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#include <stdlib.h>
#include <math.h>
#include <gmodule.h>
#include <clutter/clutter.h>
#define RECT_WIDTH 400
#define RECT_HEIGHT 300
#define N_RECTS 7
static const gchar *rect_color[N_RECTS] = {
"#edd400",
"#f57900",
"#c17d11",
"#73d216",
"#3465a4",
"#75507b",
"#cc0000"
};
static ClutterActor *rectangle[N_RECTS];
static ClutterActor *viewport = NULL;
static void
on_drag_end (ClutterDragAction *action,
ClutterActor *actor,
gfloat event_x,
gfloat event_y,
ClutterModifierType modifiers)
{
gfloat viewport_x = clutter_actor_get_x (viewport);
gfloat offset_x;
gint child_visible;
/* check if we're at the viewport edges */
if (viewport_x > 0)
{
clutter_actor_save_easing_state (viewport);
clutter_actor_set_easing_mode (viewport, CLUTTER_EASE_OUT_BOUNCE);
clutter_actor_set_x (viewport, 0);
clutter_actor_restore_easing_state (viewport);
return;
}
if (viewport_x < (-1.0f * (RECT_WIDTH * (N_RECTS - 1))))
{
clutter_actor_save_easing_state (viewport);
clutter_actor_set_easing_mode (viewport, CLUTTER_EASE_OUT_BOUNCE);
clutter_actor_set_x (viewport, -1.0f * (RECT_WIDTH * (N_RECTS - 1)));
clutter_actor_restore_easing_state (viewport);
return;
}
/* animate the viewport to fully show the child once we pass
* a certain threshold with the dragging action
*/
offset_x = fabsf (viewport_x) / RECT_WIDTH + 0.5f;
if (offset_x > (RECT_WIDTH * 0.33))
child_visible = (int) offset_x + 1;
else
child_visible = (int) offset_x;
/* sanity check on the children number */
child_visible = CLAMP (child_visible, 0, N_RECTS);
clutter_actor_save_easing_state (viewport);
clutter_actor_set_x (viewport, -1.0f * RECT_WIDTH * child_visible);
clutter_actor_restore_easing_state (viewport);
}
G_MODULE_EXPORT int
test_scrolling_main (int argc, char *argv[])
{
ClutterActor *stage;
ClutterActor *scroll;
ClutterAction *action;
gint i;
if (clutter_init (&argc, &argv) != CLUTTER_INIT_SUCCESS)
return 1;
stage = clutter_stage_new ();
clutter_stage_set_title (CLUTTER_STAGE (stage), "Scrolling");
clutter_actor_set_size (stage, 800, 600);
g_signal_connect (stage, "destroy", G_CALLBACK (clutter_main_quit), NULL);
/* scroll: the group that contains the scrolling viewport; we set its
* size to be the same as one rectangle, position it in the middle of
* the stage and set it to clip its contents to the allocated size
*/
scroll = clutter_actor_new ();
clutter_actor_add_child (stage, scroll);
clutter_actor_set_size (scroll, RECT_WIDTH, RECT_HEIGHT);
clutter_actor_add_constraint (scroll, clutter_align_constraint_new (stage, CLUTTER_ALIGN_BOTH, 0.5));
clutter_actor_set_clip_to_allocation (scroll, TRUE);
/* viewport: the actual container for the children; we scroll it using
* the Drag action constrained to the horizontal axis, and every time
* the dragging ends we check whether we're dragging past the end of
* the viewport
*/
viewport = clutter_actor_new ();
clutter_actor_set_layout_manager (viewport, clutter_box_layout_new ());
clutter_actor_add_child (scroll, viewport);
/* add dragging capabilities to the viewport; the heavy lifting is
* all done by the DragAction itself, plus the ::drag-end signal
* handler in our code
*/
action = clutter_drag_action_new ();
clutter_actor_add_action (viewport, action);
clutter_drag_action_set_drag_axis (CLUTTER_DRAG_ACTION (action),
CLUTTER_DRAG_X_AXIS);
g_signal_connect (action, "drag-end", G_CALLBACK (on_drag_end), NULL);
clutter_actor_set_reactive (viewport, TRUE);
/* children of the viewport */
for (i = 0; i < N_RECTS; i++)
{
ClutterColor color;
clutter_color_from_string (&color, rect_color[i]);
rectangle[i] = clutter_actor_new ();
clutter_actor_set_background_color (rectangle[i], &color);
clutter_actor_add_child (viewport, rectangle[i]);
clutter_actor_set_size (rectangle[i], RECT_WIDTH, RECT_HEIGHT);
}
clutter_actor_show (stage);
clutter_main ();
return EXIT_SUCCESS;
}
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