"goto_tab" key binding to jump to a specific tab, defaults to Super+N

The apprt surface must implement `gotoTab` to make this work. This is
only implemented in GTK for now.

src/Surface.zig

@@ -927,6 +927,12 @@ pub fn keyCallback(
                     } else log.warn("runtime doesn't implement gotoNextTab", .{});
                 },
 
+                .goto_tab => |n| {
+                    if (@hasDecl(apprt.Surface, "gotoTab")) {
+                        self.rt_surface.gotoTab(n);
+                    } else log.warn("runtime doesn't implement gotoTab", .{});
+                },
+
                 .close_window => {
                     _ = self.app_mailbox.push(.{ .close = self }, .{ .instant = {} });
                 },

src/apprt/gtk.zig

@@ -329,6 +329,17 @@ const Window = struct {
         }
     }
 
+    /// Go to the specific tab index.
+    fn gotoTab(self: *Window, n: usize) void {
+        if (n == 0) return;
+        const max = c.gtk_notebook_get_n_pages(self.notebook);
+        const page_idx = std.math.cast(c_int, n - 1) orelse return;
+        if (page_idx < max) {
+            c.gtk_notebook_set_current_page(self.notebook, page_idx);
+            self.focusCurrentTab();
+        }
+    }
+
     /// Grabs focus on the currently selected tab.
     fn focusCurrentTab(self: *Window) void {
         const page_idx = c.gtk_notebook_get_current_page(self.notebook);
@@ -591,6 +602,10 @@ pub const Surface = struct {
         self.window.gotoNextTab(self);
     }
 
+    pub fn gotoTab(self: *Surface, n: usize) void {
+        self.window.gotoTab(n);
+    }
+
     pub fn setShouldClose(self: *Surface) void {
         _ = self;
     }

src/config.zig

@@ -288,6 +288,19 @@ pub const Config = struct {
             .{ .key = .right_bracket, .mods = .{ .super = true, .shift = true } },
             .{ .next_tab = {} },
         );
+        {
+            // Cmd+N for goto tab N
+            const start = @enumToInt(inputpkg.Key.one);
+            const end = @enumToInt(inputpkg.Key.nine);
+            var i: usize = start;
+            while (i <= end) : (i += 1) {
+                try result.keybind.set.put(
+                    alloc,
+                    .{ .key = @intToEnum(inputpkg.Key, i), .mods = .{ .super = true } },
+                    .{ .goto_tab = (i - start) + 1 },
+                );
+            }
+        }
         if (comptime builtin.target.isDarwin()) {
             try result.keybind.set.put(
                 alloc,

src/input/Binding.zig

@@ -161,6 +161,9 @@ pub const Action = union(enum) {
     /// Go to the next tab
     next_tab: void,
 
+    /// Go to the tab with the specific number, 1-indexed.
+    goto_tab: usize,
+
     /// Close the current window or tab
     close_window: void,