gecko-dev/view/public/nsIScrollPositionListener.h

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 * The Original Code is Mozilla Communicator.
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 * The Initial Developer of the Original Code is
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 *   Patrick Beard
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#ifndef nsIScrollPositionListener_h___
#define nsIScrollPositionListener_h___

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

// IID for the nsIScrollPositionListener interface
#define NS_ISCROLLPOSITIONLISTENER_IID \
{ 0x20b82adf, 0x1f5c, 0x44f7, \
  { 0x9b, 0x74, 0xc0, 0xa3, 0x14, 0xd8, 0xcf, 0x91 } }

/**
 * 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(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(nsTArray<nsIWidget::Configuration>* aConfigurations) = 0;
	NS_IMETHOD ScrollPositionDidChange(nscoord aX, nscoord aY) = 0;
};

NS_DEFINE_STATIC_IID_ACCESSOR(nsIScrollPositionListener,
                              NS_ISCROLLPOSITIONLISTENER_IID)

#endif /* nsIScrollPositionListener_h___ */