Tom Bondur

Subscribe to Tom Bondur: eMailAlertsEmail Alerts
Get Tom Bondur: homepageHomepage mobileMobile rssRSS facebookFacebook twitterTwitter linkedinLinkedIn


Related Topics: Eclipse Platform, Open Web Magazine

Eclipse Platform: Article

Developing an Eclipse BIRT Report Item Extension

Architecture and framework

This article provides the implementation details for the most important classes in the rotated label report item extension.

For example, the RotatedLabelItemFactoryImpl class instantiates a new report item when the user drags a rotated label report item from the Palette and drops the report item in the BIRT Report Designer Editor. This class extends the adapter class, org.eclipse.birt.report.model.api.extension.ReportItemFactory.

In the implementation class, the newReportItem( ) method receives a reference to DesignElementHandle, which provides the interface to the BIRT report model. The newReportItem( ) method instantiates the report item, as shown in Listing 2.

In the RotatedLabelUI class, the getLabel( ) method provides the text representation for the label to BIRT Report Designer. RotatedLabelUI extends the adapter class, org.eclipse.birt.report.designer.ui.extensions.ReportItemLabelProvider. Listing 3 shows the code for the getLabel( ) method.

The RotatedLabelPresentationImpl class specifies how to process and render the report item at presentation time. This class extends the org.eclipse.birt.report.engine.extension.ReportItemPresentationBase class.

The method, onRowSets( ), renders the rotated label report item as an image, rotated by the angle specified in the report design, as shown in Listing 4.

In the RotatedLabelReportItemImpl class, the method, getPropertyDefinitions( ), instantiates RotatedLabelPropertyDefinitionImpl objects for the displayText and rotationAngle properties. RotatedLabelReportItemImpl extends the adapter class, org.eclipse.birt.report.model.api.extension.ReportItem. Listing 5 shows the code for the getPropertyDefinitions( ) method.

The RotatedLabelPropertyEditUIImpl class builds the UI using the RotatedLabelGeneralTabUIImpl class to set up the controls for the UI. RotatedLabelPropertyEditUIImpl implements the org.eclipse.birt.report.designer.ui.extensions.IReportItemPropertyEditUI interface.

In the RotatedLabelPropertyEditUIImpl class, the get-CategoryTabs ( ) method instantiates the RotatedLabelGeneral-TabUIImpl class, as shown in Listing 6.

The RotatedLabelGeneralTabUIImpl class contains an internal class GeneralCategoryWrapper that creates the UI contents, as shown in Listing 7.

The GraphicsUtil class creates the image containing the specified text and rotates the text image to the specified angle, using the following methods:

  • createRotatedText( ) performs the following operations:
    - Gets the display text and rotation angle properties
    - Sets the display text font and determines the font metrics
    - Creates an image the same size as the display text String
    - Draws the display text as an image
    - Calls the rotateImage( ) method to rotate the image at the specified angle
    - Disposes of the operating system resources used to render the image
    - Returns the image object
  • rotateImage( ) rotates the image and determines the width, height, and point of origin for the image
Listing 8 shows the code for createRotatedText( ) method.

On the PDE Manifest Editor, in Overview, the Testing section contains links to launch a plug-in as a separate Eclipse application in either Run or Debug mode. In Testing, choose Launch an Eclipse application. Eclipse launches the runtime workbench.

In Report Design, choose File->New->Project, and choose Report Project. Create a new report in the project by choosing File->New->Report.

In File name, type a file name if you want to change the default file name. Choose Next. New Report displays the report templates. In Report templates, choose Blank Report, and choose Finish.

The layout editor displays the report design, new_report.rptdesign. The Palette contains the RotatedText report item.

From the Palette, drag RotatedLabel to Layout, as shown in Figure 1. In new_report.rptdesign, choose Preview. The preview appears, displaying the rotated label report item, as shown in Figure 2.

This article is an excerpt from the book, Integrating and Extending BIRT by Jason Weathersby, Don French, Tom Bondur, Jane Tatchell, and Iana Chatalbasheva, soon to be published by Addison-Wesley. The book is the second volume in a two-book series about business intelligence and reporting technology. The book introduces programmers to BIRT architecture and the reporting framework. It shows programmers how to build and deploy customized reports using scripting and BIRT APIs. It also describes how to use key extension points to create a customized report item, a rendering extension for generating output other than HTML or PDF, and an Open Data Access (ODA) driver for a new data source. Integrating and Extending BIRT. Copyright 2007 Actuate. ISBN 0321443853. For more information, please visit www.awprofessional.com.

More Stories By Jason Weathersby

Jason Weathersby is a member of the extended BIRT development team at Actuate Corporation and has backgrounds in both computer science and technical writing. He has many years experience in technical consulting, training, writing, and publishing about reporting, business intelligence tools, and database technologies.

More Stories By Iana Chatalbasheva

Iana Chatalbasheva is a member of the extended BIRT development team at Actuate Corporation and has backgrounds in both computer science and technical writing. She has many years experience in technical consulting, training, writing, and publishing about reporting, business intelligence tools, and database technologies.

More Stories By Tom Bondur

Tom Bondur is a member of the extended BIRT development team at Actuate Corporation and has backgrounds in both computer science and technical writing. He has many years experience in technical consulting, training, writing, and publishing about reporting, business intelligence tools, and database technologies.

Comments (0)

Share your thoughts on this story.

Add your comment
You must be signed in to add a comment. Sign-in | Register

In accordance with our Comment Policy, we encourage comments that are on topic, relevant and to-the-point. We will remove comments that include profanity, personal attacks, racial slurs, threats of violence, or other inappropriate material that violates our Terms and Conditions, and will block users who make repeated violations. We ask all readers to expect diversity of opinion and to treat one another with dignity and respect.