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Basic SWT widgets enhancement

Revision as of 22:52, 9 August 2009 by (Talk | contribs) (Personal Info)

Personal Info

Name: Zhong Nanhai


Mentor: Ivar Meikas


SWT has been developed as a light-weight library to establish rich java GUI programmes, but there still are some popular features that current widget does not have. For example,the combo box widget still does not support an image item or a mix(image and text).Actually,there are many aspects for basic SWT widgets to be enhanced. Here, my work is just to add some basic and popular features to some widgets in SWT or Nebula.

Primary goals

Enhance some basic widgets in SWT or Nebula

  • rich combo box: this combo box will support image and mix(image and text)

I have found that there are two ways of implements such a extended combobox widget:

Enhancing the Combo-Widget with Images: you can see it on page ComboBoxEx: you can see the introduction of this widget on page

The first implementation is a good way to fulfil such a function,in which it just make some modifications of combobox source code in swt.It is simple and we do not need consider much about cross-platform problem,because it just builds on basic widgets afforded by swt like primary combobox widget.But what the problem is: maybe the SWT group does not like this coding style and it is just a workaround to implement a function,thus should not be as a part of SWT.

The second implementation may be a good style that SWT group likes.But there are many problems in it,of which the most import is the cross-platform and we will deal much with Java Native Access library.

  • rich list: this list will also support image and mix

There are not many solutions to solve this problem.I think it's a good and very fundamental function that SWT should support.And if this problem were well settled, a rich combo box supporting image,shown above,will be easily implemented.Because the combo box is just composed of three basic widgets:Text,Button,List,we can simplely replace the basic list widget with our rich list widget.The 'text' area may still only show texts;to solve this,the CLabel can be introduced to support image and text.

I have reported this as an enhancement bug and you can see the details of it at Bug 275285

  • cell merging capabilities in Grid: enhance this widget to support row merge

A Grid widget of Nebula has been created to offer features like cell selection,column grouping,column spanning,row headers and so on,which are not currently supported in the base SWT Table.But this Nebula widget currently only supports column merge,but not row merge.So I think it would be a good idea to enhance this widget.(This idea comes from Ivar Meikas,who is my mentor in this google summer code.Then many thanks to him!)

Fix bugs

  • Bug 189888[Nebula]Request for IP Address input widget control

There should be a widget control to input an ip address for SWT package,then I found it is just a bug in Nebula.But I haven't found that somebody has fixed this bug.Inputting an ip address is a popular and often used function,so I'll try to fix it.

Add some functionality

  • a batch of rich buttons: e.g. if the button style as been set style_ok, a button containing a "ok" image will be created.And there are many styles will be supported:style_ok,style_cancel,style_info,style_err,etc.

You can see the snapshot of these buttons in the following pic as a sample that our rich buttons would be implemented.If you ever used C++ Builder to developement desk GUIs,you will be familiar with these buttons containing a small image showing its apparent meaning.Buttons.jpg

Source code

The code will be hosted on google code.

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