Add GtkLayoutManager

A base abstract class for layout manager delegate objects.

Layout managers are associated to a single widget, like event
controllers, and are responsible for measuring and allocating the
children of the widget they are bound to.

1 files changed, 94 insertions, 0 deletions

diff --git a/gtk/gtklayoutmanager.h b/gtk/gtklayoutmanager.h
new file mode 100644
index 0000000000..e849e300a2
--- /dev/null
+++ b/gtk/gtklayoutmanager.h
@@ -0,0 +1,94 @@
+/* gtklayoutmanager.h: Layout manager base class
+ * Copyright 2018  The GNOME Foundation
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Author: Emmanuele Bassi
+ */
+#pragma once
+
+#include <gtk/gtkcontainer.h>
+
+G_BEGIN_DECLS
+
+#define GTK_TYPE_LAYOUT_MANAGER (gtk_layout_manager_get_type ())
+
+GDK_AVAILABLE_IN_ALL
+G_DECLARE_DERIVABLE_TYPE (GtkLayoutManager, gtk_layout_manager, GTK, LAYOUT_MANAGER, GObject)
+
+/**
+ * GtkLayoutManagerClass:
+ * @get_request_mode: a virtual function, used to return the preferred
+ *   request mode for the layout manager; for instance, "width for height"
+ *   or "height for width"; see #GtkSizeRequestMode
+ * @measure: a virtual function, used to measure the minimum and preferred
+ *   sizes of the widget using the layout manager for a given orientation
+ * @allocate: a virtual function, used to allocate the size of the widget
+ *   using the layout manager
+ *
+ * The `GtkLayoutManagerClass` structure contains only private data, and
+ * should only be accessed through the provided API, or when subclassing
+ * #GtkLayoutManager.
+ */
+struct _GtkLayoutManagerClass
+{
+  /*< private >*/
+  GObjectClass parent_class;
+
+  /*< public >*/
+  GtkSizeRequestMode (* get_request_mode) (GtkLayoutManager *manager,
+                                           GtkWidget        *widget);
+
+  void               (* measure)          (GtkLayoutManager *manager,
+                                           GtkWidget        *widget,
+                                           GtkOrientation    orientation,
+                                           int               for_size,
+                                           int              *minimum,
+                                           int              *natural,
+                                           int              *minimum_baseline,
+                                           int              *natural_baseline);
+
+  void               (* allocate)         (GtkLayoutManager *manager,
+                                           GtkWidget        *widget,
+                                           int               width,
+                                           int               height,
+                                           int               baseline);
+
+  /*< private >*/
+  gpointer _padding[16];
+};
+
+GDK_AVAILABLE_IN_ALL
+void                    gtk_layout_manager_measure              (GtkLayoutManager *manager,
+                                                                 GtkWidget        *widget,
+                                                                 GtkOrientation    orientation,
+                                                                 int               for_size,
+                                                                 int              *minimum,
+                                                                 int              *natural,
+                                                                 int              *minimum_baseline,
+                                                                 int              *natural_baseline);
+GDK_AVAILABLE_IN_ALL
+void                    gtk_layout_manager_allocate             (GtkLayoutManager *manager,
+                                                                 GtkWidget        *widget,
+                                                                 int               width,
+                                                                 int               height,
+                                                                 int               baseline);
+GDK_AVAILABLE_IN_ALL
+GtkSizeRequestMode      gtk_layout_manager_get_request_mode     (GtkLayoutManager *manager,
+                                                                 GtkWidget        *widget);
+
+GDK_AVAILABLE_IN_ALL
+void                    gtk_layout_manager_layout_changed       (GtkLayoutManager *manager);
+
+G_END_DECLS