JetBrains IntelliJ IDEA Blog

How often do you write XML configurations like that above? How many keystrokes does it take?

This one is written in just moments, with the help of the new completion features coming in IntelliJ IDEA 10. First of all, the IDE completes all required subtags for you, even nested ones. Second, you can use smart completion feature to ensure that the tags you write are in order described in your XML schema.

If you do not know where your new tag should be inserted, invoke the Generate / XML Tag action from context menu, choose the tag you want, and IntelliJ IDEA will generate a completely valid XML structure and insert it in the right place of the document.

Download the latest IntelliJ IDEA EAP build and try this in the next XML file you open.

Do you often find yourself calling a super method with a large number of parameters? Typing all those arguments one by one is soooooo boring, isn’t it?! Don’t be upset anymore — latest Maia EAP can rescue you. Just use Smart Completion (Ctrl+Shift+Space):

Say, you hit a breakpoint in Java code:

And you cleanly see that component is a label:

You now want to investigate label internals via Evaluate Expression (Alt+F8), e.g. invoke its getText() method, but component declared type is Component and it does not have this method! The only way out is to use Surround with run-time type (Ctrl+Alt+T) first to cast it to JLabel and only then completion becomes available:

Not anymore it isn’t. IntelliJ IDEA tries to help with casting wherever possible, so you can now get the same results using Basic code completion (Ctrl+Space) only:

…press Enter and the cast is done for you:

Needless to say, it works with Smart completion (Ctrl+Shift+Space), too. It works even for complex expressions with method calls. Note, that method evaluation can take a lot of time, not to mention the possible side effects, so evaluating expressions every time you hit completion is not so nice. This is why you need to press the same shortcut twice to get the run-time type variants. That’s what you’re going to see at the bottom of completion list:

And you can play with all this now!

Let’s talk about type casts — those things you hardly can avoid in JVM-based code. Being a helpful IDE, IntelliJ IDEA now does all the casting stuff for you when you are using its code completion in Java and Groovy.

To get you started, have a look at this Groovy example. In a dynamic language there’s almost no need in type casting at all — you just invoke any method on any object and hope it won’t fail. IDE can help you here, suggesting a list of acceptable choices based on preceding type checks:

In Java, there’s always a need in explicit casting. It’s easy of course, when you know the type to cast expression to. Smart completion after opening parenthesis has been able to do this for ages:

Imagine you’ve just checked an expression type via instanceof and now you want to invoke a method on the cast expression. Quite a natural wish, isn’t it? A week ago you had to write a cast manually, use a light bulb intention action or inst live template. Now you just invoke code completion after the cast expression and it suggests the members of the cast type. A lot simpler, right? Of course, the cast will be inserted automatically:

This works for both basic (Ctrl+Space) and smart completion (Ctrl+Shift+Space). I’ve been using this feature for 2 days now and I already can’t understand how could I survive without it through all the previous years.

Impressed already? But, there’s more. Say you’ve just checked that a certain expression has certain type. Then, you may want to cast that expression and assign the result to a variable, or pass it to a method. All you need is smart completion:

Moreover, as you know, IntelliJ IDEA has second smart completion feature. It’s now also aware of the run-time type checks that you made. After such a check you can perform cast and method invocation in a single action! Well, actually, you have to press Ctrl+Shift+Space two times, but that still counts:

Enjoy!

Do you use second smart completion feature? Did you know that it also can help you when you have an array and want an element of it? Just press Ctrl+Shift+Space two times when completing:

Many API include methods like setXxx(int) where int is one of the predefined values, typically declared in the same class. The fact that these are just legacy methods that have been created prior to enums invention, does not stop IntelliJ IDEA from helping you with such parameter values. For example, have a look at JList#getSelectionModel. Just invoke the Smart Completion (Ctrl+Shift+Space) inside the call parentheses: