scrolledwindow: add ::max-content-width and -height properties

The GtkScrolledWindow has support to set the minimum content size (both
width and height) which controls the minimum space allocated, but does
not exposes any way to control the maximum size the content can grow.

After the introduction of GtkPopover, which always uses the minimum
size of it's children widgets, the lack of max-content-width and -height
properties became a concrete use case.

This patch introduces the GtkScrolledWindow::max-content-width and
-height properties. The properties will alter the minimum size of
the scrolled window, making it grow up to the set value. They also
respect the previously set ::min-content-width and -height.

https://bugzilla.gnome.org/show_bug.cgi?id=742281

2 files changed, 201 insertions, 0 deletions

diff --git a/gtk/gtkscrolledwindow.c b/gtk/gtkscrolledwindow.c
index 8f5354b6a2..994ee7b377 100644
--- a/gtk/gtkscrolledwindow.c
+++ b/gtk/gtkscrolledwindow.c
@@ -232,6 +232,8 @@ struct _GtkScrolledWindowPrivate
 
   gint     min_content_width;
   gint     min_content_height;
+  gint     max_content_width;
+  gint     max_content_height;
 
   guint scroll_events_overshoot_id;
 
@@ -287,6 +289,8 @@ enum {
   PROP_MIN_CONTENT_HEIGHT,
   PROP_KINETIC_SCROLLING,
   PROP_OVERLAY_SCROLLING,
+  PROP_MAX_CONTENT_WIDTH,
+  PROP_MAX_CONTENT_HEIGHT,
   NUM_PROPERTIES
 };
 
@@ -692,6 +696,34 @@ gtk_scrolled_window_class_init (GtkScrolledWindowClass *class)
                             TRUE,
                             GTK_PARAM_READWRITE|G_PARAM_EXPLICIT_NOTIFY);
 
+  /**
+   * GtkScrolledWindow:max-content-width:
+   *
+   * The maximum content width of @scrolled_window, or -1 if not set.
+   *
+   * Since: 3.22
+   */
+  properties[PROP_MAX_CONTENT_WIDTH] =
+      g_param_spec_int ("max-content-width",
+                        P_("Maximum Content Width"),
+                        P_("The maximum width that the scrolled window will allocate to its content"),
+                        -1, G_MAXINT, -1,
+                        GTK_PARAM_READWRITE|G_PARAM_EXPLICIT_NOTIFY);
+
+  /**
+   * GtkScrolledWindow:max-content-height:
+   *
+   * The maximum content height of @scrolled_window, or -1 if not set.
+   *
+   * Since: 3.22
+   */
+  properties[PROP_MAX_CONTENT_HEIGHT] =
+      g_param_spec_int ("max-content-height",
+                        P_("Maximum Content Height"),
+                        P_("The maximum height that the scrolled window will allocate to its content"),
+                        -1, G_MAXINT, -1,
+                        GTK_PARAM_READWRITE|G_PARAM_EXPLICIT_NOTIFY);
+
   g_object_class_install_properties (gobject_class, NUM_PROPERTIES, properties);
 
   /**
@@ -1765,6 +1797,20 @@ gtk_scrolled_window_measure (GtkCssGadget   *gadget,
 		  minimum_req.width += vscrollbar_requisition.width;
 		  natural_req.width += vscrollbar_requisition.width;
 		}
+
+              if (priv->max_content_width > -1 &&
+                  priv->max_content_width > natural_req.width &&
+                  nat_child_size > natural_req.width)
+                {
+                  gint width = MIN (priv->max_content_width, min_child_size);
+
+                  /* The maximum content width must respect the minimum content width.
+                   * It'll grow at least until min_content_width, and at most until
+                   * max_content_width.
+                  */
+                  minimum_req.width = MAX (minimum_req.width, width);
+                  natural_req.width = MAX (natural_req.width, width);
+                }
 	    }
 	}
       else /* GTK_ORIENTATION_VERTICAL */
@@ -1791,6 +1837,20 @@ gtk_scrolled_window_measure (GtkCssGadget   *gadget,
 		  minimum_req.height += hscrollbar_requisition.height;
 		  natural_req.height += hscrollbar_requisition.height;
 		}
+
+              if (priv->max_content_height > -1 &&
+                  priv->max_content_height > natural_req.height &&
+                  nat_child_size > natural_req.height)
+                {
+                  gint height = MIN (priv->max_content_height, min_child_size);
+
+                  /* The maximum content height must respect the minimum content height.
+                   * It'll grow at least until min_content_height, and at most until
+                   * max_content_height.
+                   */
+                  minimum_req.height = MAX (minimum_req.height, height);
+                  natural_req.height = MAX (natural_req.height, height);
+                }
 	    }
 	}
     }
@@ -2038,6 +2098,8 @@ gtk_scrolled_window_init (GtkScrolledWindow *scrolled_window)
   priv->window_placement = GTK_CORNER_TOP_LEFT;
   priv->min_content_width = -1;
   priv->min_content_height = -1;
+  priv->max_content_width = -1;
+  priv->max_content_height = -1;
 
   priv->overlay_scrolling = TRUE;
 
@@ -2779,6 +2841,14 @@ gtk_scrolled_window_set_property (GObject      *object,
       gtk_scrolled_window_set_overlay_scrolling (scrolled_window,
                                                  g_value_get_boolean (value));
       break;
+    case PROP_MAX_CONTENT_WIDTH:
+      gtk_scrolled_window_set_max_content_width (scrolled_window,
+                                                 g_value_get_int (value));
+      break;
+    case PROP_MAX_CONTENT_HEIGHT:
+      gtk_scrolled_window_set_max_content_height (scrolled_window,
+                                                  g_value_get_int (value));
+      break;
     default:
       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
       break;
@@ -2831,6 +2901,12 @@ gtk_scrolled_window_get_property (GObject    *object,
     case PROP_OVERLAY_SCROLLING:
       g_value_set_boolean (value, priv->overlay_scrolling);
       break;
+    case PROP_MAX_CONTENT_WIDTH:
+      g_value_set_int (value, priv->max_content_width);
+      break;
+    case PROP_MAX_CONTENT_HEIGHT:
+      g_value_set_int (value, priv->max_content_height);
+      break;
     default:
       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
       break;
@@ -4384,6 +4460,9 @@ gtk_scrolled_window_get_min_content_width (GtkScrolledWindow *scrolled_window)
  * Note that this can and (usually will) be smaller than the minimum
  * size of the content.
  *
+ * It is a programming error to set the minimum content width to a
+ * value smaller than #GtkScrolledWindow:max-content-width.
+ *
  * Since: 3.0
  */
 void
@@ -4396,6 +4475,8 @@ gtk_scrolled_window_set_min_content_width (GtkScrolledWindow *scrolled_window,
 
   priv = scrolled_window->priv;
 
+  g_return_if_fail (priv->max_content_width == -1 || width <= priv->max_content_width);
+
   if (priv->min_content_width != width)
     {
       priv->min_content_width = width;
@@ -4433,6 +4514,9 @@ gtk_scrolled_window_get_min_content_height (GtkScrolledWindow *scrolled_window)
  * Note that this can and (usually will) be smaller than the minimum
  * size of the content.
  *
+ * It is a programming error to set the minimum content height to a
+ * value smaller than #GtkScrolledWindow:max-content-height.
+ *
  * Since: 3.0
  */
 void
@@ -4445,6 +4529,8 @@ gtk_scrolled_window_set_min_content_height (GtkScrolledWindow *scrolled_window,
 
   priv = scrolled_window->priv;
 
+  g_return_if_fail (priv->max_content_height == -1 || height <= priv->max_content_height);
+
   if (priv->min_content_height != height)
     {
       priv->min_content_height = height;
@@ -4502,3 +4588,107 @@ gtk_scrolled_window_get_overlay_scrolling (GtkScrolledWindow *scrolled_window)
 
   return scrolled_window->priv->overlay_scrolling;
 }
+
+/**
+ * gtk_scrolled_window_set_max_content_width:
+ * @scrolled_window: a #GtkScrolledWindow
+ * @width: the maximum content width
+ *
+ * Sets the maximum width that @scrolled_window should keep visible. The
+ * @scrolled_window will grow up to this width before it starts scrolling
+ * the content.
+ *
+ * It is a programming error to set the maximum content width to a value
+ * smaller than #GtkScrolledWindow:min-content-width.
+ *
+ * Since: 3.22
+ */
+void
+gtk_scrolled_window_set_max_content_width (GtkScrolledWindow *scrolled_window,
+                                           gint               width)
+{
+  GtkScrolledWindowPrivate *priv;
+
+  g_return_if_fail (GTK_IS_SCROLLED_WINDOW (scrolled_window));
+
+  priv = scrolled_window->priv;
+
+  g_return_if_fail (priv->min_content_width == -1 || width >= priv->min_content_width);
+
+  if (width != priv->max_content_width)
+    {
+      priv->max_content_width = width;
+      g_object_notify_by_pspec (G_OBJECT (scrolled_window), properties [PROP_MAX_CONTENT_WIDTH]);
+      gtk_widget_queue_resize (GTK_WIDGET (scrolled_window));
+    }
+}
+
+/**
+ * gtk_scrolled_window_get_max_content_width:
+ * @scrolled_window: a #GtkScrolledWindow
+ *
+ * Returns the maximum content width set.
+ *
+ * Returns: the maximum content width, or -1
+ *
+ * Since: 3.22
+ */
+gint
+gtk_scrolled_window_get_max_content_width (GtkScrolledWindow *scrolled_window)
+{
+  g_return_val_if_fail (GTK_IS_SCROLLED_WINDOW (scrolled_window), -1);
+
+  return scrolled_window->priv->max_content_width;
+}
+
+/**
+ * gtk_scrolled_window_set_max_content_height:
+ * @scrolled_window: a #GtkScrolledWindow
+ * @height: the maximum content height
+ *
+ * Sets the maximum height that @scrolled_window should keep visible. The
+ * @scrolled_window will grow up to this width before it starts scrolling
+ * the content.
+ *
+ * It is a programming error to set the maximum content height to a value
+ * smaller than #GtkScrolledWindow:min-content-height.
+ *
+ * Since: 3.22
+ */
+void
+gtk_scrolled_window_set_max_content_height (GtkScrolledWindow *scrolled_window,
+                                            gint               height)
+{
+  GtkScrolledWindowPrivate *priv;
+
+  g_return_if_fail (GTK_IS_SCROLLED_WINDOW (scrolled_window));
+
+  priv = scrolled_window->priv;
+
+  g_return_if_fail (priv->min_content_height == -1 || height >= priv->min_content_height);
+
+  if (height != priv->max_content_height)
+    {
+      priv->max_content_height = height;
+      g_object_notify_by_pspec (G_OBJECT (scrolled_window), properties [PROP_MAX_CONTENT_HEIGHT]);
+      gtk_widget_queue_resize (GTK_WIDGET (scrolled_window));
+    }
+}
+
+/**
+ * gtk_scrolled_window_get_max_content_height:
+ * @scrolled_window: a #GtkScrolledWindow
+ *
+ * Returns the maximum content height set.
+ *
+ * Returns: the maximum content height, or -1
+ *
+ * Since: 3.22
+ */
+gint
+gtk_scrolled_window_get_max_content_height (GtkScrolledWindow *scrolled_window)
+{
+  g_return_val_if_fail (GTK_IS_SCROLLED_WINDOW (scrolled_window), -1);
+
+  return scrolled_window->priv->max_content_height;
+}
diff --git a/gtk/gtkscrolledwindow.h b/gtk/gtkscrolledwindow.h
index 1a9e4d5133..0aca3ad370 100644
--- a/gtk/gtkscrolledwindow.h
+++ b/gtk/gtkscrolledwindow.h
@@ -214,6 +214,17 @@ void           gtk_scrolled_window_set_overlay_scrolling  (GtkScrolledWindow *sc
 GDK_AVAILABLE_IN_3_16
 gboolean       gtk_scrolled_window_get_overlay_scrolling (GtkScrolledWindow   *scrolled_window);
 
+GDK_AVAILABLE_IN_3_22
+void           gtk_scrolled_window_set_max_content_width  (GtkScrolledWindow *scrolled_window,
+                                                           gint               width);
+GDK_AVAILABLE_IN_3_22
+gint           gtk_scrolled_window_get_max_content_width  (GtkScrolledWindow *scrolled_window);
+
+GDK_AVAILABLE_IN_3_22
+void           gtk_scrolled_window_set_max_content_height (GtkScrolledWindow *scrolled_window,
+                                                           gint               height);
+GDK_AVAILABLE_IN_3_22
+gint           gtk_scrolled_window_get_max_content_height (GtkScrolledWindow *scrolled_window);
 
 G_END_DECLS