This is an experimental parser and runtime for a QML like markup language for Gtk+/Clutter. It is inspired by Qt's QML.

It's intended to complement the GtkBuilder format included in Gtk+.

The current implementation is written using Python, it will be ported to C when it's a bit more mature and better tested.

GML is licensed under GNU LGPL version 2 or later.

GtkWindow {
  title: "GML example"
  GtkVBox {
    GtkLabel {
      label: "Hello world"
      packing { expand: False }
    }
    GtkButton {
      label: "Click me"
      packing { expand: False }
    }
  }
}

For more examples, see the examples folder.

Creating a new toplevel object you just use the type name:

GtkWindow

You can also specify a new type without any properties:

GtkWindow {}

Properties are similar to JavaScript properties:

GtkWindow { title: "Window Title" }

You can insert newlines anywhere you like:

GtkWindow {
  title: "Window Title"
}

There's a special property called id which can is used to identify the object:

GtkWindow {
  id: window1
}

You can reference properties with an id, for instance:

GtkListStore {
  id: liststore
}
GtkTreeView {
  model: liststore
}

You can also reference objects by using a dot notation:

GtkButton {
  id: button1
  label: "Label"
}
GtkButton {
  id: button2
  label: button1.label
}

GML has a child concept implemented by a few types:

• GtkContainer

To add an child to an object, you just create it:

GtkWindow {
  GtkVBox
}

It can of course be nested:

GtkWindow {
  GtkVBox {
    GtkButton
    GtkLabel
  }
}

GtkContainers supports the concept of child properties, they are in a separate object tag called packing, eg:

GtkWindow {
  GtkVBox {
    GtkButton {
      packing { expand: true }
    }
  }
}

• Strings: "string" or 'string'
• Integers: 123
• Floating point: 0.1
• Boolean: true or false
• Identifiers / References: button1

Things to do, ordered by category

• Build system
• Add license headers
• Gtk+3/Introspection port
• Glade output
• Clutter
• C rewrite

• Lists
• New tokenizer
• Check token types better in parser
• Add error messages to parser
• Add a type for property referencs

• GtkListStore columns & rows

• Split into commands: run, validate, tokenize, parse, convert
• Add a validator
• Output: C
• Output: GtkBuilder
• Input: GtkBuilder
• Input: Existing widget tree via a GtkModule

• 100% coverage (might be redundant for Python impl)