Slide out the status overlay when the mouse pointer goes close by.

This introduces a GeditOverlayChild subclass, listening to parent
overlay mouse events to define the escaping policy.
The distance from which the widget "escapes" the mouse pointer
can be set at construction time.

https://bugzilla.gnome.org/show_bug.cgi?id=643909

4 files changed, 367 insertions, 2 deletions

diff --git a/lib/widgets/Makefile.am b/lib/widgets/Makefile.am
index a80cbde0f..66c9f9084 100644
--- a/lib/widgets/Makefile.am
+++ b/lib/widgets/Makefile.am
@@ -22,7 +22,9 @@ libephywidgets_la_SOURCES = \
 	gedit-overlay.c				\
 	gedit-overlay.h				\
 	gedit-overlay-child.c			\
-	gedit-overlay-child.h
+	gedit-overlay-child.h			\
+	ephy-overlay-escaping-child.c		\
+	ephy-overlay-escaping-child.h
 
 libephywidgets_la_CPPFLAGS = \
 	-I$(top_builddir)/lib		\
diff --git a/lib/widgets/ephy-overlay-escaping-child.c b/lib/widgets/ephy-overlay-escaping-child.c
new file mode 100644
index 000000000..65ce8322e
--- /dev/null
+++ b/lib/widgets/ephy-overlay-escaping-child.c
@@ -0,0 +1,307 @@
+/*
+ *
+ * Copyright © 2011 Igalia S.L.
+ *
+ * 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, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+#include "ephy-overlay-escaping-child.h"
+
+#define EPHY_OVERLAY_ESCAPING_CHILD_DEFAULT_DISTANCE 20
+
+G_DEFINE_TYPE (EphyOverlayEscapingChild, ephy_overlay_escaping_child, GEDIT_TYPE_OVERLAY_CHILD);
+
+/* properties */
+enum
+{
+  PROP_0,
+  PROP_ESCAPING_DISTANCE
+};
+
+struct _EphyOverlayEscapingChildPrivate
+{
+  guint escaping_distance;
+  GtkAllocation initial_allocation;
+  GdkRectangle escaping_area;
+};
+
+/* If the pointer leaves the window, restore the widget position */
+static gboolean
+parent_leave_notify_event (GtkWidget *widget,
+                           GdkEventMotion *event,
+                           GtkWidget *parent)
+{
+  EphyOverlayEscapingChildPrivate *priv = EPHY_OVERLAY_ESCAPING_CHILD (widget)->priv;
+  GtkAllocation alloc;
+
+  gtk_widget_get_allocation (widget, &alloc);
+  alloc.y = priv->initial_allocation.y;
+  gtk_widget_size_allocate (widget, &alloc);
+
+  return FALSE;
+}
+
+/* this should be in Gdk...really */
+static gboolean
+is_point_in_rectangle (int point_x,
+                       int point_y,
+                       GdkRectangle rectangle)
+{
+  int rectangle_x_higher_bound = rectangle.x + rectangle.width;
+  int rectangle_y_higher_bound = rectangle.y + rectangle.height;
+
+  return point_x >= rectangle.x && point_x < rectangle_x_higher_bound
+    && point_y >= rectangle.y && point_y < rectangle_y_higher_bound;
+}
+
+/* Keep the widget-pointer distance at at least
+ * EphyOverlayEscapingChildPrivate::escaping_distance by sliding the widget
+ * away if needed.
+ */
+static gboolean
+parent_motion_notify_event (GtkWidget *widget,
+                            GdkEventMotion *event,
+                            GtkWidget *parent)
+{
+  EphyOverlayEscapingChildPrivate *priv = EPHY_OVERLAY_ESCAPING_CHILD (widget)->priv;
+  int distance_x, distance_y;
+  GtkAllocation alloc;
+
+  gtk_widget_get_allocation (widget, &alloc);
+
+  if (is_point_in_rectangle (event->x, event->y, priv->escaping_area)) {
+    gtk_widget_get_pointer (widget, &distance_x, &distance_y);
+    alloc.y += priv->escaping_distance + distance_y;
+  }
+  else {
+    /* Put the widget at its original position if we are out of the escaping
+     * zone. Do nothing if it is already there.
+     */
+    if (alloc.y == priv->initial_allocation.y)
+      return FALSE;
+    alloc.y = priv->initial_allocation.y;
+  }
+
+  gtk_widget_size_allocate (widget, &alloc);
+
+  return FALSE;
+}
+
+/* When the parent overlay is resized, the child relative position is modified.
+ * So we update our initial_allocation to this new value and redefine our
+ * escaping area.
+ */
+static void
+parent_size_allocate (GtkWidget    *widget,
+                      GdkRectangle *allocation,
+                      GtkWidget      *parent)
+{
+  EphyOverlayEscapingChildPrivate *priv = EPHY_OVERLAY_ESCAPING_CHILD (widget)->priv;
+  GtkAllocation initial_allocation;
+
+  gtk_widget_get_allocation (widget, &initial_allocation);
+  priv->escaping_area = priv->initial_allocation = initial_allocation;
+
+  /* Define an escaping area around the widget.
+   * Current implementation only handle horizontal lowerside widgets
+   */
+  priv->escaping_area.height += priv->escaping_distance;
+  /* escape on both right and left */
+  priv->escaping_area.width += 2 * priv->escaping_distance;
+  priv->escaping_area.x -= priv->escaping_distance;
+  priv->escaping_area.y -= priv->escaping_distance;
+}
+
+/* Install listeners on our overlay parents to locate the pointer
+ * and our relative position.
+ */
+static void
+ephy_overlay_escaping_child_parent_set (GtkWidget *widget,
+                                        GtkWidget *previous_parent)
+{
+  GtkWidget *parent;
+
+  if (previous_parent != NULL) {
+    g_signal_handlers_disconnect_by_func (previous_parent,
+                                          G_CALLBACK (parent_motion_notify_event),
+                                          widget);
+    g_signal_handlers_disconnect_by_func (previous_parent,
+                                          G_CALLBACK (parent_leave_notify_event),
+                                          widget);
+    g_signal_handlers_disconnect_by_func (previous_parent,
+                                          G_CALLBACK (parent_size_allocate),
+                                          widget);
+  }
+
+  parent = gtk_widget_get_parent (widget);
+  if (parent == NULL)
+    return;
+
+  g_signal_connect_swapped (parent,
+                            "motion-notify-event",
+                            G_CALLBACK (parent_motion_notify_event),
+                            widget);
+  g_signal_connect_swapped (parent,
+                            "leave-notify-event",
+                            G_CALLBACK (parent_leave_notify_event),
+                            widget);
+  g_signal_connect_swapped (parent,
+                            "size-allocate",
+                            G_CALLBACK (parent_size_allocate),
+                            widget);
+
+}
+
+/* When the mouse is over us, translate the event coords and slide the widget
+ * accordingly
+ */
+static gboolean
+ephy_overlay_escaping_child_motion_notify_event (GtkWidget *widget,
+                                                 GdkEventMotion *event)
+{
+  EphyOverlayEscapingChildPrivate *priv = EPHY_OVERLAY_ESCAPING_CHILD (widget)->priv;
+
+  event->x += priv->initial_allocation.x;
+  event->y += priv->initial_allocation.y;
+  return parent_motion_notify_event (widget, event, gtk_widget_get_parent (widget));
+}
+
+/* Make our event window propagate mouse motion events, so we can slide the widget,
+ * when hovered.
+ */
+static void
+ephy_overlay_escaping_child_realize (GtkWidget *widget)
+{
+  GTK_WIDGET_CLASS (ephy_overlay_escaping_child_parent_class)->realize (widget);
+  GdkWindow *window = gtk_widget_get_window (widget);
+  GdkEventMask events = gdk_window_get_events (window);
+  events |= GDK_POINTER_MOTION_MASK;
+  gdk_window_set_events (window, events);
+}
+
+static void
+ephy_overlay_escaping_child_get_property (GObject *object,
+                                          guint property_id,
+                                          GValue *value,
+                                          GParamSpec *pspec)
+{
+  EphyOverlayEscapingChild *self = EPHY_OVERLAY_ESCAPING_CHILD (object);
+  EphyOverlayEscapingChildPrivate *priv = self->priv;
+
+  switch (property_id) {
+  case PROP_ESCAPING_DISTANCE:
+    g_value_set_uint (value, priv->escaping_distance);
+  break;
+  default:
+    G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+  break;
+  }
+}
+
+static void
+ephy_overlay_escaping_child_set_property (GObject *object,
+                                          guint property_id,
+                                          const GValue *value,
+                                          GParamSpec *pspec)
+{
+  EphyOverlayEscapingChild *self = EPHY_OVERLAY_ESCAPING_CHILD (object);
+  EphyOverlayEscapingChildPrivate *priv = self->priv;
+
+  switch (property_id)
+  {
+  case PROP_ESCAPING_DISTANCE:
+    priv->escaping_distance = g_value_get_uint (value);
+  break;
+  default:
+    G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+  break;
+  }
+}
+
+static void
+ephy_overlay_escaping_child_class_init (EphyOverlayEscapingChildClass *klass)
+{
+  GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
+  GtkWidgetClass *widget_class = GTK_WIDGET_CLASS (klass);
+
+  g_type_class_add_private (klass, sizeof(EphyOverlayEscapingChildPrivate));
+
+  gobject_class->get_property = ephy_overlay_escaping_child_get_property;
+  gobject_class->set_property = ephy_overlay_escaping_child_set_property;
+
+  widget_class->parent_set = ephy_overlay_escaping_child_parent_set;
+  widget_class->motion_notify_event = ephy_overlay_escaping_child_motion_notify_event;
+  widget_class->realize = ephy_overlay_escaping_child_realize;
+
+  g_object_class_install_property (gobject_class,
+                                   PROP_ESCAPING_DISTANCE,
+                                   g_param_spec_uint ("escaping-distance",
+                                                      "Escaping distance",
+                                                      "Maximum distance between the mouse pointer and the widget",
+                                                      0,
+                                                      G_MAXUINT,
+                                                      EPHY_OVERLAY_ESCAPING_CHILD_DEFAULT_DISTANCE,
+                                                      G_PARAM_CONSTRUCT_ONLY |
+                                                      G_PARAM_READWRITE |
+                                                      G_PARAM_STATIC_STRINGS));
+}
+
+static void
+ephy_overlay_escaping_child_init (EphyOverlayEscapingChild *self)
+{
+  self->priv = G_TYPE_INSTANCE_GET_PRIVATE (self,
+                                            EPHY_TYPE_OVERLAY_ESCAPING_CHILD,
+                                            EphyOverlayEscapingChildPrivate);
+}
+
+/**
+ * ephy_overlay_escaping_child_new:
+ * @widget: the wrapped #GtkWidget
+ * @escaping_distance: the distance from which the widget escapes the mouse
+ * pointer
+ *
+ * Creates a new #EphyOverlayEscapingChild object wrapping the provided
+ * widget. The widget will stay at a minimal distance of @escaping_distance pixel
+ * from the mouse pointer.
+ *
+ * Returns: a new #EphyOverlayEscapingChild object
+ */
+EphyOverlayEscapingChild *
+ephy_overlay_escaping_child_new_with_distance (GtkWidget *widget,
+                                               guint escaping_distance)
+{
+  return g_object_new (EPHY_TYPE_OVERLAY_ESCAPING_CHILD,
+                       "widget", widget,
+                       "escaping-distance", escaping_distance,
+                       NULL);
+}
+
+/**
+ * ephy_overlay_escaping_child_new:
+ * @widget: the wrapped #GtkWidget
+ *
+ * Creates a new #EphyOverlayEscapingChild object wrapping the provided
+ * widget. The widget will stay at a minimal distance of 20 pixels from
+ * the mouse pointer.
+ *
+ * Returns: a new #EphyOverlayEscapingChild object
+ */
+EphyOverlayEscapingChild *
+ephy_overlay_escaping_child_new (GtkWidget *widget)
+{
+  return g_object_new (EPHY_TYPE_OVERLAY_ESCAPING_CHILD,
+                       "widget", widget,
+                       NULL);
+}
diff --git a/lib/widgets/ephy-overlay-escaping-child.h b/lib/widgets/ephy-overlay-escaping-child.h
new file mode 100644
index 000000000..cf567fd55
--- /dev/null
+++ b/lib/widgets/ephy-overlay-escaping-child.h
@@ -0,0 +1,56 @@
+/*
+ *
+ * Copyright © 2011 Igalia S.L.
+ *
+ * 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, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+#ifndef __EPHY_OVERLAY_ESCAPING_CHILD_H__
+#define __EPHY_OVERLAY_ESCAPING_CHILD_H__
+
+#include "gedit-overlay-child.h"
+
+G_BEGIN_DECLS
+
+#define EPHY_TYPE_OVERLAY_ESCAPING_CHILD		(ephy_overlay_escaping_child_get_type())
+#define EPHY_OVERLAY_ESCAPING_CHILD(obj)		(G_TYPE_CHECK_INSTANCE_CAST ((obj), EPHY_TYPE_OVERLAY_ESCAPING_CHILD, EphyOverlayEscapingChild))
+#define EPHY_OVERLAY_ESCAPING_CHILD_CLASS(klass)	(G_TYPE_CHECK_CLASS_CAST ((klass), EPHY_TYPE_OVERLAY_ESCAPING_CHILD, EphyOverlayEscapingChildClass))
+#define IS_EPHY_OVERLAY_ESCAPING_CHILD(obj)		(G_TYPE_CHECK_INSTANCE_TYPE ((obj), EPHY_TYPE_OVERLAY_ESCAPING_CHILD))
+#define IS_EPHY_OVERLAY_ESCAPING_CHILD_CLASS(klass)	(G_TYPE_CHECK_CLASS_TYPE ((klass), EPHY_TYPE_OVERLAY_ESCAPING_CHILD))
+#define EPHY_OVERLAY_ESCAPING_CHILD_GET_CLASS(obj)	(G_TYPE_INSTANCE_GET_CLASS ((obj), EPHY_TYPE_OVERLAY_ESCAPING_CHILD, EphyOverlayEscapingChildClass))
+typedef struct _EphyOverlayEscapingChild		EphyOverlayEscapingChild;
+
+typedef struct _EphyOverlayEscapingChildClass   EphyOverlayEscapingChildClass;
+typedef struct _EphyOverlayEscapingChildPrivate	EphyOverlayEscapingChildPrivate;
+
+struct _EphyOverlayEscapingChildClass
+{
+  GeditOverlayChildClass parent_class;
+};
+
+struct _EphyOverlayEscapingChild
+{
+  GeditOverlayChild parent;
+  EphyOverlayEscapingChildPrivate *priv;
+};
+
+GType                      ephy_overlay_escaping_child_get_type          (void) G_GNUC_CONST;
+
+EphyOverlayEscapingChild  *ephy_overlay_escaping_child_new               (GtkWidget *widget);
+EphyOverlayEscapingChild  *ephy_overlay_escaping_child_new_with_distance (GtkWidget *widget,
+                                                                          guint escaping_distance);
+G_END_DECLS
+
+#endif /* __EPHY_OVERLAY_ESCAPING_CHILD_H__ */
diff --git a/lib/widgets/gedit-overlay.c b/lib/widgets/gedit-overlay.c
index 28e1010f0..45e783df6 100644
--- a/lib/widgets/gedit-overlay.c
+++ b/lib/widgets/gedit-overlay.c
@@ -209,7 +209,7 @@ gedit_overlay_realize (GtkWidget *widget)
 	attributes.wclass = GDK_INPUT_OUTPUT;
 	attributes.visual = gtk_widget_get_visual (widget);
 	attributes.event_mask = gtk_widget_get_events (widget);
-	attributes.event_mask |= GDK_EXPOSURE_MASK | GDK_BUTTON_PRESS_MASK;
+	attributes.event_mask |= GDK_EXPOSURE_MASK | GDK_BUTTON_PRESS_MASK | GDK_LEAVE_NOTIFY_MASK;
 
 	attributes_mask = GDK_WA_X | GDK_WA_Y;