Error messages from gtk callbacks are not being shown

When working with GTK in Julia, it is common to encounter error messages that are not being shown in the user interface. This can be frustrating, as it makes it difficult to identify and fix issues in the code. In this article, we will explore three different ways to solve this problem and determine which option is the best.

Option 1: Using the Gtk.showall() function

One way to solve the issue of error messages not being shown in GTK callbacks is to use the Gtk.showall() function. This function forces all widgets to be displayed, including any error messages that may be hidden. By calling this function at the appropriate place in the code, you can ensure that error messages are always visible to the user.

using Gtk

function on_button_clicked(button)
    try
        # Code that may produce an error
    catch ex
        Gtk.showall()
        error_dialog = Gtk.MessageDialog(button, Gtk.DialogFlags.MODAL, Gtk.MessageType.ERROR, Gtk.ButtonsType.OK, ex.msg)
        Gtk.show(error_dialog)
    end
end

# Connect the callback function to the button
button = Gtk.Button("Click me")
signal_connect(button, "clicked", on_button_clicked)

Option 2: Redirecting error messages to a log file

Another option to solve the issue is to redirect error messages to a log file. This way, even if the error messages are not displayed in the user interface, they can still be accessed and reviewed later. To implement this solution, you can use the Logging module in Julia to redirect error messages to a log file.

using Gtk
using Logging

# Set up logging to a file
logfile = "error.log"
file_logger = FileLogger(logfile)
global_logger(file_logger)

function on_button_clicked(button)
    try
        # Code that may produce an error
    catch ex
        error(ex)
    end
end

# Connect the callback function to the button
button = Gtk.Button("Click me")
signal_connect(button, "clicked", on_button_clicked)

Option 3: Displaying error messages in a separate window

A third option is to display error messages in a separate window, instead of within the main user interface. This can be achieved by creating a new window and showing the error message in a label or text box. By separating the error messages from the main user interface, you can ensure that they are always visible to the user.

using Gtk

function on_button_clicked(button)
    try
        # Code that may produce an error
    catch ex
        error_dialog = Gtk.MessageDialog(button, Gtk.DialogFlags.MODAL, Gtk.MessageType.ERROR, Gtk.ButtonsType.OK, ex.msg)
        Gtk.show(error_dialog)
    end
end

# Connect the callback function to the button
button = Gtk.Button("Click me")
signal_connect(button, "clicked", on_button_clicked)

After exploring these three options, it is clear that the best solution depends on the specific requirements of your application. If you want to ensure that error messages are always visible to the user, Option 1 using the Gtk.showall() function is the most suitable. However, if you prefer to log error messages for later review, Option 2 with redirecting error messages to a log file is a better choice. Lastly, if you want to display error messages in a separate window, Option 3 is the way to go. Consider your application’s needs and choose the option that best fits your requirements.