Fix border/margin/padding sizes not being recalculated on DPI change

Fixes #2346
Fixes #2347

docs/changelog.rst

@@ -28,6 +28,9 @@ To update |kitty|, :doc:`follow the instructions <binary>`.
 - Fix a bug that prevented using custom functions with the new marks feature
   (:iss:`2344`)
 
+- Fix border/margin/padding sizes not being recalculated on DPI change
+  (:iss:`2346`)
+
 
 0.16.0 [2020-01-28]
 --------------------

kitty/borders.py

@@ -48,11 +48,9 @@ def load_borders_program():
 
 class Borders:
 
-    def __init__(self, os_window_id, tab_id, opts, border_width, padding_width):
+    def __init__(self, os_window_id, tab_id, opts):
         self.os_window_id = os_window_id
         self.tab_id = tab_id
-        self.border_width = border_width
-        self.padding_width = padding_width
         self.draw_active_borders = opts.active_border_color is not None
 
     def __call__(
@@ -61,6 +59,8 @@ class Borders:
         active_window,
         current_layout,
         extra_blank_rects,
+        padding_width,
+        border_width,
         draw_window_borders=True,
     ):
         add_borders_rect(self.os_window_id, self.tab_id, 0, 0, 0, 0, BorderColor.default_bg)
@@ -68,7 +68,7 @@ class Borders:
         if not has_background_image:
             for br in chain(current_layout.blank_rects, extra_blank_rects):
                 add_borders_rect(self.os_window_id, self.tab_id, *br, BorderColor.default_bg)
-        bw, pw = self.border_width, self.padding_width
+        bw, pw = border_width, padding_width
         if bw + pw <= 0:
             return
         draw_borders = bw > 0 and draw_window_borders

kitty/boss.py

@@ -484,6 +484,7 @@ class Boss:
             sz = os_window_font_size(os_window_id)
             if sz:
                 os_window_font_size(os_window_id, sz, True)
+                tm.update_dpi_based_sizes()
                 tm.resize()
 
     def _set_os_window_background_opacity(self, os_window_id, opacity):

kitty/layout.py

@@ -180,6 +180,12 @@ class Layout:  # {{{
         self.full_name = self.name + ((':' + layout_opts) if layout_opts else '')
         self.remove_all_biases()
 
+    def update_sizes(self, margin_width, single_window_margin_width, padding_width, border_width):
+        self.border_width = border_width
+        self.margin_width = margin_width
+        self.single_window_margin_width = single_window_margin_width
+        self.padding_width = padding_width
+
     def bias_increment_for_cell(self, is_horizontal):
         self._set_dimensions()
         if is_horizontal:

kitty/tabs.py

@@ -46,12 +46,10 @@ class Tab:  # {{{
         if not self.id:
             raise Exception('No OS window with id {} found, or tab counter has wrapped'.format(self.os_window_id))
         self.opts, self.args = tab_manager.opts, tab_manager.args
-        self.margin_width, self.padding_width, self.single_window_margin_width = map(
+        self.recalculate_sizes(update_layout=False)
-            lambda x: pt_to_px(getattr(self.opts, x), self.os_window_id), (
-                'window_margin_width', 'window_padding_width', 'single_window_margin_width'))
         self.name = getattr(session_tab, 'name', '')
         self.enabled_layouts = [x.lower() for x in getattr(session_tab, 'enabled_layouts', None) or self.opts.enabled_layouts]
-        self.borders = Borders(self.os_window_id, self.id, self.opts, pt_to_px(self.opts.window_border_width, self.os_window_id), self.padding_width)
+        self.borders = Borders(self.os_window_id, self.id, self.opts)
         self.windows = deque()
         for i, which in enumerate('first second third fourth fifth sixth seventh eighth ninth tenth'.split()):
             setattr(self, which + '_window', partial(self.nth_window, num=i))
@@ -73,6 +71,15 @@ class Tab:  # {{{
             self._set_current_layout(l0)
             self.startup(session_tab)
 
+    def recalculate_sizes(self, update_layout=True):
+        self.margin_width, self.padding_width, self.single_window_margin_width = map(
+            lambda x: pt_to_px(getattr(self.opts, x), self.os_window_id), (
+                'window_margin_width', 'window_padding_width', 'single_window_margin_width'))
+        self.border_width = pt_to_px(self.opts.window_border_width, self.os_window_id)
+        if update_layout and self.current_layout:
+            self.current_layout.update_sizes(
+                self.margin_width, self.single_window_margin_width, self.padding_width, self.border_width)
+
     def take_over_from(self, other_tab):
         self.name, self.cwd = other_tab.name, other_tab.cwd
         self.enabled_layouts = list(other_tab.enabled_layouts)
@@ -176,8 +183,12 @@ class Tab:  # {{{
         if tm is not None:
             visible_windows = [w for w in self.windows if w.is_visible_in_layout]
             w = self.active_window
-            self.borders(visible_windows, w, self.current_layout,
+            self.borders(
-                         tm.blank_rects, self.current_layout.needs_window_borders and len(visible_windows) > 1)
+                windows=visible_windows, active_window=w,
+                current_layout=self.current_layout, extra_blank_rects=tm.blank_rects,
+                padding_width=self.padding_width, border_width=self.border_width,
+                draw_window_borders=self.current_layout.needs_window_borders and len(visible_windows) > 1
+            )
             if w is not None:
                 w.change_titlebar_color()
 
@@ -185,7 +196,7 @@ class Tab:  # {{{
         return create_layout_object_for(
             name, self.os_window_id, self.id, self.margin_width,
             self.single_window_margin_width, self.padding_width,
-            self.borders.border_width)
+            self.border_width)
 
     def next_layout(self):
         if len(self.enabled_layouts) > 1:
@@ -542,6 +553,10 @@ class TabManager:  # {{{
     def update_tab_bar_data(self):
         self.tab_bar.update(self.tab_bar_data)
 
+    def update_dpi_based_sizes(self):
+        for tab in self.tabs:
+            tab.recalculate_sizes()
+
     def resize(self, only_tabs=False):
         if not only_tabs:
             if not self.tab_bar_hidden: