Refactor output handling

src/output.zig

@@ -4,10 +4,52 @@ const c = @import("c.zig").c;
 const Output = struct {
     server: *Server,
     wlr_output: *c.wlr_output,
-    frame: c.wl_listener,
+    listen_frame: c.wl_listener,
+
+    pub fn init(server: *Server, wlr_output: *c.wlr_output) !@This() {
+        // Some backends don't have modes. DRM+KMS does, and we need to set a mode
+        // before we can use the output. The mode is a tuple of (width, height,
+        // refresh rate), and each monitor supports only a specific set of modes. We
+        // just pick the monitor's preferred mode, a more sophisticated compositor
+        // would let the user configure it.
+
+        // if not empty
+        if (c.wl_list_empty(&wlr_output.*.modes) == 0) {
+            const mode = c.wlr_output_preferred_mode(wlr_output);
+            c.wlr_output_set_mode(wlr_output, mode);
+            c.wlr_output_enable(wlr_output, true);
+            if (!c.wlr_output_commit(wlr_output)) {
+                return error.CantCommitWlrOutputMode;
+            }
+        }
+
+        var output = @This(){
+            .server = server,
+            .wlr_output = wlr_output,
+            .listen_frame = c.wl_listener{
+                .link = undefined,
+                .notify = handle_frame,
+            },
         };
 
-fn output_frame(listener: [*c]c.wl_listener, data: ?*c_void) callconv(.C) void {
+        // Sets up a listener for the frame notify event.
+        c.wl_signal_add(&wlr_output.*.events.frame, &output.*.listen_frame);
+
+        // Add the new output to the layout. The add_auto function arranges outputs
+        // from left-to-right in the order they appear. A more sophisticated
+        // compositor would let the user configure the arrangement of outputs in the
+        // layout.
+        c.wlr_output_layout_add_auto(server.output_layout, wlr_output);
+
+        // Creating the global adds a wl_output global to the display, which Wayland
+        // clients can see to find out information about the output (such as
+        // DPI, scale factor, manufacturer, etc).
+        c.wlr_output_create_global(wlr_output);
+
+        return output;
+    }
+
+    fn handle_frame(listener: [*c]c.wl_listener, data: ?*c_void) callconv(.C) void {
         // This function is called every time an output is ready to display a frame,
         // generally at the output's refresh rate (e.g. 60Hz).
         var output = @fieldParentPtr(Output, "frame", listener);
@@ -62,49 +104,4 @@ fn output_frame(listener: [*c]c.wl_listener, data: ?*c_void) callconv(.C) void {
         // TODO: handle failure
         _ = c.wlr_output_commit(output.*.wlr_output);
     }
-
+};
-fn server_new_output(listener: [*c]c.wl_listener, data: ?*c_void) callconv(.C) void {
-    var server = @fieldParentPtr(Server, "new_output", listener);
-    var wlr_output = @ptrCast(*c.wlr_output, @alignCast(@alignOf(*c.wlr_output), data));
-
-    // Some backends don't have modes. DRM+KMS does, and we need to set a mode
-    // before we can use the output. The mode is a tuple of (width, height,
-    // refresh rate), and each monitor supports only a specific set of modes. We
-    // just pick the monitor's preferred mode, a more sophisticated compositor
-    // would let the user configure it.
-
-    // if not empty
-    if (c.wl_list_empty(&wlr_output.*.modes) == 0) {
-        var mode = c.wlr_output_preferred_mode(wlr_output);
-        c.wlr_output_set_mode(wlr_output, mode);
-        c.wlr_output_enable(wlr_output, true);
-        if (!c.wlr_output_commit(wlr_output)) {
-            return;
-        }
-    }
-
-    // Allocates and configures our state for this output
-    server.*.outputs.append(Output{
-        .server = undefined,
-        .wlr_output = undefined,
-        .frame = undefined,
-    }) catch unreachable;
-    var output = &server.*.outputs.span()[server.*.outputs.span().len - 1];
-    output.*.wlr_output = wlr_output;
-    output.*.server = server;
-
-    // Sets up a listener for the frame notify event.
-    output.*.frame.notify = output_frame;
-    c.wl_signal_add(&wlr_output.*.events.frame, &output.*.frame);
-
-    // Adds this to the output layout. The add_auto function arranges outputs
-    // from left-to-right in the order they appear. A more sophisticated
-    // compositor would let the user configure the arrangement of outputs in the
-    // layout.
-    c.wlr_output_layout_add_auto(server.*.output_layout, wlr_output);
-
-    // Creating the global adds a wl_output global to the display, which Wayland
-    // clients can see to find out information about the output (such as
-    // DPI, scale factor, manufacturer, etc).
-    c.wlr_output_create_global(wlr_output);
-}

src/server.zig

@@ -69,7 +69,7 @@ pub const Server = struct {
     /// Create the socket, set WAYLAND_DISPLAY, and start the backend
     pub fn start(self: @This()) !void {
         // Add a Unix socket to the Wayland display.
-        const socket = c.wl_display_add_socket_auto(self.wl_display) orelse;
+        const socket = c.wl_display_add_socket_auto(self.wl_display) orelse
             return error.CantAddSocket;
 
         // Start the backend. This will enumerate outputs and inputs, become the DRM
@@ -114,4 +114,12 @@ pub const Server = struct {
         }
         return true;
     }
+
+    fn handle_new_output(listener: [*c]c.wl_listener, data: ?*c_void) callconv(.C) void {
+        var server = @fieldParentPtr(Server, "new_output", listener);
+        var wlr_output = @ptrCast(*c.wlr_output, @alignCast(@alignOf(*c.wlr_output), data));
+
+        // TODO: Handle failure
+        server.outputs.append(Output.init(server, wlr_output) orelse return);
+    }
 };