I just started to use Eclipse (for Android development) - so I am pretty new to this IDE and I don't understand some things. Sometimes (often - while or after debug) I found some my files with code in readonly mode - I can't edit my code. I see "Read-Only" label in status bar - but I don't know when exactly and why this file became read-only. I can't do anything with this file and have to close it and find once again in project tree and open - then I can edit it. I am forced to do it every few minutes - so I don't like this behaviour.

Why this happens? What can I do to avoid it? How to make file in editor editable from read-only mode?