apprt/embedded: allow noting that selection clipboard is not supported

include/ghostty.h

@@ -253,6 +253,7 @@ typedef void (*ghostty_runtime_toggle_fullscreen_cb)(void *, bool);
 
 typedef struct {
     void *userdata;
+    bool supports_selection_clipboard;
     ghostty_runtime_wakeup_cb wakeup_cb;
     ghostty_runtime_reload_config_cb reload_config_cb;
     ghostty_runtime_set_title_cb set_title_cb;

macos/Sources/Ghostty/AppState.swift

@@ -54,6 +54,7 @@ extension Ghostty {
             // uses to interface with the application runtime environment.
             var runtime_cfg = ghostty_runtime_config_s(
                 userdata: Unmanaged.passUnretained(self).toOpaque(),
+                supports_selection_clipboard: false,
                 wakeup_cb: { userdata in AppState.wakeup(userdata) },
                 reload_config_cb: { userdata in AppState.reloadConfig(userdata) },
                 set_title_cb: { userdata, title in AppState.setTitle(userdata, title: title) },

src/Surface.zig

@@ -849,6 +849,14 @@ fn setSelection(self: *Surface, sel_: ?terminal.Selection) void {
     const sel = sel_ orelse return;
     if (prev_) |prev| if (std.meta.eql(sel, prev)) return;
 
+    // Check if our runtime supports the selection clipboard at all.
+    // We can save a lot of work if it doesn't.
+    if (@hasDecl(apprt.runtime.Surface, "supportsClipboard")) {
+        if (!self.rt_surface.supportsClipboard(clipboard)) {
+            return;
+        }
+    }
+
     var buf = self.io.terminal.screen.selectionString(
         self.alloc,
         sel,

src/apprt/embedded.zig

@@ -32,6 +32,9 @@ pub const App = struct {
         /// Userdata that is passed to all the callbacks.
         userdata: AppUD = null,
 
+        /// True if the selection clipboard is supported.
+        supports_selection_clipboard: bool = false,
+
         /// Callback called to wakeup the event loop. This should trigger
         /// a full tick of the app loop.
         wakeup: *const fn (AppUD) callconv(.C) void,
@@ -239,6 +242,16 @@ pub const Surface = struct {
         );
     }
 
+    pub fn supportsClipboard(
+        self: *const Surface,
+        clipboard_type: apprt.Clipboard,
+    ) bool {
+        return switch (clipboard_type) {
+            .standard => true,
+            .selection => self.app.opts.supports_selection_clipboard,
+        };
+    }
+
     pub fn getClipboardString(
         self: *const Surface,
         clipboard_type: apprt.Clipboard,