mutter/doc/cookbook/examples/events-mouse-scroll.c
Elliot Smith 0f919fcbe3 cookbook: Handle all possible mouse scroll directions
Added empty cases for MOUSE_SCROLL_LEFT and MOUSE_SCROLL_RIGHT
to the scroll-event signal handler in the example code.
2010-08-11 18:16:07 +01:00

106 lines
3.2 KiB
C

#include <clutter/clutter.h>
#define STAGE_HEIGHT 400
#define STAGE_WIDTH STAGE_HEIGHT * 2
#define SCROLL_AMOUNT STAGE_HEIGHT * 0.2
static const ClutterColor stage_color = { 0x33, 0x33, 0x55, 0xff };
static const ClutterColor box_color = { 0xaa, 0xaa, 0x55, 0xff };
static gboolean
_scroll_event_cb (ClutterActor *scroll,
ClutterEvent *event,
gpointer user_data)
{
ClutterActor *viewport = CLUTTER_ACTOR (user_data);
gfloat y = clutter_actor_get_y (viewport);
ClutterScrollDirection direction;
direction = clutter_event_get_scroll_direction (event);
switch (direction)
{
case CLUTTER_SCROLL_UP:
y -= SCROLL_AMOUNT;
break;
case CLUTTER_SCROLL_DOWN:
y += SCROLL_AMOUNT;
break;
case CLUTTER_SCROLL_LEFT:
case CLUTTER_SCROLL_RIGHT:
break;
}
y = CLAMP (y,
clutter_actor_get_height (scroll)
+ clutter_actor_get_y (scroll)
- clutter_actor_get_height (viewport),
0.0);
clutter_actor_animate (viewport,
CLUTTER_EASE_OUT_CUBIC,
300,
"y", y,
NULL);
return TRUE;
}
int
main (int argc, char *argv[])
{
ClutterActor *stage;
ClutterActor *scroll;
ClutterActor *viewport;
ClutterActor *texture;
clutter_init (&argc, &argv);
stage = clutter_stage_get_default ();
clutter_actor_set_size (stage, STAGE_WIDTH, STAGE_HEIGHT);
clutter_stage_set_color (CLUTTER_STAGE (stage), &stage_color);
g_signal_connect (stage, "destroy", G_CALLBACK (clutter_main_quit), NULL);
/* the "letterbox" which the viewport is scrolled within */
scroll = clutter_group_new ();
clutter_actor_set_size (scroll, STAGE_WIDTH, STAGE_HEIGHT * 0.75);
clutter_actor_add_constraint (scroll, clutter_align_constraint_new (stage, CLUTTER_BIND_Y, 0.5));
clutter_actor_set_reactive (scroll, TRUE);
/* this clips all actors inside the scroll group to that group's allocation */
clutter_actor_set_clip_to_allocation (scroll, TRUE);
viewport = clutter_box_new (clutter_bin_layout_new (CLUTTER_BIN_ALIGNMENT_CENTER,
CLUTTER_BIN_ALIGNMENT_CENTER));
clutter_box_set_color (CLUTTER_BOX (viewport), &box_color);
/* the actor to scroll */
texture = clutter_texture_new ();
clutter_actor_set_request_mode (texture, CLUTTER_REQUEST_HEIGHT_FOR_WIDTH);
clutter_texture_set_keep_aspect_ratio (CLUTTER_TEXTURE (texture),
TRUE);
/* the box resizes itself to fit this texture */
clutter_actor_set_width (texture, STAGE_WIDTH);
clutter_texture_set_from_file (CLUTTER_TEXTURE (texture),
TESTS_DATA_DIR "/redhand.png",
NULL);
g_signal_connect (scroll,
"scroll-event",
G_CALLBACK (_scroll_event_cb),
viewport);
clutter_container_add_actor (CLUTTER_CONTAINER (viewport), texture);
clutter_container_add_actor (CLUTTER_CONTAINER (scroll), viewport);
clutter_container_add_actor (CLUTTER_CONTAINER (stage), scroll);
clutter_actor_show (stage);
clutter_main ();
return 0;
}