IntelliJ: customize the editor

In this post I explain the modifications I make in the configuration of the IntelliJ editor and project window. With these modifications I find it even more easier to work with source code.

I make the following modifications to the IntelliJ editor settings:

Show method separators

This option shows horizontal lines between methods with which seperate methods are easily identified. To enable method separators do the following:

1. Open the settings window
2. Open Editor -> appearance and check Show method separators.

High light usages of element at caret

This option highlights all usages of the element where the caret is positioned. To enable this option:

1. Open the settings window
2. Click Editor and check Highlight usages of element ar caret.

Highlight current scope

This option highlights the current scope of a code block in the left gutter. To enable this option:

1. Open the settings window
2. Click Editor and check Highlight current scope.

Disable allow placement of caret after end of line

To disable the placement of the caret after the end of a line do the following:

1. Open the settings window
2. Click Editor and uncheck Allow placement of caret after end of line.

Use and show soft wraps

Soft wraps are useful when the editor window is smaller than the actual line length that can be displayed. The lines that exceed the editor window wraps to the following line.

1. Open the settings window
2. Click Editor and check use soft wraps in editor and Show all soft wraps.

Tab limit

The tab limit limits the maximum open tabs so the tabs remain manageable. To limit the maximum open tabs:

1. Open the settings window
2. Click Editor -> Editor Tabs and specify a tab limit.

Optimize imports on the fly

This option automatically optimizes the imports when you are typing code. To enable this option:

1. Open the settings window
2. Click Editor -> Auto Import and check Optimize imports on the fly

The results of the above modifications can be seen in the screenshot below. I made the editor window smaller than usual to demonstrate the soft wraps.

In the project window I make the following modifications:

Autoscroll to source

This option lets me autoscroll to the editor window when a file is clicked.

Flatten packages

Abbreviate qualified package names

The above two option give a nice compact but complete overview of the package structure with abbreviated names. This can be seen in the following screenshot:

Let me know which options you use.

IntelliJ: Final parameters and variables

Different teams require different coding styles and source code metrics. We have for example a rule which states that all method parameters should be final. Without going to discuss this rule (since your mileage may vary) I will show how IntelliJ can be used to enforce this rule.

There are two use cases here:

1. Adding the final keyword to all methods generated with IntelliJ.
2. Add the final keyword to existing methods.

To add the final keyword to parameters of generated methods do the following:

1. Open up the Project Settings dialog and navigate to Code Style -> Java.
2. Click the Code Generation tab.
3. In here you will find the Final modifier section.
4. Check the "Make generated parameters final" option.

If you now generate methods, IntelliJ will insert the final keyword before every parameter.

Besides adding the final keyword to every parameter in generated methods you can also add the final keyword to parameters in existing methods. To do this, do the following:

1. Open up the settings dialog and click Inspections (in Project settings)
2. Click copy to copy the Project default inspections and name the profile anything you want.
3. Click the Rest to Empty button to disable all inspections. Disabling all inspections is a quick way to only focus on a specific inspection if you want to apply just that specific inspection.
4. Enter 'final' in the search box
5. Under the "Code style issues" check the following rule: "Local variable or parameter can be final".
6. On the left make sure the option "Report method parameters" and/or "Report Local Variables".
7. Click OK.
8. Click Analyse -> Inspect code in the menu.
9. Make sure you select the Whole project and select the profile created in step 2.
10. Click OK.
11. In the inspection dialog you see all methods where the parameter could be final.
12. Right click the inspection and click "Apply fix 'Accept suggested final modifier'" to add the final modifier to all method parameters where it can be final.

Please note that the inspection does not add the final keyword to parameters which are reassigned since this gives compile errors. You could argue if this should be included in the inspection as well. I personally feel this can be handy to add final to all parameters regardless if they are changed or not. You can then afterwards fix all compile time issues you may have.