Part II: Using the Eclipse Environment in Java

Drawing QR-Code in Java Part II: Using the Eclipse Environment

Open the Resource perspective Right-click a branch in the Navigator view s tree Then, in the resulting context menu, select Rename In response, Eclipse does what many operating systems do when you start renaming something on a branch of a tree Eclipse creates a tiny, one-line editor for the label on that branch So type a new name inside that little editor, and then press Enter Eclipse does a textual rename That is, Eclipse changes the name of a file or a folder, but doesn t update any references to the name Like the textual move, the textual rename isn t a refactoring action If you want refactored renaming, you can t start in the Navigator view If you stop and think about it, the Navigator view and textual renaming go hand-in-hand After all, the Navigator view is part of the Resource perspective, and the Resource perspective isn t much like the Java perspective Whereas the Java perspective deals with Java elements (classes, methods, fields, and those kinds of things) the Resource perspective deals with big lumps on your hard drive lumps such as files, folders, and projects The Resource perspective (along with its friend the Navigator view) isn t supposed to be smart about package names and other Java-specific things So when you rename something in the Navigator view, Eclipse doesn t bother to consider the overall Java picture In other words, Eclipse does textual renaming, not refactored renaming

11

Refactor This!

Using each of Eclipse s refactoring actions Making sense of hard-to-read parameter pages Understanding what actions can and cannot do

magine yourself working on a large Java application The application involves several people or even several teams Some people are in nearby cubicles, on opposite sides of those gloomy partitions Other people working on the application are halfway around the world You write code that counts wombats in Australia A colleague writes code that analyzes your wombat count Then you write code that uses your colleague s analysis What a tangled web you weave! When you change wmbtCnt to wombatCount, your colleague s analysis code falls apart at the seams Your code (which uses the analysis code) also stops running Your computer hangs, and that causes the server in the back office to crash, and that causes your Java-enabled coffee pot to brew decaf instead of regular As a result, you fall asleep and miss a deadline Yes, things can be very complicated But no, things aren t unmanageable When you write small programs or big applications, Eclipse s refactoring tools keep track of all the cross-references If you change things in one part of an application, Eclipse automatically changes things in another part With all the ripple effects under control, you can manage the tangled web of references, cross-references, and cross-cross-references in your code You can concentrate on the application s overall logic (or you can have more time to goof off and surf the other kind of web)

10 emphasizes some features that all refactoring actions have in common For example, all refactoring operations start with your selection of something in an editor or a view And almost all refactoring actions involve the three Ps: a parameter page, a preview page, and in the worst cases, a problem page This chapter takes a slightly different approach In this chapter, I list Eclipse s refactoring actions, and describe each action in some detail I gloss over the things refactoring actions have in common That way, you don t have to read about things like the parameter, preview, problem page cycle over and over again Remember, you don t have to retype the code in this chapter s listings You can download the code from this book s Web site