properly hide top border inside tabbed/stacked

When titlebar is hidden, top border of the topmost view inside
tabbed/stacked container will not be drawn. This is changed in layout.c

On the other hand, top border should be drawn sometimes, for example
when titlebar is hidden on a view that is not the topmost inside
tabbed/stacked container. This is changed in border.c

3 files changed, 20 insertions, 3 deletions

diff --git a/include/border.h b/include/border.h
index eb7fc656..b629ba46 100644
--- a/include/border.h
+++ b/include/border.h
@@ -20,5 +20,6 @@ void render_view_borders(wlc_handle view);
 void update_view_border(swayc_t *view);
 void map_update_view_border(swayc_t *view, void *data);
 int get_font_text_height(const char *font);
+bool should_hide_top_border(swayc_t *con, double y);
 
 #endif
diff --git a/sway/border.c b/sway/border.c
index d17d8d0c..c1a62bc6 100644
--- a/sway/border.c
+++ b/sway/border.c
@@ -332,10 +332,12 @@ void update_view_border(swayc_t *view) {
                         }
                 };
                 cr = create_border_buffer(view, g, &surface);
+
+                bool render_top = !should_hide_top_border(view, view->y);
                 if (view == focused) {
-                        render_borders(view, cr, &config->border_colors.focused, false);
+                        render_borders(view, cr, &config->border_colors.focused, render_top);
                 } else {
-                        render_borders(view, cr, &config->border_colors.focused_inactive, false);
+                        render_borders(view, cr, &config->border_colors.focused_inactive, render_top);
                 }
 
                 // generate container titles
@@ -418,3 +420,17 @@ void render_view_borders(wlc_handle view) {
                 wlc_pixels_write(WLC_RGBA8888, &c->border->geometry, c->border->buffer);
         }
 }
+
+bool should_hide_top_border(swayc_t *con, double y) {
+        // returns true if container is child of tabbed/stacked layout and is
+        // sharing top border with tabbed titlebar
+        swayc_t *par = con->parent;
+        while (par->type != C_WORKSPACE) {
+                if (par->layout == L_TABBED || par->layout == L_STACKED) {
+                        return con->y == y;
+                }
+                con = par;
+                par = par->parent;
+        }
+        return false;
+}
diff --git a/sway/layout.c b/sway/layout.c
index db9787f3..ba9a8864 100644
--- a/sway/layout.c
+++ b/sway/layout.c
@@ -587,7 +587,7 @@ void update_geometry(swayc_t *container) {
                         }
 
                         if (config->hide_edge_borders == E_VERTICAL || config->hide_edge_borders == E_BOTH) {
-                                if (geometry.origin.y == workspace->y) {
+                                if (geometry.origin.y == workspace->y || should_hide_top_border(container, geometry.origin.y)) {
                                         border_top = 0;
                                 }