gecko-dev/content/smil/nsSMILTimeContainer.h

195 строки
5.9 KiB
C
Исходник Обычный вид История

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is the Mozilla SMIL module.
*
* The Initial Developer of the Original Code is Brian Birtles.
* Portions created by the Initial Developer are Copyright (C) 2009
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* Brian Birtles <birtles@gmail.com>
*
* Alternatively, the contents of this file may be used under the terms of
* either of the GNU General Public License Version 2 or later (the "GPL"),
* or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
#ifndef NS_SMILTIMECONTAINER_H_
#define NS_SMILTIMECONTAINER_H_
#include "nscore.h"
#include "nsSMILTypes.h"
//----------------------------------------------------------------------
// nsSMILTimeContainer
//
// Common base class for a time base that can be paused, resumed, and sampled.
//
class nsSMILTimeContainer
{
public:
nsSMILTimeContainer();
virtual ~nsSMILTimeContainer();
/*
* Pause request types.
*/
enum {
PAUSE_BEGIN = 1,
PAUSE_SCRIPT = 2,
PAUSE_PAGEHIDE = 4,
PAUSE_USERPREF = 8
};
/*
* Cause the time container to records its begin time.
*/
void Begin();
/*
* Pause this time container
*
* @param aType The source of the pause request. Successive calls to Pause
* with the same aType will be ignored. The container will remain paused until
* each call to Pause of a given aType has been matched by at least one call
* to Resume with the same aType.
*/
virtual void Pause(PRUint32 aType);
/*
* Resume this time container
*
* param @aType The source of the resume request. Clears the pause flag for
* this particular type of pause request. When all pause flags have been
* cleared the time container will be resumed.
*/
virtual void Resume(PRUint32 aType);
/**
* Returns true if this time container is paused by the specified type.
* Note that the time container may also be paused by other types; this method
* does not test if aType is the exclusive pause source.
*
* @param @aType The pause source to test for.
* @return PR_TRUE if this container is paused by aType.
*/
PRBool IsPausedByType(PRUint32 aType) const { return mPauseState & aType; }
/*
* Return the time elapsed since this time container's begin time (expressed
* in parent time) minus any accumulated offset from pausing.
*/
nsSMILTime GetCurrentTime() const;
/*
* Seek the document timeline to the specified time.
*
* @param aSeekTo The time to seek to, expressed in this time container's time
* base (i.e. the same units as GetCurrentTime).
*/
void SetCurrentTime(nsSMILTime aSeekTo);
/*
* Return the current time for the parent time container if any.
*/
virtual nsSMILTime GetParentTime() const;
/*
* Updates the current time of this time container and calls DoSample to
* perform any sample-operations.
*/
void Sample();
/*
* Return if this time container should be sampled or can be skipped.
*
* This is most useful as an optimisation for skipping time containers that
* don't require a sample.
*/
PRBool NeedsSample() const { return !mPauseState || mNeedsPauseSample; }
/*
* Sets the parent time container.
*
* The callee still retains ownership of the time container.
*/
nsresult SetParent(nsSMILTimeContainer* aParent);
protected:
/*
* Per-sample operations to be performed whenever Sample() is called and
* NeedsSample() is true. Called after updating mCurrentTime;
*/
virtual void DoSample() { }
/*
* Adding and removing child containers is not implemented in the base class
* because not all subclasses need this.
*/
/*
* Adds a child time container.
*/
virtual nsresult AddChild(nsSMILTimeContainer& aChild)
{
return NS_ERROR_FAILURE;
}
/*
* Removes a child time container.
*/
virtual void RemoveChild(nsSMILTimeContainer& aChild) { }
/*
* Implementation helper to update the current time.
*/
void UpdateCurrentTime();
// The parent time container, if any
nsSMILTimeContainer* mParent;
// The current time established at the last call to Sample()
nsSMILTime mCurrentTime;
// The number of milliseconds for which the container has been paused
// (excluding the current pause interval if the container is currently
// paused).
//
// Current time = parent time - mParentOffset
//
nsSMILTime mParentOffset;
// The timestamp in milliseconds since the epoch (i.e. wallclock time) when
// the document was paused
nsSMILTime mPauseStart;
// Whether or not a pause sample is required
PRPackedBool mNeedsPauseSample;
// A bitfield of the pause state for all pause requests
PRUint32 mPauseState;
};
#endif // NS_SMILTIMECONTAINER_H_