Building Mapping Applications with QGIS电子书

Building Mapping Applications with QGIS

Table of Contents

Building Mapping Applications with QGIS

Credits

About the Author

About the Reviewers

www.PacktPub.com

Support files, eBooks, discount offers, and more

Why subscribe?

Free access for Packt account holders

Preface

What this book covers

What you need for this book

Who this book is for

Conventions

Reader feedback

Customer support

Downloading the example code

Downloading the color images of this book

Errata

Piracy

Questions

1. Getting Started with QGIS

About QGIS

Installing and running QGIS

Understanding QGIS concepts

Linking QGIS and Python

Exploring the Python Console

Examining a Python plugin

Writing an external application

Summary

2. The QGIS Python Console

Using the console

Working with geospatial data in the console

Scripting the QGIS user interface

The status bar

The message bar

Progress indicators

QGIS logging

Custom dialogs and windows

Summary

3. Learning the QGIS Python API

About the QGIS Python APIs

Deciphering the C++ documentation

Organizing the QGIS Python libraries

The qgis.core package

Maps and map layers

Coordinate reference systems

Vector layers

Displaying vector data

Accessing vector data

Spatial indexes

Raster layers

How raster data is displayed

Accessing raster data

Other useful qgis.core classes

The qgis.gui package

The QgisInterface class

The QgsMapCanvas class

The QgsMapCanvasItem class

The QgsMapTool class

Other useful qgis.gui classes

Using the PyQGIS library

Analyzing raster data

Manipulating vector data and saving it to a shapefile

Using different symbols for different features within a map

Calculating the distance between two user-defined points

Summary

4. Creating QGIS Plugins

Getting ready

Understanding the QGIS plugin architecture

Creating a simple plugin

The plugin development process

Using the Plugin Builder

Automating the build process

Plugin help files

Unit testing

Distributing your plugin

Writing a useful plugin

Possibilities and limitations of plugins

Summary

5. Using QGIS in an External Application

Introducing Lex

Getting the data

Designing the application

Creating the application's framework

Adding the user interface

Connecting the actions

Creating the map canvas

Labeling the points

Filtering the landmarks

Implementing the zoom tool

Implementing the pan tool

Implementing the explore mode

Further improvements and enhancements

Summary

6. Mastering the QGIS Python API

Working with symbol layers

Combining symbol layers

Implementing symbol layers in Python

Implementing renderers in Python

Working with custom map layers

Creating custom map canvas items

Using memory-based layers

Summary

7. Selecting and Editing Features in a PyQGIS Application

Working with selections

Using the layer editing mode

Adding Points

Editing Points

Deleting Points and other features

Adding lines and polygons

Editing lines and polygons

Summary

8. Building a Complete Mapping Application using Python and QGIS

Introducing ForestTrails

Designing the ForestTrails application

Creating the application

Laying out the application

Defining the toolbar icons

The constants.py module

The forestTrails.py module

The mapTools.py module

The ui_mainWindow.py module

Running the application

Obtaining the basemap

Defining the map layers

Defining the map renderers

The Pan Tool

Implementing the track editing mode

Summary

9. Completing the ForestTrails Application

The Add Track map tool

Testing the application

Vertex snapping

The Edit Track map tool

The Delete Track map tool

The Get Info map tool

The Set Start Point and Set End Point actions

The Find Shortest Path action

Adjusting the toolbar actions

Suggested improvements

Summary

Index