When editing XML files in the editor for Eclipse, line numbers are not displayed.
Use case:
I create a layout with many views, one of these lacks android:layout_width attribute. This causes a runtime error when the binary XML layout resource is inflated. The error log tells me to check like 361 in my XML file.
Thanks to the line number being displayed I can find the offending line and make the change without having to open the file in another editor.