Use HJKL to control page scrolling

private.xml

<?xml version="1.0"?>
<root>

  <appdef>
    <appname>Skim</appname>
    <equal>net.sourceforge.skim-app.skim</equal>
  </appdef>

  <item>
    <name>Use HJKL to control page scrolling</name>
    <identifier>private.hjkl_in_skim</identifier>

    <uielementrole_only>AXTextArea</uielementrole_only>

    <only>Skim</only>
    <autogen>
      __KeyToKey__ KeyCode::J,
      KeyCode::CURSOR_DOWN, KeyCode::CURSOR_DOWN
    </autogen>
    <autogen>
      __KeyToKey__ KeyCode::K,
      KeyCode::CURSOR_UP, KeyCode::CURSOR_UP
    </autogen>
    <autogen>
      __KeyToKey__ KeyCode::H,
      KeyCode::PAGEUP, KeyCode::PAGEUP
    </autogen>
    <autogen>
      __KeyToKey__ KeyCode::L,
      KeyCode::PAGEDOWN, KeyCode::PAGEDOWN
    </autogen>
  </item>
</root>