Windows: Support virtual folders as initial directory for file dialog.

Use the scheme "clsid" to be able to pass them as "clsid:<GUID>"
(with '{', '}' stripped).

Task-number: QTBUG-33962
Change-Id: Ib045fe81518bca6e91588007ce8a245a48479b1f
Reviewed-by: Leena Miettinen <riitta-leena.miettinen@theqtcompany.com>
Reviewed-by: Patrick Spendrin <patrick.spendrin@kdab.com>
Reviewed-by: Oliver Wolff <oliver.wolff@theqtcompany.com>
Reviewed-by: Björn Breitmeyer <bjoern.breitmeyer@kdab.com>
Reviewed-by: Joerg Bornemann <joerg.bornemann@theqtcompany.com>

3 files changed, 73 insertions, 19 deletions

diff --git a/src/plugins/platforms/windows/qwindowscontext.cpp b/src/plugins/platforms/windows/qwindowscontext.cpp
index fa355f6201..7264fdcbb6 100644
--- a/src/plugins/platforms/windows/qwindowscontext.cpp
+++ b/src/plugins/platforms/windows/qwindowscontext.cpp
@@ -225,8 +225,10 @@ bool QWindowsUser32DLL::initTouch()
 
 QWindowsShell32DLL::QWindowsShell32DLL()
     : sHCreateItemFromParsingName(0)
+    , sHGetKnownFolderIDList(0)
     , sHGetStockIconInfo(0)
     , sHGetImageList(0)
+    , sHCreateItemFromIDList(0)
 {
 }
 
@@ -234,8 +236,10 @@ void QWindowsShell32DLL::init()
 {
     QSystemLibrary library(QStringLiteral("shell32"));
     sHCreateItemFromParsingName = (SHCreateItemFromParsingName)(library.resolve("SHCreateItemFromParsingName"));
+    sHGetKnownFolderIDList = (SHGetKnownFolderIDList)(library.resolve("SHGetKnownFolderIDList"));
     sHGetStockIconInfo = (SHGetStockIconInfo)library.resolve("SHGetStockIconInfo");
     sHGetImageList = (SHGetImageList)library.resolve("SHGetImageList");
+    sHCreateItemFromIDList = (SHCreateItemFromIDList)library.resolve("SHCreateItemFromIDList");
 }
 
 QWindowsShcoreDLL::QWindowsShcoreDLL()
diff --git a/src/plugins/platforms/windows/qwindowscontext.h b/src/plugins/platforms/windows/qwindowscontext.h
index 81f4a36433..d2a3481b28 100644
--- a/src/plugins/platforms/windows/qwindowscontext.h
+++ b/src/plugins/platforms/windows/qwindowscontext.h
@@ -41,6 +41,10 @@
 #include <QtCore/QSharedPointer>
 #include <QtCore/QLoggingCategory>
 
+#define STRICT_TYPED_ITEMIDS
+#include <shlobj.h>
+#include <shlwapi.h>
+
 struct IBindCtx;
 struct _SHSTOCKICONINFO;
 
@@ -120,12 +124,16 @@ struct QWindowsShell32DLL
     inline void init();
 
     typedef HRESULT (WINAPI *SHCreateItemFromParsingName)(PCWSTR, IBindCtx *, const GUID&, void **);
+    typedef HRESULT (WINAPI *SHGetKnownFolderIDList)(const GUID &, DWORD, HANDLE, PIDLIST_ABSOLUTE *);
     typedef HRESULT (WINAPI *SHGetStockIconInfo)(int , int , _SHSTOCKICONINFO *);
     typedef HRESULT (WINAPI *SHGetImageList)(int, REFIID , void **);
+    typedef HRESULT (WINAPI *SHCreateItemFromIDList)(PCIDLIST_ABSOLUTE, REFIID, void **);
 
     SHCreateItemFromParsingName sHCreateItemFromParsingName;
+    SHGetKnownFolderIDList sHGetKnownFolderIDList;
     SHGetStockIconInfo sHGetStockIconInfo;
     SHGetImageList sHGetImageList;
+    SHCreateItemFromIDList sHCreateItemFromIDList;
 };
 
 // Shell scaling library (Windows 8.1 onwards)
diff --git a/src/plugins/platforms/windows/qwindowsdialoghelpers.cpp b/src/plugins/platforms/windows/qwindowsdialoghelpers.cpp
index 3b47829402..3284795fc1 100644
--- a/src/plugins/platforms/windows/qwindowsdialoghelpers.cpp
+++ b/src/plugins/platforms/windows/qwindowsdialoghelpers.cpp
@@ -58,16 +58,14 @@
 #include <QtCore/QExplicitlySharedDataPointer>
 #include <QtCore/QMutex>
 #include <QtCore/QMutexLocker>
+#include <QtCore/QUuid>
+#include <QtCore/QRegularExpression>
 #include <QtCore/private/qsystemlibrary_p.h>
 
 #include <algorithm>
 
 #include "qtwindows_additional.h"
 
-#define STRICT_TYPED_ITEMIDS
-#include <shlobj.h>
-#include <shlwapi.h>
-
 // #define USE_NATIVE_COLOR_DIALOG /* Testing purposes only */
 
 #ifdef Q_CC_MINGW  /* Add missing declarations for MinGW */
@@ -873,8 +871,8 @@ public:
 
     virtual void setWindowTitle(const QString &title);
     inline void setMode(QFileDialogOptions::FileMode mode, QFileDialogOptions::AcceptMode acceptMode, QFileDialogOptions::FileDialogOptions options);
-    inline void setDirectory(const QString &directory);
-    inline void updateDirectory() { setDirectory(m_data.directory().toLocalFile()); }
+    inline void setDirectory(const QUrl &directory);
+    inline void updateDirectory() { setDirectory(m_data.directory()); }
     inline QString directory() const;
     virtual void doExec(HWND owner = 0);
     virtual void setNameFilters(const QStringList &f);
@@ -916,7 +914,7 @@ protected:
     static QList<QUrl> libraryItemFolders(IShellItem *item);
     static QString libraryItemDefaultSaveFolder(IShellItem *item);
     static int itemPaths(IShellItemArray *items, QList<QUrl> *fileResult = 0);
-    static IShellItem *shellItem(const QString &path);
+    static IShellItem *shellItem(const QUrl &url);
 
     const QWindowsFileDialogSharedData &data() const { return m_data; }
     QWindowsFileDialogSharedData &data() { return m_data; }
@@ -976,25 +974,58 @@ void QWindowsNativeFileDialogBase::setWindowTitle(const QString &title)
     m_fileDialog->SetTitle(reinterpret_cast<const wchar_t *>(title.utf16()));
 }
 
-IShellItem *QWindowsNativeFileDialogBase::shellItem(const QString &path)
+IShellItem *QWindowsNativeFileDialogBase::shellItem(const QUrl &url)
 {
 #ifndef Q_OS_WINCE
-    if (QWindowsContext::shell32dll.sHCreateItemFromParsingName) {
-        IShellItem *result = 0;
-        const QString native = QDir::toNativeSeparators(path);
+    if (url.isLocalFile()) {
+        if (!QWindowsContext::shell32dll.sHCreateItemFromParsingName)
+            return Q_NULLPTR;
+        IShellItem *result = Q_NULLPTR;
+        const QString native = QDir::toNativeSeparators(url.toLocalFile());
         const HRESULT hr =
-            QWindowsContext::shell32dll.sHCreateItemFromParsingName(reinterpret_cast<const wchar_t *>(native.utf16()),
-                                                                    NULL, IID_IShellItem,
-                                                                    reinterpret_cast<void **>(&result));
-        if (SUCCEEDED(hr))
-            return result;
+                QWindowsContext::shell32dll.sHCreateItemFromParsingName(reinterpret_cast<const wchar_t *>(native.utf16()),
+                                                                        NULL, IID_IShellItem,
+                                                                        reinterpret_cast<void **>(&result));
+        if (FAILED(hr)) {
+            qErrnoWarning("%s: SHCreateItemFromParsingName(%s)) failed", __FUNCTION__, qPrintable(url.toString()));
+            return Q_NULLPTR;
+        }
+        return result;
+    } else if (url.scheme() == QLatin1String("clsid")) {
+        if (!QWindowsContext::shell32dll.sHGetKnownFolderIDList || !QWindowsContext::shell32dll.sHCreateItemFromIDList)
+            return Q_NULLPTR;
+        // Support for virtual folders via GUID
+        // (see https://msdn.microsoft.com/en-us/library/windows/desktop/dd378457(v=vs.85).aspx)
+        // specified as "clsid:<GUID>" (without '{', '}').
+        IShellItem *result = Q_NULLPTR;
+        const QUuid uuid(url.path());
+        if (uuid.isNull()) {
+            qWarning() << __FUNCTION__ << ": Invalid CLSID: " << url.path();
+            return Q_NULLPTR;
+        }
+        PIDLIST_ABSOLUTE idList;
+        HRESULT hr = QWindowsContext::shell32dll.sHGetKnownFolderIDList(uuid, 0, 0, &idList);
+        if (FAILED(hr)) {
+            qErrnoWarning("%s: SHGetKnownFolderIDList(%s)) failed", __FUNCTION__, qPrintable(url.toString()));
+            return Q_NULLPTR;
+        }
+        hr = QWindowsContext::shell32dll.sHCreateItemFromIDList(idList, IID_IShellItem, reinterpret_cast<void **>(&result));
+        CoTaskMemFree(idList);
+        if (FAILED(hr)) {
+            qErrnoWarning("%s: SHCreateItemFromIDList(%s)) failed", __FUNCTION__, qPrintable(url.toString()));
+            return Q_NULLPTR;
+        }
+        return result;
+    } else {
+        qWarning() << __FUNCTION__ << ": Unhandled scheme: " << url.scheme();
     }
+#else // !Q_OS_WINCE
+    Q_UNUSED(url)
 #endif
-    qErrnoWarning("%s: SHCreateItemFromParsingName(%s)) failed", __FUNCTION__, qPrintable(path));
     return 0;
 }
 
-void QWindowsNativeFileDialogBase::setDirectory(const QString &directory)
+void QWindowsNativeFileDialogBase::setDirectory(const QUrl &directory)
 {
     if (!directory.isEmpty()) {
         if (IShellItem *psi = QWindowsNativeFileDialogBase::shellItem(directory)) {
@@ -1284,9 +1315,20 @@ void QWindowsNativeFileDialogBase::setLabelText(QFileDialogOptions::DialogLabel
     }
 }
 
+static inline bool isClsid(const QString &s)
+{
+    // detect "374DE290-123F-4565-9164-39C4925E467B".
+   static const QRegularExpression pattern(QLatin1String("[0-9A-Fa-f]{8}-[0-9A-Fa-f]{4}-[0-9A-Fa-f]{4}-[0-9A-Fa-f]{4}-[0-9A-Fa-f]{8}"));
+   Q_ASSERT(pattern.isValid());
+   return pattern.match(s).hasMatch();
+}
+
 void QWindowsNativeFileDialogBase::selectFile(const QString &fileName) const
 {
-    m_fileDialog->SetFileName((wchar_t*)fileName.utf16());
+    // Hack to prevent CLSIDs from being set as file name due to
+    // QFileDialogPrivate::initialSelection() being QString-based.
+    if (!isClsid(fileName))
+        m_fileDialog->SetFileName((wchar_t*)fileName.utf16());
 }
 
 // Return the index of the selected filter, accounting for QFileDialog