使用 Glade（和 C）的 GTK+ 中消息对话框的信号处理程序答案

【问题标题】：Signal Handlers for Message Dialogs in GTK+ using Glade (and C)使用 Glade（和 C）的 GTK+ 中消息对话框的信号处理程序
【发布时间】：2018-01-09 22:12:05
【问题描述】：

我无法弄清楚如何在我的 C 代码中为我在 GLADE 中创建的消息对话框编写信号处理程序。如果我没有使用 GLADE，信号处理程序将包含构建消息对话框本身所需的信息。例如，“您确定要退出吗？”消息对话框的格式为：

void show_question(GtkWidget *widget, gpointer window) {

  GtkWidget *dialog;
  dialog = gtk_message_dialog_new(GTK_WINDOW(window),
          GTK_DIALOG_DESTROY_WITH_PARENT,
          GTK_MESSAGE_QUESTION,
          GTK_BUTTONS_YES_NO,
          "Are you sure to quit?");
  gtk_window_set_title(GTK_WINDOW(dialog), "Question");
  gtk_dialog_run(GTK_DIALOG(dialog));
  gtk_widget_destroy(dialog);
}

同样，“关于窗口”的格式为：

void show_about(GtkWidget *widget, gpointer data) {

  GdkPixbuf *pixbuf = gdk_pixbuf_new_from_file("battery.png", NULL);

  GtkWidget *dialog = gtk_about_dialog_new();
  gtk_about_dialog_set_name(GTK_ABOUT_DIALOG(dialog), "Battery");
  gtk_about_dialog_set_version(GTK_ABOUT_DIALOG(dialog), "0.9"); 
  gtk_about_dialog_set_copyright(GTK_ABOUT_DIALOG(dialog), "(c) Jan Bodnar");
  gtk_about_dialog_set_comments(GTK_ABOUT_DIALOG(dialog), "Battery is a simple tool for battery checking.");
  gtk_about_dialog_set_website(GTK_ABOUT_DIALOG(dialog), "http://www.batteryhq.net");
  gtk_about_dialog_set_logo(GTK_ABOUT_DIALOG(dialog), pixbuf);
  g_object_unref(pixbuf), pixbuf = NULL;
  gtk_dialog_run(GTK_DIALOG (dialog));
  gtk_widget_destroy(dialog);
}

现在我在 GLADE 中完全创建了这些窗口，我不确定信号处理程序应该采用什么形式（在 C 中）以便连接，例如，单击帮助 -> 关于在 GLADE 中创建的关于窗口，或者连接点击 File -> Quit 并在 GLADE 中创建“你确定要退出”消息对话框。我对 GTK+ 和 Glade 都是新手，我似乎找不到任何对解决这个问题有用的东西。任何帮助将不胜感激。

编辑：下面是一个示例 glade XML 文件，它由两个顶级窗口组成。第一个是带有一个包含菜单栏的单个框的主窗口。第二个是关于对话框。我正在寻找的是帮助编写信号处理程序，该处理程序将在单击菜单栏中的 File -> About 后打开 about 窗口。

<?xml version="1.0" encoding="UTF-8"?>
<!-- Generated with glade 3.18.3 -->
<interface>
  <requires lib="gtk+" version="3.12"/>
  <object class="GtkWindow" id="window1">
    <property name="can_focus">False</property>
    <child>
      <object class="GtkBox" id="box1">
        <property name="visible">True</property>
        <property name="can_focus">False</property>
        <property name="orientation">vertical</property>
        <child>
          <object class="GtkMenuBar" id="menubar1">
            <property name="visible">True</property>
            <property name="can_focus">False</property>
            <child>
              <object class="GtkMenuItem" id="menuitem1">
                <property name="visible">True</property>
                <property name="can_focus">False</property>
                <property name="label" translatable="yes">_File</property>
                <property name="use_underline">True</property>
                <child type="submenu">
                  <object class="GtkMenu" id="menu1">
                    <property name="visible">True</property>
                    <property name="can_focus">False</property>
                    <child>
                      <object class="GtkImageMenuItem" id="imagemenuitem1">
                        <property name="label">gtk-new</property>
                        <property name="visible">True</property>
                        <property name="can_focus">False</property>
                        <property name="use_underline">True</property>
                       <property name="use_stock">True</property>
                      </object>
                    </child>
                    <child>
                     <object class="GtkImageMenuItem" id="imagemenuitem2">
                        <property name="label">gtk-open</property>
                        <property name="visible">True</property>
                        <property name="can_focus">False</property>
                        <property name="use_underline">True</property>
                        <property name="use_stock">True</property>
                      </object>
                    </child>
                    <child>
                      <object class="GtkImageMenuItem" id="imagemenuitem3">
                        <property name="label">gtk-save</property>
                        <property name="visible">True</property>
                        <property name="can_focus">False</property>
                        <property name="use_underline">True</property>
                        <property name="use_stock">True</property>
                      </object>
                    </child>
                    <child>
                      <object class="GtkImageMenuItem" id="imagemenuitem4">
                        <property name="label">gtk-save-as</property>
                        <property name="visible">True</property>
                        <property name="can_focus">False</property>
                        <property name="use_underline">True</property>
                        <property name="use_stock">True</property>
                      </object>
                    </child>
                    <child>
                      <object class="GtkSeparatorMenuItem" id="separatormenuitem1">
                        <property name="visible">True</property>
                        <property name="can_focus">False</property>
                      </object>
                    </child>
                    <child>
                      <object class="GtkImageMenuItem" id="imagemenuitem5">
                        <property name="label">gtk-quit</property>
                        <property name="visible">True</property>
                        <property name="can_focus">False</property>
                        <property name="use_underline">True</property>
                        <property name="use_stock">True</property>
                      </object>
                    </child>
                  </object>
                </child>
              </object>
            </child>
            <child>
              <object class="GtkMenuItem" id="menuitem2">
                <property name="visible">True</property>
                <property name="can_focus">False</property>
                <property name="label" translatable="yes">_Edit</property>
                <property name="use_underline">True</property>
                <child type="submenu">
                  <object class="GtkMenu" id="menu2">
                    <property name="visible">True</property>
                    <property name="can_focus">False</property>
                    <child>
                      <object class="GtkImageMenuItem" id="imagemenuitem6">
                        <property name="label">gtk-cut</property>
                        <property name="visible">True</property>
                        <property name="can_focus">False</property>
                        <property name="use_underline">True</property>
                        <property name="use_stock">True</property>
                      </object>
                    </child>
                    <child>
                      <object class="GtkImageMenuItem" id="imagemenuitem7">
                        <property name="label">gtk-copy</property>
                        <property name="visible">True</property>
                        <property name="can_focus">False</property>
                        <property name="use_underline">True</property>
                        <property name="use_stock">True</property>
                      </object>
                    </child>
                    <child>
                     <object class="GtkImageMenuItem" id="imagemenuitem8">
                        <property name="label">gtk-paste</property>
                        <property name="visible">True</property>
                        <property name="can_focus">False</property>
                        <property name="use_underline">True</property>
                        <property name="use_stock">True</property>
                      </object>
                    </child>
                    <child>
                      <object class="GtkImageMenuItem" id="imagemenuitem9">
                        <property name="label">gtk-delete</property>
                        <property name="visible">True</property>
                        <property name="can_focus">False</property>
                        <property name="use_underline">True</property>
                        <property name="use_stock">True</property>
                      </object>
                    </child>
                  </object>
                </child>
              </object>
            </child>
           <child>
              <object class="GtkMenuItem" id="menuitem3">
                <property name="visible">True</property>
                <property name="can_focus">False</property>
                <property name="label" translatable="yes">_View</property>
                <property name="use_underline">True</property>
              </object>
            </child>
            <child>
              <object class="GtkMenuItem" id="menuitem4">
                <property name="visible">True</property>
                <property name="can_focus">False</property>
                <property name="label" translatable="yes">_Help</property>
                <property name="use_underline">True</property>
                <child type="submenu">
                  <object class="GtkMenu" id="menu3">
                    <property name="visible">True</property>
                    <property name="can_focus">False</property>
                    <child>
                      <object class="GtkImageMenuItem" id="imagemenuitem10">
                        <property name="label">gtk-about</property>
                        <property name="visible">True</property>
                        <property name="can_focus">False</property>
                        <property name="use_underline">True</property>
                       <property name="use_stock">True</property>
                      </object>
                    </child>
                  </object>
                </child>
              </object>
            </child>
          </object>
          <packing>
            <property name="expand">False</property>
            <property name="fill">True</property>
            <property name="position">0</property>
          </packing>
        </child>
      </object>
    </child>
  </object>
  <object class="GtkAboutDialog" id="window_about">
    <property name="can_focus">False</property>
    <property name="type_hint">dialog</property>
    <property name="program_name">Glade</property>
    <property name="logo_icon_name">image-missing</property>
    <child internal-child="vbox">
      <object class="GtkBox" id="aboutdialog-vbox1">
        <property name="can_focus">False</property>
        <property name="orientation">vertical</property>
        <property name="spacing">2</property>
        <child internal-child="action_area">
          <object class="GtkButtonBox" id="aboutdialog-action_area1">
            <property name="can_focus">False</property>
            <property name="layout_style">end</property>
          </object>
          <packing>
            <property name="expand">False</property>
            <property name="fill">False</property>
            <property name="position">0</property>
          </packing>
        </child>
        <child>
          <placeholder/>
        </child>
      </object>
    </child>
  </object>
</interface>

【问题讨论】：

您不打算尝试从信号处理程序中显示消息对话框之类的内容，是吗？只有可以从信号处理程序中安全调用的函数是async-signal-safe functions。
我没有尝试这样做。似乎这就是上面定义的函数所发生的事情。鉴于 Glade XML 文件已经预定义了消息对话框窗口，我只是在寻找有关如何构造信号处理程序的说明。

标签： c gtk glade

【解决方案1】：

如果理解正确，您不是以编程方式创建对话框，而是希望通过 glade 创建对话框。

使用 glade 你必须使用GtkBuilder。

假设您使用 glade (yesno_dialog.ui) 创建了一个简单的 Yes, No 对话框：

<?xml version="1.0" encoding="UTF-8"?>
<!-- Generated with glade 3.20.2 -->
<interface>
  <requires lib="gtk+" version="3.20"/>
  <object class="GtkDialog" id="dialog1">
    <property name="can_focus">False</property>
    <property name="modal">True</property>
    <property name="default_width">275</property>
    <property name="default_height">130</property>
    <property name="type_hint">dialog</property>
    <child internal-child="vbox">
      <object class="GtkBox">
        <property name="can_focus">False</property>
        <property name="orientation">vertical</property>
        <property name="spacing">2</property>
        <child internal-child="action_area">
          <object class="GtkButtonBox">
            <property name="can_focus">False</property>
            <property name="hexpand">True</property>
            <property name="layout_style">spread</property>
            <child>
              <object class="GtkButton" id="button1">
                <property name="label">gtk-yes</property>
                <property name="visible">True</property>
                <property name="can_focus">True</property>
                <property name="receives_default">True</property>
                <property name="use_stock">True</property>
              </object>
              <packing>
                <property name="expand">True</property>
                <property name="fill">True</property>
                <property name="position">0</property>
              </packing>
            </child>
            <child>
              <object class="GtkButton" id="button2">
                <property name="label">gtk-no</property>
                <property name="visible">True</property>
                <property name="can_focus">True</property>
                <property name="receives_default">True</property>
                <property name="use_stock">True</property>
              </object>
              <packing>
                <property name="expand">True</property>
                <property name="fill">True</property>
                <property name="position">1</property>
              </packing>
            </child>
          </object>
          <packing>
            <property name="expand">True</property>
            <property name="fill">True</property>
            <property name="position">0</property>
          </packing>
        </child>
        <child>
          <object class="GtkLabel">
            <property name="visible">True</property>
            <property name="can_focus">False</property>
            <property name="halign">center</property>
            <property name="valign">center</property>
            <property name="hexpand">True</property>
            <property name="vexpand">True</property>
            <property name="label" translatable="yes">Are you sure to quit?</property>
          </object>
          <packing>
            <property name="expand">False</property>
            <property name="fill">True</property>
            <property name="position">1</property>
          </packing>
        </child>
      </object>
    </child>
    <action-widgets>
      <action-widget response="1">button1</action-widget>
      <action-widget response="2">button2</action-widget>
    </action-widgets>
    <child>
      <placeholder/>
    </child>
  </object>
</interface>

应该是这样的：

注意 response_id 为 1 以供以后参考。

让我们测试一个带有按钮的简单窗口，该按钮将通过其clicked 信号处理程序/回调触发对话框：

#include <gtk/gtk.h>

void on_button_clicked (GtkButton *button, gpointer user_data) {
   int response;
   GtkWidget  *dialog;
   GtkBuilder *builder;

   g_return_if_fail (user_data != NULL);

   builder = gtk_builder_new_from_file("yesno_dialog.ui");

   dialog = GTK_WIDGET(gtk_builder_get_object (builder, "dialog1"));
   gtk_window_set_transient_for (GTK_WINDOW(dialog), GTK_WINDOW(user_data));

   gtk_widget_show_all(dialog);

   response = gtk_dialog_run(GTK_DIALOG(dialog));

   gtk_widget_destroy(dialog);

   g_object_unref(G_OBJECT(builder));

   g_print ("Response is %s\n", response == 1 ? "Yes" : "No");
}


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

   gtk_init(&argc,&argv);

   button = gtk_button_new_with_label("Press for dialog");
   window = gtk_window_new(GTK_WINDOW_TOPLEVEL);

   gtk_container_add(GTK_CONTAINER(window), button);

   g_signal_connect(G_OBJECT(button), "clicked", G_CALLBACK(on_button_clicked), window);
   g_signal_connect(G_OBJECT(window), "destroy", G_CALLBACK(gtk_main_quit), NULL);

   gtk_widget_show_all(window);

   gtk_main();

   return 0;
}

当您使用标准响应 ID 以编程方式构建对话框时，您可以使用预定义的枚举器来检查响应。使用 glade，即使我们定义了 Stock 按钮，我们也必须定义（用户定义的）响应 ID，以便 gtk_dialog_run 函数了解用户选择了响应。

编译：

gcc -o dialog main.c `pkg-config --cflags --libs gtk+-3.0`

应该会产生类似这样的结果：

【讨论】：

何塞，我感谢您的彻底回复，但这并没有回答最初的问题。请参阅对原始问题的编辑以进行澄清。谢谢！
@LeighK 该示例可以应用于您的目标。这里的基本步骤是通过 GtkBuilder 从 Glade XML 定义中检索自动实例化的小部件。 GtkBuilder 函数 get_object 允许您按名称获取 glade 小部件。因此，在您的回调中，您可以传递构建器对象或对话框。稍后我可以尝试补充我的答案。
何塞，我刚刚运行了您的示例，看来您确实是正确的。但是，存在一些差异。首先，我习惯于看到 GtkBuilder 在 main 中被引用。您不在 main 中引用它，而是在“on_button_clicked”信号处理程序中引用它（然后取消引用它）。我想我可以在 main 和我有兴趣编写的信号处理程序中引用它？
最大的问题是你的“on_button_clicked”信号处理程序被提供了一个指向你在main中创建的GtkButton的指针。在我的例子中，它需要链接到 GtkImageMenuItem “gtk-about”。我不确定如何做到这一点。除了这个警告之外，我怀疑您编写的信号处理程序可以完成这项工作。
@LeighK 这很简单。您只需要了解“Gtk”框架。注意加入 Gtk 聊天，以便我们可以通过充分了解问题并详细说明答案来尝试帮助您。聊天：chat.stackoverflow.com/rooms/160557/gtk

【解决方案2】：

与@Jose Fonte 讨论后，我的问题的解决方案如下：

// Signal Handler for Clicking File -> Quit
void file_quit_clicked (__attribute__((unused)) GtkMenuItem *item, gpointer user_data) 
{
    GtkBuilder *builder = (GtkBuilder *) user_data;

    GtkDialog *dialog = GTK_DIALOG(gtk_builder_get_object(builder, "quit_dialog"));

    gtk_widget_show_all(GTK_WIDGET(dialog));

    // This switch statement and gtk_widget_hide is needed so that the dialog window can be closed 
    // and reopened again without causing errors (i.e. if the user clicks "no" when asked "are you
    // sure you want to quit." Without these, the window errors out the second time opened.
    gint result = gtk_dialog_run (dialog);
    switch (result)
    {
        case GTK_RESPONSE_ACCEPT:
           // do_application_specific_something (); - Nothing Required
           break;
        default:
           // do_nothing_since_dialog_was_cancelled (); - Nothing Required
           break;
    }
    gtk_widget_hide(GTK_WIDGET(dialog));

}

将以下sn-p插入到主函数中：

    // So the "Are you sure you want to quit?" Dialog Box is hidden after clicking "x"
    GtkDialog *quit_dialog = GTK_DIALOG(gtk_builder_get_object(builder, "quit_dialog"));
    gtk_widget_hide_on_delete (GTK_WIDGET(quit_dialog));

【讨论】：

gint result = gtk_dialog_run (GTK_DIALOG (dialog)); 不需要 GTK_DIALOG() 宏，因为它被定义为 GtkDialog。我将编辑答案以反映这一点。
好交易何塞。非常感谢您为制定解决方案提供的所有帮助！