Earlier this month I switched from writing my Android projects in Eclipse to writing them in IntelliJ IDEA. Overall the experience has been great, and I much prefer using IDEA to Eclipse for Android development. And now that IntelliJ IDEA 11 EAP (Early Access) has a visual layout window, there is almost no reason for me to write my Android apps in anything else. I wrote this post to help other users along their way when converting between the IDEs.
Why IntelliJ IDEA for Android?
There’s no need to ask why if IDEA is already your favorite IDE or if your company is forcing you to use it. But just in case you’re not already a raving fanboy, here are some of the features specific to Android that made me want to switch.
Find usages (Alt+F7) is aware of Android XML resources (and the semantic meaning of their content), so searching across project assets is easier. Plus, I just find IDEA’s search capabilities a little saner than Eclipse’s. Below you can see what happens when I search from within my layout XML file for a certain widget ID:
Because IDEA knows about the Android XML resources, refactorings like Rename (Shift+F6) work across Java code and XML. You can rename a widget’s ID from the XML file and have the Java code updated, or rename from the Java code and have the XML updated. Here I am renaming a widget ID in XML. Nice. In general, I do not search within comments and Strings because it is a little too aggressive.
There are several Android specific intentions that make life easier in IDEA. Intentions are the quick-fixes that are activated in Eclipse with Ctrl+1. In IDEA you use Alt+Enter. For example, if there is a static String referenced from your code then you should make that String a resource by moving it to strings.xml. Put your cursor into the String, press Alt+Enter, accept the name suggestion, and you’re ready to go. Ctrl+Z for undo on refactorings work great, too. One of the big differences between IDEA and Eclipse is refactoring support. In IDEA, the source files do not need to compile in order for refactorings to work. It is quite common to have a broken file and fix it through a couple automated renames or refactors.
Finally, before IDEA 11, the killer feature for Eclipse Android was the visual editor for XML based layout files. Personally, I don’t often use drag and drop layout editors but I do value seeing my code changes immediately without recompiling and redeploying. Eclipse had the better feature set. But IDEA 11 now has a layout “Preview” mode. Make a change in the XML and see it immediately updated in the preview. You can also quickly change the theme, preview in landscape and portrait, switch to night mode, and select different screen sizes. If you absolutely need a visual editor, then Eclipse is the way to go. Otherwise, the Preview in IDEA 11 is good enough. More info available on the IDEA blog.
Let’s get started with a tour of IDEA.
Getting Oriented in IDEA
The basic layout of IDEA is not all that different from Eclipse. You have a main code window (right, in image below), you have a Project View (upper left), and you have a Structure View (lower left). If there is a window for it in Eclipse, then there is probably a window for it in IDEA. A good way to get started and get familiar with IDEA is to read the DZone IDEA RefCard I wrote a few years ago. It is still relevant today. I highlighted the image to show the relevant details.
At any time you can jump to the code window by pressing Escape, and you can close any open tool window with Shift+Escape. On thing that IDEA does not have is perspectives. Maybe you love Eclipse perspectives. Maybe you love when your code view shrinks up into a postage sized porthole whenever you launch a debugger. Who knows, perhaps this is useful to you somehow. I am trying very hard to be positive here, and the nicest thing I have to say about perspectives is that I hate them. Another thing IDEA does not have is a “Team Plugin”. There is no single “Team” abstraction that somehow fits on top of every version control system. Instead, when you enable Subversion then you use Subversion features. Git uses Git Features. Version control systems are enabled using the Tools->Enable Version Control menu item. Then the Alt+9 shortcut brings up the Version Control View.
Running, Debugging, and the Android Tools
Running and Debugging an application is slightly different in IDEA than in Eclipse. You manage your “Run Configurations” using your Run/Debug dropdown menu at the top of the screen:
You can create temporary and permanent run configurations. Right clicking a test and choosing Run creates a temporary run config. If you want to run the target repeatedly then just save it so it is permanent. And you Maven users: you can right click a goal in the Maven view and create a run target, such as a run:jetty goal. The Maven support is amazing in IDEA, so you are actually lucky to be a Maven user in this case.
The features of the debuggers are fairly close between the two products. Set a break point by clicking in the gutter (Ctrl+F8), select and right click a reference to add to the watch window. I’ve noticed that Eclipse users love to enable and disable breakpoints rather than just set and remove them. Well, you can press Ctrl+Shift+F8 to manage all your breakpoints if that’s the sort of thing you like to do. Also, notice the Logcat tab on the debugger, which shows you the Android log. If you are Running (and not debugging), then the Logcat output is in the “Android Logcat” view that you see on the bottom toolbar:
The main Android Tools from the SDK are available under the Tools->Android menu. You can export a signed package this way and also launch the AVD to manage your emulators and environments. If you need the other SDK tools like “hierarchyviewer” or “monkeyrunner” then you’ll have to launch them from the command line. There is built-in Android testing support in IDEA, and when you run a unit test then the IDE will ask you whether to run it as a JUnit test or an Android test. It remembers your answer, so if you make a mistake then just delete the run configuration and start over. It will ask you again.
Managing Your IDEA Project
The two hardest parts of switching IDEs is Project configuration and Web Server configuration. Luckily we avoid the latter in an Android tutorial. But you still need to set up the project. First, some terminology. An “Eclipse Workspace” is an “IDEA Project”. An “Eclipse Project” is an “IDEA Module”. An Eclipse Workspace is composed of several projects. An IDEA Project is composed of several modules. If you have Eclipse project files then IDEA should be able to import them with no problems, and this is the fastest way to get started.
The Project is configured using the File->Project Structure menu item. You can also open the window using the Ctrl+Alt+Shift+S shortcut, which I call the Paw Mash because holding your left hand like a bear paw and mashing the keyboard usually suffices to open the window. This is where you specify your source folders, your SDK version, and your dependencies. If there is no Project SDK selected in the dropdown list, or if the list shows an error, then click on the SDKs item in the left side pane to create a new one.
Configure the modules by clicking the module entry on the left side. Here you can mark certain folders as source or as tests. By default, a fresh IDEA Android project has no “tests” folder, so you should add the folder and then come in here as mark it as Test Sources. You can also change some of the Android compiler settings by clicking the Android facet shown in the middle.
One last thing to configure before leaving the window. If you are writing JUnit tests then you’ll need to add JUnit to your project dependencies. If you just annotate a method as @Test then IDEA prompts you to add the junit.jar to your classpath. The problem is that they add it as the last dependency, which causes the test to fail with the error “java.lang.RuntimeException: Stub!”. Come into this window and move JUnit up in the dependency list. Or configure Ivy/Maven/Whatever to do this automatically for you.
That’s the quick tour of Project Structure… lets move on to Settings. Settings are the options not directly related to compiling the project. Things like code style, version control, plugins, and much more. Open Settings using File->Settings or use your Claw Attack to hit Ctrl+Alt+S. I call this shortcut the claw attack because if you pinch your left hand into an eagle claw and swoop it down on your keyboard then the Settings window usually opens right up. It helps to let out a mighty, “Ka-KAW” when you do it.
There are thousands of settings in here. I heard the advice recently that new users of either IDE should spent a few hours just clicking around the settings page, and I honestly think that is pretty good advice. If you know what you’re looking for but can’t find it, then enter your search term in the upper left side search box and the settings list dynamically displays only those pages with matching entries. For instance, if you know you want to show line numbers, then type in Line or Line Numbers and click through the resulting pages. In this case, the highlighting you see in the image was created by IDEA and is used to point you to the correct setting.
You most definitely want to change some of the default settings. Showing Line Numbers is under Editor->Appearance. Changing your tabs and space settings are done on a per-file type basis, and is accessed from Editor -> Code Style. By default IDEA allows you to place the cursor past the end of the line in a text file, and you turn this off under the Editor page. And Version Control is something you really must configure as well, which is under Version Control. GitHub integration in IDEA is tip-top and goes beyond just Git support, but lately I’ve been using and recommending BitBucket for free, private git hosting. In general I find myself using the IDE to make local commits and manage changelists, and the command line to perform pushes.
That’s it! There are tons of ways to learn more, and here are my favorite links:
- IntelliJ IDEA RefCard from me
- IDEA Shortcut Wallpaper from me again
- JetBrains’ IDEA Q&A for Eclipse Users
- 10 Hints for Moving from Eclipse to IDEA from me
- All of my IDEA Related Blog Posts
- All of Canoo’s IDEA Related Blog Posts
- My Other Videos on JetBrains.tv
- IDEA Keyboard Stickers, so you can learn the shortcuts
- And last, you could try reading the manual
As always, feel free to keep in touch by leaving a comment. You can read more from me on my blog at http://hamletdarcy.blogspot.com/, see my YouTube channel for more screencasts, and follow me on Twitter: @HamletDRC