From 5732b1184f013ce9ca33580e214d60400f00d271 Mon Sep 17 00:00:00 2001
From: Elliot Smith <elliot.smith@intel.com>
Date: Tue, 8 Mar 2011 14:54:00 +0000
Subject: [PATCH] docs: Add example of setting background color with
ClutterEffect
Add example of a simple background color effect applied via
pre_paint() implementation in a ClutterEffect subclass.
This is a simple effect with an incomplete GObject
implementation (no properties, setters or getters)
to make it as easy to follow as possible.
---
doc/cookbook/examples/Makefile.am | 6 +-
doc/cookbook/examples/cb-background-effect.c | 110 +++++++++++++++++++
doc/cookbook/examples/cb-background-effect.h | 42 +++++++
doc/cookbook/examples/effects-basic.c | 37 +++++--
4 files changed, 182 insertions(+), 13 deletions(-)
create mode 100644 doc/cookbook/examples/cb-background-effect.c
create mode 100644 doc/cookbook/examples/cb-background-effect.h
diff --git a/doc/cookbook/examples/Makefile.am b/doc/cookbook/examples/Makefile.am
index 6f0c4b396..52fec52f7 100644
--- a/doc/cookbook/examples/Makefile.am
+++ b/doc/cookbook/examples/Makefile.am
@@ -84,7 +84,11 @@ animations_reuse_SOURCES = animations-reuse.c
animations_rotating_SOURCES = animations-rotating.c
animations_scaling_SOURCES = animations-scaling.c
animations_scaling_zoom_SOURCES = animations-scaling-zoom.c
-effects_basic_SOURCES = cb-border-effect.c cb-border-effect.h effects-basic.c
+effects_basic_SOURCES = cb-border-effect.c \
+ cb-border-effect.h \
+ cb-background-effect.c \
+ cb-background-effect.h \
+ effects-basic.c
effects_built_in_SOURCES = effects-built-in.c
effects_custom_deform_SOURCES = cb-page-fold-effect.c cb-page-fold-effect.h effects-custom-deform.c
text_shadow_SOURCES = text-shadow.c
diff --git a/doc/cookbook/examples/cb-background-effect.c b/doc/cookbook/examples/cb-background-effect.c
new file mode 100644
index 000000000..71b2ceee2
--- /dev/null
+++ b/doc/cookbook/examples/cb-background-effect.c
@@ -0,0 +1,110 @@
+#include "cb-background-effect.h"
+
+G_DEFINE_TYPE (CbBackgroundEffect, cb_background_effect, CLUTTER_TYPE_EFFECT);
+
+#define CB_BACKGROUND_EFFECT_GET_PRIVATE(obj) (G_TYPE_INSTANCE_GET_PRIVATE ((obj), \
+ CB_TYPE_BACKGROUND_EFFECT, \
+ CbBackgroundEffectPrivate))
+
+struct _CbBackgroundEffectPrivate
+{
+ CoglMaterial *background;
+ CoglColor *color;
+};
+
+/* ClutterEffect implementation */
+
+/* note that if pre_paint() returns FALSE
+ * any post_paint() defined for the effect will not be called
+ */
+static gboolean
+cb_background_effect_pre_paint (ClutterEffect *self)
+{
+ ClutterActor *actor;
+ gfloat width;
+ gfloat height;
+ CbBackgroundEffectPrivate *priv;
+
+ ClutterActorMeta *meta = CLUTTER_ACTOR_META (self);
+
+ /* check that the effect is enabled before applying it */
+ if (!clutter_actor_meta_get_enabled (meta))
+ return TRUE;
+
+ priv = CB_BACKGROUND_EFFECT (self)->priv;
+
+ /* get the associated actor's dimensions */
+ actor = clutter_actor_meta_get_actor (CLUTTER_ACTOR_META (self));
+ clutter_actor_get_size (actor, &width, &height);
+
+ /* draw a grey Cogl rectangle in the background */
+ cogl_set_source (priv->background);
+
+ cogl_rectangle (0, 0, width, height);
+
+ return TRUE;
+}
+
+/* GObject implementation */
+static void
+cb_background_effect_dispose (GObject *gobject)
+{
+ CbBackgroundEffectPrivate *priv = CB_BACKGROUND_EFFECT (gobject)->priv;
+
+ if (priv->background != COGL_INVALID_HANDLE)
+ {
+ cogl_handle_unref (priv->background);
+ priv->background = COGL_INVALID_HANDLE;
+ }
+
+ if (priv->color != NULL)
+ {
+ cogl_color_free (priv->color);
+ priv->color = NULL;
+ }
+
+ G_OBJECT_CLASS (cb_background_effect_parent_class)->dispose (gobject);
+}
+
+static void
+cb_background_effect_class_init (CbBackgroundEffectClass *klass)
+{
+ ClutterEffectClass *effect_class = CLUTTER_EFFECT_CLASS (klass);
+ GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
+
+ effect_class->pre_paint = cb_background_effect_pre_paint;
+ gobject_class->dispose = cb_background_effect_dispose;
+
+ g_type_class_add_private (klass, sizeof (CbBackgroundEffectPrivate));
+}
+
+static void
+cb_background_effect_init (CbBackgroundEffect *self)
+{
+ CbBackgroundEffectPrivate *priv;
+
+ priv = self->priv = CB_BACKGROUND_EFFECT_GET_PRIVATE (self);
+
+ priv->background = cogl_material_new ();
+
+ /* grey color for filling the background material */
+ priv->color = cogl_color_new ();
+ cogl_color_init_from_4ub (priv->color, 122, 122, 122, 255);
+
+ cogl_material_set_color (priv->background, priv->color);
+}
+
+/* public API */
+
+/**
+ * cb_background_effect_new:
+ *
+ * Creates a new #ClutterEffect which adds a grey background
+ * when applied to a rectangular actor.
+ */
+ClutterEffect *
+cb_background_effect_new ()
+{
+ return g_object_new (CB_TYPE_BACKGROUND_EFFECT,
+ NULL);
+}
diff --git a/doc/cookbook/examples/cb-background-effect.h b/doc/cookbook/examples/cb-background-effect.h
new file mode 100644
index 000000000..b2ce987e3
--- /dev/null
+++ b/doc/cookbook/examples/cb-background-effect.h
@@ -0,0 +1,42 @@
+#ifndef __CB_BACKGROUND_EFFECT_H__
+#define __CB_BACKGROUND_EFFECT_H__
+
+#include <clutter/clutter.h>
+
+GType cb_background_effect_get_type (void);
+
+#define CB_TYPE_BACKGROUND_EFFECT (cb_background_effect_get_type ())
+#define CB_BACKGROUND_EFFECT(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), \
+ CB_TYPE_BACKGROUND_EFFECT, \
+ CbBackgroundEffect))
+#define CB_IS_BACKGROUND_EFFECT(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), \
+ CB_TYPE_BACKGROUND_EFFECT))
+#define CB_BACKGROUND_EFFECT_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST ((klass), \
+ CB_TYPE_BACKGROUND_EFFECT, \
+ CbBackgroundEffectClass))
+#define CB_IS_BACKGROUND_EFFECT_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), \
+ CB_TYPE_BACKGROUND_EFFECT))
+#define CB_BACKGROUND_EFFECT_GET_CLASS(obj) (G_TYPE_INSTANCE_GET_CLASS ((obj), \
+ CB_TYPE_BACKGROUND_EFFECT, \
+ CbBackgroundEffectClass))
+
+typedef struct _CbBackgroundEffectPrivate CbBackgroundEffectPrivate;
+typedef struct _CbBackgroundEffect CbBackgroundEffect;
+typedef struct _CbBackgroundEffectClass CbBackgroundEffectClass;
+
+/* object */
+struct _CbBackgroundEffect
+{
+ ClutterEffect parent_instance;
+ CbBackgroundEffectPrivate *priv;
+};
+
+/* class */
+struct _CbBackgroundEffectClass
+{
+ ClutterEffectClass parent_class;
+};
+
+ClutterEffect *cb_background_effect_new ();
+
+#endif /* __CB_BACKGROUND_EFFECT_H__ */
diff --git a/doc/cookbook/examples/effects-basic.c b/doc/cookbook/examples/effects-basic.c
index a59291f24..875e4c8e5 100644
--- a/doc/cookbook/examples/effects-basic.c
+++ b/doc/cookbook/examples/effects-basic.c
@@ -2,14 +2,15 @@
#include <clutter/clutter.h>
#include "cb-border-effect.h"
+#include "cb-background-effect.h"
static const ClutterColor stage_color = { 0x33, 0x33, 0x55, 0xff };
static ClutterColor red_color = { 0xff, 0x00, 0x00, 0xff };
static gboolean
-add_highlight (ClutterActor *actor,
- ClutterEvent *event,
- gpointer user_data)
+toggle_highlight (ClutterActor *actor,
+ ClutterEvent *event,
+ gpointer user_data)
{
ClutterActorMeta *meta = CLUTTER_ACTOR_META (user_data);
@@ -30,7 +31,9 @@ main (int argc,
ClutterActor *box;
ClutterLayoutManager *layout_manager;
ClutterActor *texture;
- ClutterEffect *effect;
+ ClutterEffect *background_effect;
+ ClutterEffect *border_effect;
+ ClutterConstraint *width_constraint;
gchar *filename;
guint i;
GError *error = NULL;
@@ -57,7 +60,10 @@ main (int argc,
10);
box = clutter_box_new (layout_manager);
- clutter_actor_add_constraint (box, clutter_bind_constraint_new (stage, CLUTTER_BIND_WIDTH, 0.0));
+ width_constraint = clutter_bind_constraint_new (stage,
+ CLUTTER_BIND_WIDTH,
+ 0.0);
+ clutter_actor_add_constraint (box, width_constraint);
/* loop through the files specified on the command line, adding
* each one into the box
@@ -80,18 +86,25 @@ main (int argc,
filename,
error->message);
- /* create a 5 pixel red border effect */
- effect = cb_border_effect_new (5.0, &red_color);
+ /* create a grey background effect */
+ background_effect = cb_background_effect_new ();
- /* add the effect to the actor, but disabled */
- clutter_actor_add_effect (texture, effect);
- clutter_actor_meta_set_enabled (CLUTTER_ACTOR_META (effect), FALSE);
+ /* apply the effect to the actor */
+ clutter_actor_add_effect (texture, background_effect);
+
+ /* create a 5 pixel red border effect */
+ border_effect = cb_border_effect_new (5.0, &red_color);
+
+ /* apply the effect to the actor, but disabled */
+ clutter_actor_add_effect (texture, border_effect);
+ clutter_actor_meta_set_enabled (CLUTTER_ACTOR_META (border_effect),
+ FALSE);
/* on mouse click, toggle the "enabled" property of the border effect */
g_signal_connect (texture,
"button-press-event",
- G_CALLBACK (add_highlight),
- effect);
+ G_CALLBACK (toggle_highlight),
+ border_effect);
clutter_container_add_actor (CLUTTER_CONTAINER (box), texture);
}