void scroll_widget::wheelEvent(QGraphicsSceneWheelEvent *a_event_ptr) {
if (a_event_ptr->delta() < 0) {
scroll_by(0, -10);
} else {
scroll_by(0, 10);
}
a_event_ptr->accept();
//?
widget::wheelEvent(a_event_ptr);
}
/* Scroll event handler for the image view. We zoom with an event without
* modifiers rather than scroll; we use the Shift modifier to scroll.
* Rationale: images are not primarily vertical, and in EOG you scan scroll by
* dragging the image with button 1 anyways.
*/
static gboolean
image_view_scroll_event (GtkWidget *widget, GdkEventScroll *event)
{
ImageView *view;
ImageViewPrivate *priv;
double zoom_factor;
int xofs, yofs;
view = IMAGE_VIEW (widget);
priv = view->priv;
/* Compute zoom factor and scrolling offsets; we'll only use either of them */
xofs = priv->hadj->page_increment / 2; /* same as in gtkscrolledwindow.c */
yofs = priv->vadj->page_increment / 2;
switch (event->direction) {
case GDK_SCROLL_UP:
zoom_factor = IMAGE_VIEW_ZOOM_MULTIPLIER;
xofs = 0;
yofs = -yofs;
break;
case GDK_SCROLL_LEFT:
zoom_factor = 1.0 / IMAGE_VIEW_ZOOM_MULTIPLIER;
xofs = -xofs;
yofs = 0;
break;
case GDK_SCROLL_DOWN:
zoom_factor = 1.0 / IMAGE_VIEW_ZOOM_MULTIPLIER;
xofs = 0;
yofs = yofs;
break;
case GDK_SCROLL_RIGHT:
zoom_factor = IMAGE_VIEW_ZOOM_MULTIPLIER;
xofs = xofs;
yofs = 0;
break;
default:
g_assert_not_reached ();
return FALSE;
}
if ((event->state & GDK_SHIFT_MASK) == 0)
image_view_set_zoom (view, priv->zoomx * zoom_factor, priv->zoomy * zoom_factor,
TRUE, event->x, event->y);
else
scroll_by (view, xofs, yofs);
return TRUE;
}
void TBScrollBox::page_backward(DimensionName d) {
scroll_by(d, long(large_scroll(d)));
}
void TBScrollBox::scroll_backward(DimensionName d) {
scroll_by(d, long(small_scroll(d)));
}
/* Key press event handler for the image view */
static gboolean
image_view_key_press_event (GtkWidget *widget, GdkEventKey *event)
{
ImageView *view;
ImageViewPrivate *priv;
gboolean do_zoom;
double zoomx, zoomy;
gboolean do_scroll;
int xofs, yofs;
view = IMAGE_VIEW (widget);
priv = view->priv;
do_zoom = FALSE;
do_scroll = FALSE;
xofs = yofs = 0;
zoomx = zoomy = 1.0;
if ((event->state & (GDK_MODIFIER_MASK & ~GDK_LOCK_MASK)) != 0)
return FALSE;
switch (event->keyval) {
case GDK_Up:
do_scroll = TRUE;
xofs = 0;
yofs = -SCROLL_STEP_SIZE;
break;
case GDK_Down:
do_scroll = TRUE;
xofs = 0;
yofs = SCROLL_STEP_SIZE;
break;
case GDK_Left:
do_scroll = TRUE;
xofs = -SCROLL_STEP_SIZE;
yofs = 0;
break;
case GDK_Right:
do_scroll = TRUE;
xofs = SCROLL_STEP_SIZE;
yofs = 0;
break;
case GDK_plus:
case GDK_KP_Add:
do_zoom = TRUE;
zoomx = priv->zoomx * IMAGE_VIEW_ZOOM_MULTIPLIER;
zoomy = priv->zoomy * IMAGE_VIEW_ZOOM_MULTIPLIER;
break;
case GDK_minus:
case GDK_KP_Subtract:
do_zoom = TRUE;
zoomx = priv->zoomx / IMAGE_VIEW_ZOOM_MULTIPLIER;
zoomy = priv->zoomy / IMAGE_VIEW_ZOOM_MULTIPLIER;
break;
case GDK_1:
do_zoom = TRUE;
zoomx = zoomy = 1.0;
break;
case GDK_F:
case GDK_f:
g_signal_emit (view, image_view_signals [ZOOM_FIT], 0);
break;
default:
return FALSE;
}
if (do_zoom) {
gint x, y;
gdk_window_get_pointer (widget->window, &x, &y, NULL);
image_view_set_zoom (view, zoomx, zoomy, TRUE, x, y);
}
if (do_scroll)
scroll_by (view, xofs, yofs);
return TRUE;
}