widget/windows/nsNativeDragSource.cpp

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #include "nsNativeDragSource.h"
   7 #include <stdio.h>
   8 #include "nsISupportsImpl.h"
   9 #include "nsString.h"
  10 #include "nsToolkit.h"
  11 #include "nsWidgetsCID.h"
  12 #include "nsIDragService.h"
  13 #include "nsServiceManagerUtils.h"
  14 #include "mozilla/dom/DataTransfer.h"
  15
  16 /*
  17  * class nsNativeDragSource
  18  */
  19 nsNativeDragSource::nsNativeDragSource(
  20     mozilla::dom::DataTransfer* aDataTransfer)
  21     : m_cRef(0), m_hCursor(nullptr), mUserCancelled(false) {
  22   mDataTransfer = aDataTransfer;
  23 }
  24
  25 nsNativeDragSource::~nsNativeDragSource() {}
  26
  27 STDMETHODIMP
  28 nsNativeDragSource::QueryInterface(REFIID riid, void** ppv) {
  29   *ppv = nullptr;
  30
  31   if (IID_IUnknown == riid || IID_IDropSource == riid) *ppv = this;
  32
  33   if (nullptr != *ppv) {
  34     ((LPUNKNOWN)*ppv)->AddRef();
  35     return S_OK;
  36   }
  37
  38   return E_NOINTERFACE;
  39 }
  40
  41 STDMETHODIMP_(ULONG)
  42 nsNativeDragSource::AddRef(void) {
  43   ++m_cRef;
  44   NS_LOG_ADDREF(this, m_cRef, "nsNativeDragSource", sizeof(*this));
  45   return m_cRef;
  46 }
  47
  48 STDMETHODIMP_(ULONG)
  49 nsNativeDragSource::Release(void) {
  50   --m_cRef;
  51   NS_LOG_RELEASE(this, m_cRef, "nsNativeDragSource");
  52   if (0 != m_cRef) return m_cRef;
  53
  54   delete this;
  55   return 0;
  56 }
  57
  58 STDMETHODIMP
  59 nsNativeDragSource::QueryContinueDrag(BOOL fEsc, DWORD grfKeyState) {
  60   nsCOMPtr<nsIDragService> dragService =
  61       do_GetService("@mozilla.org/widget/dragservice;1");
  62   if (dragService) {
  63     nsCOMPtr<nsIDragSession> session;
  64     dragService->GetCurrentSession(nullptr, getter_AddRefs(session));
  65     if (session) {
  66       DWORD pos = ::GetMessagePos();
  67       session->DragMoved(GET_X_LPARAM(pos), GET_Y_LPARAM(pos));
  68     }
  69   }
  70
  71   if (fEsc) {
  72     mUserCancelled = true;
  73     return DRAGDROP_S_CANCEL;
  74   }
  75
  76   if (!(grfKeyState & MK_LBUTTON) || (grfKeyState & MK_RBUTTON))
  77     return DRAGDROP_S_DROP;
  78
  79   return S_OK;
  80 }
  81
  82 STDMETHODIMP
  83 nsNativeDragSource::GiveFeedback(DWORD dwEffect) {
  84   // For drags involving tabs, we do some custom work with cursors.
  85   if (mDataTransfer) {
  86     nsAutoString cursor;
  87     mDataTransfer->GetMozCursor(cursor);
  88     if (cursor.EqualsLiteral("default")) {
  89       m_hCursor = ::LoadCursor(0, IDC_ARROW);
  90     } else {
  91       m_hCursor = nullptr;
  92     }
  93   }
  94
  95   if (m_hCursor) {
  96     ::SetCursor(m_hCursor);
  97     return S_OK;
  98   }
  99
 100   // Let the system choose which cursor to apply.
 101   return DRAGDROP_S_USEDEFAULTCURSORS;
 102 }