CODEWITHSUNDEEP
pythonkivy
crystalattice
crystalattice

Reputation: 5089

How to make a Kivy GUI for a CLI Python program

I'm not really sure how to ask this question so it makes the most sense. I have a console-based Python program that simulates a fuel storage and transfer system (schematic drawing).

The current program is nothing special, just uses valve and pump instances to see if valves are open/closed, pumps on/off, and the associated flow rates and pressure across the devices.

I'm looking to make a Kivy program that simulates a human-machine interface. In this case, simple toggle buttons next to the valves to show if they are open or closed, and whether the pumps are on or off.

I've gone through the Kivy tutorials and read a Kivy book but they don't answer my problems, as they tend to focus more on mobile games rather than desktop-oriented apps. I've figured out how to add the buttons to the schematic but I don't know how to make the .py/.kv files interact with my existing Python code. I don't want to rewrite my existing code if at all possible.

Below is what I have so far; all it does is make a ToggleButton underneath valve 1. When pressed, the button sends the word "pressed" to the console output.

hmi.py

import kivy
kivy.require("1.10.0")

from kivy.app import App
from kivy.uix.floatlayout import FloatLayout
from kivy.config import Config
from kivy.uix.togglebutton import ToggleButton, ToggleButtonBehavior

Config.set("graphics", "width", "1062")
Config.set("graphics", "height", "849")


class HMI(FloatLayout):
    pass


class HMIApp(App):
    def build(self):
        return HMI()


if __name__ == "__main__":
    HMIApp().run()

hmi.kv

#:kivy 1.10.0

<HMIButton@ToggleButton>:
    color: 1, 1, 1, 1
    size_hint: (.01, .01)

<HMI>:
    canvas.before:
        Rectangle:
            pos: self.pos
            size: self.size
            source: "fuel_schematic.png"
    HMIButton:
        id: _valve_1
        text: "1"
        pos: 360, 285
        on_press: print("pressed")

My main question is, what is the best way to take the valve instance at VirtualPLC.Models.FuelFarm.components.gate1 and the functions at VirtualPLC.Models.FuelFarm.functionality.gate1_open() [and close()] and tie them to the toggle button I've added to the Kivy code?

Can I simply import these modules or do I have to rewrite them into the Kivy program?

Upvotes: 0

Views: 526

Answers (1)

ikolim
ikolim

Reputation: 16011

Solution

When you touch or click on ToggleButton widget, the state toggles between ‘normal’ and ‘down’ (as opposed to a Button that is only ‘down’ as long as it is pressed).

Yes, you can import those modules.

kv file

  1. Replace on_press with on_state event, and bind it to a callback method and passing an instance of the ToggleButton e.g. on_state: root.on_state(self).
  2. Add group: to each ToggleButton so that you know which value it is.

Snippet - kv

HMIButton:
    id: _valve_1
    text: "1"
    pos: 360, 285
    group: "valve1"
    on_state: root.on_state(self)

Python code

Implement a callback method inside class HMI().

Snippet - Python

class HMI(FloatLayout):

    def on_state(self, instance):
        if instance.state == "down":
            print(instance.group, "Opened")
        else:
            print(instance.group, "Closed")

Upvotes: 1

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