Hi Mahesh,
Le 04/10/2013 07:41, Mahesh Chaudhari a écrit :
> Hi List,
> I have drawn five circles in GtkDrawingArea as below :
>
> #include <gtk/gtk.h>
> #include <cairo.h>
> #include<math.h>
>
> GtkWidget* window;
> GtkWidget* darea;
> static gboolean on_expose_event(GtkWidget *widget, GdkEventExpose *event,
> gpointer data)
> {
> cairo_t *cr;
> cr = gdk_cairo_create(darea->window);
> cairo_arc(cr,50,60,20,0,2*M_PI);
> cairo_arc(cr,110,60,20,0,2*M_PI);
> cairo_arc(cr,170,60,20,0,2*M_PI);
> cairo_arc(cr,230,60,20,0,2*M_PI);
> cairo_arc(cr,300,60,20,0,2*M_PI);
> cairo_set_source_rgba (cr, 0.5, 0, 0, 0.5);
> cairo_fill(cr);
You need to return a boolean here, see
https://developer.gnome.org/gtk2/stable/GtkWidget.html#GtkWidget-expose-event
You also should destroy the cairo_t you created at the start of the
function using cairo_destroy().
> }
> int main(int argc, char **argv)
> {
> gtk_init(&argc, &argv);
> window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
> gtk_window_set_default_size(GTK_WINDOW(window), 400, 100);
> darea = gtk_drawing_area_new();
> gtk_container_add(GTK_CONTAINER(window), darea);
> g_signal_connect(darea, "expose-event",
> G_CALLBACK(on_expose_event), NULL);
>
> gtk_widget_show_all(window);
> gtk_main();
> return 0;
> }
>
> I want to put label(text) above each circle,
Use Pango and its Cairo rendering capabilities:
https://developer.gnome.org/pango/stable/pango-Cairo-Rendering.html
A very basic example could be:
PangoLayout *l = pango_cairo_create_layout (cr);
PangoFontDescription *font = pango_font_description_from_string ("sans
42");
pango_layout_set_text (l, "hello world", -1);
pango_layout_set_font_description (l, font);
pango_font_description_free (font);
pango_layout_set_width (l, width_you_want * PANGO_SCALE);
pango_layout_set_height (l, height_you_want * PANGO_SCALE);
pango_cairo_show_layout (cr, l);
g_object_unref (l);
Check the Pango docs for more details and features
https://developer.gnome.org/pango/stable/index.html
> Also colour should be change after few seconds
Put a timeout (g_timeout_add()) and when it fires change the color and
queue a redraw (gtk_widget_queue_draw()).
> How can I do this ? I have to use CentOS-5.3 which has gtk+-2.10.0
> _______________________________________________
> gtk-app-devel-list mailing list
> gtk-app-devel-list@gnome.org
> https://mail.gnome.org/mailman/listinfo/gtk-app-devel-list
>
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