title: IntellIj IDEA cannot find source files
body: <p>I'm trying to attach sources for <a href="http://iharder.sourceforge.net/current/java/filedrop/" rel="nofollow">this library called FileDrop</a> so I can view documentation. When I click Attach Sources... and select the directory with the source code, nothing changes. It still has the <em>Sources not found</em> message at the top of the class. However, in my external libraries section, if I manually expand the library jar file, I can view the original source in there. I think this is because the library jar has the full, uncompressed source in it.</p>
  
  <p>The zip file of the library has this structure after downloading and extracting it:</p>
  
  <pre><code>filedrop-1.1
      Example.java
      filedrop.jar
      FileDrop.java
  </code></pre>
  
  <p>So the source files do not have any package...not sure if that is part of the problem. The two .java files are also in the jar file. So when I create a library in IDEA, the jar shows up in External Libraries under the library I created, but the source does not.</p>
  
  <p>In the Project Structure -> Libraries screen, it shows the jar file under Classes, and it shows the parent directory (filedrop-1.1) under both Classes and Sources, but it is apparently not detecting any sources within them. This is the screen where I've been trying to add the sources, and they show up here as expected, but apparently no sources are found.</p>
  
  <p>This is IntelliJ IDEA 13.1.4.</p>