Refactor xdg_shell handling

src/main.zig

@@ -9,14 +9,6 @@ pub fn main() !void {
     var server = try Server.init(std.heap.c_allocator);
     defer server.deinit();
 
-    // Set up our list of views and the xdg-shell. The xdg-shell is a Wayland
-    // protocol which is used for application windows.
-    // https://drewdevault.com/2018/07/29/Wayland-shells.html
-    server.views = std.ArrayList(View).init(std.heap.c_allocator);
-    server.xdg_shell = c.wlr_xdg_shell_create(server.wl_display);
-    server.new_xdg_surface.notify = server_new_xdg_surface;
-    c.wl_signal_add(&server.xdg_shell.*.events.new_surface, &server.new_xdg_surface);
-
     try server.start();
 
     // Spawn an instance of alacritty

src/server.zig

@@ -11,8 +11,10 @@ pub const Server = struct {
 
     listen_new_output: c.wl_listener,
 
-    xdg_shell: *c.wlr_xdg_shell,
+    wlr_xdg_shell: *c.wlr_xdg_shell,
-    new_xdg_surface: c.wl_listener,
+    listen_new_xdg_surface: c.wl_listener,
+
+    // Must stay ordered bottom to top
     views: std.ArrayList(View),
 
     pub fn init(allocator: *std.mem.Allocator) !@This() {
@@ -57,6 +59,17 @@ pub const Server = struct {
         // Setup a listener for new outputs
         server.listen_new_output = handle_new_output;
         c.wl_signal_add(&server.wlr_backend.*.events.new_output, &server.listen_new_output);
+
+        // Set up our list of views and the xdg-shell. The xdg-shell is a Wayland
+        // protocol which is used for application windows.
+        // https://drewdevault.com/2018/07/29/Wayland-shells.html
+        server.views = std.ArrayList(View).init(std.heap.c_allocator);
+        server.wlr_xdg_shell = c.wlr_xdg_shell_create(server.wl_display) orelse
+            return error.CantCreateWlrXdgShell;
+        server.listen_new_xdg_surface.notify = handle_new_xdg_surface;
+        c.wl_signal_add(&server.xdg_shell.*.events.new_surface, &server.listen_new_xdg_surface);
+
+        return server;
     }
 
     /// Free allocated memory and clean up
@@ -120,6 +133,31 @@ pub const Server = struct {
         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);
+        server.outputs.append(Output.init(server, wlr_output) catch unreachable);
+    }
+
+    fn handle_new_xdg_surface(listener: [*c]c.wl_listener, data: ?*c_void) callconv(.C) void {
+        // This event is raised when wlr_xdg_shell receives a new xdg surface from a
+        // client, either a toplevel (application window) or popup.
+        var server = @fieldParentPtr(Server, "listen_new_xdg_surface", listener);
+        var wlr_xdg_surface = @ptrCast(*c.wlr_xdg_surface, @alignCast(@alignOf(*c.wlr_xdg_surface), data));
+
+        if (wlr_xdg_surface.role != c.enum_wlr_xdg_surface_role.WLR_XDG_SURFACE_ROLE_TOPLEVEL) {
+            return;
+        }
+
+        // Init a View to handle this surface
+        server.*.views.append(View.init(server, wlr_xdg_surface)) catch unreachable;
+    }
+
+    /// Finds the top most view under the output layout coordinates lx, ly
+    /// returns the view if found, and a pointer to the wlr_surface as well as the surface coordinates
+    pub fn desktop_view_at(self: *@This(), lx: f64, ly: f64, surface: *?*c.wlr_surface, sx: *f64, sy: *f64) ?*View {
+        for (server.*.views.span()) |*view| {
+            if (view.is_at(lx, ly, surface, sx, sy)) {
+                return view;
+            }
+        }
+        return null;
     }
 };

src/view.zig

@@ -3,18 +3,88 @@ const c = @import("c.zig").c;
 
 pub const View = struct {
     server: *Server,
-    xdg_surface: *c.wlr_xdg_surface,
+    wlr_xdg_surface: *c.wlr_xdg_surface,
-    map: c.wl_listener,
+
-    unmap: c.wl_listener,
+    listen_map: c.wl_listener,
-    destroy: c.wl_listener,
+    listen_unmap: c.wl_listener,
-    request_move: c.wl_listener,
+    listen_destroy: c.wl_listener,
-    request_resize: c.wl_listener,
+    // listen_request_move: c.wl_listener,
+    // listen_request_resize: c.wl_listener,
+
     mapped: bool,
     x: c_int,
     y: c_int,
-};
 
-fn focus_view(view: *View, surface: *c.wlr_surface) void {
+    pub fn init(server: *Server, wlr_xdg_surface: *c.wlr_xdg_surface) @This() {
+        var view = @This(){
+            .server = server,
+            .wlr_xdg_surface = wlr_xdg_surface,
+            .listen_map = c.wl_listener{
+                .link = undefined,
+                .notify = handle_map,
+            },
+            .listen_unmap = c.wl_listener{
+                .link = undefined,
+                .notify = handle_unmap,
+            },
+            .listen_destroy = c.wl_listener{
+                .link = undefined,
+                .notify = handle_destroy,
+            },
+            // .listen_request_move = c.wl_listener{
+            //     .link = undefined,
+            //     .notify = handle_request_move,
+            // },
+            // .listen_request_resize = c.wl_listener{
+            //     .link = undefined,
+            //     .notify = handle_request_resize,
+            // },
+        };
+
+        // Listen to the various events it can emit
+        c.wl_signal_add(&xdg_surface.*.events.map, &view.*.listen_map);
+        c.wl_signal_add(&xdg_surface.*.events.unmap, &view.*.listen_unmap);
+        c.wl_signal_add(&xdg_surface.*.events.destroy, &view.*.listen_destroy);
+
+        // var toplevel = xdg_surface.*.unnamed_160.toplevel;
+        // c.wl_signal_add(&toplevel.*.events.request_move, &view.*.request_move);
+        // c.wl_signal_add(&toplevel.*.events.request_resize, &view.*.request_resize);
+
+        return view;
+    }
+
+    fn handle_map(listener: [*c]c.wl_listener, data: ?*c_void) callconv(.C) void {
+        // Called when the surface is mapped, or ready to display on-screen.
+        var view = @fieldParentPtr(View, "map", listener);
+        view.*.mapped = true;
+        focus_view(view, view.*.xdg_surface.*.surface);
+    }
+
+    fn handle_unmap(listener: [*c]c.wl_listener, data: ?*c_void) callconv(.C) void {
+        var view = @fieldParentPtr(View, "unmap", listener);
+        view.*.mapped = false;
+    }
+
+    fn handle_destroy(listener: [*c]c.wl_listener, data: ?*c_void) callconv(.C) void {
+        var view = @fieldParentPtr(View, "destroy", listener);
+        var server = view.*.server;
+        const idx = for (server.*.views.span()) |*v, i| {
+            if (v == view) {
+                break i;
+            }
+        } else return;
+        _ = server.*.views.orderedRemove(idx);
+    }
+
+    // fn xdg_toplevel_request_move(listener: [*c]c.wl_listener, data: ?*c_void) callconv(.C) void {
+    //     // ignore for now
+    // }
+
+    // fn xdg_toplevel_request_resize(listener: [*c]c.wl_listener, data: ?*c_void) callconv(.C) void {
+    //     // ignore for now
+    // }
+
+    fn focus_view(view: *View, surface: *c.wlr_surface) void {
         const server = view.server;
         const seat = server.*.seat;
         const prev_surface = seat.*.keyboard_state.focused_surface;
@@ -52,9 +122,9 @@ fn focus_view(view: *View, surface: *c.wlr_surface) void {
         // clients without additional work on your part.
         var keyboard = c.wlr_seat_get_keyboard(seat);
         c.wlr_seat_keyboard_notify_enter(seat, moved_view.*.xdg_surface.*.surface, &keyboard.*.keycodes, keyboard.*.num_keycodes, &keyboard.*.modifiers);
-}
+    }
 
-fn view_at(view: *View, lx: f64, ly: f64, surface: *?*c.wlr_surface, sx: *f64, sy: *f64) bool {
+    fn is_at(self: *@This(), lx: f64, ly: f64, surface: *?*c.wlr_surface, sx: *f64, sy: *f64) bool {
         // XDG toplevels may have nested surfaces, such as popup windows for context
         // menus or tooltips. This function tests if any of those are underneath the
         // coordinates lx and ly (in output Layout Coordinates). If so, it sets the
@@ -78,15 +148,5 @@ fn view_at(view: *View, lx: f64, ly: f64, surface: *?*c.wlr_surface, sx: *f64, s
         }
 
         return false;
-}
-
-fn desktop_view_at(server: *Server, lx: f64, ly: f64, surface: *?*c.wlr_surface, sx: *f64, sy: *f64) ?*View {
-    // This iterates over all of our surfaces and attempts to find one under the
-    // cursor. This relies on server.*.views being ordered from top-to-bottom.
-    for (server.*.views.span()) |*view| {
-        if (view_at(view, lx, ly, surface, sx, sy)) {
-            return view;
     }
-    }
+};
-    return null;
-}

src/xdg_shell.zig

@@ -1,68 +0,0 @@
-const std = @import("std");
-const c = @import("c.zig").c;
-
-fn xdg_surface_map(listener: [*c]c.wl_listener, data: ?*c_void) callconv(.C) void {
-    // Called when the surface is mapped, or ready to display on-screen.
-    var view = @fieldParentPtr(View, "map", listener);
-    view.*.mapped = true;
-    focus_view(view, view.*.xdg_surface.*.surface);
-}
-
-fn xdg_surface_unmap(listener: [*c]c.wl_listener, data: ?*c_void) callconv(.C) void {
-    var view = @fieldParentPtr(View, "unmap", listener);
-    view.*.mapped = false;
-}
-
-fn xdg_surface_destroy(listener: [*c]c.wl_listener, data: ?*c_void) callconv(.C) void {
-    var view = @fieldParentPtr(View, "destroy", listener);
-    var server = view.*.server;
-    const idx = for (server.*.views.span()) |*v, i| {
-        if (v == view) {
-            break i;
-        }
-    } else return;
-    _ = server.*.views.orderedRemove(idx);
-}
-
-fn xdg_toplevel_request_move(listener: [*c]c.wl_listener, data: ?*c_void) callconv(.C) void {
-    // ignore for now
-}
-
-fn xdg_toplevel_request_resize(listener: [*c]c.wl_listener, data: ?*c_void) callconv(.C) void {
-    // ignore for now
-}
-
-fn server_new_xdg_surface(listener: [*c]c.wl_listener, data: ?*c_void) callconv(.C) void {
-    // This event is raised when wlr_xdg_shell receives a new xdg surface from a
-    // client, either a toplevel (application window) or popup.
-    var server = @fieldParentPtr(Server, "new_xdg_surface", listener);
-    var xdg_surface = @ptrCast(*c.wlr_xdg_surface, @alignCast(@alignOf(*c.wlr_xdg_surface), data));
-
-    if (xdg_surface.*.role != c.enum_wlr_xdg_surface_role.WLR_XDG_SURFACE_ROLE_TOPLEVEL) {
-        return;
-    }
-
-    // Allocate a View for this surface
-    server.*.views.append(undefined) catch unreachable;
-    var view = &server.*.views.span()[server.*.views.span().len - 1];
-
-    view.*.server = server;
-    view.*.xdg_surface = xdg_surface;
-
-    // Listen to the various events it can emit
-    view.*.map.notify = xdg_surface_map;
-    c.wl_signal_add(&xdg_surface.*.events.map, &view.*.map);
-
-    view.*.unmap.notify = xdg_surface_unmap;
-    c.wl_signal_add(&xdg_surface.*.events.unmap, &view.*.unmap);
-
-    view.*.destroy.notify = xdg_surface_destroy;
-    c.wl_signal_add(&xdg_surface.*.events.destroy, &view.*.destroy);
-
-    var toplevel = xdg_surface.*.unnamed_160.toplevel;
-    view.*.request_move.notify = xdg_toplevel_request_move;
-    c.wl_signal_add(&toplevel.*.events.request_move, &view.*.request_move);
-
-    view.*.request_resize.notify = xdg_toplevel_request_resize;
-    c.wl_signal_add(&toplevel.*.events.request_resize, &view.*.request_resize);
-}