"custom_progress_bar": {
    "$update_string": "mana:",
    "$max_string": "maxmana:",
    "type": "panel",
    "size": [70, 6],
    "offset": [0, 110],
    "controls": [
        {
            "bar_bg": {
                "type": "image",
                "texture": "textures/ui/experiencebarempty",
                "size": ["100%", "100%"],
                "controls": [
                    {
                        "progress": {
                            "type": "image",
                            "size": ["100%c", "100%"],
                            "layer": 1,
                            "texture": "textures/ui/experiencebarfull",
                            "bindings": [
                                {
                                    "binding_name": "#hud_title_text_string"
                                },
                                {
                                    "binding_name": "#hud_subtitle_text_string"
                                },
                                {
                                    "binding_type": "view",
                                    "source_property_name": "((#hud_subtitle_text_string - $max_string) * 1.0)",
                                    "target_property_name": "#max_val"
                                },
                                {
                                    "binding_type": "view",
                                    "source_property_name": "((#hud_title_text_string - $update_string) * 1.0)",
                                    "target_property_name": "#cur_val"
                                },
                                {
                                    "binding_type": "view",
                                    "source_property_name": "(#cur_val / #max_val)",
                                    "target_property_name": "#size_binding_x_multiplier"
                                }
                            ]
                        }
                    }
                ]
            }
        }
    ]
}