gecko/widget/src/windows/nsNativeDragSource.cpp

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
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 * The Original Code is mozilla.org code.
 *
 * The Initial Developer of the Original Code is
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 *
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#include "nsNativeDragSource.h"
#include <stdio.h>
#include "nsISupportsImpl.h"
#include "nsString.h"

/*
 * class nsNativeDragSource
 */
nsNativeDragSource::nsNativeDragSource(nsIDOMDataTransfer* aDataTransfer) :
  m_cRef(0),
  mUserCancelled(PR_FALSE),
  m_hCursor(nsnull)
{
  mDataTransfer = do_QueryInterface(aDataTransfer);
}

nsNativeDragSource::~nsNativeDragSource()
{
}

STDMETHODIMP
nsNativeDragSource::QueryInterface(REFIID riid, void** ppv)
{
  *ppv=NULL;

  if (IID_IUnknown==riid || IID_IDropSource==riid)
    *ppv=this;

  if (NULL!=*ppv) {
    ((LPUNKNOWN)*ppv)->AddRef();
    return NOERROR;
  }

  return ResultFromScode(E_NOINTERFACE);
}


STDMETHODIMP_(ULONG)
nsNativeDragSource::AddRef(void)
{
  ++m_cRef;
  NS_LOG_ADDREF(this, m_cRef, "nsNativeDragSource", sizeof(*this));
  return m_cRef;
}

STDMETHODIMP_(ULONG)
nsNativeDragSource::Release(void)
{
  --m_cRef;
  NS_LOG_RELEASE(this, m_cRef, "nsNativeDragSource");
  if (0 != m_cRef)
    return m_cRef;

  delete this;
  return 0;
}

STDMETHODIMP
nsNativeDragSource::QueryContinueDrag(BOOL fEsc, DWORD grfKeyState)
{
#ifdef DEBUG
  //printf("QueryContinueDrag: ");
#endif
  if (fEsc) {
#ifdef DEBUG
    //printf("fEsc\n");
#endif
    mUserCancelled = PR_TRUE;
    return ResultFromScode(DRAGDROP_S_CANCEL);
  }

  if (!(grfKeyState & MK_LBUTTON) || (grfKeyState & MK_RBUTTON)) {
#ifdef DEBUG
    //printf("grfKeyState & MK_LBUTTON\n");
#endif
    return ResultFromScode(DRAGDROP_S_DROP);
  }

#ifdef DEBUG
  //printf("NOERROR\n");
#endif
	return NOERROR;
}

STDMETHODIMP
nsNativeDragSource::GiveFeedback(DWORD dwEffect)
{
#ifdef DEBUG
  //printf("GiveFeedback\n");
#endif
  
  // For drags involving tabs, we do some custom work with cursors. 
  if (mDataTransfer) {
    nsAutoString cursor;
    mDataTransfer->GetMozCursor(cursor);
    if (cursor.EqualsASCII("default")) {
      m_hCursor = ::LoadCursor(0, IDC_ARROW);
    } else {
      m_hCursor =  nsnull;
    }
  }

  if (m_hCursor) {
    ::SetCursor(m_hCursor);
    return S_OK;
  }
  
  // Let the system choose which cursor to apply.
	return ResultFromScode(DRAGDROP_S_USEDEFAULTCURSORS);
}