static void
clamp_adjustments (ChamplainKineticScrollView *scroll)
{
ChamplainKineticScrollViewPrivate *priv = scroll->priv;
if (priv->viewport)
{
ChamplainAdjustment *hadj, *vadj;
gdouble d, value, lower, step_increment;
champlain_viewport_get_adjustments (CHAMPLAIN_VIEWPORT (priv->viewport),
&hadj, &vadj);
/* Snap to the nearest step increment on hadjustment */
champlain_adjustment_get_values (hadj, &value, &lower, NULL,
&step_increment);
d = (rint ((value - lower) / step_increment) *
step_increment) + lower;
champlain_adjustment_set_value (hadj, d);
/* Snap to the nearest step increment on vadjustment */
champlain_adjustment_get_values (vadj, &value, &lower, NULL,
&step_increment);
d = (rint ((value - lower) / step_increment) *
step_increment) + lower;
champlain_adjustment_set_value (vadj, d);
}
}
static void
deceleration_new_frame_cb (ClutterTimeline *timeline,
gint frame_num,
ChamplainKineticScrollView *scroll)
{
ChamplainKineticScrollViewPrivate *priv = scroll->priv;
if (priv->viewport)
{
gdouble value, lower, upper;
ChamplainAdjustment *hadjust, *vadjust;
gint i;
gboolean stop = TRUE;
champlain_viewport_get_adjustments (CHAMPLAIN_VIEWPORT (priv->viewport),
&hadjust,
&vadjust);
for (i = 0; i < clutter_timeline_get_delta (timeline) / 15; i++)
{
champlain_adjustment_set_value (hadjust,
priv->dx +
champlain_adjustment_get_value (hadjust));
champlain_adjustment_set_value (vadjust,
priv->dy +
champlain_adjustment_get_value (vadjust));
priv->dx = (priv->dx / priv->decel_rate);
priv->dy = (priv->dy / priv->decel_rate);
}
/* Check if we've hit the upper or lower bounds and stop the timeline */
champlain_adjustment_get_values (hadjust, &value, &lower, &upper,
NULL);
if (((priv->dx > 0) && (value < upper)) ||
((priv->dx < 0) && (value > lower)))
stop = FALSE;
if (stop)
{
champlain_adjustment_get_values (vadjust, &value, &lower, &upper,
NULL);
if (((priv->dy > 0) && (value < upper)) ||
((priv->dy < 0) && (value > lower)))
stop = FALSE;
}
if (stop)
{
clutter_timeline_stop (timeline);
deceleration_completed_cb (timeline, scroll);
}
}
}
static void
champlain_viewport_get_property (GObject *object,
guint prop_id,
GValue *value,
GParamSpec *pspec)
{
ChamplainAdjustment *adjustment;
ChamplainViewportPrivate *priv = CHAMPLAIN_VIEWPORT (object)->priv;
switch (prop_id)
{
case PROP_X_ORIGIN:
g_value_set_int (value, priv->x);
break;
case PROP_Y_ORIGIN:
g_value_set_int (value, priv->y);
break;
case PROP_HADJUST:
champlain_viewport_get_adjustments (CHAMPLAIN_VIEWPORT (object), &adjustment, NULL);
g_value_set_object (value, adjustment);
break;
case PROP_VADJUST:
champlain_viewport_get_adjustments (CHAMPLAIN_VIEWPORT (object), NULL, &adjustment);
g_value_set_object (value, adjustment);
break;
case PROP_SYNC_ADJUST:
g_value_set_boolean (value, priv->sync_adjustments);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static gboolean
button_release_event_cb (ClutterActor *stage,
ClutterButtonEvent *event,
ChamplainKineticScrollView *scroll)
{
ChamplainKineticScrollViewPrivate *priv = scroll->priv;
ClutterActor *actor = CLUTTER_ACTOR (scroll);
gboolean decelerating = FALSE;
if ((event->type != CLUTTER_MOTION || event->modifier_state & CLUTTER_BUTTON1_MASK) &&
(event->type != CLUTTER_BUTTON_RELEASE || event->button != 1) &&
(event->type != CLUTTER_TOUCH_END || priv->sequence != clutter_event_get_event_sequence ((ClutterEvent *) event)))
return FALSE;
g_signal_handlers_disconnect_by_func (stage,
motion_event_cb,
scroll);
g_signal_handlers_disconnect_by_func (stage,
button_release_event_cb,
scroll);
if (priv->kinetic && priv->viewport)
{
gfloat x, y;
if (clutter_actor_transform_stage_point (actor,
event->x,
event->y,
&x, &y))
{
double frac, x_origin, y_origin;
GTimeVal release_time, motion_time;
ChamplainAdjustment *hadjust, *vadjust;
glong time_diff;
gint i;
/* Get time delta */
g_get_current_time (&release_time);
/* Get average position/time of last x mouse events */
priv->last_motion++;
x_origin = y_origin = 0;
motion_time = (GTimeVal){ 0, 0 };
for (i = 0; i < priv->last_motion; i++)
{
ChamplainKineticScrollViewMotion *motion =
&g_array_index (priv->motion_buffer, ChamplainKineticScrollViewMotion, i);
/* FIXME: This doesn't guard against overflows - Should
* either fix that, or calculate the correct maximum
* value for the buffer size
*/
x_origin += motion->x;
y_origin += motion->y;
motion_time.tv_sec += motion->time.tv_sec;
motion_time.tv_usec += motion->time.tv_usec;
}
x_origin /= priv->last_motion;
y_origin /= priv->last_motion;
motion_time.tv_sec /= priv->last_motion;
motion_time.tv_usec /= priv->last_motion;
if (motion_time.tv_sec == release_time.tv_sec)
time_diff = release_time.tv_usec - motion_time.tv_usec;
else
time_diff = release_time.tv_usec +
(G_USEC_PER_SEC - motion_time.tv_usec);
/* On a macbook that's running Ubuntu 9.04 sometimes 'time_diff' is 0
and this causes a division by 0 when computing 'frac'. This check
avoids this error.
*/
if (time_diff != 0)
{
/* Work out the fraction of 1/60th of a second that has elapsed */
frac = (time_diff / 1000.0) / (1000.0 / 60.0);
/* See how many units to move in 1/60th of a second */
priv->dx = (x_origin - x) / frac;
priv->dy = (y_origin - y) / frac;
/* Get adjustments to do step-increment snapping */
champlain_viewport_get_adjustments (CHAMPLAIN_VIEWPORT (priv->viewport),
&hadjust,
&vadjust);
if (ABS (priv->dx) > 1 ||
ABS (priv->dy) > 1)
{
gdouble value, lower, step_increment, d, a, x, y, n;
/* TODO: Convert this all to fixed point? */
/* We want n, where x / y n < z,
* x = Distance to move per frame
* y = Deceleration rate
* z = maximum distance from target
*
* Rearrange to n = log (x / z) / log (y)
* To simplify, z = 1, so n = log (x) / log (y)
*
* As z = 1, this will cause stops to be slightly abrupt -
* add a constant 15 frames to compensate.
*/
x = MAX (ABS (priv->dx), ABS (priv->dy));
y = priv->decel_rate;
n = logf (x) / logf (y) + 15.0;
/* Now we have n, adjust dx/dy so that we finish on a step
* boundary.
*
* Distance moved, using the above variable names:
*
* d = x + x/y + x/y 2 + ... + x/y n
*
* Using geometric series,
*
* d = (1 - 1/y (n+1))/(1 - 1/y)*x
*
* Let a = (1 - 1/y (n+1))/(1 - 1/y),
*
* d = a * x
*
* Find d and find its nearest page boundary, then solve for x
*
* x = d / a
*/
/* Get adjustments, work out y n */
a = (1.0 - 1.0 / pow (y, n + 1)) / (1.0 - 1.0 / y);
/* Solving for dx */
d = a * priv->dx;
champlain_adjustment_get_values (hadjust, &value, &lower, NULL,
&step_increment);
d = ((rint (((value + d) - lower) / step_increment) *
step_increment) + lower) - value;
priv->dx = (d / a);
/* Solving for dy */
d = a * (priv->dy);
champlain_adjustment_get_values (vadjust, &value, &lower, NULL,
&step_increment);
d = ((rint (((value + d) - lower) / step_increment) *
step_increment) + lower) - value;
priv->dy = (d / a);
priv->deceleration_timeline = clutter_timeline_new ((n / 60) * 1000.0);
}
else
{
gdouble value, lower, step_increment, d, a, y;
/* Start a short effects timeline to snap to the nearest step
* boundary (see equations above)
*/
y = priv->decel_rate;
a = (1.0 - 1.0 / pow (y, 4 + 1)) / (1.0 - 1.0 / y);
champlain_adjustment_get_values (hadjust, &value, &lower, NULL,
&step_increment);
d = ((rint ((value - lower) / step_increment) *
step_increment) + lower) - value;
priv->dx = (d / a);
champlain_adjustment_get_values (vadjust, &value, &lower, NULL,
&step_increment);
d = ((rint ((value - lower) / step_increment) *
step_increment) + lower) - value;
priv->dy = (d / a);
priv->deceleration_timeline = clutter_timeline_new (250);
}
g_signal_connect (priv->deceleration_timeline, "new_frame",
G_CALLBACK (deceleration_new_frame_cb), scroll);
g_signal_connect (priv->deceleration_timeline, "completed",
G_CALLBACK (deceleration_completed_cb), scroll);
clutter_timeline_start (priv->deceleration_timeline);
decelerating = TRUE;
}
}
}
priv->sequence = NULL;
/* Reset motion event buffer */
priv->last_motion = 0;
if (!decelerating)
{
clamp_adjustments (scroll);
g_signal_emit_by_name (scroll, "panning-completed", NULL);
}
/* Due to the way gestures in progress connect to the stage in order to
* receive events, we must let these events go through, as they could be
* essential for the management of the ClutterZoomGesture in the
* ChamplainView.
*/
return FALSE;
}
static gboolean
motion_event_cb (ClutterActor *stage,
ClutterMotionEvent *event,
ChamplainKineticScrollView *scroll)
{
ChamplainKineticScrollViewPrivate *priv = scroll->priv;
ClutterActor *actor = CLUTTER_ACTOR (scroll);
gfloat x, y;
if ((event->type != CLUTTER_MOTION || !(event->modifier_state & CLUTTER_BUTTON1_MASK)) &&
(event->type != CLUTTER_TOUCH_UPDATE || priv->sequence != clutter_event_get_event_sequence ((ClutterEvent *) event)))
return FALSE;
if (clutter_actor_transform_stage_point (actor,
event->x,
event->y,
&x, &y))
{
ChamplainKineticScrollViewMotion *motion;
if (priv->viewport)
{
gdouble dx, dy;
ChamplainAdjustment *hadjust, *vadjust;
champlain_viewport_get_adjustments (CHAMPLAIN_VIEWPORT (priv->viewport),
&hadjust,
&vadjust);
motion = &g_array_index (priv->motion_buffer,
ChamplainKineticScrollViewMotion, priv->last_motion);
if (hadjust)
{
dx = (motion->x - x) +
champlain_adjustment_get_value (hadjust);
champlain_adjustment_set_value (hadjust, dx);
}
if (vadjust)
{
dy = (motion->y - y) +
champlain_adjustment_get_value (vadjust);
champlain_adjustment_set_value (vadjust, dy);
}
}
priv->last_motion++;
if (priv->last_motion == priv->motion_buffer->len)
{
priv->motion_buffer = g_array_remove_index (priv->motion_buffer, 0);
g_array_set_size (priv->motion_buffer, priv->last_motion);
priv->last_motion--;
}
motion = &g_array_index (priv->motion_buffer,
ChamplainKineticScrollViewMotion, priv->last_motion);
motion->x = x;
motion->y = y;
g_get_current_time (&motion->time);
}
/* Due to the way gestures in progress connect to the stage in order to
* receive events, we must let these events go through, as they could be
* essential for the management of the ClutterZoomGesture in the
* ChamplainView.
*/
return FALSE;
}
static gboolean
motion_event_cb (ClutterActor *stage,
ClutterMotionEvent *event,
ChamplainKineticScrollView *scroll)
{
ChamplainKineticScrollViewPrivate *priv = scroll->priv;
ClutterActor *actor = CLUTTER_ACTOR (scroll);
gfloat x, y;
if (event->type != CLUTTER_MOTION || !(event->modifier_state & CLUTTER_BUTTON1_MASK))
return FALSE;
if (clutter_actor_transform_stage_point (actor,
event->x,
event->y,
&x, &y))
{
ChamplainKineticScrollViewMotion *motion;
if (priv->viewport)
{
gdouble dx, dy;
ChamplainAdjustment *hadjust, *vadjust;
champlain_viewport_get_adjustments (CHAMPLAIN_VIEWPORT (priv->viewport),
&hadjust,
&vadjust);
motion = &g_array_index (priv->motion_buffer,
ChamplainKineticScrollViewMotion, priv->last_motion);
if (hadjust)
{
dx = (motion->x - x) +
champlain_adjustment_get_value (hadjust);
champlain_adjustment_set_value (hadjust, dx);
}
if (vadjust)
{
dy = (motion->y - y) +
champlain_adjustment_get_value (vadjust);
champlain_adjustment_set_value (vadjust, dy);
}
}
priv->last_motion++;
if (priv->last_motion == priv->motion_buffer->len)
{
priv->motion_buffer = g_array_remove_index (priv->motion_buffer, 0);
g_array_set_size (priv->motion_buffer, priv->last_motion);
priv->last_motion--;
}
motion = &g_array_index (priv->motion_buffer,
ChamplainKineticScrollViewMotion, priv->last_motion);
motion->x = x;
motion->y = y;
g_get_current_time (&motion->time);
}
return TRUE;
}