Cocoa File Dialog: Remove sandbox-ufriendly file system watcher

QFileSystemWatcher causes sandboxing errors since its backend uses
POSIX API in a relatively liberal way.

Also, Cocoa already acts as a file system watcher, and calls
-[QNSOpenSavePanelDelegate panel:shouldShowFilename:] on each
file. From a logical point of view, caching the directory content
can be replaced by testing the current file against the filter
setting. We expect Cocoa to cache results, and by using NSFileManager
things should remain relatively fast.

Task-number: QTBUG-34107
Change-Id: Ia872b9b1244f7b390d173a498011379b9309b3c6
Reviewed-by: Cyril Oblikov <munknex@gmail.com>
Reviewed-by: Morten Johan Sørvig <morten.sorvig@digia.com>

src/plugins/platforms/cocoa/qcocoafiledialoghelper.mm

@@ -61,12 +61,12 @@
 #include <stdlib.h>
 #include <qabstracteventdispatcher.h>
 #include "qcocoaautoreleasepool.h"
-#include <QFileSystemWatcher>
 #include <QDir>
 
 #include <qpa/qplatformnativeinterface.h>
 
 #import <AppKit/NSSavePanel.h>
+#import <CoreFoundation/CFNumber.h>
 
 QT_FORWARD_DECLARE_CLASS(QString)
 QT_FORWARD_DECLARE_CLASS(QStringList)
@@ -74,30 +74,6 @@ QT_FORWARD_DECLARE_CLASS(QFileInfo)
 QT_FORWARD_DECLARE_CLASS(QWindow)
 QT_USE_NAMESPACE
 
-class CachedEntries: public QObject {
-public:
-    CachedEntries(QDir::Filters filters) : mFilters(filters) {
-        QObject::connect(&mFSWatcher, &QFileSystemWatcher::directoryChanged, this, &CachedEntries::updateDirCache);
-    }
-    QString directory() const {
-        const QStringList &dirs = mFSWatcher.directories();
-        return (dirs.count() ? dirs[0] : QString());
-    }
-    QStringList entries() const {
-        return mQDirFilterEntryList;
-    }
-    void updateDirCache(const QString &path) {
-        mFSWatcher.removePaths(mFSWatcher.directories());
-        mFSWatcher.addPath(path);
-        mQDirFilterEntryList = QDir(path).entryList(mFilters);
-    }
-
-private:
-    QFileSystemWatcher mFSWatcher;
-    QStringList mQDirFilterEntryList;
-    QDir::Filters mFilters;
-};
-
 typedef QSharedPointer<QFileDialogOptions> SharedPointerFileDialogOptions;
 
 @class QT_MANGLE_NAMESPACE(QNSOpenSavePanelDelegate);
@@ -117,7 +93,6 @@ typedef QSharedPointer<QFileDialogOptions> SharedPointerFileDialogOptions;
     int mReturnCode;
 
     SharedPointerFileDialogOptions mOptions;
-    CachedEntries *mCachedEntries;
     QString *mCurrentSelection;
     QStringList *mNameFilterDropDownList;
     QStringList *mSelectedNameFilter;
@@ -164,7 +139,6 @@ QT_NAMESPACE_ALIAS_OBJC_CLASS(QNSOpenSavePanelDelegate);
     [mSavePanel setDelegate:self];
     mReturnCode = -1;
     mHelper = helper;
-    mCachedEntries = new CachedEntries(mOptions->filter());
     mNameFilterDropDownList = new QStringList(mOptions->nameFilters());
     QString selectedVisualNameFilter = mOptions->initiallySelectedNameFilter();
     mSelectedNameFilter = new QStringList([self findStrippedFilterWithVisualFilterName:selectedVisualNameFilter]);
@@ -197,7 +171,6 @@ QT_NAMESPACE_ALIAS_OBJC_CLASS(QNSOpenSavePanelDelegate);
 
 - (void)dealloc
 {
-    delete mCachedEntries;
     delete mNameFilterDropDownList;
     delete mSelectedNameFilter;
     delete mCurrentSelection;
@@ -308,6 +281,22 @@ static QString strippedText(QString s)
     }];
 }
 
+- (BOOL)isHiddenFile:(NSString *)filename isDir:(BOOL)isDir
+{
+    CFURLRef url = CFURLCreateWithFileSystemPath(kCFAllocatorDefault, (CFStringRef)filename, kCFURLPOSIXPathStyle, isDir);
+    CFBooleanRef isHidden;
+    Boolean errorOrHidden = false;
+    if (!CFURLCopyResourcePropertyForKey(url, kCFURLIsHiddenKey, &isHidden, NULL)) {
+        errorOrHidden = true;
+    } else {
+        if (CFBooleanGetValue(isHidden))
+            errorOrHidden = true;
+        CFRelease(isHidden);
+    }
+    CFRelease(url);
+    return errorOrHidden;
+}
+
 - (BOOL)panel:(id)sender shouldShowFilename:(NSString *)filename
 {
     Q_UNUSED(sender);
@@ -316,8 +305,13 @@ static QString strippedText(QString s)
         return NO;
 
     // Always accept directories regardless of their names (unless it is a bundle):
-    BOOL isDir;
+    NSFileManager *fm = [NSFileManager defaultManager];
-    if ([[NSFileManager defaultManager] fileExistsAtPath:filename isDirectory:&isDir] && isDir) {
+    NSDictionary *fileAttrs = [fm attributesOfItemAtPath:filename error:nil];
+    if (!fileAttrs)
+        return NO; // Error accessing the file means 'no'.
+    NSString *fileType = [fileAttrs fileType];
+    bool isDir = [fileType isEqualToString:NSFileTypeDirectory];
+    if (isDir) {
         if ([mSavePanel treatsFilePackagesAsDirectories] == NO) {
             if ([[NSWorkspace sharedWorkspace] isFilePackageAtPath:filename] == NO)
                 return YES;
@@ -325,24 +319,35 @@ static QString strippedText(QString s)
     }
 
     QString qtFileName = QCFString::toQString(filename);
-    QFileInfo info(qtFileName.normalized(QString::NormalizationForm_C));
+    // No filter means accept everything
-    QString path = info.absolutePath();
+    bool nameMatches = mSelectedNameFilter->isEmpty();
-    if (mCachedEntries->directory() != path) {
+    // Check if the current file name filter accepts the file:
-        mCachedEntries->updateDirCache(path);
+    for (int i = 0; !nameMatches && i < mSelectedNameFilter->size(); ++i) {
+        if (QDir::match(mSelectedNameFilter->at(i), qtFileName))
+            nameMatches = true;
     }
-    // Check if the QDir filter accepts the file:
+    if (!nameMatches)
-    if (!mCachedEntries->entries().contains(info.fileName()))
         return NO;
 
-    // No filter means accept everything
+    QDir::Filters filter = mOptions->filter();
-    if (mSelectedNameFilter->isEmpty())
+    if ((!(filter & (QDir::Dirs | QDir::AllDirs)) && isDir)
-        return YES;
+        || (!(filter & QDir::Files) && [fileType isEqualToString:NSFileTypeRegular])
-    // Check if the current file name filter accepts the file:
+        || ((filter & QDir::NoSymLinks) && [fileType isEqualToString:NSFileTypeSymbolicLink]))
-    for (int i=0; i<mSelectedNameFilter->size(); ++i) {
+        return NO;
-        if (QDir::match(mSelectedNameFilter->at(i), qtFileName))
+
-            return YES;
+    bool filterPermissions = ((filter & QDir::PermissionMask)
+                              && (filter & QDir::PermissionMask) != QDir::PermissionMask);
+    if (filterPermissions) {
+        if ((!(filter & QDir::Readable) && [fm isReadableFileAtPath:filename])
+            || (!(filter & QDir::Writable) && [fm isWritableFileAtPath:filename])
+            || (!(filter & QDir::Executable) && [fm isExecutableFileAtPath:filename]))
+            return NO;
     }
-    return NO;
+    if (!(filter & QDir::Hidden)
+        && (qtFileName.startsWith(QLatin1Char('.')) || [self isHiddenFile:filename isDir:isDir]))
+            return NO;
+
+    return YES;
 }
 
 - (NSString *)panel:(id)sender userEnteredFilename:(NSString *)filename confirmed:(BOOL)okFlag