Wayland: improve support of addition/removal of displays while FLTK runs

2 files changed, 22 insertions, 35 deletions

diff --git a/src/drivers/Wayland/Fl_Wayland_Screen_Driver.cxx b/src/drivers/Wayland/Fl_Wayland_Screen_Driver.cxx
index 304395936..534d70bb5 100644
--- a/src/drivers/Wayland/Fl_Wayland_Screen_Driver.cxx
+++ b/src/drivers/Wayland/Fl_Wayland_Screen_Driver.cxx
@@ -1114,11 +1114,6 @@ static void output_mode(void *data, struct wl_output *wl_output, uint32_t flags,
 }
 
 
-static bool compute_full_and_maximized_areas(Fl_Wayland_Screen_Driver::output *output,
-                                             int& Wfullscreen, int& Hfullscreen,
-                                             int& Wworkarea, int& Hworkarea);
-
-
 static void output_done(void *data, struct wl_output *wl_output)
 {
   // Runs at startup and when desktop scale factor is changed or screen added
@@ -1147,13 +1142,7 @@ static void output_done(void *data, struct wl_output *wl_output)
   Fl_Wayland_Screen_Driver *scr_driver = (Fl_Wayland_Screen_Driver*)Fl::screen_driver();
   if (scr_driver->screen_count_get() > 0) { // true when output_done runs after initial screen dectection
     scr_driver->screen_count_set( wl_list_length(&(scr_driver->outputs)) );
-    int Wfullscreen, Hfullscreen, Wworkarea, Hworkarea;
-    compute_full_and_maximized_areas(output, Wfullscreen, Hfullscreen, Wworkarea, Hworkarea);
-    if (Wfullscreen && Hfullscreen) {
-      output->width = Wfullscreen * output->wld_scale; // pixels
-      output->height = Hfullscreen * output->wld_scale; // pixels
-    }
-    Fl::handle(FL_SCREEN_CONFIGURATION_CHANGED, NULL);
+    scr_driver->init_workarea();
   }
 }
 
@@ -1290,7 +1279,11 @@ static void registry_handle_global(void *user_data, struct wl_registry *wl_regis
     wl_list_for_each(elt, &scr_driver->outputs, link) {
       if (elt == output) found = true;
     }
-    if (!found) wl_list_insert(&(scr_driver->outputs), &output->link);
+    if (!found) { // add to end of the linked list of displays
+      struct wl_list *e = &scr_driver->outputs;
+      while (e->next != &scr_driver->outputs) e = e->next; // move e to end of linked list
+      wl_list_insert(e, &output->link);
+    }
 //fprintf(stderr, "wl_output: id=%d wl_output=%p \n", id, output->wl_output);
 
   } else if (strcmp(interface, xdg_wm_base_interface.name) == 0) {
@@ -1333,25 +1326,12 @@ static void registry_handle_global(void *user_data, struct wl_registry *wl_regis
 
 
 static void registry_handle_global_remove(void *data, struct wl_registry *registry, uint32_t name) {
-  Fl_Wayland_Screen_Driver::output *output, *tmp;
+  Fl_Wayland_Screen_Driver::output *output;
 //fprintf(stderr, "registry_handle_global_remove data=%p id=%u\n", data, name);
   Fl_Wayland_Screen_Driver *scr_driver = (Fl_Wayland_Screen_Driver*)Fl::screen_driver();
   bool has_removed_screen = false;
-  wl_list_for_each_safe(output, tmp, &(scr_driver->outputs), link) { // all screens
+  wl_list_for_each(output, &(scr_driver->outputs), link) { // all screens
     if (output->id == name) { // the screen being removed
-      again:
-      Fl_X *xp = Fl_X::first;
-      while (xp) { // all mapped windows
-        struct wld_window *win = (struct wld_window*)xp->xid;
-        struct Fl_Wayland_Window_Driver::surface_output *s_output;
-        wl_list_for_each(s_output, &win->outputs, link) {
-          if (output == s_output->output) {
-            delete win->fl_win;
-            goto again;
-          }
-      }
-        xp = xp->next;
-      }
       wl_list_remove(&output->link);
       wl_output_destroy(output->wl_output);
       free(output);
diff --git a/src/drivers/Wayland/Fl_Wayland_Window_Driver.cxx b/src/drivers/Wayland/Fl_Wayland_Window_Driver.cxx
index 75d3f05b7..8e12091ba 100644
--- a/src/drivers/Wayland/Fl_Wayland_Window_Driver.cxx
+++ b/src/drivers/Wayland/Fl_Wayland_Window_Driver.cxx
@@ -658,6 +658,14 @@ static struct libdecor_interface libdecor_iface = {
 };
 
 
+
+static void delayed_rescale(Fl_Window *win) {
+  Fl_Window_Driver::driver(win)->is_a_rescale(true);
+  win->size(win->w(), win->h());
+  Fl_Window_Driver::driver(win)->is_a_rescale(false);
+}
+
+
 void change_scale(Fl_Wayland_Screen_Driver::output *output, struct wld_window *window,
                   float pre_scale) {
   Fl_Wayland_Window_Driver *win_driver = Fl_Wayland_Window_Driver::driver(window->fl_win);
@@ -681,9 +689,8 @@ void change_scale(Fl_Wayland_Screen_Driver::output *output, struct wld_window *w
       Fl_Wayland_Graphics_Driver::buffer_release(window);
       window->fl_win->redraw();
     } else {
-      win_driver->is_a_rescale(true);
-      window->fl_win->size(window->fl_win->w(), window->fl_win->h());
-      win_driver->is_a_rescale(false);
+      // delaying the rescaling is necessary to set first the window's size_range according to the new screen
+      Fl::add_timeout(0, (Fl_Timeout_Handler)delayed_rescale, window->fl_win);
     }
   }
   if (window->fl_win->as_gl_window())
@@ -715,7 +722,7 @@ static void surface_enter(void *data, struct wl_surface *wl_surface,
   while (e->next != &window->outputs) e = e->next; // move e to end of linked list
   wl_list_insert(e, &surface_output->link);
 //printf("window %p enters screen id=%d length=%d\n", window->fl_win, output->id, wl_list_length(&window->outputs));
-  if (list_was_empty) {
+  if (list_was_empty && !window->fl_win->parent()) {
     change_scale(output, window, pre_scale);
   }
 }
@@ -741,7 +748,7 @@ static void surface_leave(void *data, struct wl_surface *wl_surface,
       break;
     }
   }
-  if (count == 1 && !wl_list_empty(&window->outputs)) {
+  if (count == 1 && !wl_list_empty(&window->outputs) && !window->fl_win->parent()) {
     s_output = wl_container_of(window->outputs.next, s_output, link);
     change_scale(s_output->output, window, pre_scale);
   }
@@ -1353,11 +1360,11 @@ bool Fl_Wayland_Window_Driver::process_menu_or_tooltip(struct wld_window *new_wi
     // results in tall popup windows starting at the top of the screen, what we want.
     // Unfortunately, we know the work area height exactly only for single-screen systems,
     // otherwise FLTK returns work area height == screen height. In that case we estimate
-    // work area height ≈ screen height - 40.
+    // work area height ≈ screen height - 44.
     int V, work_area_H, screen_H;
     Fl::screen_work_area(V, V, V, work_area_H, origin_win->screen_num());
     Fl::screen_xywh(V, V, V, screen_H, origin_win->screen_num());
-    if (work_area_H == screen_H) work_area_H -= 40;
+    if (work_area_H == screen_H) work_area_H -= 44;
     if (positioner_H > work_area_H) positioner_H = work_area_H;
   }
   xdg_positioner_set_size(positioner, pWindow->w() * f , positioner_H * f );