GTK应用程序：如何使用Qt / C ++创建工作指标？

Question

I've tried in 2 forums, but I had no luck so far.

So, I am using Qt IDE in order to build my application so as to participate to the Ubuntu Showdown contest. In my application, I've done the following:

    void show_app(MainWindow *data)
{
    //this works fine:
    app_indicator_set_status(appindicator, APP_INDICATOR_STATUS_PASSIVE);
    //this crashes the application:
    data->show();
}


void MainWindow::make_indicator()
{
    if(appindicator){
        //appindicator has already been created
        return;
    }
    appindicator = app_indicator_new("Format Junkie Indicator", "formatjunkie", APP_INDICATOR_CATEGORY_APPLICATION_STATUS);
    GtkWidget* showapp_option;
    GtkWidget* indicatormenu = gtk_menu_new();
    GtkWidget* item = gtk_menu_item_new_with_label("Format Junkie main menu");
    gtk_menu_item_set_submenu(GTK_MENU_ITEM(item), indicatormenu);

    showapp_option = gtk_menu_item_new_with_label("Show App!");
    g_signal_connect(showapp_option, "activate", G_CALLBACK(show_app), this);
    gtk_menu_shell_append(GTK_MENU_SHELL(indicatormenu), showapp_option);

    gtk_widget_show_all(indicatormenu);
    app_indicator_set_status(appindicator, APP_INDICATOR_STATUS_ACTIVE);
    app_indicator_set_attention_icon(appindicator, "dialog-warning");

    app_indicator_set_menu(appindicator, GTK_MENU (indicatormenu));
}

So, basically I am trying to make a simple indicator entry, which, on click, it will hide the indicator and display the application. The indicator can be successfully hidden using the PASSIVE thingy over there, but, during the call data->show();, the application crashes.

Any help on what I am doing wrong would be appreciated! Also, please help me to correct this problem I'm facing (alternatively, I will migrate to the old and good tray icon (it works fine in Ubuntu 12.04, anyway) which I can handle very easily and efficiently)

Answer 1

The callback for the activate signal needs to have the following type:

void callback(GtkMenuItem *, gpointer)

So show_app should be defined like this

void show_app(GtkMenuItem *showapp_option, MainWindow *data)

That should solve your problem.