[gnome-control-center] sound: Fix mouse scrolls on sliders

[Bastien Nocera <hadess src gnome org>]

commit bb531687ca957072470a5851c499993fe056ea85
Author: Matthias Clasen <mclasen redhat com>
Date:   Mon Mar 19 22:11:00 2012 +0000

    sound: Fix mouse scrolls on sliders
    
    Use gdk_event_get_scroll_deltas() to get the scroll direction.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=671724

 panels/sound/gvc-balance-bar.c        |   43 +++++++++++++++++++++++---------
 panels/sound/gvc-channel-bar.c        |   42 ++++++++++++++++++++++++-------
 panels/sound/gvc-channel-bar.h        |    4 +-
 panels/sound/gvc-stream-status-icon.c |    2 +-
 4 files changed, 66 insertions(+), 25 deletions(-)
---
diff --git a/panels/sound/gvc-balance-bar.c b/panels/sound/gvc-balance-bar.c
index bae395d..a24174a 100644
--- a/panels/sound/gvc-balance-bar.c
+++ b/panels/sound/gvc-balance-bar.c
@@ -425,32 +425,51 @@ on_scale_scroll_event (GtkWidget      *widget,
                        GvcBalanceBar  *bar)
 {
         gdouble value;
+        gdouble dx, dy;
 
         value = gtk_adjustment_get_value (bar->priv->adjustment);
 
+        if (!gdk_event_get_scroll_deltas ((GdkEvent*)event, &dx, &dy)) {
+                dx = 0.0;
+                dy = 0.0;
+
+                switch (event->direction) {
+                case GDK_SCROLL_UP:
+                case GDK_SCROLL_RIGHT:
+                        dy = 1.0;
+                        break;
+                case GDK_SCROLL_DOWN:
+                case GDK_SCROLL_LEFT:
+                        dy = -1.0;
+                        break;
+                default:
+                        ;
+                }
+        }
+
         if (bar->priv->btype == BALANCE_TYPE_LFE) {
-                if (event->direction == GDK_SCROLL_UP) {
-                        if (value + ADJUSTMENT_MAX_NORMAL/100.0 > ADJUSTMENT_MAX_NORMAL)
+                if (dy > 0) {
+                        if (value + dy * ADJUSTMENT_MAX_NORMAL/100.0 > ADJUSTMENT_MAX_NORMAL)
                                 value = ADJUSTMENT_MAX_NORMAL;
                         else
-                                value = value + ADJUSTMENT_MAX_NORMAL/100.0;
-                } else if (event->direction == GDK_SCROLL_DOWN) {
-                        if (value - ADJUSTMENT_MAX_NORMAL/100.0 < 0)
+                                value = value + dy * ADJUSTMENT_MAX_NORMAL/100.0;
+                } else if (dy < 0) {
+                        if (value + dy * ADJUSTMENT_MAX_NORMAL/100.0 < 0)
                                 value = 0.0;
                         else
-                                value = value - ADJUSTMENT_MAX_NORMAL/100.0;
+                                value = value + dy * ADJUSTMENT_MAX_NORMAL/100.0;
                 }
         } else {
-                if (event->direction == GDK_SCROLL_UP) {
-                        if (value + 0.01 > 1.0)
+                if (dy > 0) {
+                        if (value + dy * 0.01 > 1.0)
                                 value = 1.0;
                         else
-                                value = value + 0.01;
-                } else if (event->direction == GDK_SCROLL_DOWN) {
-                        if (value - 0.01 < -1.0)
+                                value = value + dy * 0.01;
+                } else if (dy < 0) {
+                        if (value + dy * 0.01 < -1.0)
                                 value = -1.0;
                         else
-                                value = value - 0.01;
+                                value = value + dy * 0.01;
                 }
         }
         gtk_adjustment_set_value (bar->priv->adjustment, value);
diff --git a/panels/sound/gvc-channel-bar.c b/panels/sound/gvc-channel-bar.c
index ef12640..3d854c9 100644
--- a/panels/sound/gvc-channel-bar.c
+++ b/panels/sound/gvc-channel-bar.c
@@ -416,16 +416,20 @@ on_scale_button_release_event (GtkWidget      *widget,
 }
 
 gboolean
-gvc_channel_bar_scroll (GvcChannelBar *bar, GdkScrollDirection direction)
+gvc_channel_bar_scroll (GvcChannelBar *bar, GdkEventScroll *event)
 {
         GtkAdjustment *adj;
         gdouble value;
+        GdkScrollDirection direction;
+        gdouble dx, dy;
 
         g_return_val_if_fail (bar != NULL, FALSE);
         g_return_val_if_fail (GVC_IS_CHANNEL_BAR (bar), FALSE);
 
+        direction = event->direction;
+
         if (bar->priv->orientation == GTK_ORIENTATION_VERTICAL) {
-                if (direction != GDK_SCROLL_UP && direction != GDK_SCROLL_DOWN)
+                if (direction == GDK_SCROLL_LEFT || direction == GDK_SCROLL_RIGHT)
                         return FALSE;
         } else {
                 /* Switch direction for RTL */
@@ -442,25 +446,43 @@ gvc_channel_bar_scroll (GvcChannelBar *bar, GdkScrollDirection direction)
                         direction = GDK_SCROLL_DOWN;
         }
 
+	if (!gdk_event_get_scroll_deltas ((GdkEvent*)event, &dx, &dy)) {
+		dx = 0.0;
+		dy = 0.0;
+
+		switch (direction) {
+		case GDK_SCROLL_UP:
+		case GDK_SCROLL_LEFT:
+			dy = 1.0;
+			break;
+		case GDK_SCROLL_DOWN:
+		case GDK_SCROLL_RIGHT:
+			dy = -1.0;
+			break;
+		default:
+			;
+		}
+	}
+
         adj = gtk_range_get_adjustment (GTK_RANGE (bar->priv->scale));
         if (adj == bar->priv->zero_adjustment) {
-                if (direction == GDK_SCROLL_UP)
+                if (dy > 0)
                         gvc_channel_bar_set_is_muted (bar, FALSE);
                 return TRUE;
         }
 
         value = gtk_adjustment_get_value (adj);
 
-        if (direction == GDK_SCROLL_UP) {
-                if (value + SCROLLSTEP > ADJUSTMENT_MAX)
+        if (dy > 0) {
+                if (value + dy * SCROLLSTEP > ADJUSTMENT_MAX)
                         value = ADJUSTMENT_MAX;
                 else
-                        value = value + SCROLLSTEP;
-        } else if (direction == GDK_SCROLL_DOWN) {
-                if (value - SCROLLSTEP < 0)
+                        value = value + dy * SCROLLSTEP;
+        } else if (dy < 0) {
+                if (value + dy * SCROLLSTEP < 0)
                         value = 0.0;
                 else
-                        value = value - SCROLLSTEP;
+                        value = value + dy * SCROLLSTEP;
         }
 
         gvc_channel_bar_set_is_muted (bar, (value == 0.0));
@@ -475,7 +497,7 @@ on_scale_scroll_event (GtkWidget      *widget,
                        GdkEventScroll *event,
                        GvcChannelBar  *bar)
 {
-        return gvc_channel_bar_scroll (bar, event->direction);
+        return gvc_channel_bar_scroll (bar, event);
 }
 
 static void
diff --git a/panels/sound/gvc-channel-bar.h b/panels/sound/gvc-channel-bar.h
index 6d3402d..0b607e8 100644
--- a/panels/sound/gvc-channel-bar.h
+++ b/panels/sound/gvc-channel-bar.h
@@ -81,8 +81,8 @@ gboolean            gvc_channel_bar_get_ellipsize       (GvcChannelBar *bar);
 void                gvc_channel_bar_set_ellipsize       (GvcChannelBar *bar,
                                                          gboolean       ellipsized);
 
-gboolean            gvc_channel_bar_scroll              (GvcChannelBar *bar,
-                                                         GdkScrollDirection direction);
+gboolean            gvc_channel_bar_scroll              (GvcChannelBar  *bar,
+                                                         GdkEventScroll *event);
 
 G_END_DECLS
 
diff --git a/panels/sound/gvc-stream-status-icon.c b/panels/sound/gvc-stream-status-icon.c
index 1f02613..88d5198 100644
--- a/panels/sound/gvc-stream-status-icon.c
+++ b/panels/sound/gvc-stream-status-icon.c
@@ -293,7 +293,7 @@ on_status_icon_scroll_event (GtkStatusIcon       *status_icon,
                              GdkEventScroll      *event,
                              GvcStreamStatusIcon *icon)
 {
-        return gvc_channel_bar_scroll (GVC_CHANNEL_BAR (icon->priv->bar), event->direction);
+        return gvc_channel_bar_scroll (GVC_CHANNEL_BAR (icon->priv->bar), event);
 }
 
 static void