/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
/*
* st-scroll-view-fade.h: Edge fade effect for StScrollView
*
* Copyright 2010 Intel Corporation.
* Copyright 2011 Adel Gadllah
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU Lesser General Public License,
* version 2.1, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT ANY
* WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
* FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for
* more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "st-scroll-view-fade.h"
#include "st-scroll-view.h"
#include "st-widget.h"
#include "st-theme-node.h"
#include "st-scroll-bar.h"
#include "st-scrollable.h"
#include <clutter/clutter.h>
#include <cogl/cogl.h>
#define DEFAULT_FADE_OFFSET 68.0f
#include "st-scroll-view-fade-generated.c"
struct _StScrollViewFade
{
ClutterShaderEffect parent_instance;
/* a back pointer to our actor, so that we can query it */
ClutterActor *actor;
StAdjustment *vadjustment;
StAdjustment *hadjustment;
guint fade_edges : 1;
float vfade_offset;
float hfade_offset;
};
G_DEFINE_TYPE (StScrollViewFade,
st_scroll_view_fade,
CLUTTER_TYPE_SHADER_EFFECT);
enum {
PROP_0,
PROP_VFADE_OFFSET,
PROP_HFADE_OFFSET,
PROP_FADE_EDGES
};
static CoglTexture *
st_scroll_view_fade_create_texture (ClutterOffscreenEffect *effect,
gfloat min_width,
gfloat min_height)
{
CoglContext *ctx =
clutter_backend_get_cogl_context (clutter_get_default_backend ());
return COGL_TEXTURE (cogl_texture_2d_new_with_size (ctx, min_width, min_height));
}
static char *
st_scroll_view_fade_get_static_shader_source (ClutterShaderEffect *effect)
{
return g_strdup (st_scroll_view_fade_glsl);
}
static void
st_scroll_view_fade_paint_target (ClutterOffscreenEffect *effect)
{
StScrollViewFade *self = ST_SCROLL_VIEW_FADE (effect);
ClutterShaderEffect *shader = CLUTTER_SHADER_EFFECT (effect);
ClutterOffscreenEffectClass *parent;
gdouble value, lower, upper, page_size;
ClutterActor *vscroll = st_scroll_view_get_vscroll_bar (ST_SCROLL_VIEW (self->actor));
ClutterActor *hscroll = st_scroll_view_get_hscroll_bar (ST_SCROLL_VIEW (self->actor));
gboolean h_scroll_visible, v_scroll_visible;
ClutterActorBox allocation, content_box, paint_box;
float fade_area_topleft[2];
float fade_area_bottomright[2];
ClutterVertex verts[4];
clutter_actor_get_paint_box (self->actor, &paint_box);
clutter_actor_get_abs_allocation_vertices (self->actor, verts);
clutter_actor_get_allocation_box (self->actor, &allocation);
st_theme_node_get_content_box (st_widget_get_theme_node (ST_WIDGET (self->actor)),
(const ClutterActorBox *)&allocation, &content_box);
/*
* The FBO is based on the paint_volume's size which can be larger then the actual
* allocation, so we have to account for that when passing the positions
*/
fade_area_topleft[0] = content_box.x1 + (verts[0].x - paint_box.x1);
fade_area_topleft[1] = content_box.y1 + (verts[0].y - paint_box.y1);
fade_area_bottomright[0] = content_box.x2 + (verts[3].x - paint_box.x2) + 1;
fade_area_bottomright[1] = content_box.y2 + (verts[3].y - paint_box.y2) + 1;
g_object_get (ST_SCROLL_VIEW (self->actor),
"hscrollbar-visible", &h_scroll_visible,
"vscrollbar-visible", &v_scroll_visible,
NULL);
if (v_scroll_visible)
{
if (clutter_actor_get_text_direction (self->actor) == CLUTTER_TEXT_DIRECTION_RTL)
fade_area_topleft[0] += clutter_actor_get_width (vscroll);
fade_area_bottomright[0] -= clutter_actor_get_width (vscroll);
}
if (h_scroll_visible)
fade_area_bottomright[1] -= clutter_actor_get_height (hscroll);
st_adjustment_get_values (self->vadjustment, &value, &lower, &upper, NULL, NULL, &page_size);
value = (value - lower) / (upper - page_size - lower);
clutter_shader_effect_set_uniform (shader, "fade_edges_top", G_TYPE_INT, 1, self->fade_edges ? value >= 0.0 : value > 0.0);
clutter_shader_effect_set_uniform (shader, "fade_edges_bottom", G_TYPE_INT, 1, self->fade_edges ? value <= 1.0 : value < 1.0);
st_adjustment_get_values (self->hadjustment, &value, &lower, &upper, NULL, NULL, &page_size);
value = (value - lower) / (upper - page_size - lower);
clutter_shader_effect_set_uniform (shader, "fade_edges_left", G_TYPE_INT, 1, self->fade_edges ? value >= 0.0 : value > 0.0);
clutter_shader_effect_set_uniform (shader, "fade_edges_right", G_TYPE_INT, 1, self->fade_edges ? value <= 1.0 : value < 1.0);
clutter_shader_effect_set_uniform (shader, "vfade_offset", G_TYPE_FLOAT, 1, self->vfade_offset);
clutter_shader_effect_set_uniform (shader, "hfade_offset", G_TYPE_FLOAT, 1, self->hfade_offset);
clutter_shader_effect_set_uniform (shader, "tex", G_TYPE_INT, 1, 0);
clutter_shader_effect_set_uniform (shader, "height", G_TYPE_FLOAT, 1, clutter_actor_get_height (self->actor));
clutter_shader_effect_set_uniform (shader, "width", G_TYPE_FLOAT, 1, clutter_actor_get_width (self->actor));
clutter_shader_effect_set_uniform (shader, "fade_area_topleft", CLUTTER_TYPE_SHADER_FLOAT, 2, fade_area_topleft);
clutter_shader_effect_set_uniform (shader, "fade_area_bottomright", CLUTTER_TYPE_SHADER_FLOAT, 2, fade_area_bottomright);
parent = CLUTTER_OFFSCREEN_EFFECT_CLASS (st_scroll_view_fade_parent_class);
parent->paint_target(effect);
}
static void
on_adjustment_changed (StAdjustment *adjustment,
ClutterEffect *effect)
{
gdouble value, lower, upper, page_size;
gboolean needs_fade;
StScrollViewFade *self = ST_SCROLL_VIEW_FADE (effect);
st_adjustment_get_values (self->vadjustment, &value, &lower, &upper, NULL, NULL, &page_size);
needs_fade = (value > lower + 0.1) || (value < upper - page_size - 0.1);
if (!needs_fade)
{
st_adjustment_get_values (self->hadjustment, &value, &lower, &upper, NULL, NULL, &page_size);
needs_fade = (value > lower + 0.1) || (value < upper - page_size - 0.1);
}
clutter_actor_meta_set_enabled (CLUTTER_ACTOR_META (effect), needs_fade);
}
static void
st_scroll_view_fade_set_actor (ClutterActorMeta *meta,
ClutterActor *actor)
{
StScrollViewFade *self = ST_SCROLL_VIEW_FADE (meta);
ClutterActorMetaClass *parent;
g_return_if_fail (actor == NULL || ST_IS_SCROLL_VIEW (actor));
if (!clutter_feature_available (CLUTTER_FEATURE_SHADERS_GLSL))
{
/* if we don't have support for GLSL shaders then we
* forcibly disable the ActorMeta
*/
clutter_actor_meta_set_enabled (meta, FALSE);
return;
}
if (self->vadjustment)
{
g_signal_handlers_disconnect_by_func (self->vadjustment,
(gpointer)on_adjustment_changed,
self);
self->vadjustment = NULL;
}
if (self->hadjustment)
{
g_signal_handlers_disconnect_by_func (self->hadjustment,
(gpointer)on_adjustment_changed,
self);
self->hadjustment = NULL;
}
if (actor)
{
StScrollView *scroll_view = ST_SCROLL_VIEW (actor);
StScrollBar *vscroll = ST_SCROLL_BAR (st_scroll_view_get_vscroll_bar (scroll_view));
StScrollBar *hscroll = ST_SCROLL_BAR (st_scroll_view_get_hscroll_bar (scroll_view));
self->vadjustment = ST_ADJUSTMENT (st_scroll_bar_get_adjustment (vscroll));
self->hadjustment = ST_ADJUSTMENT (st_scroll_bar_get_adjustment (hscroll));
g_signal_connect (self->vadjustment, "changed",
G_CALLBACK (on_adjustment_changed),
self);
g_signal_connect (self->hadjustment, "changed",
G_CALLBACK (on_adjustment_changed),
self);
on_adjustment_changed (NULL, CLUTTER_EFFECT (self));
}
parent = CLUTTER_ACTOR_META_CLASS (st_scroll_view_fade_parent_class);
parent->set_actor (meta, actor);
/* we keep a back pointer here, to avoid going through the ActorMeta */
self->actor = clutter_actor_meta_get_actor (meta);
}
static void
st_scroll_view_fade_dispose (GObject *gobject)
{
StScrollViewFade *self = ST_SCROLL_VIEW_FADE (gobject);
if (self->vadjustment)
{
g_signal_handlers_disconnect_by_func (self->vadjustment,
(gpointer)on_adjustment_changed,
self);
self->vadjustment = NULL;
}
if (self->hadjustment)
{
g_signal_handlers_disconnect_by_func (self->hadjustment,
(gpointer)on_adjustment_changed,
self);
self->hadjustment = NULL;
}
self->actor = NULL;
G_OBJECT_CLASS (st_scroll_view_fade_parent_class)->dispose (gobject);
}
static void
st_scroll_view_vfade_set_offset (StScrollViewFade *self,
float fade_offset)
{
if (self->vfade_offset == fade_offset)
return;
g_object_freeze_notify (G_OBJECT (self));
self->vfade_offset = fade_offset;
if (self->actor != NULL)
clutter_actor_queue_redraw (self->actor);
g_object_notify (G_OBJECT (self), "vfade-offset");
g_object_thaw_notify (G_OBJECT (self));
}
static void
st_scroll_view_hfade_set_offset (StScrollViewFade *self,
float fade_offset)
{
if (self->hfade_offset == fade_offset)
return;
g_object_freeze_notify (G_OBJECT (self));
self->hfade_offset = fade_offset;
if (self->actor != NULL)
clutter_actor_queue_redraw (self->actor);
g_object_notify (G_OBJECT (self), "hfade-offset");
g_object_thaw_notify (G_OBJECT (self));
}
static void
st_scroll_view_fade_set_fade_edges (StScrollViewFade *self,
gboolean fade_edges)
{
if (self->fade_edges == fade_edges)
return;
g_object_freeze_notify (G_OBJECT (self));
self->fade_edges = fade_edges;
if (self->actor != NULL)
clutter_actor_queue_redraw (self->actor);
g_object_notify (G_OBJECT (self), "fade-edges");
g_object_thaw_notify (G_OBJECT (self));
}
static void
st_scroll_view_fade_set_property (GObject *object,
guint prop_id,
const GValue *value,
GParamSpec *pspec)
{
StScrollViewFade *self = ST_SCROLL_VIEW_FADE (object);
switch (prop_id)
{
case PROP_VFADE_OFFSET:
st_scroll_view_vfade_set_offset (self, g_value_get_float (value));
break;
case PROP_HFADE_OFFSET:
st_scroll_view_hfade_set_offset (self, g_value_get_float (value));
break;
case PROP_FADE_EDGES:
st_scroll_view_fade_set_fade_edges (self, g_value_get_boolean (value));
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
st_scroll_view_fade_get_property (GObject *object,
guint prop_id,
GValue *value,
GParamSpec *pspec)
{
StScrollViewFade *self = ST_SCROLL_VIEW_FADE (object);
switch (prop_id)
{
case PROP_HFADE_OFFSET:
g_value_set_float (value, self->hfade_offset);
break;
case PROP_VFADE_OFFSET:
g_value_set_float (value, self->vfade_offset);
break;
case PROP_FADE_EDGES:
g_value_set_boolean (value, self->fade_edges);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
st_scroll_view_fade_class_init (StScrollViewFadeClass *klass)
{
GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
ClutterShaderEffectClass *shader_class;
ClutterOffscreenEffectClass *offscreen_class;
ClutterActorMetaClass *meta_class = CLUTTER_ACTOR_META_CLASS (klass);
gobject_class->dispose = st_scroll_view_fade_dispose;
gobject_class->get_property = st_scroll_view_fade_get_property;
gobject_class->set_property = st_scroll_view_fade_set_property;
meta_class->set_actor = st_scroll_view_fade_set_actor;
shader_class = CLUTTER_SHADER_EFFECT_CLASS (klass);
shader_class->get_static_shader_source = st_scroll_view_fade_get_static_shader_source;
offscreen_class = CLUTTER_OFFSCREEN_EFFECT_CLASS (klass);
offscreen_class->create_texture = st_scroll_view_fade_create_texture;
offscreen_class->paint_target = st_scroll_view_fade_paint_target;
g_object_class_install_property (gobject_class,
PROP_VFADE_OFFSET,
g_param_spec_float ("vfade-offset",
"Vertical Fade Offset",
"The height of the area which is faded at the edge",
0.f, G_MAXFLOAT, DEFAULT_FADE_OFFSET,
G_PARAM_READWRITE));
g_object_class_install_property (gobject_class,
PROP_HFADE_OFFSET,
g_param_spec_float ("hfade-offset",
"Horizontal Fade Offset",
"The width of the area which is faded at the edge",
0.f, G_MAXFLOAT, DEFAULT_FADE_OFFSET,
G_PARAM_READWRITE));
g_object_class_install_property (gobject_class,
PROP_FADE_EDGES,
g_param_spec_boolean ("fade-edges",
"Fade Edges",
"Whether the faded area should extend to the edges",
FALSE,
G_PARAM_READWRITE));
}
static void
st_scroll_view_fade_init (StScrollViewFade *self)
{
self->vfade_offset = DEFAULT_FADE_OFFSET;
self->hfade_offset = DEFAULT_FADE_OFFSET;
}
ClutterEffect *
st_scroll_view_fade_new (void)
{
return g_object_new (ST_TYPE_SCROLL_VIEW_FADE, NULL);
}