Add PanAxis mode that automatically pins scroll based on initial movement

This code is inspired by the implementation of the same feature for the
Mx toolkit's MxKineticScrollView. See commit 4d08771.

https://bugzilla.gnome.org/show_bug.cgi?id=707982

1 files changed, 54 insertions, 4 deletions

diff --git a/examples/pan-action.c b/examples/pan-action.c
index e8733056b..4e3f73f25 100644
--- a/examples/pan-action.c
+++ b/examples/pan-action.c
@@ -83,7 +83,7 @@ create_scroll_actor (ClutterActor *stage)
   pan_action = clutter_pan_action_new ();
   clutter_pan_action_set_interpolate (CLUTTER_PAN_ACTION (pan_action), TRUE);
   g_signal_connect (pan_action, "pan", G_CALLBACK (on_pan), NULL);
-  clutter_actor_add_action (scroll, pan_action);
+  clutter_actor_add_action_with_name (scroll, "pan", pan_action);
 
   clutter_actor_set_reactive (scroll, TRUE);
 
@@ -113,10 +113,45 @@ on_key_press (ClutterActor *stage,
   return CLUTTER_EVENT_STOP;
 }
 
+static gboolean
+label_clicked_cb (ClutterText *label, ClutterEvent *event, ClutterActor *scroll)
+{
+  ClutterPanAction *action = CLUTTER_PAN_ACTION (clutter_actor_get_action (scroll, "pan"));
+  const gchar *label_text = clutter_text_get_text (label);
+
+  if (g_str_equal (label_text, "X AXIS"))
+    clutter_pan_action_set_pan_axis (action, CLUTTER_PAN_X_AXIS);
+  else if (g_str_equal (label_text, "Y AXIS"))
+    clutter_pan_action_set_pan_axis (action, CLUTTER_PAN_Y_AXIS);
+  else if (g_str_equal (label_text, "AUTO"))
+    clutter_pan_action_set_pan_axis (action, CLUTTER_PAN_AXIS_AUTO);
+  else
+    clutter_pan_action_set_pan_axis (action, CLUTTER_PAN_AXIS_NONE);
+
+  return TRUE;
+}
+
+static void
+add_label (const gchar *text, ClutterActor *box, ClutterActor *scroll)
+{
+  ClutterActor *label;
+
+  label = clutter_text_new_with_text (NULL, text);
+  clutter_actor_set_reactive (label, TRUE);
+  clutter_actor_set_x_align (label, CLUTTER_ACTOR_ALIGN_START);
+  clutter_actor_set_x_expand (label, TRUE);
+
+  clutter_actor_add_child (box, label);
+
+  g_signal_connect (label, "button-release-event",
+                    G_CALLBACK (label_clicked_cb), scroll);
+}
+
 int
 main (int argc, char *argv[])
 {
-  ClutterActor *stage, *scroll, *info;
+  ClutterActor *stage, *scroll, *box, *info;
+  ClutterLayoutManager *layout;
 
   if (clutter_init (&argc, &argv) != CLUTTER_INIT_SUCCESS)
     return EXIT_FAILURE;
@@ -129,9 +164,24 @@ main (int argc, char *argv[])
   scroll = create_scroll_actor (stage);
   clutter_actor_add_child (stage, scroll);
 
+  box = clutter_actor_new ();
+  clutter_actor_add_child (stage, box);
+  clutter_actor_set_position (box, 12, 12);
+
+  layout = clutter_box_layout_new ();
+  clutter_box_layout_set_orientation (CLUTTER_BOX_LAYOUT (layout), CLUTTER_ORIENTATION_VERTICAL);
+  clutter_actor_set_layout_manager (box, layout);
+
   info = clutter_text_new_with_text (NULL, "Press <space> to reset the image position.");
-  clutter_actor_add_child (stage, info);
-  clutter_actor_set_position (info, 12, 12);
+  clutter_actor_add_child (box, info);
+
+  info = clutter_text_new_with_text (NULL, "Click labels below to change AXIS pinning.");
+  clutter_actor_add_child (box, info);
+
+  add_label ("NONE", box, scroll);
+  add_label ("X AXIS", box, scroll);
+  add_label ("Y AXIS", box, scroll);
+  add_label ("AUTO", box, scroll);
 
   g_signal_connect (stage, "destroy", G_CALLBACK (clutter_main_quit), NULL);
   g_signal_connect (stage, "key-press-event", G_CALLBACK (on_key_press), scroll);