macos: show URL on OSC8 hover

src/Surface.zig

@@ -2813,14 +2813,34 @@ pub fn cursorPosCallback(
     }
     self.mouse.link_point = pos_vp;
 
-    if (try self.linkAtPos(pos)) |_| {
+    if (try self.linkAtPos(pos)) |link| {
         self.renderer_state.mouse.point = pos_vp;
         self.mouse.over_link = true;
         self.renderer_state.terminal.screen.dirty.hyperlink_hover = true;
         try self.rt_surface.setMouseShape(.pointer);
+
+        switch (link[0]) {
+            .open => {},
+
+            ._open_osc8 => link: {
+                // Show the URL in the status bar
+                const pin = link[1].start();
+                const page = &pin.page.data;
+                const cell = pin.rowAndCell().cell;
+                const link_id = page.lookupHyperlink(cell) orelse {
+                    log.warn("failed to find hyperlink for cell", .{});
+                    break :link;
+                };
+                const entry = page.hyperlink_set.get(page.memory, link_id);
+                const uri = entry.uri.offset.ptr(page.memory)[0..entry.uri.len];
+                self.rt_surface.mouseOverLink(uri);
+            },
+        }
+
         try self.queueRender();
     } else if (over_link) {
         try self.rt_surface.setMouseShape(self.io.terminal.mouse_shape);
+        self.rt_surface.mouseOverLink(null);
         try self.queueRender();
     }
 }

src/apprt/embedded.zig

@@ -128,6 +128,11 @@ pub const App = struct {
 
         /// Called when the health of the renderer changes.
         update_renderer_health: ?*const fn (SurfaceUD, renderer.Health) void = null,
+
+        /// Called when the mouse goes over a link. The link target is the
+        /// parameter. The link target will be null if the mouse is no longer
+        /// over a link.
+        mouse_over_link: ?*const fn (SurfaceUD, ?[*]const u8, usize) void = null,
     };
 
     /// Special values for the goto_tab callback.
@@ -1101,6 +1106,19 @@ pub const Surface = struct {
 
         func(self.userdata, health);
     }
+
+    pub fn mouseOverLink(self: *const Surface, uri: ?[]const u8) void {
+        const func = self.app.opts.mouse_over_link orelse {
+            log.info("runtime embedder does not support over_link", .{});
+            return;
+        };
+
+        if (uri) |v| {
+            func(self.userdata, v.ptr, v.len);
+        } else {
+            func(self.userdata, null, 0);
+        }
+    }
 };
 
 /// Inspector is the state required for the terminal inspector. A terminal