[gtk+] gtk-demo: Use GdkAxisUse instead of axis labels

[Carlos Garnacho <carlosg src gnome org>]

commit 6c2a078bf2110d41c8f4d96d74c5dbf6d17eaf92
Author: Stephen Chandler Paul <thatslyude gmail com>
Date:   Mon Feb 9 19:44:50 2015 -0500

    gtk-demo: Use GdkAxisUse instead of axis labels
    
    Axis labels are very X specific, and are not really possible to port to other
    backends such as Wayland. As such, it makes more sense to use GdkAxisUse and
    GdkAxisUseFlag in order to determine the axis capabilities of a device and draw
    their axes.
    
    Signed-off-by: Stephen Chandler Paul <thatslyude gmail com>

 demos/gtk-demo/event_axes.c |  106 ++++++++++++++++++-------------------------
 1 files changed, 45 insertions(+), 61 deletions(-)
---
diff --git a/demos/gtk-demo/event_axes.c b/demos/gtk-demo/event_axes.c
index bfec8b7..a12168a 100644
--- a/demos/gtk-demo/event_axes.c
+++ b/demos/gtk-demo/event_axes.c
@@ -24,7 +24,7 @@
 
 typedef struct {
   GdkDevice *last_source;
-  GHashTable *axes; /* axis label atom -> value */
+  gdouble *axes;
   GdkRGBA color;
   gdouble x;
   gdouble y;
@@ -59,8 +59,6 @@ axes_info_new (void)
 
   info = g_new0 (AxesInfo, 1);
   gdk_rgba_parse (&info->color, colors[cur_color]);
-  info->axes = g_hash_table_new_full (NULL, NULL, NULL,
-                                      (GDestroyNotify) g_free);
 
   cur_color = (cur_color + 1) % G_N_ELEMENTS (colors);
 
@@ -70,32 +68,9 @@ axes_info_new (void)
 static void
 axes_info_free (AxesInfo *info)
 {
-  g_hash_table_destroy (info->axes);
   g_free (info);
 }
 
-static gboolean
-axes_info_lookup (AxesInfo    *info,
-                  const gchar *axis_label,
-                  gdouble     *value)
-{
-  gdouble *val;
-  GdkAtom atom;
-
-  atom = gdk_atom_intern (axis_label, FALSE);
-
-  if (atom == GDK_NONE)
-    return FALSE;
-
-  val = g_hash_table_lookup (info->axes, GDK_ATOM_TO_POINTER (atom));
-
-  if (!val)
-    return FALSE;
-
-  *value = *val;
-  return TRUE;
-}
-
 static EventData *
 event_data_new (void)
 {
@@ -121,13 +96,11 @@ static void
 update_axes_from_event (GdkEvent  *event,
                         EventData *data)
 {
-  GdkDevice *device, *source_device;
+  GdkDevice *source_device;
   GdkEventSequence *sequence;
-  gdouble x, y, value;
-  GList *l, *axes;
+  gdouble x, y;
   AxesInfo *info;
 
-  device = gdk_event_get_device (event);
   source_device = gdk_event_get_source_device (event);
   sequence = gdk_event_get_event_sequence (event);
 
@@ -163,41 +136,32 @@ update_axes_from_event (GdkEvent  *event,
     }
 
   if (info->last_source != source_device)
-    {
-      g_hash_table_remove_all (info->axes);
-      info->last_source = source_device;
-    }
+    info->last_source = source_device;
+
+  g_clear_pointer (&info->axes, g_free);
 
   if (event->type == GDK_TOUCH_BEGIN ||
-      event->type == GDK_TOUCH_UPDATE ||
-      event->type == GDK_MOTION_NOTIFY ||
-      event->type == GDK_BUTTON_PRESS ||
-      event->type == GDK_BUTTON_RELEASE)
+      event->type == GDK_TOUCH_UPDATE)
     {
-      axes = gdk_device_list_axes (device);
-
       if (sequence && event->touch.emulating_pointer)
         {
           if (data->pointer_info)
             axes_info_free (data->pointer_info);
           data->pointer_info = NULL;
         }
-
-      for (l = axes; l; l = l->next)
-        {
-          gdouble *ptr;
-
-          /* All those event types are compatible wrt axes position in the struct */
-          if (!gdk_device_get_axis_value (device, event->motion.axes,
-                                          l->data, &value))
-            continue;
-
-          ptr = g_new0 (gdouble, 1);
-          *ptr = value;
-          g_hash_table_insert (info->axes, GDK_ATOM_TO_POINTER (l->data), ptr);
-        }
-
-      g_list_free (axes);
+    }
+  if (event->type == GDK_MOTION_NOTIFY)
+    {
+      info->axes =
+      g_memdup (event->motion.axes,
+                sizeof (gdouble) * gdk_device_get_n_axes (source_device));
+    }
+  else if (event->type == GDK_BUTTON_PRESS ||
+           event->type == GDK_BUTTON_RELEASE)
+    {
+      info->axes =
+      g_memdup (event->button.axes,
+                sizeof (gdouble) * gdk_device_get_n_axes (source_device));
     }
 
   if (gdk_event_get_coords (event, &x, &y))
@@ -243,6 +207,7 @@ draw_axes_info (cairo_t       *cr,
                 GtkAllocation *allocation)
 {
   gdouble pressure, tilt_x, tilt_y, wheel;
+  GdkAxisFlags axes = gdk_device_get_axes (info->last_source);
 
   cairo_save (cr);
 
@@ -257,10 +222,19 @@ draw_axes_info (cairo_t       *cr,
 
   cairo_translate (cr, info->x, info->y);
 
-  if (axes_info_lookup (info, "Abs Pressure", &pressure))
+  if (!info->axes)
+    {
+      cairo_restore (cr);
+      return;
+    }
+
+  if (axes & GDK_AXIS_FLAG_PRESSURE)
     {
       cairo_pattern_t *pattern;
 
+      gdk_device_get_axis (info->last_source, info->axes, GDK_AXIS_PRESSURE,
+                           &pressure);
+
       pattern = cairo_pattern_create_radial (0, 0, 0, 0, 0, 100);
       cairo_pattern_add_color_stop_rgba (pattern, pressure, 1, 0, 0, pressure);
       cairo_pattern_add_color_stop_rgba (pattern, 1, 0, 0, 1, 0);
@@ -273,12 +247,22 @@ draw_axes_info (cairo_t       *cr,
       cairo_pattern_destroy (pattern);
     }
 
-  if (axes_info_lookup (info, "Abs Tilt X", &tilt_x) &&
-      axes_info_lookup (info, "Abs Tilt Y", &tilt_y))
-    render_arrow (cr, tilt_x * 100, tilt_y * 100, "Tilt");
+  if (axes & GDK_AXIS_FLAG_XTILT &&
+      axes & GDK_AXIS_FLAG_YTILT)
+    {
+      gdk_device_get_axis (info->last_source, info->axes, GDK_AXIS_XTILT,
+                           &tilt_x);
+      gdk_device_get_axis (info->last_source, info->axes, GDK_AXIS_YTILT,
+                           &tilt_y);
+
+      render_arrow (cr, tilt_x * 100, tilt_y * 100, "Tilt");
+    }
 
-  if (axes_info_lookup (info, "Abs Wheel", &wheel))
+  if (axes & GDK_AXIS_FLAG_WHEEL)
     {
+      gdk_device_get_axis (info->last_source, info->axes, GDK_AXIS_WHEEL,
+                           &wheel);
+
       cairo_save (cr);
       cairo_set_line_width (cr, 10);
       cairo_set_source_rgba (cr, 0, 0, 0, 0.5);