Changeset 470 for trunk/src/gui/kernel

Timestamp:

Jan 23, 2010, 3:44:11 PM (16 years ago)

Author:

Dmitry A. Kuminov

Message:

gui: DnD: Added support for dragging empty QMimeData with no formats (used in particular by QDesigner for in-process drag and drop).

Location:

trunk/src/gui/kernel

Files:

• qdnd_pm.cpp (modified) (1 diff)
• qmime_pm.cpp (modified) (10 diffs)

trunk/src/gui/kernel/qdnd_pm.cpp

@@ -913 +913 @@
     }
 
+    if (!mimeData->formats().count()) {
+        // The drag source doesn't provide any format, so we've got no workers.
+        // Although it may look strange, but it is a supported case: for
+        // example, designer uses it a lot for in-process DnD. Instead of MIME
+        // data, it works directly with the QMimeData object from the drag
+        // source. We will go through the converters passing a special value of
+        // QString::null as MIME type -- one of them (e.g. QPMAnyMime) should
+        // take it over and return itself.
+        Q_ASSERT(!workers.count());
+        DEBUG(() << "QPMCoopDragWorker: Source provides NO data, looking for a "
+                    "converter that can handle this");
+        foreach (QPMMime *mime, QPMMime::all()) {
+            DragWorker *wrk = mime->dragWorkerFor(QString::null, mimeData);
+            if (wrk) {
+                workers.append(wrk);
+                break;
+            }
+        }
+    }
+
 #if defined(QDND_DEBUG)
     foreach (DragWorker *wrk, workers) {

trunk/src/gui/kernel/qmime_pm.cpp

@@ -365 +365 @@
         return formats;
 
-    // DRM_SHAREDMEM comes first to prevent native DRM_OS2FILE
-    // rendering on the target side w/o involving the source.
-    // Also, we add <DRM_SHAREDMEM,DRF_POINTERDATA> just like WPS does it
-    // (however, it doesn't help when dropping objects to it -- WPS still
-    // chooses DRM_OS2FILE).
-    formats = "(DRM_SHAREDMEM,DRM_OS2FILE)x(" + formats + "),"
-              "<DRM_SHAREDMEM,DRF_POINTERDATA>";
+    if (qstrcmp(formats, "DRF_NULL") == 0) {
+        // special case, see QPMMimeAnyMime::dragWorkerFor()
+        formats = "<DRM_NULL," + formats + ">";
+    } else {
+        // DRM_SHAREDMEM comes first to prevent native DRM_OS2FILE
+        // rendering on the target side w/o involving the source.
+        // Also, we add <DRM_SHAREDMEM,DRF_POINTERDATA> just like WPS does it
+        // (however, it doesn't help when dropping objects to it -- WPS still
+        // chooses DRM_OS2FILE).
+        formats = "(DRM_SHAREDMEM,DRM_OS2FILE)x(" + formats + "),"
+                  "<DRM_SHAREDMEM,DRF_POINTERDATA>";
+    }
 
     DEBUG(() << "DefaultDragWorker: formats" << formats
@@ -477 +482 @@
                  << req->provider);
 
-        // We would lile to post WM_USER to ourselves to do actual rendering
+        // We would like to post WM_USER to ourselves to do actual rendering
         // after we return from DM_RENDER. But we are inside DrgDrag() at this
         // point (our DND implementation is fully synchronous by design), so
@@ -483 +488 @@
         // DrgDrag(). Thus, we have to send it.
 
-        WinSendMsg(hwnd(), WM_USER, MPFROMLONG(xfer->pditem->ulItemID),
-                                     MPFROMP(req));
+        WinSendMsg(hwnd(), WM_USER,
+                   MPFROMLONG(xfer->pditem->ulItemID), MPFROMP(req));
 
         return (MRESULT)TRUE;
@@ -827 +832 @@
     if (!provider)
         return ret;
+
+    if (mimeType.isEmpty()) {
+        // special case, see QPMMimeAnyMime::dropWorkerFor()
+        return ret;
+    }
 
     QByteArray drf = provider->drf(mimeType);
@@ -1117 +1127 @@
                                              Provider *provider)
 {
-    Q_ASSERT(!mimeType.isEmpty() && provider);
-    if (!mimeType.isEmpty() && provider && !d->exclusive) {
+    // note: as a special case, mimeType may be null (see
+    // QPMCoopDragWorker::collectWorkers())
+
+    Q_ASSERT(provider);
+    if (provider && !d->exclusive) {
         // ensure there are no dups (several providers for the same mime)
         if (!d->providerFor(mimeType))
@@ -1291 +1304 @@
 {
     ULONG cf = WinAddAtom(WinQuerySystemAtomTable(), mime.toLocal8Bit());
-    if (!cf) {
 #ifndef QT_NO_DEBUG
+    if (!cf)
         qWarning("QPMMime: WinAddAtom failed with 0x%lX",
                  WinGetLastError(NULLHANDLE));
 #endif
-        return 0;
-    }
 
     return cf;
@@ -2723 +2734 @@
                                                QString &type, QString &ext)
 {
-    // file type = mime
-    type = format(drf);
-    Q_ASSERT(!type.isEmpty());
+    if (qstrcmp(drf, "DRF_NULL") == 0) {
+        // special case (see QPMMimeAnyMime::dragWorkerFor())
+        type = QString::null;
+    } else {
+        // file type = mime
+        type = format(drf);
+        Q_ASSERT(!type.isEmpty());
+    }
 
     // no way to determine the extension
@@ -2759 +2775 @@
                                                    QMimeData *mimeData)
 {
+    if (mimeType.isEmpty()) {
+        // special case: QMimeData with no formats() (see
+        // QPMCoopDragWorker::collectWorkers())
+        Q_ASSERT(!mimeData->formats().count());
+        // add an exclusive provider with a special format DRF_NULL. Note that
+        // any attemt to render this format should fail so we don't expect
+        // AnyDragProvider::format()/provide() to be actually called.
+        DefaultDragWorker *defWorker = defaultExclDragWorker();
+        defWorker->addProvider(QByteArray("DRF_NULL"), &anyDragProvider);
+        return defWorker;
+    }
+
     ULONG cf = cfMap.value(mimeType);
     if (!cf)
@@ -2788 +2816 @@
         DefaultDropWorker *defWorker = defaultDropWorker();
         bool atLeastOneSupported = false;
+
+        if (qstrcmp(queryHSTR(item->hstrRMF), "<DRM_NULL,DRF_NULL>") == 0) {
+            // special case: QMimeData with no formats() (see
+            // QPMCoopDragWorker::collectWorkers()), use a special MIME format
+            // value of null.  Note that any attemt to retrieve data in this
+            // format should fail so we don't expect AnyDropProvider::drf()/
+            // provide() to be actually called.
+            defWorker->addProvider(QString::null, &anyDropProvider);
+            return defWorker;
+        }
 
         // check that we support one of DRMs and the format is CF_hhhhhhh
@@ -2864 +2902 @@
     if (atomStr.startsWith(mimePrefix)) {
         // the format represents the mime type we can recognize
-        // increase the reference count
-        ULONG cf = QPMMime::registerMimeType(atomStr);
-        Q_ASSERT(cf == format);
         // extract the real mime type (w/o our prefix)
         mime = atomStr.mid(mimePrefix.size());
+        Q_ASSERT(!mime.isEmpty());
         if (!mime.isEmpty()) {
+            // increase the reference count (will decrease on destruction)
+            ULONG cf = QPMMime::registerMimeType(atomStr);
+            Q_ASSERT(cf == format);
             cfMap[mime] = cf;
             mimeMap[cf] = mime;