nsXFormsMDGEngine Class Reference

#include <nsXFormsMDGEngine.h>

Inheritance diagram for nsXFormsMDGEngine:

Collaboration diagram for nsXFormsMDGEngine:

Detailed Description

This class handles all the necessary logic to create and maintain the MDG, and update the instance data accordingly.

A bit about the graph: As specified in the spec., one node (nsXFormsMDGNode) is created in the graph for each of the attributes (readonly, calculate, etc.) for a nsIDOMNode. These graph nodes are owned by the mNodeToMDG hash table, which maps from a nsIDOMNode to the first node in a single-linked list (mNext) of nodes for the same nsIDOMNode.

Todo:: Merge SetNodeValue() with nsXFormsUtils::SetNodeValue() (XXX)


Public Member Functions
	nsXFormsMDGEngine ()
	Constructor.
	~nsXFormsMDGEngine ()
nsresult	Init (nsXFormsModelElement *aModel)
	Initializes the internal structures.
nsresult	AddMIP (ModelItemPropName aType, nsIDOMNSXPathExpression aExpression, nsCOMArray< nsIDOMNode > aDependencies, PRBool aDynFunc, nsIDOMNode *aContextNode, PRInt32 aContextPos, PRInt32 aContextSize)
	Insert new MIP (Model Item Property) into graph.
nsresult	Recalculate (nsCOMArray< nsIDOMNode > *aChangedNodes)
	Recalculate the MDG.
nsresult	Revalidate (nsCOMArray< nsIDOMNode > *aNodes)
	Revalidate nodes.
nsresult	Rebuild ()
	Rebuilds the MDG.
nsresult	Clear ()
	Clears all information in the MDG.
nsresult	ClearDispatchFlags ()
	Clears all Dispatch flags.
nsresult	MarkNodeAsChanged (nsIDOMNode *aContextNode)
	Mark a node as changed.
nsresult	SetNodeValue (nsIDOMNode aContextNode, const nsAString &aNodeValue, PRBool aNodeChanged=nsnull)
	Set the value of a node -- the public version of SetNodeValueInternal().
nsresult	SetNodeContent (nsIDOMNode aContextNode, nsIDOMNode aContentEnvelope)
	Set the contents of a node.
const nsXFormsNodeState *	GetNodeState (nsIDOMNode *aContextNode)
	External interface of GetNCNodeState(), returns const pointer to the node state.
void	PrintDot (const char *aFile=nsnull)
	Write MDG graph to a file in GraphViz dot format.
Protected Member Functions
	nsXFormsMDGEngine (nsXFormsMDGEngine &)
	Hidden copy constructor.
nsXFormsNodeState *	GetNCNodeState (nsIDOMNode *aContextNode)
	Get non-const (NC) node state for a node, create a new node state if necessary.
nsresult	CreateNewChild (nsIDOMNode aContextNode, const nsAString &aNodeValue, nsIDOMNode aBeforeNode=nsnull)
	Inserts a new text child for aContextNode.
nsXFormsMDGNode *	GetNode (nsIDOMNode *aDomNode, ModelItemPropName aType, PRBool aCreate=PR_TRUE)
	Retrieve a node from the graph.
PRBool	AndFlags (PRUint16 aAndMask)
	Boolean AND _all_ flags with a mask.
nsresult	BooleanExpression (nsXFormsMDGNode *aNode, PRBool &aRes)
	Evaluates the expression for the given node and returns the boolean result.
nsresult	ComputeMIP (eFlag_t aStateFlag, eFlag_t aDispatchFlag, nsXFormsMDGNode *aNode, PRBool &aDidChange)
	Compute MIP value for node types with boolean result (all except calculate).
nsresult	ComputeMIPWithInheritance (eFlag_t aStateFlag, eFlag_t aDispatchFlag, eFlag_t aInheritanceFlag, nsXFormsMDGNode aNode, nsCOMArray< nsIDOMNode > aSet)
	Same as ComputeMIP(), but also handles any inheritance of attributes.
nsresult	AttachInheritance (nsCOMArray< nsIDOMNode > aSet, nsIDOMNode aSrc, PRBool aState, eFlag_t aStateFlag)
	Attaches inheritance to all children of a given node.
nsresult	Invalidate ()
	Invalidate the information, ie.
nsresult	SetNodeValueInternal (nsIDOMNode aContextNode, const nsAString &aNodeValue, PRBool aMarkNode=PR_TRUE, PRBool aIsCalculate=PR_FALSE, PRBool aNodeChanged=nsnull)
	Set the value of a node.
nsresult	HandleMarkedNodes (nsCOMArray< nsIDOMNode > *aArray)
	Handle nodes nodes marked as dirty, and insert into "changed nodes array".
Static Protected Member Functions
static PLDHashOperator PR_CALLBACK	DeleteLinkedNodes (nsISupports aKey, nsAutoPtr< nsXFormsMDGNode > &aNode, void aArg)
	Used by Clear() and ~ to delete the linked nodes in mNodeToMDG, the hash table itself handles the main nodes.
static PLDHashOperator PR_CALLBACK	AddStartNodes (nsISupports aKey, nsXFormsMDGNode aNode, void *aDeque)
	Used by Rebuild() to find the start nodes for mGraph, that is nodes where mCount == 0.
static PLDHashOperator PR_CALLBACK	AndFlag (nsISupports aKey, nsAutoPtr< nsXFormsNodeState > &aState, void aMask)
	Used by AndFlags() to boolean AND _all_ flags with aMask.
Protected Attributes
nsClassHashtable < nsISupportsHashKey, nsXFormsMDGNode >	mNodeToMDG
	Maps from nsIDOMNode to nsXFormsMDGNode.
nsClassHashtable < nsISupportsHashKey, nsXFormsNodeState >	mNodeStates
	Maps from nsIDOMNode to nsXFormsNodeState.
nsXFormsNodeState	mDefaultState
	Default node state.
PRBool	mJustRebuilt
	True when Rebuild() has been run, but not ClearDispatchFlags().
PRBool	mFirstCalculate
	True when last Calculate() was run when mJustRebuilt was true.
nsVoidArray	mGraph
	The actual MDG.
nsXFormsModelElement *	mModel
	The model that created the MDG.
nsCOMArray< nsIDOMNode >	mMarkedNodes
	Nodes that are marked as changed, and should be included in recalculation.
PRInt32	mNodesInGraph
	Number of nodes in the graph.

Constructor & Destructor Documentation

nsXFormsMDGEngine::nsXFormsMDGEngine ( nsXFormsMDGEngine & ) [inline, protected]

nsXFormsMDGEngine::nsXFormsMDGEngine ( )

nsXFormsMDGEngine::~nsXFormsMDGEngine ( )

Member Function Documentation

PLDHashOperator nsXFormsMDGEngine::DeleteLinkedNodes	(	nsISupports *	aKey,
		nsAutoPtr< nsXFormsMDGNode > &	aNode,
		void *	aArg
	)			`[static, protected]`

PLDHashOperator nsXFormsMDGEngine::AddStartNodes	(	nsISupports *	aKey,
		nsXFormsMDGNode *	aNode,
		void *	aDeque
	)			`[static, protected]`

Todo:: Is it not possible to check error condition? (XXX)

PLDHashOperator nsXFormsMDGEngine::AndFlag	(	nsISupports *	aKey,
		nsAutoPtr< nsXFormsNodeState > &	aState,
		void *	aMask
	)			`[static, protected]`

nsXFormsNodeState * nsXFormsMDGEngine::GetNCNodeState ( nsIDOMNode * aContextNode ) [protected]

Parameters:

aContextNode

The node to get the state for

Returns:: The state (owned by nsXFormsMDGEngine)

nsresult nsXFormsMDGEngine::CreateNewChild	(	nsIDOMNode *	aContextNode,
		const nsAString &	aNodeValue,
		nsIDOMNode *	aBeforeNode = `nsnull`
	)			`[protected]`

Parameters:

	aContextNode	The node to create a child for
	aNodeValue	The value of the new node
	aBeforeNode	If non-null, insert new node before this node

nsXFormsMDGNode * nsXFormsMDGEngine::GetNode	(	nsIDOMNode *	aDomNode,
		ModelItemPropName	aType,
		PRBool	aCreate = `PR_TRUE`
	)			`[protected]`

Parameters:

	aDomNode	The DOM node to retrieve
	aType	The type to retrieve (readonly, calculate, etc)
	aCreate	Create the node and insert it into the graph if it does not exist?

Returns:: The node, nsnull if not found and aCreate != PR_TRUE

Note:: aType == eModel_type means "any type", as we do not store type information in the MDG.

PRBool nsXFormsMDGEngine::AndFlags ( PRUint16 aAndMask ) [protected]

Parameters:

aAndMask

The mask

Returns:: Did operation succeed?

nsresult nsXFormsMDGEngine::BooleanExpression	(	nsXFormsMDGNode *	aNode,
		PRBool &	aRes
	)			`[protected]`

Parameters:

	aNode	The node to evaluate
	aRes	The result of the evaluation

nsresult nsXFormsMDGEngine::ComputeMIP	(	eFlag_t	aStateFlag,
		eFlag_t	aDispatchFlag,
		nsXFormsMDGNode *	aNode,
		PRBool &	aDidChange
	)			`[protected]`

Parameters:

	aStateFlag	The flag for the type of MIP
	aDispatchFlag	The dispatch flag
	aNode	The context node
	aDidChange	Was the node changed?

nsresult nsXFormsMDGEngine::ComputeMIPWithInheritance	(	eFlag_t	aStateFlag,
		eFlag_t	aDispatchFlag,
		eFlag_t	aInheritanceFlag,
		nsXFormsMDGNode *	aNode,
		nsCOMArray< nsIDOMNode > *	aSet
	)			`[protected]`

Parameters:

	aStateFlag	The flag for the type of MIP
	aDispatchFlag	The dispatch flag
	aInheritanceFlag	The inheritance flag for the type of MIP
	aNode	The context node
	aSet	Set of the nodes influenced by operation

nsresult nsXFormsMDGEngine::AttachInheritance	(	nsCOMArray< nsIDOMNode > *	aSet,
		nsIDOMNode *	aSrc,
		PRBool	aState,
		eFlag_t	aStateFlag
	)			`[protected]`

Parameters:

	aSet	Set of the nodes influenced by operation
	aSrc	The node
	aState	The state of the flag
	aStateFlag	The flag

nsresult nsXFormsMDGEngine::Invalidate ( ) [protected]

mark all nodes as dirty.

nsresult nsXFormsMDGEngine::SetNodeValueInternal	(	nsIDOMNode *	aContextNode,
		const nsAString &	aNodeValue,
		PRBool	aMarkNode = `PR_TRUE`,
		PRBool	aIsCalculate = `PR_FALSE`,
		PRBool *	aNodeChanged = `nsnull`
	)			`[protected]`

Parameters:

	aContextNode	The node to set the value for
	aNodeValue	The value
	aMarkNode	Whether to mark node as changed
	aNodeChanged	Was node changed?
	aIsCalculate	Is it a setting the value?

Todo:: Better feedback for readonly nodes? (XXX)

Unsupported nodeType

Todo:: Should return more specific error? (XXX)

nsresult nsXFormsMDGEngine::HandleMarkedNodes ( nsCOMArray< nsIDOMNode > * aArray ) [protected]

Parameters:

aArray

The "changed nodes array" to insert into

nsresult nsXFormsMDGEngine::Init ( nsXFormsModelElement * aModel )

Needs to be called before class is used!

Parameters:

aModel

The model that created this MDGEngine instance.

nsresult nsXFormsMDGEngine::AddMIP	(	ModelItemPropName	aType,
		nsIDOMNSXPathExpression *	aExpression,
		nsCOMArray< nsIDOMNode > *	aDependencies,
		PRBool	aDynFunc,
		nsIDOMNode *	aContextNode,
		PRInt32	aContextPos,
		PRInt32	aContextSize
	)

Parameters:

	aType	The type of MIP
	aExpression	The XPath expression
	aDependencies	Set of nodes expression depends on
	aDynFunc	True if expression uses dynamic functions
	aContextNode	The context node for aExpression
	aContextPos	The context positions of aExpression
	aContextSize	The context size for aExpression