CODEWITHSUNDEEP
c++user-interfacegtk
nitin kumar
nitin kumar

Reputation: 652

how to stretch an image in GTK+?

I'm using the following code to set the background Image but as size of image is small I want to stretch the size to fit the screen or if the image is larger than screen in that case too I need the same.

Im using Gtk+3.2

#include <gtk/gtk.h>

int main( int argc, char *argv[])
{
GtkWidget *window;
GtkWidget *layout;
GtkWidget *image;
GtkWidget *button;

gtk_init(&argc, &argv);

window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
gtk_window_set_default_size(GTK_WINDOW(window), 290, 200);
gtk_window_set_position(GTK_WINDOW(window), GTK_WIN_POS_CENTER);

layout = gtk_layout_new(NULL, NULL);
gtk_container_add(GTK_CONTAINER (window), layout);
gtk_widget_show(layout);

image = gtk_image_new_from_file("/home/my_background_image.jpg");
gtk_layout_put(GTK_LAYOUT(layout), image, 0, 0);

button = gtk_button_new_with_label("Button");
gtk_layout_put(GTK_LAYOUT(layout), button, 150, 50);
gtk_widget_set_size_request(button, 80, 35);

g_signal_connect_swapped(G_OBJECT(window), "destroy",
G_CALLBACK(gtk_main_quit), NULL);

gtk_widget_show_all(window);

gtk_main();

return 0;
}

Upvotes: 0

Views: 1127

Answers (1)

vicky
vicky

Reputation: 895

I dont think you really need layout for setting background image. You can overload "draw" signal and in handler you can paint background image. The following code will work for you.

gboolean GtkDrawing::window_draw_cb (GtkWidget * widget, cairo_t * cr, cairo_surface_t* m_bgImage)
{
    gint root_width,root_height;

        cairo_set_source_surface (cr,m_bgImage, 0, 0);

        gtk_window_get_size (GTK_WINDOW(widget), &root_width, &root_height);
        cairo_rectangle (cr, 0, 0,root_width, root_height);
        cairo_fill (cr);

        //Enable Below code to draw child widget after background rendering
        //gtk_widget_draw (childwidget, cr);
        //cairo_fill (cr);


    return TRUE;
}

cairo_surface_t* m_bgImage=cairo_image_surface_create_from_png("/home/my_background_image.png");
g_signal_connect (G_OBJECT (window), "draw", G_CALLBACK(GtkDrawing::window_draw_cb), m_bgImage);

In the above handler function, to stretch the image you can modify cairo_rectangle parameters.

Upvotes: 1

Related Questions