Re: How to resize an image to fit the window in GTK3

[Martin Guy <martinwguy gmail com>]

Many thanks, that works smoothly.

Cheers

    M

On 18/11/2016, cecashon aol com <cecashon aol com> wrote:
> I like the GTK drawing area for this sort of thing. With the drawing area
> you can rescale and draw your image when the size of the window changes
> automatically.
>
> Make sure to add a picture to the following test code.
>
> Eric
>
>
> /*
>     gcc -Wall da_resize.c -o da_resize `pkg-config gtk+-3.0 --cflags
> --libs`
>     Tested on Ubuntu16.04, GTK3.18.
> */
>
> #include<gtk/gtk.h>
>
> gboolean draw_picture(GtkWidget *da, cairo_t *cr, gpointer data)
> {
>   gint width=gtk_widget_get_allocated_width(da);
>   gint height=gtk_widget_get_allocated_height(da);
>
>   GdkPixbuf *temp=gdk_pixbuf_scale_simple((GdkPixbuf*)data, width, height,
> GDK_INTERP_BILINEAR);
>   gdk_cairo_set_source_pixbuf(cr, temp, 0, 0);
>   cairo_paint(cr);
>
>   g_object_unref(temp);
>   return FALSE;
> }
> int main(int argc, char *argv[])
> {
>   gtk_init(&argc, &argv);
>
>   GtkWidget *window=gtk_window_new(GTK_WINDOW_TOPLEVEL);
>   gtk_window_set_title(GTK_WINDOW(window), "Resize Picture");
>   gtk_window_set_position(GTK_WINDOW(window), GTK_WIN_POS_CENTER);
>   gtk_window_set_default_size(GTK_WINDOW(window), 400, 400);
>
>   g_signal_connect(window, "destroy", G_CALLBACK(gtk_main_quit), NULL);
>
>   //Needs a valid picture.
>   GdkPixbuf *pixbuf=gdk_pixbuf_new_from_file("headlight_toggle1.png",
> NULL);
>
>   GtkWidget *da1=gtk_drawing_area_new();
>   gtk_widget_set_hexpand(da1, TRUE);
>   gtk_widget_set_vexpand(da1, TRUE);
>   g_signal_connect(da1, "draw", G_CALLBACK(draw_picture), pixbuf);
>
>   GtkWidget *grid=gtk_grid_new();
>   gtk_grid_attach(GTK_GRID(grid), da1, 0, 0, 1, 1);
>
>   gtk_container_add(GTK_CONTAINER(window), grid);
>   gtk_widget_show_all(window);
>
>   gtk_main();
>
>   g_object_unref(pixbuf);
>
>   return 0;
> }