QFileSystemWatcher/Win32: Listen for WM_DEVICECHANGE

Add a class QWindowsRemovableDriveListener to
QWindowsFileSystemWatcherEngine listening to the WM_DEVICECHANGE messages
sent to the top level windows to detect insertion and removal of USB drives.
In addition, hook into QWindowsFileSystemWatcherEngine::addPaths() when
watching on removable drives, registering a notification for a
volume-lock-for-removal message on the internal window handle obtained from
QEventDispatcherWin32. When a request to lock the volume for removal is
received, remove the paths from the watcher, enabling removal.

The class instance is set as a dynamic property on the QFileSystemWatcher where
it can be retrieved from clients. This is primarily intended for use by
QFileInfoGatherer/QFileSystemModel.

Task-number: QTBUG-14290
Task-number: QTBUG-18729
Task-number: QTBUG-55459
Change-Id: Ic95b9d9291b1ec6f426c0702bad896bb064b9346
Reviewed-by: Lars Knoll <lars.knoll@qt.io>

1 files changed, 11 insertions, 4 deletions

diff --git a/src/corelib/io/qfilesystemwatcher_win_p.h b/src/corelib/io/qfilesystemwatcher_win_p.h
index e8f5c49dec..51c7082483 100644
--- a/src/corelib/io/qfilesystemwatcher_win_p.h
+++ b/src/corelib/io/qfilesystemwatcher_win_p.h
@@ -66,6 +66,7 @@
 QT_BEGIN_NAMESPACE
 
 class QWindowsFileSystemWatcherEngineThread;
+class QWindowsRemovableDriveListener;
 
 // Even though QWindowsFileSystemWatcherEngine is derived of QThread
 // via QFileSystemWatcher, it does not start a thread.
@@ -75,9 +76,7 @@ class QWindowsFileSystemWatcherEngine : public QFileSystemWatcherEngine
 {
     Q_OBJECT
 public:
-    inline QWindowsFileSystemWatcherEngine(QObject *parent)
-        : QFileSystemWatcherEngine(parent)
-    { }
+    explicit QWindowsFileSystemWatcherEngine(QObject *parent);
     ~QWindowsFileSystemWatcherEngine();
 
     QStringList addPaths(const QStringList &paths, QStringList *files, QStringList *directories);
@@ -121,9 +120,17 @@ public:
                     || lastModified != fileInfo.lastModified());
         }
     };
+
+signals:
+    void driveLockForRemoval(const QString &);
+    void driveLockForRemovalFailed(const QString &);
+    void driveRemoved(const QString &);
+
 private:
     QList<QWindowsFileSystemWatcherEngineThread *> threads;
-
+#ifndef Q_OS_WINRT
+    QWindowsRemovableDriveListener *m_driveListener;
+#endif
 };
 
 class QFileSystemWatcherPathKey : public QString