overlay: Add GtkOverlay::measure child property

It determines whether a child is included in the overlay's size
measurement.

The first user is (gonna be) GtkVideo.

3 files changed, 130 insertions, 1 deletions

diff --git a/docs/reference/gtk/gtk4-sections.txt b/docs/reference/gtk/gtk4-sections.txt
index 7ced016fcb..39bcade5e6 100644
--- a/docs/reference/gtk/gtk4-sections.txt
+++ b/docs/reference/gtk/gtk4-sections.txt
@@ -5969,6 +5969,8 @@ gtk_overlay_add_overlay
 gtk_overlay_reorder_overlay
 gtk_overlay_get_overlay_pass_through
 gtk_overlay_set_overlay_pass_through
+gtk_overlay_get_measure_overlay
+gtk_overlay_set_measure_overlay
 
 <SUBSECTION Standard>
 GTK_TYPE_OVERLAY
diff --git a/gtk/gtkoverlay.c b/gtk/gtkoverlay.c
index 5d069e359c..3dc65aca77 100644
--- a/gtk/gtkoverlay.c
+++ b/gtk/gtkoverlay.c
@@ -64,7 +64,8 @@ typedef struct _GtkOverlayChild GtkOverlayChild;
 
 struct _GtkOverlayChild
 {
-  guint pass_through: 1;
+  guint pass_through : 1;
+  guint measure : 1;
   double blur;
 };
 
@@ -77,6 +78,7 @@ enum
 {
   CHILD_PROP_0,
   CHILD_PROP_PASS_THROUGH,
+  CHILD_PROP_MEASURE,
   CHILD_PROP_BLUR,
   CHILD_PROP_INDEX
 };
@@ -104,6 +106,43 @@ gtk_overlay_get_overlay_child (GtkWidget *widget)
 }
 
 static void
+gtk_overlay_measure (GtkWidget      *widget,
+                     GtkOrientation  orientation,
+                     int             for_size,
+                     int            *minimum,
+                     int            *natural,
+                     int            *minimum_baseline,
+                     int            *natural_baseline)
+{
+  GtkWidget *child;
+
+  for (child = gtk_widget_get_first_child (widget);
+       child != NULL;
+       child = gtk_widget_get_next_sibling (child))
+    {
+      GtkOverlayChild *child_data = gtk_overlay_get_overlay_child (child);
+
+      if (child_data == NULL || child_data->measure)
+        {
+          int child_min, child_nat, child_min_baseline, child_nat_baseline;
+
+          gtk_widget_measure (child,
+                              orientation,
+                              for_size,
+                              &child_min, &child_nat,
+                              &child_min_baseline, &child_nat_baseline);
+
+          *minimum = MAX (*minimum, child_min);
+          *natural = MAX (*natural, child_nat);
+          if (child_min_baseline > -1)
+            *minimum_baseline = MAX (*minimum_baseline, child_min_baseline);
+          if (child_nat_baseline > -1)
+            *natural_baseline = MAX (*natural_baseline, child_nat_baseline);
+        }
+    }
+}
+
+static void
 gtk_overlay_compute_child_allocation (GtkOverlay      *overlay,
                                       GtkWidget       *widget,
                                       GtkOverlayChild *child,
@@ -509,6 +548,17 @@ gtk_overlay_set_child_property (GtkContainer *container,
 	    }
 	}
       break;
+    case CHILD_PROP_MEASURE:
+      if (child_info)
+	{
+	  if (g_value_get_boolean (value) != child_info->measure)
+	    {
+	      child_info->measure = g_value_get_boolean (value);
+	      gtk_container_child_notify (container, child, "measure");
+              gtk_widget_queue_resize (GTK_WIDGET (overlay));
+	    }
+	}
+      break;
     case CHILD_PROP_BLUR:
       if (child_info)
 	{
@@ -567,6 +617,12 @@ gtk_overlay_get_child_property (GtkContainer *container,
       else
 	g_value_set_boolean (value, FALSE);
       break;
+    case CHILD_PROP_MEASURE:
+      if (child_info)
+	g_value_set_boolean (value, child_info->measure);
+      else
+	g_value_set_boolean (value, TRUE);
+      break;
     case CHILD_PROP_BLUR:
       if (child_info)
 	g_value_set_double (value, child_info->blur);
@@ -690,6 +746,7 @@ gtk_overlay_class_init (GtkOverlayClass *klass)
   GtkWidgetClass *widget_class = GTK_WIDGET_CLASS (klass);
   GtkContainerClass *container_class = GTK_CONTAINER_CLASS (klass);
 
+  widget_class->measure = gtk_overlay_measure;
   widget_class->size_allocate = gtk_overlay_size_allocate;
   widget_class->snapshot = gtk_overlay_snapshot;
 
@@ -712,6 +769,18 @@ gtk_overlay_class_init (GtkOverlayClass *klass)
                             GTK_PARAM_READWRITE));
 
   /**
+   * GtkOverlay:measure:
+   *
+   * Include this child in determining the child request.
+   *
+   * The main child will always be measured.
+   */
+  gtk_container_class_install_child_property (container_class, CHILD_PROP_MEASURE,
+      g_param_spec_boolean ("measure", P_("Measure"), P_("Include in size measurement"),
+                            FALSE,
+                            GTK_PARAM_READWRITE));
+
+  /**
    * GtkOverlay:blur:
    *
    * Blur the content behind this child with a Gaussian blur of this radius.
@@ -891,3 +960,54 @@ gtk_overlay_get_overlay_pass_through (GtkOverlay *overlay,
 
   return pass_through;
 }
+
+/**
+ * gtk_overlay_set_measure_overlay:
+ * @overlay: a #GtkOverlay
+ * @widget: an overlay child of #GtkOverlay
+ * @measure: whether the child should be measured
+ *
+ * Sets whether @widget is included in the measured size of @overlay.
+ *
+ * The overlay will request the size of the largest child that has
+ * this property set to %TRUE. Children who are not included may
+ * be drawn outside of @overlay's allocation if they are too large.
+ */
+void
+gtk_overlay_set_measure_overlay (GtkOverlay *overlay,
+				 GtkWidget  *widget,
+				 gboolean    measure)
+{
+  g_return_if_fail (GTK_IS_OVERLAY (overlay));
+  g_return_if_fail (GTK_IS_WIDGET (widget));
+
+  gtk_container_child_set (GTK_CONTAINER (overlay), widget,
+			   "measure", measure,
+			   NULL);
+}
+
+/**
+ * gtk_overlay_get_measure_overlay:
+ * @overlay: a #GtkOverlay
+ * @widget: an overlay child of #GtkOverlay
+ *
+ * Gets whether @widget's size is included in the measurement of
+ * @overlay.
+ *
+ * Returns: whether the widget is measured
+ */
+gboolean
+gtk_overlay_get_measure_overlay (GtkOverlay *overlay,
+				 GtkWidget  *widget)
+{
+  gboolean measure;
+
+  g_return_val_if_fail (GTK_IS_OVERLAY (overlay), FALSE);
+  g_return_val_if_fail (GTK_IS_WIDGET (widget), FALSE);
+
+  gtk_container_child_get (GTK_CONTAINER (overlay), widget,
+			   "measure", &measure,
+			   NULL);
+
+  return measure;
+}
diff --git a/gtk/gtkoverlay.h b/gtk/gtkoverlay.h
index e59a3926a0..0cd3aa891a 100644
--- a/gtk/gtkoverlay.h
+++ b/gtk/gtkoverlay.h
@@ -92,6 +92,13 @@ GDK_AVAILABLE_IN_ALL
 void       gtk_overlay_set_overlay_pass_through (GtkOverlay *overlay,
 						 GtkWidget  *widget,
 						 gboolean    pass_through);
+GDK_AVAILABLE_IN_ALL
+gboolean   gtk_overlay_get_measure_overlay (GtkOverlay *overlay,
+					    GtkWidget  *widget);
+GDK_AVAILABLE_IN_ALL
+void       gtk_overlay_set_measure_overlay (GtkOverlay *overlay,
+					    GtkWidget  *widget,
+					    gboolean    measure);
 
 G_END_DECLS