The focus_follows_mouse option now also works across top-level kitty OS windows

Fixes #772

docs/changelog.rst

@@ -36,7 +36,10 @@ Changelog
   file is text (:pull:`752`)
 
 - kitty @ new-window: Add a new option :option:`kitty @ new-window --window-type`
-  to create top-level OS windows. (:iss:`770`)
+  to create top-level OS windows (:iss:`770`)
+
+- The :opt:`focus_follows_mouse` option now also works across top-level kitty OS windows
+  (:iss:`754`)
 
 
 0.11.3 [2018-07-10]

glfw/cocoa_window.m

@@ -739,7 +739,7 @@ - (void)updateTrackingAreas
     }
 
     const NSTrackingAreaOptions options = NSTrackingMouseEnteredAndExited |
-                                          NSTrackingActiveInKeyWindow |
+                                          NSTrackingActiveAlways |
                                           NSTrackingEnabledDuringMouseDrag |
                                           NSTrackingCursorUpdate |
                                           NSTrackingInVisibleRect |
@@ -1083,7 +1083,7 @@ - (void)doNothing:(id)object
 }
 
 - (void)loadMainMenu
-{ // removed by Kovid as it generated compiler warnings 
+{ // removed by Kovid as it generated compiler warnings
 }
 
 @end

kitty/cocoa_window.m

@@ -218,6 +218,12 @@ + (GlobalMenuTarget *) shared_instance
     return true;
 }
 
+void
+cocoa_focus_window(void *w) {
+    NSWindow *window = (NSWindow*)w;
+    [window makeKeyWindow];
+}
+
 static PyObject*
 cocoa_get_lang(PyObject UNUSED *self) {
     NSString* locale = nil;

kitty/data-types.h

@@ -280,6 +280,7 @@ void colorprofile_push_dynamic_colors(ColorProfile*);
 void colorprofile_pop_dynamic_colors(ColorProfile*);
 
 void set_mouse_cursor(MouseShape);
+void enter_event();
 void mouse_event(int, int);
 void focus_in_event();
 void wakeup_io_loop(bool);

kitty/glfw.c

@@ -9,6 +9,7 @@
 #include <structmember.h>
 #include "glfw-wrapper.h"
 extern bool cocoa_make_window_resizable(void *w, bool);
+extern void cocoa_focus_window(void *w);
 extern void cocoa_create_global_menu(void);
 extern void cocoa_set_hide_from_tasks(void);
 extern void cocoa_set_titlebar_color(void *w, color_type color);
@@ -138,6 +139,18 @@ key_callback(GLFWwindow *w, int key, int scancode, int action, int mods, const c
     global_state.callback_os_window = NULL;
 }
 
+static void
+cursor_enter_callback(GLFWwindow *w, int entered) {
+    if (!set_callback_window(w)) return;
+    if (entered) {
+        show_mouse_cursor(w);
+        double now = monotonic();
+        global_state.callback_os_window->last_mouse_activity_at = now;
+        if (is_window_ready_for_callbacks()) enter_event();
+    }
+    global_state.callback_os_window = NULL;
+}
+
 static void
 mouse_button_callback(GLFWwindow *w, int button, int action, int mods) {
     if (!set_callback_window(w)) return;
@@ -489,6 +502,7 @@ create_os_window(PyObject UNUSED *self, PyObject *args) {
     glfwSetFramebufferSizeCallback(glfw_window, framebuffer_size_callback);
     glfwSetWindowContentScaleCallback(glfw_window, dpi_change_callback);
     glfwSetWindowRefreshCallback(glfw_window, refresh_callback);
+    glfwSetCursorEnterCallback(glfw_window, cursor_enter_callback);
     glfwSetMouseButtonCallback(glfw_window, mouse_button_callback);
     glfwSetScrollCallback(glfw_window, scroll_callback);
     glfwSetCursorPosCallback(glfw_window, cursor_pos_callback);
@@ -544,8 +558,16 @@ destroy_os_window(OSWindow *w) {
 }
 
 void
-focus_os_window(OSWindow *w) {
-    if (w->handle) glfwFocusWindow(w->handle);
+focus_os_window(OSWindow *w, bool also_raise) {
+    if (w->handle) {
+#ifdef __APPLE__
+        if (!also_raise) cocoa_focus_window(glfwGetCocoaWindow(w->handle));
+        else glfwFocusWindow(w->handle);
+#else
+        (void)also_raise;
+        glfwFocusWindow(w->handle);
+#endif
+    }
 }
 
 #ifdef __APPLE__

kitty/mouse.c

@@ -451,6 +451,13 @@ focus_in_event() {
     if (w && w->render_data.screen) screen_mark_url(w->render_data.screen, 0, 0, 0, 0);
 }
 
+void
+enter_event() {
+    if (OPT(focus_follows_mouse) && !global_state.callback_os_window->is_focused) {
+        focus_os_window(global_state.callback_os_window, false);
+    }
+}
+
 void
 mouse_event(int button, int modifiers) {
     MouseShape old_cursor = mouse_cursor_shape;

kitty/state.c

@@ -499,9 +499,10 @@ PYWRAP1(mark_os_window_for_close) {
 
 PYWRAP1(focus_os_window) {
     id_type os_window_id;
-    PA("K", &os_window_id);
+    int also_raise = 1;
+    PA("K|p", &os_window_id, &also_raise);
     WITH_OS_WINDOW(os_window_id)
-        if (!os_window->is_focused) focus_os_window(os_window);
+        if (!os_window->is_focused) focus_os_window(os_window, also_raise);
         Py_RETURN_TRUE;
     END_WITH_OS_WINDOW
     Py_RETURN_FALSE;

kitty/state.h

@@ -170,7 +170,7 @@ void swap_window_buffers(OSWindow *w);
 void make_window_context_current(OSWindow *w);
 void hide_mouse(OSWindow *w);
 void destroy_os_window(OSWindow *w);
-void focus_os_window(OSWindow *w);
+void focus_os_window(OSWindow *w, bool also_raise);
 void set_os_window_title(OSWindow *w, const char *title);
 OSWindow* os_window_for_kitty_window(id_type);
 OSWindow* add_os_window();