From f31bde48fc556e41b712e69862e74ed56ce73347 Mon Sep 17 00:00:00 2001
From: Mitchell Hashimoto <mitchell.hashimoto@gmail.com>
Date: Sat, 9 Sep 2023 13:00:23 -0700
Subject: [PATCH] macos: add prev/next tab custom binding support

---
 include/ghostty.h                             |  5 +++
 .../Features/Primary Window/PrimaryView.swift | 25 +++++++++++---
 src/apprt/embedded.zig                        | 34 +++++++++++++++++--
 3 files changed, 58 insertions(+), 6 deletions(-)

diff --git a/include/ghostty.h b/include/ghostty.h
index 8d5c8cf8c..d11b49fb1 100644
--- a/include/ghostty.h
+++ b/include/ghostty.h
@@ -76,6 +76,11 @@ typedef enum {
     GHOSTTY_NON_NATIVE_FULLSCREEN_VISIBLE_MENU,
 } ghostty_non_native_fullscreen_e;
 
+typedef enum {
+    GHOSTTY_TAB_PREVIOUS = -1,
+    GHOSTTY_TAB_NEXT = -2,
+} ghostty_tab_e;
+
 // This is a packed struct (see src/input/mouse.zig) but the C standard
 // afaik doesn't let us reliably define packed structs so we build it up
 // from scratch.
diff --git a/macos/Sources/Features/Primary Window/PrimaryView.swift b/macos/Sources/Features/Primary Window/PrimaryView.swift
index 48950dabd..cd9f8e920 100644
--- a/macos/Sources/Features/Primary Window/PrimaryView.swift	
+++ b/macos/Sources/Features/Primary Window/PrimaryView.swift	
@@ -148,11 +148,28 @@ struct PrimaryView: View {
         guard let tabGroup = windowController.window?.tabGroup else { return }
         let tabbedWindows = tabGroup.windows
         
-        // Tabs are 0-indexed here, so we subtract one from the key the user hit.
-        let adjustedIndex = Int(tabIndex - 1);
-        guard adjustedIndex >= 0 && adjustedIndex < tabbedWindows.count else { return }
+        // This will be the index we want to actual go to
+        let finalIndex: Int
         
-        let targetWindow = tabbedWindows[adjustedIndex]
+        // An index that is invalid is used to signal some special values.
+        if (tabIndex <= 0) {
+            guard let selectedWindow = tabGroup.selectedWindow else { return }
+            guard let selectedIndex = tabbedWindows.firstIndex(where: { $0 == selectedWindow }) else { return }
+            
+            if (tabIndex == GHOSTTY_TAB_PREVIOUS.rawValue) {
+                finalIndex = selectedIndex - 1
+            } else if (tabIndex == GHOSTTY_TAB_NEXT.rawValue) {
+                finalIndex = selectedIndex + 1
+            } else {
+                return
+            }
+        } else {
+            // Tabs are 0-indexed here, so we subtract one from the key the user hit.
+            finalIndex = Int(tabIndex - 1)
+        }
+        
+        guard finalIndex >= 0 && finalIndex < tabbedWindows.count else { return }
+        let targetWindow = tabbedWindows[finalIndex]
         targetWindow.makeKeyAndOrderFront(nil)
     }
 
diff --git a/src/apprt/embedded.zig b/src/apprt/embedded.zig
index 7d246c940..650bee842 100644
--- a/src/apprt/embedded.zig
+++ b/src/apprt/embedded.zig
@@ -76,12 +76,19 @@ pub const App = struct {
         toggle_split_zoom: ?*const fn (SurfaceUD) callconv(.C) void = null,
 
         /// Goto tab
-        goto_tab: ?*const fn (SurfaceUD, usize) callconv(.C) void = null,
+        goto_tab: ?*const fn (SurfaceUD, GotoTab) callconv(.C) void = null,
 
         /// Toggle fullscreen for current window.
         toggle_fullscreen: ?*const fn (SurfaceUD, configpkg.NonNativeFullscreen) callconv(.C) void = null,
     };
 
+    /// Special values for the goto_tab callback.
+    const GotoTab = enum(i32) {
+        previous = -1,
+        next = -2,
+        _,
+    };
+
     core_app: *CoreApp,
     config: *const Config,
     opts: Options,
@@ -637,7 +644,30 @@ pub const Surface = struct {
             return;
         };
 
-        func(self.opts.userdata, n);
+        const idx = std.math.cast(i32, n) orelse {
+            log.warn("cannot cast tab index to i32 n={}", .{n});
+            return;
+        };
+
+        func(self.opts.userdata, @enumFromInt(idx));
+    }
+
+    pub fn gotoPreviousTab(self: *Surface) void {
+        const func = self.app.opts.goto_tab orelse {
+            log.info("runtime embedder does not goto_tab", .{});
+            return;
+        };
+
+        func(self.opts.userdata, .previous);
+    }
+
+    pub fn gotoNextTab(self: *Surface) void {
+        const func = self.app.opts.goto_tab orelse {
+            log.info("runtime embedder does not goto_tab", .{});
+            return;
+        };
+
+        func(self.opts.userdata, .next);
     }
 
     pub fn toggleFullscreen(self: *Surface, nonNativeFullscreen: configpkg.NonNativeFullscreen) void {