Book Image

Qt5 Python GUI Programming Cookbook

By : B. M. Harwani
Book Image

Qt5 Python GUI Programming Cookbook

By: B. M. Harwani

Overview of this book

PyQt is one of the best cross-platform interface toolkits currently available; it's stable, mature, and completely native. If you want control over all aspects of UI elements, PyQt is what you need. This book will guide you through every concept necessary to create fully functional GUI applications using PyQt, with only a few lines of code. As you expand your GUI using more widgets, you will cover networks, databases, and graphical libraries that greatly enhance its functionality. Next, the book guides you in using Qt Designer to design user interfaces and implementing and testing dialogs, events, the clipboard, and drag and drop functionality to customize your GUI. You will learn a variety of topics, such as look and feel customization, GUI animation, graphics rendering, implementing Google Maps, and more. Lastly, the book takes you through how Qt5 can help you to create cross-platform apps that are compatible with Android and iOS. You will be able to develop functional and appealing software using PyQt through interesting and fun recipes that will expand your knowledge of GUIs
Table of Contents (20 chapters)
Title Page
Dedication
Packt Upsell
Contributors
Preface
Index

Drawing a circle of a desired size


In this recipe, we will be learning to draw a circle. The user will click and drag the mouse to define the diameter of the circle, and the circle will be drawn at the diameter specified by the user.

How to do it...

A circle is nothing but an arc that is drawn from 0 to 360 degrees. The length of the arc, or you can say the diameter of the circle, is determined by the distance of mouse press event and mouse release events. A rectangle is defined internally from mouse press event until mouse release event, and the circle is drawn within that rectangle. Here are the complete steps to create this application:

  1. Let's create an application based on the Dialog without Buttons template.
  2. Add a QLabel widget to the form by dragging and dropping a Label widget on the form.
  3. Set the text property of the Label widget to Click the mouse and drag it to draw a  circle of the desired size.
  4. Save the application by name as demoDrawCircle.ui. The form will now appear as shown in the...