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Fancy List Items

Articles from Qt Quarterly - Sun, 14/12/2003 - 10:00pm
Qt's list view class can provide list and tree views and is capable of handling large amounts of data. But out of the box it can only have one background color and one font for all of its items. The same applies to Qt's list box widget. In this article we present a a list box item subclass and a list view item subclass that can have custom fonts and background colors.

Laying out MDI Children

Articles from Qt Quarterly - Sun, 14/12/2003 - 10:00pm
Qt provides support for MDI (Multiple Document Interface) through its QWorkspace widget. The workspace provides two strategies for laying out its child widgets. In this article we will show how easy it is to add new layout strategies to QWorkspace.

Fields on Forms

Articles from Qt Quarterly - Sun, 14/12/2003 - 10:00pm
Forms that have lots of line edits often use a grid layout with labels in the first column and line edits in the second column. This looks attractive, except that fields that can only accept a short amount of text, say one or two characters, are given the same width as fields that can take a long line of text. This deprives users of the visual cue that proportional widths would give. This article provides a simple solution.

What's New in Qt 3.2

Articles from Qt Quarterly - Wed, 15/10/2003 - 12:00am
Qt 3.2 is now available. This new version introduces many new classes and some features that you might want to use right away in your Qt applications. We will review many of these in this article. For a complete list of what has changed, see Changes 3.2.0.

A Model/View Table for Large Datasets

Articles from Qt Quarterly - Wed, 15/10/2003 - 12:00am
This article shows how to handle large datasets with QTable using a model/view approach, and without using QTableItems. Model/view means that only the data that the user can see needs to be retrieved and held in memory. This approach also makes it easy to show the same dataset in multiple tables without duplicating any data.

Customizing for Completion

Articles from Qt Quarterly - Wed, 15/10/2003 - 12:00am
QTextEdit can be used to provide a simple text editor within an application. QTextEdit provides a lot of functionality out of the box, but one feature it doesn't provide is automatic completion. In this article, we present a QTextEdit subclass that provides completion and that demonstrates how to extend and enhance QTextEdit's functionality.

Mini-Quiz Answers

Articles from Qt Quarterly - Wed, 15/10/2003 - 12:00am
In Issue 7 we asked for the longest gramatically correct English sentence that consists entirely of Qt 3.2.0 function names, e.g. ``take back all animated green children'' (6 words).

Implementing a Popup Calendar

Articles from Qt Quarterly - Wed, 15/10/2003 - 12:00am
We often need to constrain user input for particular widgets. Qt provides many ways of doing this, but for some complex data types we may want to provide our own "value picker" that lets the user pop up a little dialog through which they can choose a valid value. In this article we present a small calendar popup that demonstrates the necessary techniques.

A Model/View Table for Large Datasets

Articles from Qt Quarterly - Tue, 14/10/2003 - 9:00pm
This article shows how to handle large datasets with QTable using a model/view approach, and without using QTableItems. Model/view means that only the data that the user can see needs to be retrieved and held in memory. This approach also makes it easy to show the same dataset in multiple tables without duplicating any data.

Customizing for Completion

Articles from Qt Quarterly - Tue, 14/10/2003 - 9:00pm
QTextEdit can be used to provide a simple text editor within an application. QTextEdit provides a lot of functionality out of the box, but one feature it doesn't provide is automatic completion. In this article, we present a QTextEdit subclass that provides completion and that demonstrates how to extend and enhance QTextEdit's functionality.

Implementing a Popup Calendar

Articles from Qt Quarterly - Tue, 14/10/2003 - 9:00pm
We often need to constrain user input for particular widgets. Qt provides many ways of doing this, but for some complex data types we may want to provide our own "value picker" that lets the user pop up a little dialog through which they can choose a valid value. In this article we present a small calendar popup that demonstrates the necessary techniques.

Mini-Quiz Answers

Articles from Qt Quarterly - Tue, 14/10/2003 - 9:00pm
In Issue 7 we asked for the longest gramatically correct English sentence that consists entirely of Qt 3.2.0 function names, e.g. ``take back all animated green children'' (6 words).

What's New in Qt 3.2

Articles from Qt Quarterly - Tue, 14/10/2003 - 9:00pm
Qt 3.2 is now available. This new version introduces many new classes and some features that you might want to use right away in your Qt applications. We will review many of these in this article. For a complete list of what has changed, see Changes 3.2.0.

Far-Reaching QFtp and QHttp

Articles from Qt Quarterly - Thu, 12/06/2003 - 12:00am
Qt's QUrlOperator provides simple and convenient access to remote files that are accessible using the FTP or HTTP protocols. New in Qt 3.1 are more direct interfaces to these protocols in the QFtp and QHttp classes. In this article we will explore how these classes can give Qt programmers more power and control over remote files and servers.

Fast and Flicker-Free

Articles from Qt Quarterly - Thu, 12/06/2003 - 12:00am
Many applications are written using Qt's standard widgets. But sometimes none of the standard widgets is suitable, and it is necessary to write a custom widget. It is not hard to create a custom widget, especially when you start from a QWidget, QFrame or QScrollView subclass and reimplement paintEvent() or drawContents(). But one common problem that can affect custom widgets is flicker. In this article we will explain why flicker occurs and how to avoid it.

Glimpsing the Third Dimension

Articles from Qt Quarterly - Thu, 12/06/2003 - 12:00am
Qt's QGL module makes it easy to integrate OpenGL rendering into Qt applications. In this article we will demonstrate how to create a custom QGLContext that can make use of implementation-specific features not covered by the QGL abstraction. We will also present a simple example of a multiplatform multithreaded OpenGL Qt application.

Multi-Page Dialogs

Articles from Qt Quarterly - Thu, 12/06/2003 - 12:00am
Multi-page dialogs present information on pages that are superimposed on screen, so that only one page is visible at any one time. This articles demonstrates two kinds of multi-page dialog and explains how to achieve automatic dialog resizing when a new page is made visible.

Multi-Page Dialogs

Articles from Qt Quarterly - Wed, 11/06/2003 - 9:00pm
Multi-page dialogs present information on pages that are superimposed on screen, so that only one page is visible at any one time. This articles demonstrates two kinds of multi-page dialog and explains how to achieve automatic dialog resizing when a new page is made visible.

Far-Reaching QFtp and QHttp

Articles from Qt Quarterly - Wed, 11/06/2003 - 9:00pm
Qt's QUrlOperator provides simple and convenient access to remote files that are accessible using the FTP or HTTP protocols. New in Qt 3.1 are more direct interfaces to these protocols in the QFtp and QHttp classes. In this article we will explore how these classes can give Qt programmers more power and control over remote files and servers.

Fast and Flicker-Free

Articles from Qt Quarterly - Wed, 11/06/2003 - 9:00pm
Many applications are written using Qt's standard widgets. But sometimes none of the standard widgets is suitable, and it is necessary to write a custom widget. It is not hard to create a custom widget, especially when you start from a QWidget, QFrame or QScrollView subclass and reimplement paintEvent() or drawContents(). But one common problem that can affect custom widgets is flicker. In this article we will explain why flicker occurs and how to avoid it.

Glimpsing the Third Dimension

Articles from Qt Quarterly - Wed, 11/06/2003 - 9:00pm
Qt's QGL module makes it easy to integrate OpenGL rendering into Qt applications. In this article we will demonstrate how to create a custom QGLContext that can make use of implementation-specific features not covered by the QGL abstraction. We will also present a simple example of a multiplatform multithreaded OpenGL Qt application.

Comment moderation

Drupal Modules - Fri, 14/03/2003 - 1:04pm

Edit moderation votes for comments. Moderation in Drupal is similar in spirit to Slashdot and Kuro5hin

Achtung! Binary and Character Data

Articles from Qt Quarterly - Tue, 04/03/2003 - 12:00am
Qt's QString, QCString and QByteArray classes are all alternatives for old-fashioned and limited char arrays. Their proper use can make your applications faster, smaller, and more reliable. QString also brings the internationalization benefits of Unicode, and Qt's QDataStream and QTextStream classes make portable I/O easy. This article explains how to realize the benefits offered by these classes.

Canvas Item Groupies

Articles from Qt Quarterly - Tue, 04/03/2003 - 12:00am
Diagram editors and similar programs often provide their users with a means of grouping graphical items together. Grouping makes it easier for users to apply an operation to many items at once. This article presents one simple approach to grouping canvas items using a generic CanvasGroup class. We also provide a QCanvasView subclass as a practical example of use.

Generating XML

Articles from Qt Quarterly - Tue, 04/03/2003 - 12:00am
Qt provides the SAX and DOM classes for parsing XML, but does not include a dedicated class to generate XML. In this article we will develop a straightforward XmlWriter class based on QTextStream, and demonstrate how to use it in practice, with an example that generates a Qt Designer .ui file.

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