forked from AuroraMiddleware/gtk
124 lines
3.1 KiB
C
124 lines
3.1 KiB
C
#include <math.h>
|
|
#include "demo4widget.h"
|
|
#include "hsla.h"
|
|
|
|
struct _Demo4Widget
|
|
{
|
|
GtkWidget parent_instance;
|
|
PangoLayout *layout;
|
|
GskColorStop stops[8];
|
|
gsize n_stops;
|
|
|
|
guint tick;
|
|
};
|
|
|
|
struct _Demo4WidgetClass
|
|
{
|
|
GtkWidgetClass parent_class;
|
|
};
|
|
|
|
G_DEFINE_TYPE (Demo4Widget, demo4_widget, GTK_TYPE_WIDGET)
|
|
|
|
static void
|
|
rotate_color (GdkRGBA *rgba)
|
|
{
|
|
GdkHSLA hsla;
|
|
|
|
_gdk_hsla_init_from_rgba (&hsla, rgba);
|
|
hsla.hue -= 1;
|
|
_gdk_rgba_init_from_hsla (rgba, &hsla);
|
|
}
|
|
|
|
static gboolean
|
|
rotate_colors (GtkWidget *widget,
|
|
GdkFrameClock *clock,
|
|
gpointer user_data)
|
|
{
|
|
Demo4Widget *self = DEMO4_WIDGET (widget);
|
|
|
|
for (unsigned int i = 0; i < self->n_stops; i++)
|
|
rotate_color (&self->stops[i].color);
|
|
|
|
gtk_widget_queue_draw (widget);
|
|
|
|
return G_SOURCE_CONTINUE;
|
|
}
|
|
|
|
static void
|
|
demo4_widget_init (Demo4Widget *self)
|
|
{
|
|
PangoFontDescription *desc;
|
|
|
|
self->n_stops = 8;
|
|
self->stops[0].offset = 0;
|
|
self->stops[0].color = (GdkRGBA) { 1, 0, 0, 1 };
|
|
|
|
for (unsigned int i = 1; i < self->n_stops; i++)
|
|
{
|
|
GdkHSLA hsla;
|
|
|
|
self->stops[i].offset = i / (double)(self->n_stops - 1);
|
|
_gdk_hsla_init_from_rgba (&hsla, &self->stops[i - 1].color);
|
|
hsla.hue += 360.0 / (double)(self->n_stops - 1);
|
|
_gdk_rgba_init_from_hsla (&self->stops[i].color, &hsla);
|
|
}
|
|
|
|
self->layout = gtk_widget_create_pango_layout (GTK_WIDGET (self), "123");
|
|
desc = pango_font_description_from_string ("Cantarell Bold 210");
|
|
pango_layout_set_font_description (self->layout, desc);
|
|
pango_font_description_free (desc);
|
|
|
|
self->tick = gtk_widget_add_tick_callback (GTK_WIDGET (self), rotate_colors, NULL, NULL);
|
|
}
|
|
|
|
static void
|
|
demo4_widget_dispose (GObject *object)
|
|
{
|
|
Demo4Widget *self = DEMO4_WIDGET (object);
|
|
|
|
g_clear_object (&self->layout);
|
|
gtk_widget_remove_tick_callback (GTK_WIDGET (self), self->tick);
|
|
|
|
G_OBJECT_CLASS (demo4_widget_parent_class)->dispose (object);
|
|
}
|
|
|
|
static void
|
|
demo4_widget_snapshot (GtkWidget *widget,
|
|
GtkSnapshot *snapshot)
|
|
{
|
|
Demo4Widget *self = DEMO4_WIDGET (widget);
|
|
int width, height;
|
|
|
|
width = gtk_widget_get_width (widget);
|
|
height = gtk_widget_get_height (widget);
|
|
|
|
gtk_snapshot_push_mask (snapshot, GSK_MASK_MODE_INVERTED_ALPHA);
|
|
gtk_snapshot_append_layout (snapshot, self->layout, &(GdkRGBA) { 0, 0, 0, 1 });
|
|
gtk_snapshot_pop (snapshot);
|
|
|
|
gtk_snapshot_append_linear_gradient (snapshot,
|
|
&GRAPHENE_RECT_INIT (0, 0, width, height),
|
|
&GRAPHENE_POINT_INIT (0, 0),
|
|
&GRAPHENE_POINT_INIT (width, height),
|
|
self->stops,
|
|
self->n_stops);
|
|
gtk_snapshot_pop (snapshot);
|
|
}
|
|
|
|
static void
|
|
demo4_widget_class_init (Demo4WidgetClass *class)
|
|
{
|
|
GObjectClass *object_class = G_OBJECT_CLASS (class);
|
|
GtkWidgetClass *widget_class = GTK_WIDGET_CLASS (class);
|
|
|
|
object_class->dispose = demo4_widget_dispose;
|
|
|
|
widget_class->snapshot = demo4_widget_snapshot;
|
|
}
|
|
|
|
GtkWidget *
|
|
demo4_widget_new (void)
|
|
{
|
|
return g_object_new (DEMO4_TYPE_WIDGET, NULL);
|
|
}
|