title-bar: Respect CSS min-width and min-height

src/hdy-title-bar.c

@@ -164,6 +164,106 @@ hdy_title_bar_draw (GtkWidget *widget,
   return GTK_WIDGET_CLASS (hdy_title_bar_parent_class)->draw (widget, cr);
 }
 
+/* This private method is prefixed by the class name because it will be a
+ * virtual method in GTK 4.
+ */
+static void
+hdy_title_bar_measure (GtkWidget      *widget,
+                       GtkOrientation  orientation,
+                       gint            for_size,
+                       gint           *minimum,
+                       gint           *natural,
+                       gint           *minimum_baseline,
+                       gint           *natural_baseline)
+{
+  GtkWidget *child;
+  gint parent_min, parent_nat;
+  gint css_width, css_height, css_min;
+
+  child = gtk_bin_get_child (GTK_BIN (widget));
+
+  gtk_style_context_get (gtk_widget_get_style_context (widget),
+                         gtk_widget_get_state_flags (widget),
+                         "min-width", &css_width,
+                         "min-height", &css_height,
+                         NULL);
+
+  if (orientation == GTK_ORIENTATION_HORIZONTAL)
+    css_min = css_width;
+  else
+    css_min = css_height;
+
+  if (child)
+    if (orientation == GTK_ORIENTATION_HORIZONTAL)
+      if (for_size != 1)
+        gtk_widget_get_preferred_width_for_height (child,
+                                                   MAX (for_size, css_height),
+                                                   &parent_min, &parent_nat);
+      else
+        gtk_widget_get_preferred_width (child, &parent_min, &parent_nat);
+    else
+      if (for_size != 1)
+        gtk_widget_get_preferred_height_for_width (child,
+                                                   MAX (for_size, css_width),
+                                                   &parent_min, &parent_nat);
+      else
+        gtk_widget_get_preferred_height (child, &parent_min, &parent_nat);
+  else {
+    parent_min = 0;
+    parent_nat = 0;
+  }
+
+  if (minimum)
+    *natural = MAX (parent_min, css_min);
+
+  if (minimum)
+    *natural = MAX (parent_nat, css_min);
+
+  if (minimum_baseline)
+    *minimum_baseline = -1;
+
+  if (natural_baseline)
+    *natural_baseline = -1;
+}
+
+static void
+hdy_title_bar_get_preferred_width (GtkWidget *widget,
+                                   gint      *minimum,
+                                   gint      *natural)
+{
+  hdy_title_bar_measure (widget, GTK_ORIENTATION_HORIZONTAL, -1,
+                         minimum, natural, NULL, NULL);
+}
+
+static void
+hdy_title_bar_get_preferred_width_for_height (GtkWidget *widget,
+                                              gint       height,
+                                              gint      *minimum,
+                                              gint      *natural)
+{
+  hdy_title_bar_measure (widget, GTK_ORIENTATION_HORIZONTAL, height,
+                         minimum, natural, NULL, NULL);
+}
+
+static void
+hdy_title_bar_get_preferred_height (GtkWidget *widget,
+                                    gint      *minimum,
+                                    gint      *natural)
+{
+  hdy_title_bar_measure (widget, GTK_ORIENTATION_VERTICAL, -1,
+                         minimum, natural, NULL, NULL);
+}
+
+static void
+hdy_title_bar_get_preferred_height_for_width (GtkWidget *widget,
+                                              gint       width,
+                                              gint      *minimum,
+                                              gint      *natural)
+{
+  hdy_title_bar_measure (widget, GTK_ORIENTATION_VERTICAL, width,
+                         minimum, natural, NULL, NULL);
+}
+
 static void
 hdy_title_bar_size_allocate (GtkWidget     *widget,
                              GtkAllocation *allocation)
@@ -192,6 +292,10 @@ hdy_title_bar_class_init (HdyTitleBarClass *klass)
   object_class->set_property = hdy_title_bar_set_property;
 
   widget_class->draw = hdy_title_bar_draw;
+  widget_class->get_preferred_width = hdy_title_bar_get_preferred_width;
+  widget_class->get_preferred_width_for_height = hdy_title_bar_get_preferred_width_for_height;
+  widget_class->get_preferred_height = hdy_title_bar_get_preferred_height;
+  widget_class->get_preferred_height_for_width = hdy_title_bar_get_preferred_height_for_width;
   widget_class->size_allocate = hdy_title_bar_size_allocate;
 
   /**