Book Image

QGIS Python Programming Cookbook, Second Edition - Second Edition

By : Joel Lawhead
Book Image

QGIS Python Programming Cookbook, Second Edition - Second Edition

By: Joel Lawhead

Overview of this book

QGIS is a desktop geographic information system that facilitates data viewing, editing, and analysis. Paired with the most efficient scripting language—Python, we can write effective scripts that extend the core functionality of QGIS. Based on version QGIS 2.18, this book will teach you how to write Python code that works with spatial data to automate geoprocessing tasks in QGIS. It will cover topics such as querying and editing vector data and using raster data. You will also learn to create, edit, and optimize a vector layer for faster queries, reproject a vector layer, reduce the number of vertices in a vector layer without losing critical data, and convert a raster to a vector. Following this, you will work through recipes that will help you compose static maps, create heavily customized maps, and add specialized labels and annotations. As well as this, we’ll also share a few tips and tricks based on different aspects of QGIS.
Table of Contents (16 chapters)
QGIS Python Programming Cookbook - Second Edition
Credits
About the Author
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface

Creating tabs


Tabs allow you to condense the information from several screens into a relatively small place. Tabs provide titles at the top of the window, which present an individual widget layout for each title when clicked. In this recipe, we'll create a simple tabbed interface.

Getting ready

Open the QGIS Python console by selecting the Plugins menu and then clicking on Python Console.

How to do it...

We will create an overarching tab widget. Then, we'll create three generic widgets to represent our tabs. We'll set up layouts with three different GUI widgets and assign each layout to our tab widgets. Finally, we'll add our tabs to the tab widget and display it. To do this, we need to perform the following steps:

  1. First, we need to import the GUI and QGIS core libraries:

            from PyQt4.QtCore import * 
            from PyQt4.QtGui import * 
    
  2. Next, we create our tab and configure its title and size:

            qtw = QTabWidget() 
            qtw.setWindowTitle("PyQGIS Tab Example") 
    ...