如何製作帶背景圖像的GTK3 +窗口

Question

由於廢棄/刪除，Pixbuf方法不再適用於GTK3 +。我想在GtkFixed或GtkBox的gdk部分放置背景圖片。我相信我需要開羅圖形庫來做到這一點。

能愉快的靈魂引導我朝着正確的方向嗎？

Answer 1

我一起砍了一個例子。它用圖像填充頂層應用程序窗口的背景。

作爲背景圖片，我選擇了一顆小星星（1）。編譯例子調用gcc像

gcc `pkg-config --libs --cflags glib-2.0 gtk+-3.0` <source> -o <executable> 

在我的機器，結果看起來像

1：http://upload.wikimedia.org/wikipedia/commons/thumb/b/b2/Featured_Star_green.svg/32px-Featured_Star_green.svg.png

---

#include <gtk/gtk.h> 
#include <glib-2.0/glib.h> 

typedef struct Texture_ 
{ 
    gint root_width, root_height; 
    cairo_surface_t *bg_image; 
} Texture; 

typedef struct Ui_ 
{ 
    GtkWidget *window; 
    GtkWidget *grid; 
    GtkWidget *button; 

    Texture *texture; 

    gulong window_draw_cb_handler_id; 
} Ui; 

gboolean window_draw_cb (GtkWidget *, cairo_t *, Ui *); 

void 
button_clicked_cb (GtkWidget * widget, Ui * ui) 
{ 
    gboolean ret; 

    ret = 
     g_signal_handler_is_connected (ui->window, 
             ui->window_draw_cb_handler_id); 

    if (ret) { 
     g_signal_handler_disconnect (ui->window, ui->window_draw_cb_handler_id); 
    } 
    else { 
     ui->window_draw_cb_handler_id = 
      g_signal_connect (ui->window, "draw", G_CALLBACK (window_draw_cb), 
           ui); 
    } 

    gtk_widget_queue_draw (ui->window); 
} 

void 
destroy_cb (GtkWidget * widget, gpointer data) 
{ 
    gtk_main_quit(); 
} 

gboolean 
window_draw_cb (GtkWidget * widget, cairo_t * cr, Ui * ui) 
{ 

    cairo_set_source_surface (cr, ui->texture->bg_image, 0, 0); 

    cairo_rectangle (cr, 0, 0, 
        ui->texture->root_width, ui->texture->root_height); 

    cairo_fill (cr); 

    /* draw all widgets attached to `grid` to the 
    * cairo context of the mainwindow */ 

    gtk_widget_draw (ui->grid, cr); 
    cairo_fill (cr); 

    return TRUE; 
} 

void 
ui_texture_init (Ui * ui) 
{ 
    gint root_width, root_height, width, height; 
    guint n_x, n_y, i, k; 
    cairo_format_t format; 
    cairo_surface_t *bg_image, *target; 
    cairo_status_t ret; 
    GdkWindow *root; 
    cairo_t *cr; 

    ui->texture = g_new (Texture, 1); 

    bg_image = 
     cairo_image_surface_create_from_png ("./Featured_Star_green.svg.png"); 

    ret = cairo_surface_status (bg_image); 

    g_assert (ret == 0); 

    format = cairo_image_surface_get_format (bg_image); 

    width = cairo_image_surface_get_width (bg_image); 
    height = cairo_image_surface_get_height (bg_image); 

    root = gdk_get_default_root_window(); 

    gdk_window_get_geometry (root, NULL, NULL, &root_width, &root_height); 

    target = cairo_image_surface_create (format, root_width, root_height); 

    cr = cairo_create (target); 

    n_x = root_width/width; 
    n_y = root_height/height; 

    for (i = 0; i <= n_x; i++) { 

     for (k = 0; k <= n_y; k++) { 
      cairo_set_source_surface (cr, bg_image, i * width, k * height); 

      cairo_rectangle (cr, i * width, k * height, width, height); 

      cairo_fill (cr); 
     } 
    } 

    ui->texture->root_width = root_width; 
    ui->texture->root_height = root_height; 

    ui->texture->bg_image = target; 
} 

void 
forall_container (GtkWidget * widget, gpointer data) 
{ 

    gtk_widget_set_halign (widget, GTK_ALIGN_CENTER); 
    gtk_widget_set_valign (widget, GTK_ALIGN_CENTER); 
    gtk_widget_set_margin_top (widget, 10); 
    gtk_widget_set_margin_bottom (widget, 10); 
    gtk_widget_set_margin_left (widget, 10); 
    gtk_widget_set_margin_right (widget, 10); 
} 

Ui * 
ui_init() 
{ 
    Ui *ui; 

    GtkWidget *label, *entry; 
    PangoAttrList *attributes; 

    ui = g_new (Ui, 1); 

    ui_texture_init (ui); 

    ui->window = gtk_window_new (GTK_WINDOW_TOPLEVEL); 

    ui->grid = gtk_grid_new(); 

    gtk_grid_set_column_homogeneous (GTK_GRID (ui->grid), TRUE); 
    gtk_grid_set_row_homogeneous (GTK_GRID (ui->grid), TRUE); 
    gtk_grid_set_row_spacing (GTK_GRID (ui->grid), 10); 

    label = gtk_label_new ("Label:"); 

    attributes = pango_attr_list_new(); 

    pango_attr_list_insert (attributes, pango_attr_size_new_absolute (30000)); 

    gtk_label_set_attributes (GTK_LABEL (label), attributes); 
    entry = gtk_entry_new(); 
    ui->button = gtk_button_new_with_label ("Toggle background image"); 

    gtk_grid_attach (GTK_GRID (ui->grid), label, 0, 0, 1, 1); 
    gtk_grid_attach (GTK_GRID (ui->grid), entry, 1, 0, 1, 1); 
    gtk_grid_attach (GTK_GRID (ui->grid), ui->button, 0, 1, 2, 1); 

    gtk_container_foreach (GTK_CONTAINER (ui->grid), &forall_container, NULL); 

    gtk_container_add (GTK_CONTAINER (ui->window), ui->grid); 

    return ui; 
} 

int 
main (int argc, char *argv[]) 
{ 

    Ui *ui; 

    gtk_init (&argc, &argv); 

    ui = ui_init(); 

    g_signal_connect (ui->window, "destroy", G_CALLBACK (destroy_cb), ui); 

    ui->window_draw_cb_handler_id = 
     g_signal_connect (ui->window, "draw", G_CALLBACK (window_draw_cb), ui); 

    g_signal_connect (ui->button, "clicked", G_CALLBACK (button_clicked_cb), 
         ui); 

    gtk_widget_show_all (ui->window); 

    gtk_main(); 
}