value.nelements(),
+    );
+}