gecko-dev/dom/xul/nsForwardReference.h

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/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef nsForwardReference_h__
#define nsForwardReference_h__
class nsForwardReference
{
protected:
nsForwardReference() {}
public:
virtual ~nsForwardReference() {}
/**
* Priority codes returned from GetPhase()
*/
enum Phase {
/** A dummy marker, used to indicate unstarted resolution */
eStart,
/** The initial pass, after which the content model will be
fully built */
eConstruction,
/** A second pass, after which all 'magic attribute' hookup
will have been performed */
eHookup,
/** A dummy marker, used in kPasses to indicate termination */
eDone
};
/**
* Forward references are categorized by 'priority', and all
* forward references in a higher priority are resolved before any
* reference in a lower priority. This variable specifies this
* ordering. The last Priority is guaranteed to be eDone.
*/
static const Phase kPasses[];
/**
* Get the state in which the forward reference should be resolved.
* 'eConstruction' references are all resolved before 'eHookup' references
* are resolved.
*
* @return the Phase in which the reference needs to be resolved
*/
virtual Phase GetPhase() = 0;
/**
* Result codes returned from Resolve()
*/
enum Result {
/** Resolution succeeded, I'm done. */
eResolve_Succeeded,
/** Couldn't resolve, but try me later. */
eResolve_Later,
/** Something bad happened, don't try again. */
eResolve_Error
};
/**
* Attempt to resolve the forward reference.
*
* @return a Result that tells the resolver how to treat
* the reference.
*/
virtual Result Resolve() = 0;
};
#endif // nsForwardReference_h__