gnome-shell/src/shell-slicer.c
Colin Walters 262f92e0be [ShellSlicer] New class to display center of child
A #StBin that has 0 minimum size, and will clip its child
in the middle.

https://bugzilla.gnome.org/show_bug.cgi?id=605491
2010-01-07 18:33:00 -05:00

163 lines
4.4 KiB
C

/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
/**
* SECTION:shell-slicer
* @short_description: Display only part of another actor
*
* A #StBin that has 0 minimum size, and will clip its child
* in the middle.
*/
#include "config.h"
#include "shell-slicer.h"
G_DEFINE_TYPE (ShellSlicer,
shell_slicer,
ST_TYPE_BIN);
static void
shell_slicer_get_preferred_width (ClutterActor *self,
gfloat for_height,
gfloat *min_width_p,
gfloat *natural_width_p)
{
ClutterActor *child = st_bin_get_child (ST_BIN (self));
StThemeNode *theme_node = st_widget_get_theme_node (ST_WIDGET (self));
st_theme_node_adjust_for_height (theme_node, &for_height);
if (min_width_p)
*min_width_p = 0;
if (child == NULL)
{
if (natural_width_p)
*natural_width_p = 0;
}
else
{
clutter_actor_get_preferred_width (child, for_height,
NULL,
natural_width_p);
}
st_theme_node_adjust_preferred_width (theme_node, min_width_p, natural_width_p);
}
static void
shell_slicer_get_preferred_height (ClutterActor *self,
gfloat for_width,
gfloat *min_height_p,
gfloat *natural_height_p)
{
ClutterActor *child = st_bin_get_child (ST_BIN (self));
StThemeNode *theme_node = st_widget_get_theme_node (ST_WIDGET (self));
st_theme_node_adjust_for_width (theme_node, &for_width);
if (min_height_p)
*min_height_p = 0;
if (child == NULL)
{
if (natural_height_p)
*natural_height_p = 0;
}
else
{
clutter_actor_get_preferred_height (child, for_width,
NULL,
natural_height_p);
}
st_theme_node_adjust_preferred_height (theme_node, min_height_p, natural_height_p);
}
static void
shell_slicer_allocate (ClutterActor *self,
const ClutterActorBox *box,
ClutterAllocationFlags flags)
{
ClutterActor *child;
/* Chain up directly to ClutterActor to set actor->allocation. We explicitly skip our parent class
* StBin here because we want to override the allocate function. */
CLUTTER_ACTOR_CLASS (g_type_class_peek (clutter_actor_get_type ()))->allocate (self, box, flags);
child = st_bin_get_child (ST_BIN (self));
if (child)
clutter_actor_allocate_preferred_size (child, flags);
}
static void
shell_slicer_paint_child (ShellSlicer *self)
{
ClutterActor *child;
ClutterActorBox self_box;
ClutterActorBox child_box;
float width, height, child_width, child_height;
double x_align, y_align;
child = st_bin_get_child (ST_BIN (self));
if (!child)
return;
_st_bin_get_align_factors (ST_BIN (self), &x_align, &y_align);
clutter_actor_get_allocation_box (CLUTTER_ACTOR (self), &self_box);
clutter_actor_get_allocation_box (child, &child_box);
width = self_box.x2 - self_box.x1;
height = self_box.y2 - self_box.y1;
child_width = child_box.x2 - child_box.x1;
child_height = child_box.y2 - child_box.y1;
cogl_push_matrix ();
cogl_clip_push (0, 0, width, height);
cogl_translate ((int)(0.5 + x_align * (width - child_width)),
(int)(0.5 + y_align * (height - child_height)),
0);
clutter_actor_paint (child);
cogl_clip_pop ();
cogl_pop_matrix ();
}
static void
shell_slicer_paint (ClutterActor *self)
{
/* StWidget paints CSS elements */
CLUTTER_ACTOR_CLASS (g_type_class_peek (st_widget_get_type ()))->paint (self);
shell_slicer_paint_child (SHELL_SLICER (self));
}
static void
shell_slicer_pick (ClutterActor *self,
const ClutterColor *pick_color)
{
shell_slicer_paint_child (SHELL_SLICER (self));
}
static void
shell_slicer_class_init (ShellSlicerClass *klass)
{
ClutterActorClass *actor_class = CLUTTER_ACTOR_CLASS (klass);
actor_class->get_preferred_width = shell_slicer_get_preferred_width;
actor_class->get_preferred_height = shell_slicer_get_preferred_height;
actor_class->allocate = shell_slicer_allocate;
actor_class->paint = shell_slicer_paint;
actor_class->pick = shell_slicer_pick;
}
static void
shell_slicer_init (ShellSlicer *actor)
{
}