Retrieving font preference setting in Eclipse JDT plugin

Question

I have an Eclipse plugin which creates a JavaSourceViewer to visualize specific source code in a separate view. I would like to configure the font of the viewer to match the settings of the Java Editor Text Font preference:

JavaSourceViewer textViewer = new JavaSourceViewer(...);
...

// get the SWT component which displays the text
StyledText textControl = textViewer.getTextWidget();

// retrieve the font preference from the theme manager
IThemeManager themeManager = PlatformUI.getWorkbench().getThemeManager();
ITheme currentTheme = themeManager.getCurrentTheme();
FontRegistry fontRegistry = currentTheme.getFontRegistry();
Font font = fontRegistry.get(PreferenceConstants.EDITOR_TEXT_FONT);

// set the font on the SWT component
textControl.setFont(font);

My question is especially about the code block which retrieves the font from the theme manager:

• Is this the correct approach to get the font?
• Is there anything else which needs to be considered?

Answer 1

I'm not familiar with Eclipse plugin development, so just two minor notes after going through javadoc of the relevant APIs:

1. FontRegistry has an addListener method which you might want and/or need to listen to and change the font of the textControl when the user changes their font settings.

2. The comment could be a great method name here (retrieveFontPreference, for example):

   // retrieve the font preference from the theme manager
   IThemeManager themeManager = PlatformUI.getWorkbench().getThemeManager();
   ITheme currentTheme = themeManager.getCurrentTheme();
   FontRegistry fontRegistry = currentTheme.getFontRegistry();
   Font font = fontRegistry.get(PreferenceConstants.EDITOR_TEXT_FONT);
   

   See also: Clean Code by Robert C. Martin, Bad Comments, p67: Don’t Use a Comment When You Can Use a Function or a Variable