add_task.kv

<AddTaskScreen>:
    orientation: "vertical"
    GridLayout:
        cols: 2
        Label:
            text:"Name"
        TextInput:
            id: taskname
            hint_text: "Name of Task"
            text: root.noneToString(root.task.name)
        Label:
            text:"Description"
        TextInput:
            id: taskdescription
            hint_text: "Description of task"
            text: root.noneToString(root.task.description)
        Label:
            text:"Duration"
        TextInput:
            id:taskduration
            hint_text: "Duration of task in hours"
            text: root.noneToString(root.task.duration)
        Label:
            text:"Deadline"
        TextInput:
            id: taskdeadline
            hint_text: "Deadline of task"
            text: root.noneToString(root.task.deadline)

    Button:
        text: 'Create new Task'
        size_hint_y: 0.2
        on_press: root.createParentTask(taskname.text,taskdescription.text,taskduration.text,taskdeadline.text)