Python Kivy: Build a standard calculator application – GUI part 3

In this part of the tutorial, we will continue building the graphical user interface (GUI) for a standard calculator application using Python Kivy.

Adding Buttons and Layouts

First, we need to create the buttons for the calculator. We will use the GridLayout layout manager to organize the buttons in a grid-like fashion. This will make it easier for users to navigate and use the calculator.


<GridLayout>
<Button text="7" />
<Button text="8" />
<Button text="9" />
<Button text="/" />
<Button text="4" />
<Button text="5" />
<Button text="6" />
<Button text="*" />
<Button text="1" />
<Button text="2" />
<Button text="3" />
<Button text="-" />
<Button text="0" />
<Button text="." />
<Button text="=" />
<Button text="+" />
</GridLayout>


Next, we will add the functionality to the buttons so that they perform the appropriate calculations when clicked. We will also add a display widget to show the input and output of the calculator.

Styling the GUI

To make the calculator application look more appealing, we can apply some styling to the buttons and the display widget. We can use the background_color and foreground_color properties to change the color of the buttons, and we can adjust the font size and text color of the display widget.


<Button
text="7"
background_color=(0.2, 0.6, 1, 1)
foreground_color=(1, 1, 1, 1) />

<Label
text="0"
font_size=30
color=(0.2, 0.6, 1, 1) />


Conclusion

With the addition of buttons, layouts, and styling, we have completed the GUI part of the calculator application. In the next part of the tutorial, we will focus on adding the functionality to the buttons and implementing the calculations behind the scenes.