Book Image

PrimeFaces Cookbook

Book Image

PrimeFaces Cookbook

Overview of this book

PrimeFaces is the de facto standard in the Java web development. PrimeFaces is a lightweight library with one jar, zero-configuration, and no required dependencies. You just need to download PrimeFaces, add the primefaces-{version}.jar to your classpath and import the namespace to get started. This cookbook provides a head start by covering all the knowledge needed for working with PrimeFaces components in the real world. "PrimeFaces Cookbook" covers over 100 effective recipes for PrimeFaces 3.x which is a leading component suite to boost JSF applications. The book's range is wide‚Äí from AJAX basics, theming, and input components to advanced usage of datatable, menus, drag & drop, and charts. It also includes creating custom components and PrimeFaces Extensions.You will start with the basic concepts such as installing PrimeFaces, configuring it, and writing a first simple page. You will learn PrimeFaces' theming concept and common inputs and selects components. After that more advanced components and use cases will be discussed. The topics covered are grouping content with panels, data iteration components, endless menu variations, working with files and images, using drag & drop, creating charts, and maps. The last chapters describe solutions for frequent, advanced scenarios and give answers on how to write custom components based on PrimeFaces and also show the community-driven open source project PrimeFaces Extension in action.
Table of Contents (17 chapters)
PrimeFaces Cookbook
Credits
About the Authors
About the Reviewers
www.PacktPub.com
Preface
Index

Cropping images


The imageCropper component provides image cropping functionality by allowing to us crop a certain region of an image, which could either be a local image or an external image. After cropping, a new image is created. It contains the cropped region and it is assigned to a CroppedImage instance.

How to do it...

The org.primefaces.model.CroppedImage class belongs to the PrimeFaces API, and the structure of the class is as follows:

public class CroppedImage {
  String originalFilename;
  byte[] bytes;
  int left;
  int top;
  int width;
  int height;
}

A simple definition of the image cropper for cropping a local image would be as shown in the following code line. The value of the component is bound with an instance of CroppedImage.

<p:imageCropper value="#{imageController.croppedImageSimple}" image="/resources/images/crop/primefaces.jpg" />

When hovered on the image, the cursor of the mouse will change to crosshairs for making the crop region selection. When the region is selected...