GTK Developer Matthias Clasen gtk4-builder-tool 1 User Commands gtk4-builder-tool GtkBuilder file utility gtk4-builder-tool COMMAND OPTION FILE gtk4-builder-tool can perform various operations on GtkBuilder .ui files. The validate command validates the .ui file and reports errors to stderr. The enumerate command lists all the named objects that are created in the .ui file. The preview command displays the .ui file. This command accepts options to specify the ID of the toplevel object and a .css file to use. The simplify command simplifies the .ui file by removing properties that are set to their default values and writes the resulting XML to stdout, or back to the input file. When the --3to4 is specified, simplify interprets the input as a GTK 3 ui file and attempts to convert it to GTK 4 equivalents. It performs various conversions, such as renaming properties, translating child properties to layout properties, rewriting the setup for GtkNotebook, GtkStack, GtkAssistant or changing toolbars into boxes. You should always test the modified .ui files produced by gtk4-builder-tool before using them in production. Note in particular that the conversion done with --3to4 is meant as a starting point for a port from GTK 3 to GTK 4. It is expected that you will have to do manual fixups after the initial conversion. The simplify command accepts the following options: --replace Write the content back to the .ui file instead of stdout. --3to4 Transform a GTK 3 ui file to GTK 4 The preview command accepts the following options: --id=ID The ID of the object to preview. If not specified, gtk4-builder-tool will choose a suitable object on its own. --css=FILE Load style information from the given .css file.