[gtk+/gestures: 8/16] Add GtkGestureDrag

[Carlos Garnacho <carlosg src gnome org>]

commit e1554de3eea05d049032950d9ae202eded242e29
Author: Carlos Garnacho <carlosg gnome org>
Date:   Thu Feb 20 17:04:49 2014 +0100

    Add GtkGestureDrag
    
    This gesture interprets and reports drags as an offset to the drag
    start point.

 gtk/Makefile.am      |    2 +
 gtk/gtk.h            |    1 +
 gtk/gtkgesturedrag.c |  210 ++++++++++++++++++++++++++++++++++++++++++++++++++
 gtk/gtkgesturedrag.h |   80 +++++++++++++++++++
 4 files changed, 293 insertions(+), 0 deletions(-)
---
diff --git a/gtk/Makefile.am b/gtk/Makefile.am
index e77dd0a..a7465c6 100644
--- a/gtk/Makefile.am
+++ b/gtk/Makefile.am
@@ -258,6 +258,7 @@ gtk_public_h_sources =              \
        gtkfontchooserwidget.h  \
        gtkframe.h              \
        gtkgesture.h            \
+       gtkgesturedrag.h        \
        gtkgesturelongpress.h   \
        gtkgesturerotate.h      \
        gtkgestureswipe.h       \
@@ -747,6 +748,7 @@ gtk_base_c_sources =                \
        gtkframe.c              \
        gtkgladecatalog.c       \
        gtkgesture.c            \
+       gtkgesturedrag.c        \
        gtkgesturelongpress.c   \
        gtkgesturerotate.c      \
        gtkgestureswipe.c       \
diff --git a/gtk/gtk.h b/gtk/gtk.h
index e0b61d5..dba574b 100644
--- a/gtk/gtk.h
+++ b/gtk/gtk.h
@@ -108,6 +108,7 @@
 #include <gtk/gtkfontchooserwidget.h>
 #include <gtk/gtkframe.h>
 #include <gtk/gtkgesture.h>
+#include <gtk/gtkgesturedrag.h>
 #include <gtk/gtkgesturelongpress.h>
 #include <gtk/gtkgesturerotate.h>
 #include <gtk/gtkgestureswipe.h>
diff --git a/gtk/gtkgesturedrag.c b/gtk/gtkgesturedrag.c
new file mode 100644
index 0000000..cc96ff4
--- /dev/null
+++ b/gtk/gtkgesturedrag.c
@@ -0,0 +1,210 @@
+/* GTK - The GIMP Toolkit
+ * Copyright (C) 2014, 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/>.
+ *
+ * Author(s): Carlos Garnacho <carlosg gnome org>
+ */
+#include "config.h"
+#include <gtk/gtkgesturedrag.h>
+
+#define CAPTURE_THRESHOLD_MS 150
+
+typedef struct _GtkGestureDragPrivate GtkGestureDragPrivate;
+typedef struct _EventData EventData;
+
+struct _GtkGestureDragPrivate
+{
+  gdouble start_x;
+  gdouble start_y;
+  gdouble last_x;
+  gdouble last_y;
+};
+
+enum {
+  DRAG_BEGIN,
+  DRAG_UPDATE,
+  DRAG_END,
+  N_SIGNALS
+};
+
+static guint signals[N_SIGNALS] = { 0 };
+
+G_DEFINE_TYPE_WITH_PRIVATE (GtkGestureDrag, gtk_gesture_drag, GTK_TYPE_GESTURE)
+
+static void
+gtk_gesture_drag_begin (GtkGesture       *gesture,
+                        GdkEventSequence *sequence)
+{
+  GtkGestureDragPrivate *priv;
+
+  priv = gtk_gesture_drag_get_instance_private (GTK_GESTURE_DRAG (gesture));
+  gtk_gesture_get_point (gesture, sequence, &priv->start_x, &priv->start_y);
+  g_signal_emit (gesture, signals[DRAG_BEGIN], 0, priv->start_x, priv->start_y);
+}
+
+static void
+gtk_gesture_drag_update (GtkGesture       *gesture,
+                         GdkEventSequence *sequence)
+{
+  GtkGestureDragPrivate *priv;
+  gdouble x, y;
+
+  priv = gtk_gesture_drag_get_instance_private (GTK_GESTURE_DRAG (gesture));
+  gtk_gesture_get_point (gesture, sequence, &priv->last_x, &priv->last_y);
+  x = priv->last_x - priv->start_x;
+  y = priv->last_y - priv->start_y;
+
+  g_signal_emit (gesture, signals[DRAG_UPDATE], 0, x, y);
+}
+
+static void
+gtk_gesture_drag_end (GtkGesture       *gesture,
+                      GdkEventSequence *sequence)
+{
+  GtkGestureDragPrivate *priv;
+  gdouble x, y;
+
+  priv = gtk_gesture_drag_get_instance_private (GTK_GESTURE_DRAG (gesture));
+  gtk_gesture_get_point (gesture, sequence, &priv->last_x, &priv->last_y);
+  x = priv->last_x - priv->start_x;
+  y = priv->last_y - priv->start_y;
+
+  g_signal_emit (gesture, signals[DRAG_END], 0, x, y);
+}
+
+static void
+gtk_gesture_drag_class_init (GtkGestureDragClass *klass)
+{
+  GtkGestureClass *gesture_class = GTK_GESTURE_CLASS (klass);
+
+  gesture_class->begin = gtk_gesture_drag_begin;
+  gesture_class->update = gtk_gesture_drag_update;
+  gesture_class->end = gtk_gesture_drag_end;
+
+  signals[DRAG_BEGIN] =
+    g_signal_new ("drag-begin",
+                  G_TYPE_FROM_CLASS (klass),
+                  G_SIGNAL_RUN_LAST,
+                  G_STRUCT_OFFSET (GtkGestureDragClass, drag_begin),
+                  NULL, NULL, NULL,
+                  G_TYPE_NONE, 2, G_TYPE_DOUBLE, G_TYPE_DOUBLE);
+  signals[DRAG_UPDATE] =
+    g_signal_new ("drag-update",
+                  G_TYPE_FROM_CLASS (klass),
+                  G_SIGNAL_RUN_LAST,
+                  G_STRUCT_OFFSET (GtkGestureDragClass, drag_update),
+                  NULL, NULL, NULL,
+                  G_TYPE_NONE, 2, G_TYPE_DOUBLE, G_TYPE_DOUBLE);
+  signals[DRAG_END] =
+    g_signal_new ("drag-end",
+                  G_TYPE_FROM_CLASS (klass),
+                  G_SIGNAL_RUN_LAST,
+                  G_STRUCT_OFFSET (GtkGestureDragClass, drag_end),
+                  NULL, NULL, NULL,
+                  G_TYPE_NONE, 2, G_TYPE_DOUBLE, G_TYPE_DOUBLE);
+}
+
+static void
+gtk_gesture_drag_init (GtkGestureDrag *gesture)
+{
+}
+
+/**
+ * gtk_gesture_drag_new:
+ * @widget: a #GtkWidget
+ *
+ * Returns a newly created #GtkGesture that recognizes drags
+ *
+ * Returns: a newly created #GtkGestureDrag
+ *
+ * Since: 3.14
+ **/
+GtkGesture *
+gtk_gesture_drag_new (GtkWidget *widget)
+{
+  return g_object_new (GTK_TYPE_GESTURE_DRAG,
+                       "widget", widget,
+                       NULL);
+}
+
+/**
+ * gtk_gesture_drag_get_start_point:
+ * @gesture: a #GtkGesture
+ * @x: X coordinate for the drag start point
+ * @y: Y coordinate for the drag start point
+ *
+ * If the @gesture is active, this function returns %TRUE
+ * and fills in @x and @y with the drag start coordinates,
+ * in window-relative coordinates.
+ *
+ * Returns: #TRUE if the gesture is active.
+ *
+ * Since: 3.14
+ **/
+gboolean
+gtk_gesture_drag_get_start_point (GtkGestureDrag *gesture,
+                                  gint           *x,
+                                  gint           *y)
+{
+  GtkGestureDragPrivate *priv;
+
+  if (!gtk_gesture_is_active (GTK_GESTURE (gesture)))
+    return FALSE;
+
+  priv = gtk_gesture_drag_get_instance_private (gesture);
+
+  if (x)
+    *x = priv->start_x;
+
+  if (y)
+    *y = priv->start_y;
+
+  return TRUE;
+}
+
+/**
+ * gtk_gesture_drag_get_current_point:
+ * @gesture: a #GtkGesture
+ * @x: X coordinate for the current point
+ * @y: Y coordinate for the current point
+ *
+ * If the @gesture is active, this function returns %TRUE and
+ * fills in @x and @y with the coordinates of the current point,
+ * as an offset to the starting drag point.
+ *
+ * Returns: #TRUE if the gesture is active.
+ *
+ * Since: 3.14
+ **/
+gboolean
+gtk_gesture_drag_get_current_point (GtkGestureDrag *gesture,
+                                    gint           *x,
+                                    gint           *y)
+{
+  GtkGestureDragPrivate *priv;
+
+  if (!gtk_gesture_is_active (GTK_GESTURE (gesture)))
+    return FALSE;
+
+  priv = gtk_gesture_drag_get_instance_private (gesture);
+
+  if (x)
+    *x = priv->last_x;
+
+  if (y)
+    *y = priv->last_y;
+
+  return TRUE;
+}
diff --git a/gtk/gtkgesturedrag.h b/gtk/gtkgesturedrag.h
new file mode 100644
index 0000000..f6a0a4d
--- /dev/null
+++ b/gtk/gtkgesturedrag.h
@@ -0,0 +1,80 @@
+/* GTK - The GIMP Toolkit
+ * Copyright (C) 2014, 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/>.
+ *
+ * Author(s): Carlos Garnacho <carlosg gnome org>
+ */
+#ifndef __GTK_GESTURE_DRAG_H__
+#define __GTK_GESTURE_DRAG_H__
+
+#if !defined (__GTK_H_INSIDE__) && !defined (GTK_COMPILATION)
+#error "Only <gtk/gtk.h> can be included directly."
+#endif
+
+#include <gtk/gtkwidget.h>
+#include <gtk/gtkgesture.h>
+
+G_BEGIN_DECLS
+
+#define GTK_TYPE_GESTURE_DRAG         (gtk_gesture_drag_get_type ())
+#define GTK_GESTURE_DRAG(o)           (G_TYPE_CHECK_INSTANCE_CAST ((o), GTK_TYPE_GESTURE_DRAG, 
GtkGestureDrag))
+#define GTK_GESTURE_DRAG_CLASS(k)     (G_TYPE_CHECK_CLASS_CAST ((k), GTK_TYPE_GESTURE_DRAG, 
GtkGestureDragClass))
+#define GTK_IS_GESTURE_DRAG(o)        (G_TYPE_CHECK_INSTANCE_TYPE ((o), GTK_TYPE_GESTURE_DRAG))
+#define GTK_IS_GESTURE_DRAG_CLASS(k)  (G_TYPE_CHECK_CLASS_TYPE ((k), GTK_TYPE_GESTURE_DRAG))
+#define GTK_GESTURE_DRAG_GET_CLASS(o) (G_TYPE_INSTANCE_GET_CLASS ((o), GTK_TYPE_GESTURE_DRAG, 
GtkGestureDragClass))
+
+typedef struct _GtkGestureDrag GtkGestureDrag;
+typedef struct _GtkGestureDragClass GtkGestureDragClass;
+
+struct _GtkGestureDrag
+{
+  GtkGesture parent_instance;
+};
+
+struct _GtkGestureDragClass
+{
+  GtkGestureClass parent_class;
+
+  void (* drag_begin)  (GtkGestureDrag *gesture,
+                        gdouble         start_x,
+                        gdouble         start_y);
+  void (* drag_update) (GtkGestureDrag *gesture,
+                        gdouble         offset_x,
+                        gdouble         offset_y);
+  void (* drag_end)    (GtkGestureDrag *gesture,
+                        gdouble         offset_x,
+                        gdouble         offset_y);
+  /*<private>*/
+  gpointer padding[10];
+};
+
+GDK_AVAILABLE_IN_3_14
+GType        gtk_gesture_drag_get_type          (void) G_GNUC_CONST;
+
+GDK_AVAILABLE_IN_3_14
+GtkGesture * gtk_gesture_drag_new               (GtkWidget      *widget);
+
+GDK_AVAILABLE_IN_3_14
+gboolean     gtk_gesture_drag_get_start_point   (GtkGestureDrag *gesture,
+                                                 gint           *x,
+                                                 gint           *y);
+GDK_AVAILABLE_IN_3_14
+gboolean     gtk_gesture_drag_get_current_point (GtkGestureDrag *gesture,
+                                                 gint           *x,
+                                                 gint           *y);
+
+G_END_DECLS
+
+#endif /* __GTK_GESTURE_DRAG_H__ */