c-GTK3调整大小的尝试使窗口呈指数级增长

Question

我有一个C GTK3程序，它有一个带有两个图像的笔记本。我希望能够抓住窗口的一角并调整当前显示的图像的大小。我目前拥有的是一个程序，一旦启动，窗口就会不断增长，直到我使用ctrl-c从终端杀死它。我在回叫中打了一个睡眠电话来减缓它的速度，但它仍然在增长。除非我"抓住"窗户的一角并自己调整，否则我如何阻止窗户生长？

#include <stdio.h>
#include <gtk/gtk.h>
#include <gdk-pixbuf/gdk-pixbuf.h>
GtkWidget *notebook;
gboolean resize_image(GtkWidget *widget, GdkRectangle *allocation,
gpointer user_data)
{
int w,h, pagenum;
GdkPixbuf *pxbscaled;
GtkWidget *image;
GdkPixbuf *pixbuf;
pagenum = gtk_notebook_get_current_page (GTK_NOTEBOOK(notebook));
image = gtk_notebook_get_nth_page (GTK_NOTEBOOK(notebook), pagenum);
//  GtkImageType image_type = gtk_image_get_storage_type
//      (GTK_IMAGE(image));
pixbuf = gtk_image_get_pixbuf(GTK_IMAGE(image));
h = allocation->height;
w = (gdk_pixbuf_get_width(pixbuf) * h) / gdk_pixbuf_get_height(pixbuf);
pxbscaled = gdk_pixbuf_scale_simple(pixbuf, w, h, GDK_INTERP_BILINEAR);
printf("Allocation height %d width %d.n", h, w);
gtk_image_set_from_pixbuf(GTK_IMAGE(image), pxbscaled);
g_object_unref (pxbscaled);
sleep(2);
return FALSE;
}
static gboolean delete( GtkWidget *widget,
GtkWidget *event,
gpointer   data )
{
gtk_main_quit ();
return FALSE;
}
int main( int argc,
char *argv[] )
{
GtkWidget *window;
GtkWidget *button;
GtkWidget *table;
GtkWidget *label;
GtkWidget *image;
int i;
char bufferl[32];
gtk_init (&argc, &argv);
window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
//  gtk_widget_set_size_request (GTK_WIDGET(window), 800, 480);
g_signal_connect (window, "delete-event",
G_CALLBACK (delete), NULL);
gtk_container_set_border_width (GTK_CONTAINER (window), 10);
table = gtk_grid_new ();
gtk_container_add (GTK_CONTAINER (window), table);
/* Create notebook, place position of tabs */
notebook = gtk_notebook_new ();
gtk_notebook_set_tab_pos (GTK_NOTEBOOK (notebook), GTK_POS_TOP);
gtk_grid_attach (GTK_GRID (table), notebook, 0, 6, 3, 3);
gtk_widget_show (notebook);
/* Append pages to the notebook */
for (i = 0; i < 2; i++) {
sprintf(bufferl, "Page %d", i + 1);
if (i == 0) {
image = gtk_image_new_from_file("image1.jpg");
} else {
image = gtk_image_new_from_file("image2.jpg");
}
gtk_widget_set_halign(image, GTK_ALIGN_START);
gtk_widget_set_valign(image, GTK_ALIGN_START);
g_signal_connect(window, "size-allocate", 
G_CALLBACK(resize_image), NULL);
label = gtk_label_new (bufferl);
gtk_notebook_append_page (GTK_NOTEBOOK(notebook), 
image, label);
}
/* Create a close button */
button = gtk_button_new_with_label ("close");
g_signal_connect (button, "clicked",
G_CALLBACK (delete), NULL);
gtk_grid_attach (GTK_GRID (table), button, 0, 10, 1, 1);
gtk_widget_show_all (window);
gtk_main ();
return 0;
}

用户需要提供image1.jpg和image2.jpg。编辑睡眠调用将导致程序非常快地填充屏幕。

编辑：我也在gtk邮件列表上问过这个问题。

Answer 1

带有图像的窗口正在增长，因为我正在将窗口的大小应用于图像。因此，图像变得更大，从而使窗口变得更大。它以无休止的方式继续着，"规模分配"信号不断被调用。我通过将回调中的分配高度乘以0.75来修复它。现在我可以轻松地扩展和收缩窗口，它不会失控。图像确实会很快变丑，但这是另一个问题。