当我单击一个小部件时，如何取消 GTK 中的所有其他小部件的焦点？

Question

在我的 GTK 程序中，我有一个 TextEntry 小部件和一个 TreeView 小部件。当我单击 TextEntry 小部件并选择一些文本，然后单击 TreeView 小部件时，它不会取消选择 TextEntry 小部件中的文本。当我单击 TreeView 小部件时，如何让它取消选择 TextEntry 小部件中的文本？

Answer 1

您可以将gtk_editable_select_region 绑定到条目的"focus-out-event" 信号，请参见下面的示例：

#include <gtk/gtk.h>

gboolean unselect_on_focus_lost (GtkWidget *widget)
{
    gtk_editable_select_region (GTK_EDITABLE (widget), 0, 0);
    return FALSE;
}

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

    gtk_init (&argc, &argv);

    window = gtk_window_new (GTK_WINDOW_TOPLEVEL);

    gtk_window_set_position (GTK_WINDOW (window), GTK_WIN_POS_CENTER);
    gtk_container_set_border_width (GTK_CONTAINER (window), 5);
    gtk_window_set_default_size (GTK_WINDOW (window), 400, 130);

    box = gtk_box_new (GTK_ORIENTATION_VERTICAL, 8);
    gtk_container_add (GTK_CONTAINER (window), box);

    entry = gtk_entry_new ();
    gtk_entry_set_placeholder_text (GTK_ENTRY (entry), "I will lose my selection when you click the button below");
    g_signal_connect (G_OBJECT (entry), "focus-out-event", G_CALLBACK (unselect_on_focus_lost), NULL);
    gtk_container_add (GTK_CONTAINER (box), entry);

    entry = gtk_entry_new ();
    gtk_entry_set_placeholder_text (GTK_ENTRY (entry), "I will NOT lose my selection when you click the button below");
    gtk_container_add (GTK_CONTAINER (box), entry);

    /* I used a button instead of a treeview to keep the code short */
    button = gtk_button_new_with_label("Click me");
    gtk_container_add (GTK_CONTAINER (box), button);
    gtk_widget_grab_focus (button);

    g_signal_connect (G_OBJECT (window), "destroy", G_CALLBACK (gtk_main_quit), NULL);
    gtk_widget_show_all (window);
    gtk_main ();

    return 0;
}