view/public/nsIScrollPositionListener.h
author Brian Smith <bsmith@mozilla.com>
Wed, 02 Nov 2011 17:42:07 -0700
branchGECKO19224_2011103116_RELBRANCH
changeset 35217 7239e49f6d37e77c5ede4cb3fa779fa66fd11bb3
parent 30540 ff084019260e93cca76ba924909a2730e211aff6
permissions -rw-r--r--
Bug 698753 r=rrelyea, a=johnath

/* -*- Mode: IDL; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
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#ifndef nsIScrollPositionListener_h___
#define nsIScrollPositionListener_h___

#include "nsISupports.h"
#include "nsCoord.h"
#include "nsTArray.h"
#include "nsIWidget.h"

// forward declarations
class nsIScrollableView;

// IID for the nsIScrollPositionListener interface
#define NS_ISCROLLPOSITIONLISTENER_IID \
  { 0x9654a477, 0x49a7, 0x4aea, \
    { 0xb7, 0xe3, 0x90, 0xe5, 0xe5, 0xd4, 0x28, 0xcd } }

/**
 * Provides a way for a client of an nsIScrollableView to learn about scroll position
 * changes.
 */
class nsIScrollPositionListener : public nsISupports {
public:
	NS_DECLARE_STATIC_IID_ACCESSOR(NS_ISCROLLPOSITIONLISTENER_IID)

	NS_IMETHOD ScrollPositionWillChange(nsIScrollableView* aScrollable, nscoord aX, nscoord aY) = 0;
	// The scrollframe implementation of this method appends a list of widget
	// configuration requests to aConfigurations. No other implementor
	// should touch it.
	virtual void ViewPositionDidChange(nsIScrollableView* aScrollable,
	                                   nsTArray<nsIWidget::Configuration>* aConfigurations) = 0;
	NS_IMETHOD ScrollPositionDidChange(nsIScrollableView* aScrollable, nscoord aX, nscoord aY) = 0;
};

NS_DEFINE_STATIC_IID_ACCESSOR(nsIScrollPositionListener,
                              NS_ISCROLLPOSITIONLISTENER_IID)

#endif /* nsIScrollPositionListener_h___ */