gtk: Introduce GtkPointerFocus

These objects (tied to a toplevel) track the focus of a pointer/touchpoint.
The info in these basically consists of current toplevel coordinates and the
current target widget.

1 files changed, 98 insertions, 0 deletions

diff --git a/gtk/gtkpointerfocus.c b/gtk/gtkpointerfocus.c
new file mode 100644
index 0000000000..7c522a0dd0
--- /dev/null
+++ b/gtk/gtkpointerfocus.c
@@ -0,0 +1,98 @@
+/* GTK - The GIMP Toolkit
+ * Copyright (C) 2017 - Red Hat Inc.
+ *
+ * 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 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/>.
+ */
+
+#include "gtkpointerfocusprivate.h"
+#include "gtkprivate.h"
+
+static void
+target_destroyed (gpointer  data,
+                  GObject  *object_location)
+{
+  GtkPointerFocus *focus = data;
+
+  focus->target = NULL;
+  gtk_pointer_focus_repick_target (focus);
+}
+
+GtkPointerFocus *
+gtk_pointer_focus_new (GtkWindow        *toplevel,
+                       GtkWidget        *widget,
+                       GdkDevice        *device,
+                       GdkEventSequence *sequence,
+                       gdouble           x,
+                       gdouble           y)
+{
+  GtkPointerFocus *focus;
+
+  focus = g_new0 (GtkPointerFocus, 1);
+  focus->toplevel = toplevel;
+  focus->device = device;
+  focus->sequence = sequence;
+  gtk_pointer_focus_set_target (focus, widget);
+  gtk_pointer_focus_set_coordinates (focus, x, y);
+
+  return focus;
+}
+
+void
+gtk_pointer_focus_free (GtkPointerFocus *focus)
+{
+  gtk_pointer_focus_set_target (focus, NULL);
+  gtk_pointer_focus_set_implicit_grab (focus, NULL);
+  g_free (focus);
+}
+
+void
+gtk_pointer_focus_set_target (GtkPointerFocus *focus,
+                              GtkWidget       *target)
+{
+  if (focus->target == target)
+    return;
+
+  if (focus->target)
+    g_object_weak_unref (G_OBJECT (focus->target), target_destroyed, focus);
+
+  focus->target = target;
+
+  if (focus->target)
+    g_object_weak_ref (G_OBJECT (focus->target), target_destroyed, focus);
+}
+
+GtkWidget *
+gtk_pointer_focus_get_target (GtkPointerFocus *focus)
+{
+  return focus->target;
+}
+
+void
+gtk_pointer_focus_set_coordinates (GtkPointerFocus *focus,
+                                   gdouble          x,
+                                   gdouble          y)
+{
+  focus->x = x;
+  focus->y = y;
+}
+
+void
+gtk_pointer_focus_repick_target (GtkPointerFocus *focus)
+{
+  GtkWidget *target;
+
+  target = _gtk_toplevel_pick (focus->toplevel, focus->x, focus->y,
+                               NULL, NULL);
+  gtk_pointer_focus_set_target (focus, target);
+}