GTK+ Forums

kprasanna16 · Familiar Face Joined: 08 Dec 2006 Posts: 11

/*Hi .. I have modified scribble-simple.c from gtk/examples to check the behaviour of foregrond/background color of this application over X and then over DFB. in expose_event() I have set the new foreground color, it is working fine over X but over DirectFB it doesn't has any effect... any reason/explanation..*/

#include <stdlib.h>
#include <gtk/gtk.h>

/* Backing pixmap for drawing area */
static GdkPixmap *pixmap = NULL;

/* Create a new backing pixmap of the appropriate size */
static gboolean configure_event( GtkWidget *widget,
GdkEventConfigure *event )
{
GdkColor color;

if (pixmap)
g_object_unref (pixmap);

color.red = 0xffff;
color.green = 0xffff;
color.blue = 0x0;
gdk_gc_set_rgb_fg_color (widget->style->white_gc, &color);

pixmap = gdk_pixmap_new (widget->window,
widget->allocation.width,
widget->allocation.height,
-1);
gdk_draw_rectangle (pixmap,
widget->style->white_gc,
TRUE,
0, 0,
widget->allocation.width,
widget->allocation.height);

return TRUE;
}

/* Redraw the screen from the backing pixmap */
static gboolean expose_event( GtkWidget *widget,
GdkEventExpose *event )
{
GdkColor color;

color.red = 0xffff;

gdk_gc_set_rgb_fg_color (widget->style->fg_gc[GTK_WIDGET_STATE(widget)], &color);
gdk_draw_drawable (widget->window,
widget->style->fg_gc[GTK_WIDGET_STATE (widget)],
pixmap,
event->area.x, event->area.y,
event->area.x, event->area.y,
event->area.width, event->area.height);

return FALSE;
}

/* Draw a rectangle on the screen */
static void draw_brush( GtkWidget *widget,
gdouble x,
gdouble y)
{
GdkRectangle update_rect;

update_rect.x = x - 5;
update_rect.y = y - 5;
update_rect.width = 10;
update_rect.height = 10;

gdk_draw_rectangle (pixmap,
widget->style->black_gc,
TRUE,
update_rect.x, update_rect.y,
update_rect.width, update_rect.height);
gtk_widget_queue_draw_area (widget,
update_rect.x, update_rect.y,
update_rect.width, update_rect.height);
}

static gboolean button_press_event( GtkWidget *widget,
GdkEventButton *event )
{
if (event->button == 1 && pixmap != NULL)
draw_brush (widget, event->x, event->y);

return TRUE;
}

static gboolean motion_notify_event( GtkWidget *widget,
GdkEventMotion *event )
{
int x, y;
GdkModifierType state;

if (event->is_hint)
gdk_window_get_pointer (event->window, &x, &y, &state);
else
{
x = event->x;
y = event->y;
state = event->state;
}

if (state & GDK_BUTTON1_MASK && pixmap != NULL)
draw_brush (widget, x, y);

return TRUE;
}

void quit ()
{
exit (0);
}

int main( int argc,
char *argv[] )
{
GtkWidget *window;
GtkWidget *drawing_area;
GtkWidget *vbox;

GtkWidget *button;

gtk_init (&argc, &argv);

window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
gtk_widget_set_name (window, "Test Input");

vbox = gtk_vbox_new (FALSE, 0);
gtk_container_add (GTK_CONTAINER (window), vbox);
gtk_widget_show (vbox);

g_signal_connect (G_OBJECT (window), "destroy",
G_CALLBACK (quit), NULL);

/* Create the drawing area */

drawing_area = gtk_drawing_area_new ();
gtk_widget_set_size_request (GTK_WIDGET (drawing_area), 200, 200);
gtk_box_pack_start (GTK_BOX (vbox), drawing_area, TRUE, TRUE, 0);

gtk_widget_show (drawing_area);

/* Signals used to handle backing pixmap */

g_signal_connect (G_OBJECT (drawing_area), "expose_event",
G_CALLBACK (expose_event), NULL);
g_signal_connect (G_OBJECT (drawing_area),"configure_event",
G_CALLBACK (configure_event), NULL);

/* Event signals */

g_signal_connect (G_OBJECT (drawing_area), "motion_notify_event",
G_CALLBACK (motion_notify_event), NULL);
g_signal_connect (G_OBJECT (drawing_area), "button_press_event",
G_CALLBACK (button_press_event), NULL);

gtk_widget_set_events (drawing_area, GDK_EXPOSURE_MASK
| GDK_LEAVE_NOTIFY_MASK
| GDK_BUTTON_PRESS_MASK
| GDK_POINTER_MOTION_MASK
| GDK_POINTER_MOTION_HINT_MASK);

/* .. And a quit button */
button = gtk_button_new_with_label ("Quit");
gtk_box_pack_start (GTK_BOX (vbox), button, FALSE, FALSE, 0);

g_signal_connect_swapped (G_OBJECT (button), "clicked",
G_CALLBACK (gtk_widget_destroy),
G_OBJECT (window));
gtk_widget_show (button);

gtk_widget_show (window);

gtk_main ();

return 0;
}