color-management-v1: only expose the protocol with vulkan

src/cli/color_management.rs

@@ -56,9 +56,17 @@ impl ColorManagement {
         jay_color_management::Enabled::handle(tc, id, enabled.clone(), |iv, msg| {
             iv.set(msg.enabled != 0);
         });
+        let available = Rc::new(Cell::new(false));
+        jay_color_management::Available::handle(tc, id, available.clone(), |iv, msg| {
+            iv.set(msg.available != 0);
+        });
         tc.round_trip().await;
         if enabled.get() {
-            println!("Enabled");
+            print!("Enabled");
+            if !available.get() {
+                print!(" (Unavailable)");
+            }
+            println!();
         } else {
             println!("Disabled");
         }

src/gfx_api.rs

@@ -742,6 +742,10 @@ pub trait GfxContext: Debug {
         width: i32,
         height: i32,
     ) -> Result<Rc<dyn GfxBlendBuffer>, GfxError>;
+
+    fn supports_color_management(&self) -> bool {
+        false
+    }
 }
 
 #[derive(Clone, Debug)]

src/gfx_apis/vulkan.rs

@@ -363,6 +363,10 @@ impl GfxContext for Context {
         let buffer = self.0.acquire_blend_buffer(width, height)?;
         Ok(buffer)
     }
+
+    fn supports_color_management(&self) -> bool {
+        self.0.device.descriptor_buffer.is_some()
+    }
 }
 
 impl Drop for Context {

src/ifs/color_management/wp_color_manager_v1.rs

@@ -201,7 +201,7 @@ impl Global for WpColorManagerV1Global {
     }
 
     fn exposed(&self, state: &State) -> bool {
-        state.color_management_enabled.get()
+        state.color_management_available()
     }
 }
 

src/ifs/jay_color_management.rs

@@ -23,6 +23,13 @@ impl JayColorManagement {
             enabled: self.client.state.color_management_enabled.get() as u32,
         });
     }
+
+    fn send_available(&self) {
+        self.client.event(Available {
+            self_id: self.id,
+            available: self.client.state.color_management_available() as u32,
+        });
+    }
 }
 
 impl JayColorManagementRequestHandler for JayColorManagement {
@@ -35,6 +42,7 @@ impl JayColorManagementRequestHandler for JayColorManagement {
 
     fn get(&self, _req: Get, _slf: &Rc<Self>) -> Result<(), Self::Error> {
         self.send_enabled();
+        self.send_available();
         Ok(())
     }
 

src/state.rs

@@ -1315,6 +1315,16 @@ impl State {
     pub fn tray_icon_size(&self) -> i32 {
         (self.theme.sizes.title_height.get() - 2).max(0)
     }
+
+    pub fn color_management_available(&self) -> bool {
+        if !self.color_management_enabled.get() {
+            return false;
+        }
+        let Some(ctx) = self.render_ctx.get() else {
+            return false;
+        };
+        ctx.supports_color_management()
+    }
 }
 
 #[derive(Debug, Error)]

wire/jay_color_management.txt

@@ -13,3 +13,7 @@ request set_enabled {
 event enabled {
     enabled: u32,
 }
+
+event available {
+    available: u32,
+}