nsISelection Interface

 Adds a range to the current selection.

void addRange(in nsIDOMRange range)

 Collapses the selection to a single point, at the specified offset
 in the given DOM node. When the selection is collapsed, and the content
 is focused and editable, the caret will blink there.
 @param parentNode      The given dom node where the selection will be set
 @param offset          Where in given dom node to place the selection (the offset into the given node)

void collapse(in nsIDOMNode parentNode, in long offset)

 Collapses the whole selection to a single point at the end
 of the current selection (irrespective of direction).  If content
 is focused and editable, the caret will blink there.

void collapseToEnd()

 Collapses the whole selection to a single point at the start
 of the current selection (irrespective of direction).  If content
 is focused and editable, the caret will blink there.

void collapseToStart()

 Indicates whether the node is part of the selection. If partlyContained 
 is set to PR_TRUE, the function returns true when some part of the node 
 is part of the selection. If partlyContained is set to PR_FALSE, the
 function only returns true when the entire node is part of the selection.

boolean containsNode(in nsIDOMNode node, in boolean partlyContained)

 Deletes this selection from document the nodes belong to.

void deleteFromDocument()

 Extends the selection by moving the selection end to the specified node and offset,
 preserving the selection begin position. The new selection end result will always
 be from the anchorNode to the new focusNode, regardless of direction.
 @param parentNode      The node where the selection will be extended to
 @param offset          Where in node to place the offset in the new selection end

void extend(in nsIDOMNode parentNode, in long offset)

 Returns the range at the specified index.

nsIDOMRange getRangeAt(in long index)

 Removes all ranges from the current selection.

void removeAllRanges()

 Removes a range from the current selection.

void removeRange(in nsIDOMRange range)

 Adds all children of the specified node to the selection.
 @param parentNode  the parent of the children to be added to the selection.

void selectAllChildren(in nsIDOMNode parentNode)

 Modifies the cursor Bidi level after a change in keyboard direction
 @param langRTL is PR_TRUE if the new language is right-to-left or
                PR_FALSE if the new language is left-to-right.

void selectionLanguageChange(in boolean langRTL)

 Returns the whole selection into a plain text string.

wstring toString()