///////////////////////////////////////////////////////////
// snav.enabled
///////////////////////////////////////////////////////////


///////////////////////////////////////////////////////////
// snav.ignoreTextFields
///////////////////////////////////////////////////////////

 This preference when enabled will ensure that text fields
and inputs retain focus even if spatial navigation was
requested.

Default: TRUE
  
///////////////////////////////////////////////////////////
// snav.directionalBias
///////////////////////////////////////////////////////////

When calculating distances between elements on the screen,
elements may be given a bias if the elements are in the
direction of navigation.  The bias is a given by a fraction
such that:

  bias distance = true distance / directional bias

DEFAULT: 3

///////////////////////////////////////////////////////////
// snav.disableJS
///////////////////////////////////////////////////////////

Disable onFocus event that an element may recieve during
spatial navigation.  On some pages we have found that the
page decides to move the focus as if the targeted content
was clicked.  This may lead to an undesirable behavior.

DEFAULT:  TRUE

///////////////////////////////////////////////////////////
// snav.rectFudge
///////////////////////////////////////////////////////////

To reduce the chance that a element overlaps with another
element, we reduce the elements height and width by this
value.  

DEFAULT: 20

///////////////////////////////////////////////////////////
// snav.keyCode.left
///////////////////////////////////////////////////////////

This preference is the key code which corresponds to the
left direction.

DEFAULT:  DOM_VK_LEFT
SEE:      nsIDOMKeyEvent

///////////////////////////////////////////////////////////
// snav.keyCode.right
///////////////////////////////////////////////////////////

This preference is the key code which corresponds to the
right direction.

DEFAULT:  DOM_VK_RIGHT
SEE:      nsIDOMKeyEvent


///////////////////////////////////////////////////////////
// snav.keyCode.up
///////////////////////////////////////////////////////////

This preference is the key code which corresponds to the
up direction.

DEFAULT:  DOM_VK_UP
SEE:      nsIDOMKeyEvent

///////////////////////////////////////////////////////////
// snav.keyCode.down
///////////////////////////////////////////////////////////

This preference is the key code which corresponds to the
down direction.

DEFAULT:  DOM_VK_DOWN
SEE:      nsIDOMKeyEvent

///////////////////////////////////////////////////////////
// snav.keyCode.modifier
///////////////////////////////////////////////////////////

This preference is the key code which corresponds to the
required modifier keys.  These values are given as follows:

    NONE           = 0  
    SHIFT          = 0x00100000
    CONTROL        = 0x00001100
    ALT            = 0x00000012


DEFAULT:  ALT | SHIFT