Figure 8-5: The Insert Spaces for Tab check box in Java

Creator Quick Response Code in Java Figure 8-5: The Insert Spaces for Tab check box

4 Leave the Editor page and move to the Java Code Style Code Formatter page 5 On the Code Formatter page, click Show or Edit (whichever button appears) 6 On the resulting Show Profile or Edit Profile dialog, select the Indentation tab The Tab Size field and the Use Tab Character check box live on this Indentation tab page (See Figure 8-6)

Here s how these options affect the behavior of Source Shift Right:

if Insert Sspaces for Ttab is unchecked Eclipse inserts a tab //Take whatever number is in the Displayed Ttab Wwidth //field The tab looks like that number of spaces else Eclipse inserts the number of spaces in the Tab Ssize field

Notice that the Use Tab Character check box in Figure 8-6 has no effect on shifting The Use Tab Character check box affects only the Source Format and Source Format Element actions With all the noise in this section about the Shift Right action, you re probably feeling nonchalant about Shift Left When you choose Source Shift Left, Eclipse eliminates tabs or spaces from the beginnings of your selected lines One strange thing can happen with the Shift Left action Suppose you select ten lines of code, and one of these lines starts with only three blank spaces (This three space gap is smaller than the value 4 in the Tab Size field See Step 6 in this section s instructions) In this situation, choosing Source Shift Left has no effect None of the selected lines get shifted Oh, well! A line of code can contain both tabs and blank spaces If you don t know which you have, things can become really confusing when you choose Shift Right or Shift Left Unfortunately, the editor in Eclipse Version 30 provides no way to display tabs or spaces as visible characters

I don t have much to say about the Source Sort Members action When you choose this menu option, Eclipse rearranges the things inside your Java class s source code (By things I mean fields, initializers, constructors, methods, and inner classes) Sorting things in an agreed upon order makes code much easier to maintain You can change which things Eclipse puts before which other things Just visit the Java Appearance Sort Members Order page of the Window Preferences dialog Select an item in either of the page s lists, and press the corresponding Up or Down button

All other things being equal, Eclipse sorts things in alphabetical order For example, with the boolean isClosed and double accountBalance fields, Eclipse moves the accountBalance declaration above the isClosed declaration (Eclipse doesn t sort on type names such as boolean and double Instead, Eclipse sorts on member names, such as isClosed and accountBalance) The Sort Members action doesn t work on local variables inside methods If your local variables aren t in the right order, get ready for some good, oldfashioned cutting and pasting

Someday soon, someone will extend Eclipse with colorful graphics Before you use an import handling action, you ll see Barbara Eden coming out of a bottle Jeannie, do anything that needs to be done with import declarations in my code Yes, Master That s how Eclipse s Import actions work You can ignore everything having to do with imports until the very last minute Then choose Source Organize Imports or Source Add Import, and Eclipse performs its magic

Eclipse provides at least two ways to play with your code s import declarations (declarations like import javautilIterator that you put near the top your code) This section deals with the first way choosing Source Organize Imports Many things happen when you apply this Organize Imports action: Eclipse removes any import declarations that you don t use If your code starts with

import javaxswingJButton;

but you never use a JButton, then Eclipse deletes the JButton import declaration Eclipse deletes the declaration even if you use JButton, but