swipeable: Use HdyNavigationDirection for begin_swipe() direction

Update HdySwipeTracker, HdySwipeGroup, HdyCarousel and HdyLeaflet to
reflect this change.
Signed-off-by: Alexander Mikhaylenko <alexm@gnome.org>

src/hdy-carousel.c

@@ -10,6 +10,7 @@
 #include "hdy-carousel.h"
 
 #include "hdy-carousel-box-private.h"
+#include "hdy-navigation-direction.h"
 #include "hdy-swipe-tracker-private.h"
 #include "hdy-swipeable-private.h"
 
@@ -119,9 +120,9 @@ hdy_carousel_switch_child (HdySwipeable *swipeable,
 }
 
 static void
-hdy_carousel_begin_swipe (HdySwipeable *swipeable,
-                          gint          direction,
-                          gboolean      direct)
+hdy_carousel_begin_swipe (HdySwipeable           *swipeable,
+                          HdyNavigationDirection  direction,
+                          gboolean                direct)
 {
   HdyCarousel *self = HDY_CAROUSEL (swipeable);
   gdouble distance, position, closest_point;

src/hdy-leaflet.c

@@ -3212,8 +3212,8 @@ hdy_leaflet_switch_child (HdySwipeable *swipeable,
 }
 
 static HdyLeafletChildInfo *
-find_swipeable_child (HdyLeaflet *self,
-                      gint        direction)
+find_swipeable_child (HdyLeaflet             *self,
+                      HdyNavigationDirection  direction)
 {
   HdyLeafletPrivate *priv;
   GList *children;
@@ -3223,7 +3223,7 @@ find_swipeable_child (HdyLeaflet *self,
 
   children = g_list_find (priv->children, priv->visible_child);
   do {
-    children = (direction < 0) ? children->prev : children->next;
+    children = (direction == HDY_NAVIGATION_DIRECTION_BACK) ? children->prev : children->next;
 
     if (children == NULL)
       break;
@@ -3234,6 +3234,22 @@ find_swipeable_child (HdyLeaflet *self,
   return child;
 }
 
+static gboolean
+can_swipe_in_direction (HdyLeaflet             *self,
+                        HdyNavigationDirection  direction)
+{
+  HdyLeafletPrivate *priv = hdy_leaflet_get_instance_private (self);
+
+  switch (direction) {
+  case HDY_NAVIGATION_DIRECTION_BACK:
+    return priv->child_transition.can_swipe_back;
+  case HDY_NAVIGATION_DIRECTION_FORWARD:
+    return priv->child_transition.can_swipe_forward;
+  default:
+    g_assert_not_reached ();
+  }
+}
+
 static double
 get_current_progress (HdyLeaflet *self)
 {
@@ -3259,9 +3275,9 @@ get_current_progress (HdyLeaflet *self)
 }
 
 static void
-hdy_leaflet_begin_swipe (HdySwipeable *swipeable,
-                         gint          direction,
-                         gboolean      direct)
+hdy_leaflet_begin_swipe (HdySwipeable           *swipeable,
+                         HdyNavigationDirection  direction,
+                         gboolean                direct)
 {
   HdyLeaflet *self = HDY_LEAFLET (swipeable);
   HdyLeafletPrivate *priv = hdy_leaflet_get_instance_private (self);
@@ -3274,32 +3290,35 @@ hdy_leaflet_begin_swipe (HdySwipeable *swipeable,
     distance = gtk_widget_get_allocated_height (GTK_WIDGET (self));
 
   if (priv->child_transition.tick_id > 0) {
-    gint current_direction;
-    gboolean is_rtl;
+    gboolean is_rtl =
+      (gtk_widget_get_direction (GTK_WIDGET (self)) == GTK_TEXT_DIR_RTL);
 
-    is_rtl = (gtk_widget_get_direction (GTK_WIDGET (self)) == GTK_TEXT_DIR_RTL);
+    n = 2;
+    points = g_new0 (gdouble, n);
 
     switch (priv->child_transition.active_direction) {
     case GTK_PAN_DIRECTION_UP:
-      current_direction = 1;
+      points[1] = 1;
       break;
     case GTK_PAN_DIRECTION_DOWN:
-      current_direction = -1;
+      points[0] = -1;
       break;
     case GTK_PAN_DIRECTION_LEFT:
-      current_direction = is_rtl ? -1 : 1;
+      if (is_rtl)
+        points[0] = -1;
+      else
+        points[1] = 1;
       break;
     case GTK_PAN_DIRECTION_RIGHT:
-      current_direction = is_rtl ? 1 : -1;
+      if (is_rtl)
+        points[1] = 1;
+      else
+        points[0] = -1;
       break;
     default:
       g_assert_not_reached ();
     }
 
-    n = 2;
-    points = g_new0 (gdouble, n);
-    points[current_direction > 0 ? 1 : 0] = current_direction;
-
     progress = get_current_progress (self);
 
     gtk_widget_remove_tick_callback (GTK_WIDGET (self), priv->child_transition.tick_id);
@@ -3309,9 +3328,7 @@ hdy_leaflet_begin_swipe (HdySwipeable *swipeable,
   } else {
     HdyLeafletChildInfo *child;
 
-    if (((direction < 0 && priv->child_transition.can_swipe_back) ||
-        (direction > 0 && priv->child_transition.can_swipe_forward) ||
-         !direct) && priv->folded)
+    if ((can_swipe_in_direction (self, direction) || !direct) && priv->folded)
       child = find_swipeable_child (self, direction);
     else
       child = NULL;
@@ -3329,7 +3346,16 @@ hdy_leaflet_begin_swipe (HdySwipeable *swipeable,
     n = child ? 2 : 1;
     points = g_new0 (gdouble, n);
     if (child)
-      points[direction > 0 ? 1 : 0] = direction;
+      switch (direction) {
+      case HDY_NAVIGATION_DIRECTION_BACK:
+        points[0] = -1;
+        break;
+      case HDY_NAVIGATION_DIRECTION_FORWARD:
+        points[1] = 1;
+        break;
+      default:
+        g_assert_not_reached ();
+      }
   }
 
   hdy_swipe_tracker_confirm_swipe (priv->tracker, distance, points, n, progress, 0);

src/hdy-swipe-group.c

@@ -8,6 +8,7 @@
 
 #include "hdy-swipe-group.h"
 #include <gtk/gtk.h>
+#include "hdy-navigation-direction.h"
 #include "hdy-swipeable-private.h"
 
 #define BUILDABLE_TAG_OBJECT "object"
@@ -117,9 +118,9 @@ switch_child_cb (HdySwipeGroup *self,
 }
 
 static void
-begin_swipe_cb (HdySwipeGroup *self,
-                gint           direction,
-                HdySwipeable  *swipeable)
+begin_swipe_cb (HdySwipeGroup          *self,
+                HdyNavigationDirection  direction,
+                HdySwipeable           *swipeable)
 {
   GSList *swipeables;
 

src/hdy-swipe-tracker.c

@@ -8,6 +8,7 @@
 #include <glib/gi18n-lib.h>
 
 #include "hdy-swipe-tracker-private.h"
+#include "hdy-navigation-direction.h"
 
 #include <math.h>
 
@@ -142,8 +143,8 @@ reset (HdySwipeTracker *self)
 }
 
 static void
-gesture_prepare (HdySwipeTracker *self,
-                 gint             direction)
+gesture_prepare (HdySwipeTracker        *self,
+                 HdyNavigationDirection  direction)
 {
   if (self->state != HDY_SWIPE_TRACKER_STATE_NONE)
     return;
@@ -319,7 +320,7 @@ drag_update_cb (HdySwipeTracker *self,
 
   if (self->state == HDY_SWIPE_TRACKER_STATE_NONE) {
     if (is_vertical == is_offset_vertical)
-      gesture_prepare (self, offset > 0 ? 1 : -1);
+      gesture_prepare (self, offset > 0 ? HDY_NAVIGATION_DIRECTION_FORWARD : HDY_NAVIGATION_DIRECTION_BACK);
     else
       gtk_gesture_set_state (self->touch_gesture, GTK_EVENT_SEQUENCE_DENIED);
     return;
@@ -418,7 +419,7 @@ captured_scroll_event (HdySwipeTracker *self,
       return GDK_EVENT_PROPAGATE;
 
     if (is_vertical == is_delta_vertical)
-      gesture_prepare (self, delta > 0 ? 1 : -1);
+      gesture_prepare (self, delta > 0 ? HDY_NAVIGATION_DIRECTION_FORWARD : HDY_NAVIGATION_DIRECTION_BACK);
     else {
       self->is_scrolling = TRUE;
       return GDK_EVENT_PROPAGATE;

src/hdy-swipeable-private.h

@@ -14,9 +14,9 @@ G_BEGIN_DECLS
 void hdy_swipeable_switch_child (HdySwipeable *self,
                                  guint         index,
                                  gint64        duration);
-void hdy_swipeable_begin_swipe  (HdySwipeable *self,
-                                 gint          direction,
-                                 gboolean      direct);
+void hdy_swipeable_begin_swipe  (HdySwipeable           *self,
+                                 HdyNavigationDirection  direction,
+                                 gboolean                direct);
 void hdy_swipeable_update_swipe (HdySwipeable *self,
                                  gdouble       value);
 void hdy_swipeable_end_swipe    (HdySwipeable *self,

src/hdy-swipeable.c

@@ -79,7 +79,7 @@ hdy_swipeable_default_init (HdySwipeableInterface *iface)
                   NULL, NULL, NULL,
                   G_TYPE_NONE,
                   1,
-                  G_TYPE_INT);
+                  HDY_TYPE_NAVIGATION_DIRECTION);
 
   /**
    * HdySwipeable::update-swipe:
@@ -151,7 +151,7 @@ hdy_swipeable_switch_child (HdySwipeable *self,
 /**
  * hdy_swipeable_begin_swipe:
  * @self: a #HdySwipeable
- * @direction: The direction of the swipe, can be 1 or -1
+ * @direction: The direction of the swipe
  * @direct: %TRUE if the swipe is directly triggered by a gesture,
  *   %FALSE if it's triggered via a #HdySwipeGroup
  *
@@ -168,9 +168,9 @@ hdy_swipeable_switch_child (HdySwipeable *self,
  * Since: 0.0.12
  */
 void
-hdy_swipeable_begin_swipe (HdySwipeable *self,
-                           gint          direction,
-                           gboolean      direct)
+hdy_swipeable_begin_swipe (HdySwipeable           *self,
+                           HdyNavigationDirection  direction,
+                           gboolean                direct)
 {
   HdySwipeableInterface *iface;
 

src/hdy-swipeable.h

@@ -7,6 +7,7 @@
 #pragma once
 
 #include <gtk/gtk.h>
+#include "hdy-navigation-direction.h"
 
 G_BEGIN_DECLS
 
@@ -33,9 +34,9 @@ struct _HdySwipeableInterface
   void (*switch_child) (HdySwipeable *self,
                         guint         index,
                         gint64        duration);
-  void (*begin_swipe)  (HdySwipeable *self,
-                        gint          direction,
-                        gboolean      direct);
+  void (*begin_swipe)  (HdySwipeable           *self,
+                        HdyNavigationDirection  direction,
+                        gboolean                direct);
   void (*update_swipe) (HdySwipeable *self,
                         gdouble       value);
   void (*end_swipe)    (HdySwipeable *self,