xwayland: allow windows to scale themselves

src/ifs/jay_xwayland.rs

@@ -0,0 +1,84 @@
+use {
+    crate::{
+        client::{Client, ClientError},
+        leaks::Tracker,
+        object::{Object, Version},
+        wire::{jay_xwayland::*, JayXwaylandId},
+    },
+    jay_config::xwayland::XScalingMode,
+    std::rc::Rc,
+    thiserror::Error,
+};
+
+pub struct JayXwayland {
+    pub id: JayXwaylandId,
+    pub client: Rc<Client>,
+    pub tracker: Tracker<Self>,
+    pub version: Version,
+}
+
+impl JayXwayland {
+    pub fn send_scaling_mode(&self) {
+        let xw = &self.client.state.xwayland;
+        self.client.event(ScalingMode {
+            self_id: self.id,
+            mode: match xw.use_wire_scale.get() {
+                false => XScalingMode::DEFAULT.0,
+                true => XScalingMode::DOWNSCALED.0,
+            },
+        });
+    }
+
+    pub fn send_implied_scale(&self) {
+        let xw = &self.client.state.xwayland;
+        if let Some(scale) = xw.wire_scale.get() {
+            self.client.event(ImpliedScale {
+                self_id: self.id,
+                scale,
+            });
+        }
+    }
+}
+
+impl JayXwaylandRequestHandler for JayXwayland {
+    type Error = JayXwaylandError;
+
+    fn get_scaling(&self, _req: GetScaling, _slf: &Rc<Self>) -> Result<(), Self::Error> {
+        self.send_scaling_mode();
+        self.send_implied_scale();
+        Ok(())
+    }
+
+    fn set_scaling_mode(&self, req: SetScalingMode, _slf: &Rc<Self>) -> Result<(), Self::Error> {
+        let use_wire_scale = match XScalingMode(req.mode) {
+            XScalingMode::DEFAULT => false,
+            XScalingMode::DOWNSCALED => true,
+            _ => return Err(JayXwaylandError::UnknownMode(req.mode)),
+        };
+        self.client
+            .state
+            .xwayland
+            .use_wire_scale
+            .set(use_wire_scale);
+        self.client.state.update_xwayland_wire_scale();
+        Ok(())
+    }
+}
+
+object_base! {
+    self = JayXwayland;
+    version = self.version;
+}
+
+impl Object for JayXwayland {}
+
+simple_add_obj!(JayXwayland);
+
+#[derive(Debug, Error)]
+pub enum JayXwaylandError {
+    #[error(transparent)]
+    ClientError(Box<ClientError>),
+    #[error("Unknown scaling mode {}", .0)]
+    UnknownMode(u32),
+}
+efrom!(JayXwaylandError, ClientError);