Bug 494989 - Windows drag and drop does not use temporary file when needed--fixes dragging image to apps that can handle images. r=roc, r=jmathies.

widget/src/windows/nsDataObj.cpp

@@ -63,6 +63,7 @@
 #include "nscore.h"
 #include "prtypes.h"
 #include "nsDirectoryServiceDefs.h"
+#include "nsITimer.h"
 
 // XXX Duped from profile/src/nsProfile.cpp.
 #include <stdlib.h>
@@ -448,6 +449,22 @@ STDMETHODIMP_(ULONG) nsDataObj::Release()
 	if (0 != m_cRef)
 		return m_cRef;
 
+  // We have released our last ref on this object and need to delete the
+  // temp file. External app acting as drop target may still need to open the
+  // temp file. Addref a timer so it can delay deleting file and destroying
+  // this object. Delete file anyway and destroy this obj if there's a problem.
+  if (mCachedTempFile) {
+    nsresult rv;
+    mTimer = do_CreateInstance(NS_TIMER_CONTRACTID, &rv);
+    if (NS_SUCCEEDED(rv)) {
+      mTimer->InitWithFuncCallback(nsDataObj::RemoveTempFile, this,
+                                   500, nsITimer::TYPE_ONE_SHOT);
+      return AddRef();
+    }
+    mCachedTempFile->Remove(PR_FALSE);
+    mCachedTempFile = NULL;
+  }
+
 	delete this;
 
 	return 0;
@@ -622,15 +639,6 @@ IUnknown* nsDataObj::GetCanonicalIUnknown(IUnknown *punk)
 STDMETHODIMP nsDataObj::SetData(LPFORMATETC pFE, LPSTGMEDIUM pSTM, BOOL fRelease)
 {
   PRNTDEBUG("nsDataObj::SetData\n");
-  static CLIPFORMAT PerformedDropEffect = ::RegisterClipboardFormat( CFSTR_PERFORMEDDROPEFFECT );  
-
-  if (pFE && pFE->cfFormat == PerformedDropEffect) {
-    // The drop operation has completed.  Delete the temp file if it exists.
-    if (mCachedTempFile) {
-      mCachedTempFile->Remove(PR_FALSE);
-      mCachedTempFile = NULL;
-    }
-  }
   // Store arbitrary system formats
   LPDATAENTRY pde;
   HRESULT hres = FindFORMATETC(pFE, &pde, TRUE); // add
@@ -1355,8 +1363,6 @@ HRESULT nsDataObj::GetText(const nsACString & aDataFlavor, FORMATETC& aFE, STGME
 //-----------------------------------------------------
 HRESULT nsDataObj::GetFile(FORMATETC& aFE, STGMEDIUM& aSTG)
 {
-  HRESULT res = S_OK;
-
   // We do  not support 'application/x-moz-file-promise' since CF_HDROP does not
   // allow for delayed rendering of content. We'll need to write the content out emmediately
   // and return the path to it. Confirm we have support for 'application/x-moz-nativeimage',
@@ -1449,6 +1455,7 @@ HRESULT nsDataObj::DropFile(FORMATETC& aFE, STGMEDIUM& aSTG)
 HRESULT nsDataObj::DropImage(FORMATETC& aFE, STGMEDIUM& aSTG)
 {
   nsresult rv;
+  if (!mCachedTempFile) {
     PRUint32 len = 0;
     nsCOMPtr<nsISupports> genericDataWrapper;
 
@@ -1482,19 +1489,16 @@ HRESULT nsDataObj::DropImage(FORMATETC& aFE, STGMEDIUM& aSTG)
       return E_FAIL;
     }
 
-  if (mCachedTempFile) {
-    mCachedTempFile->Remove(PR_FALSE);
-    mCachedTempFile = NULL;
-  }
-
     // Save the bitmap to a temporary location.      
     nsCOMPtr<nsIFile> dropFile;
     rv = NS_GetSpecialDirectory(NS_OS_TEMP_DIR, getter_AddRefs(dropFile));
-  if (!dropFile)
+    if (!dropFile) {
+      GlobalFree(bits);
       return E_FAIL;
+    }
 
-  // Filename must be random so as not to confuse apps like Photshop which handle
-  // multiple drags into a single window.
+    // Filename must be random so as not to confuse apps like
+    // Photoshop which handle multiple drags into a single window.
     char buf[13];
     nsCString filename;
     MakeRandomString(buf, 8);
@@ -1507,7 +1511,9 @@ HRESULT nsDataObj::DropImage(FORMATETC& aFE, STGMEDIUM& aSTG)
       return E_FAIL;
     }
 
-  // Cache the temp file so we can delete it later.
+    // Cache the temp file so we can delete it later and so
+    // it doesn't get recreated over and over on multiple calls
+    // which does occur from windows shell.
     dropFile->Clone(getter_AddRefs(mCachedTempFile));
 
     // Write the data to disk.
@@ -1537,14 +1543,12 @@ HRESULT nsDataObj::DropImage(FORMATETC& aFE, STGMEDIUM& aSTG)
     outStream->Close();
 
     GlobalUnlock(bits);
-
-  if (NS_FAILED(rv)) { 
     GlobalFree(bits);
+
+    if (NS_FAILED(rv))
       return E_FAIL;
   }
   
-  GlobalFree(bits);
-  
   // Pass the file name back to the drop target so that it can access the file.
   nsAutoString path;
   rv = mCachedTempFile->GetPath(path);
@@ -2073,3 +2077,13 @@ HRESULT nsDataObj::GetFileContents_IStream(FORMATETC& aFE, STGMEDIUM& aSTG)
 
   return S_OK;
 }
+
+void nsDataObj::RemoveTempFile(nsITimer* aTimer, void* aClosure)
+{
+  nsDataObj *timedDataObj = static_cast<nsDataObj *>(aClosure);
+  if (timedDataObj->mCachedTempFile) {
+    timedDataObj->mCachedTempFile->Remove(PR_FALSE);
+    timedDataObj->mCachedTempFile = NULL;
+  }
+  timedDataObj->Release();
+}

widget/src/windows/nsDataObj.h

@@ -52,6 +52,8 @@
 #include "nsIInputStream.h"
 #include "nsIChannel.h"
 #include "nsTPtrArray.h"
+#include "nsCOMArray.h"
+#include "nsITimer.h"
 
 // XXX for older version of PSDK where IAsyncOperation and related stuff is not available
 // but thisdefine  should be removed when parocles config is updated
@@ -333,6 +335,8 @@ class nsDataObj : public IDataObject,
                             BOOL fCopyIn);
     IUnknown* GetCanonicalIUnknown(IUnknown *punk);
     HGLOBAL GlobalClone(HGLOBAL hglobIn);
+    static void RemoveTempFile(nsITimer* aTimer, void* aClosure);
+    nsCOMPtr<nsITimer> mTimer;
 };
 
 

widget/src/windows/nsDragService.cpp

@@ -365,30 +365,6 @@ nsDragService::StartInvokingDragSession(IDataObject * aDataObj,
   SetDragEndPoint(nsIntPoint(cpos.x, cpos.y));
   EndDragSession(PR_TRUE);
 
-  // For some drag/drop interactions, IDataObject::SetData doesn't get
-  // called with a CFSTR_PERFORMEDDROPEFFECT format and the
-  // intermediate file (if it was created) isn't deleted.  See
-  // http://bugzilla.mozilla.org/show_bug.cgi?id=203847#c4 for a
-  // detailed description of the different cases.  Now that we know
-  // that the drag/drop operation has ended, call SetData() so that
-  // the intermediate file is deleted.
-  static CLIPFORMAT PerformedDropEffect =
-    ::RegisterClipboardFormat(CFSTR_PERFORMEDDROPEFFECT);
-
-  FORMATETC fmte =
-    {
-      (CLIPFORMAT)PerformedDropEffect,
-      NULL,
-      DVASPECT_CONTENT,
-      -1,
-      TYMED_NULL
-    };
-
-  STGMEDIUM medium;
-  medium.tymed = TYMED_NULL;
-  medium.pUnkForRelease = NULL;
-  aDataObj->SetData(&fmte, &medium, FALSE);
-
   mDoingDrag = PR_FALSE;
 
   return DRAGDROP_S_DROP == res ? NS_OK : NS_ERROR_FAILURE;