FileChooser: misc fixes and improvements to iOS and Android file choosers.

examples/Demo/Source/Demos/DialogsDemo.cpp

@@ -331,17 +331,34 @@ private:
                                       useNativeVersion);
 
                 fc->launchAsync (FileBrowserComponent::saveMode | FileBrowserComponent::canSelectFiles,
-                                 [] (const FileChooser& chooser)
+                                 [fileToSave] (const FileChooser& chooser)
                                  {
                                      auto result = chooser.getURLResult();
                                      auto name = result.isEmpty() ? String()
                                                                   : (result.isLocalFile() ? result.getLocalFile().getFullPathName()
                                                                                           : result.toString (true));
 
+                                     // Android and iOS file choosers will create placeholder files for chosen
+                                     // paths, so we may as well write into those files.
+                                   #if JUCE_ANDROID || JUCE_IOS
+                                     if (! result.isEmpty())
+                                     {
+                                         ScopedPointer<InputStream> wi (fileToSave.createInputStream());
+                                         ScopedPointer<OutputStream> wo (result.createOutputStream());
+
+                                         if (wi != nullptr && wo != nullptr)
+                                         {
+                                             auto numWritten = wo->writeFromInputStream (*wi, -1);
+                                             jassert (numWritten > 0);
+                                             ignoreUnused (numWritten);
+                                         }
+                                     }
+                                   #endif
+
                                      AlertWindow::showMessageBoxAsync (AlertWindow::InfoIcon,
                                                                        "File Chooser...",
                                                                        "You picked: " + name);
-                                 }, nullptr, fileToSave);
+                                 });
             }
             else if (type == directoryChooser)
             {

modules/juce_core/native/juce_android_Files.cpp

@@ -33,8 +33,9 @@ DECLARE_JNI_CLASS (MediaScannerConnection, "android/media/MediaScannerConnection
 #undef JNI_CLASS_MEMBERS
 
 #define JNI_CLASS_MEMBERS(METHOD, STATICMETHOD, FIELD, STATICFIELD) \
- METHOD (query,           "query",           "(Landroid/net/Uri;[Ljava/lang/String;Ljava/lang/String;[Ljava/lang/String;Ljava/lang/String;)Landroid/database/Cursor;") \
- METHOD (openInputStream, "openInputStream", "(Landroid/net/Uri;)Ljava/io/InputStream;") \
+ METHOD (query,            "query",            "(Landroid/net/Uri;[Ljava/lang/String;Ljava/lang/String;[Ljava/lang/String;Ljava/lang/String;)Landroid/database/Cursor;") \
+ METHOD (openInputStream,  "openInputStream",  "(Landroid/net/Uri;)Ljava/io/InputStream;") \
+ METHOD (openOutputStream, "openOutputStream", "(Landroid/net/Uri;)Ljava/io/OutputStream;")
 
 DECLARE_JNI_CLASS (ContentResolver, "android/content/ContentResolver");
 #undef JNI_CLASS_MEMBERS
@@ -61,6 +62,14 @@ DECLARE_JNI_CLASS (AndroidEnvironment, "android/os/Environment");
 DECLARE_JNI_CLASS (AndroidFile, "java/io/File");
 #undef JNI_CLASS_MEMBERS
 
+#define JNI_CLASS_MEMBERS(METHOD, STATICMETHOD, FIELD, STATICFIELD) \
+ METHOD (close, "close", "()V") \
+ METHOD (flush, "flush", "()V") \
+ METHOD (write, "write", "([BII)V")
+
+DECLARE_JNI_CLASS (AndroidOutputStream, "java/io/OutputStream");
+#undef JNI_CLASS_MEMBERS
+
 #define JNI_CLASS_MEMBERS(METHOD, STATICMETHOD, FIELD, STATICFIELD) \
  STATICMETHOD (withAppendedId, "withAppendedId", "(Landroid/net/Uri;J)Landroid/net/Uri;") \
 
@@ -71,7 +80,7 @@ DECLARE_JNI_CLASS (ContentUris, "android/content/ContentUris");
 struct AndroidContentUriResolver
 {
 public:
-    static LocalRef<jobject> getInputStreamForContentUri (const URL& url)
+    static LocalRef<jobject> getStreamForContentUri (const URL& url, bool inputStream)
     {
         // only use this method for content URIs
         jassert (url.getScheme() == "content");
@@ -80,7 +89,10 @@ public:
         LocalRef<jobject> contentResolver (android.activity.callObjectMethod (JuceAppActivity.getContentResolver));
 
         if (contentResolver)
-            return LocalRef<jobject> ((env->CallObjectMethod (contentResolver.get(), ContentResolver.openInputStream, urlToUri (url).get())));
+            return LocalRef<jobject> ((env->CallObjectMethod (contentResolver.get(),
+                                                              inputStream ? ContentResolver.openInputStream
+                                                                          : ContentResolver.openOutputStream,
+                                                              urlToUri (url).get())));
 
         return LocalRef<jobject>();
     }
@@ -354,6 +366,62 @@ private:
     }
 };
 
+//==============================================================================
+struct AndroidContentUriOutputStream :  public OutputStream
+{
+    AndroidContentUriOutputStream (LocalRef<jobject>&& outputStream)
+        : stream (outputStream)
+    {
+    }
+
+    ~AndroidContentUriOutputStream()
+    {
+        stream.callVoidMethod (AndroidOutputStream.close);
+    }
+
+    void flush() override
+    {
+        stream.callVoidMethod (AndroidOutputStream.flush);
+    }
+
+    bool setPosition (int64 newPos) override
+    {
+        return (newPos == pos);
+    }
+
+    int64 getPosition() override
+    {
+        return pos;
+    }
+
+    bool write (const void* dataToWrite, size_t numberOfBytes) override
+    {
+        if (numberOfBytes == 0)
+            return true;
+
+        JNIEnv* env = getEnv();
+
+        jbyteArray javaArray = env->NewByteArray ((jsize) numberOfBytes);
+        env->SetByteArrayRegion (javaArray, 0, (jsize) numberOfBytes, (const jbyte*) dataToWrite);
+
+        stream.callVoidMethod (AndroidOutputStream.write, javaArray, 0, (jint) numberOfBytes);
+        env->DeleteLocalRef (javaArray);
+
+        pos += static_cast<int64> (numberOfBytes);
+        return true;
+    }
+
+    GlobalRef stream;
+    int64 pos = 0;
+};
+
+OutputStream* juce_CreateContentURIOutputStream (const URL& url)
+{
+    auto stream = AndroidContentUriResolver::getStreamForContentUri (url, false);
+
+    return (stream.get() != 0 ? new AndroidContentUriOutputStream (static_cast<LocalRef<jobject>&&> (stream)) : nullptr);
+}
+
 //==============================================================================
 class MediaScannerConnectionClient : public AndroidInterfaceImplementer
 {

modules/juce_core/native/juce_android_Network.cpp

@@ -137,7 +137,7 @@ public:
 
         if (isContentURL)
         {
-            auto inputStream = AndroidContentUriResolver::getInputStreamForContentUri (url);
+            auto inputStream = AndroidContentUriResolver::getStreamForContentUri (url, true);
 
             if (inputStream != nullptr)
             {

modules/juce_core/network/juce_URL.cpp

@@ -197,6 +197,9 @@ URL::URL (URL&& other)
       parameterNames  (static_cast<StringArray&&> (other.parameterNames)),
       parameterValues (static_cast<StringArray&&> (other.parameterValues)),
       filesToUpload   (static_cast<ReferenceCountedArray<Upload>&&> (other.filesToUpload))
+   #if JUCE_IOS
+    , bookmark        (other.bookmark)
+   #endif
 {
 }
 
@@ -207,6 +210,9 @@ URL& URL::operator= (URL&& other)
     parameterNames  = static_cast<StringArray&&> (other.parameterNames);
     parameterValues = static_cast<StringArray&&> (other.parameterValues);
     filesToUpload   = static_cast<ReferenceCountedArray<Upload>&&> (other.filesToUpload);
+  #if JUCE_IOS
+    bookmark        = other.bookmark;
+   #endif
 
     return *this;
 }
@@ -494,6 +500,114 @@ bool URL::isProbablyAnEmailAddress (const String& possibleEmailAddress)
         && ! possibleEmailAddress.endsWithChar ('.');
 }
 
+#if JUCE_IOS
+void setURLBookmark (URL& u, void* bookmark)
+{
+    u.bookmark = bookmark;
+}
+
+void* getURLBookmark (URL& u)
+{
+    return u.bookmark;
+}
+
+template <typename Stream> struct iOSFileStreamWrapperFlush    { static void flush (Stream*) {} };
+template <> struct iOSFileStreamWrapperFlush<FileOutputStream> { static void flush (OutputStream* o) { o->flush(); } };
+
+template <typename Stream>
+class iOSFileStreamWrapper : public Stream
+{
+public:
+    iOSFileStreamWrapper (URL& urlToUse)
+        : Stream (getLocalFileAccess (urlToUse)),
+          url (urlToUse)
+    {}
+
+    ~iOSFileStreamWrapper()
+    {
+        iOSFileStreamWrapperFlush<Stream>::flush (this);
+
+        if (NSData* bookmark = (NSData*) getURLBookmark (url))
+        {
+            BOOL isBookmarkStale = false;
+            NSError* error = nil;
+
+            auto* nsURL = [NSURL URLByResolvingBookmarkData: bookmark
+                                                    options: 0
+                                              relativeToURL: nil
+                                        bookmarkDataIsStale: &isBookmarkStale
+                                                      error: &error];
+
+            if (error == nil)
+            {
+                if (isBookmarkStale)
+                    updateStaleBookmark (nsURL, url);
+
+                [nsURL stopAccessingSecurityScopedResource];
+            }
+            else
+            {
+                auto* desc = [error localizedDescription];
+                ignoreUnused (desc);
+                jassertfalse;
+            }
+        }
+    }
+
+private:
+    URL url;
+    bool securityAccessSucceeded = false;
+
+    File getLocalFileAccess (URL& urlToUse)
+    {
+        if (NSData* bookmark = (NSData*) getURLBookmark (urlToUse))
+        {
+            BOOL isBookmarkStale = false;
+            NSError* error = nil;
+
+            auto* nsURL = [NSURL URLByResolvingBookmarkData: bookmark
+                                                    options: 0
+                                              relativeToURL: nil
+                                        bookmarkDataIsStale: &isBookmarkStale
+                                                      error: &error];
+
+            if (error == nil)
+            {
+                securityAccessSucceeded = [nsURL startAccessingSecurityScopedResource];
+
+                if (isBookmarkStale)
+                    updateStaleBookmark (nsURL, urlToUse);
+
+                return urlToUse.getLocalFile();
+            }
+            else
+            {
+                auto* desc = [error localizedDescription];
+                ignoreUnused (desc);
+                jassertfalse;
+            }
+        }
+
+        return urlToUse.getLocalFile();
+    }
+
+    void updateStaleBookmark (NSURL* nsURL, URL& juceUrl)
+    {
+        NSError* error = nil;
+
+        NSData* bookmark = [nsURL bookmarkDataWithOptions: NSURLBookmarkCreationSuitableForBookmarkFile
+                           includingResourceValuesForKeys: nil
+                                            relativeToURL: nil
+                                                    error: &error];
+
+        if (error == nil)
+            setURLBookmark (juceUrl, (void*) bookmark);
+        else
+            jassertfalse;
+    }
+};
+#endif
+
 //==============================================================================
 InputStream* URL::createInputStream (const bool usePostCommand,
                                      OpenStreamProgressCallback* const progressCallback,
@@ -506,7 +620,15 @@ InputStream* URL::createInputStream (const bool usePostCommand,
                                      String httpRequestCmd) const
 {
     if (isLocalFile())
+    {
+       #if JUCE_IOS
+        // We may need to refresh the embedded bookmark.
+        return new iOSFileStreamWrapper<FileInputStream> (const_cast<URL&>(*this));
+       #else
         return getLocalFile().createInputStream();
+       #endif
+
+    }
 
     ScopedPointer<WebInputStream> wi (new WebInputStream (*this, usePostCommand));
 
@@ -558,6 +680,29 @@ InputStream* URL::createInputStream (const bool usePostCommand,
     return wi.release();
 }
 
+#if JUCE_ANDROID
+OutputStream* juce_CreateContentURIOutputStream (const URL&);
+#endif
+
+OutputStream* URL::createOutputStream() const
+{
+    if (isLocalFile())
+    {
+       #if JUCE_IOS
+        // We may need to refresh the embedded bookmark.
+        return new iOSFileStreamWrapper<FileOutputStream> (const_cast<URL&> (*this));
+       #else
+        return new FileOutputStream (getLocalFile());
+       #endif
+    }
+
+   #if JUCE_ANDROID
+    return juce_CreateContentURIOutputStream (*this);
+   #else
+    return nullptr;
+   #endif
+}
+
 //==============================================================================
 bool URL::readEntireBinaryStream (MemoryBlock& destData, bool usePostCommand) const
 {

modules/juce_core/network/juce_URL.h

@@ -327,6 +327,13 @@ public:
                                     int numRedirectsToFollow = 5,
                                     String httpRequestCmd = String()) const;
 
+    /** Attempts to open an output stream to a URL for writing
+
+        This method can only be used for certain scheme types such as local files
+        and content:// URIs on Android.
+    */
+    OutputStream* createOutputStream() const;
+
     //==============================================================================
     /** Represents a download task.
         Returned by downloadToFile to allow querying and controling the download task.
@@ -521,6 +528,13 @@ private:
     friend struct ContainerDeletePolicy<Upload>;
     ReferenceCountedArray<Upload> filesToUpload;
 
+  #if JUCE_IOS
+    void* bookmark;
+
+    friend void setURLBookmark (URL&, void*);
+    friend void* getURLBookmark (URL&);
+  #endif
+
     URL (const String&, int);
     void init();
     void addParameter (const String&, const String&);

modules/juce_gui_basics/filebrowser/juce_FileChooser.cpp

@@ -73,7 +73,7 @@ private:
                 result.add (URL (browserComponent.getSelectedFile (i)));
         }
 
-        owner.finished (result, true);
+        owner.finished (result);
     }
 
     //==============================================================================
@@ -137,13 +137,12 @@ bool FileChooser::browseForMultipleFilesOrDirectories (FilePreviewComponent* pre
                        previewComp);
 }
 
-bool FileChooser::browseForFileToSave (const bool warnAboutOverwrite,
-                                       const File& fileWhichShouldBeSaved)
+bool FileChooser::browseForFileToSave (const bool warnAboutOverwrite)
 {
     return showDialog (FileBrowserComponent::saveMode
                         | FileBrowserComponent::canSelectFiles
                         | (warnAboutOverwrite ? FileBrowserComponent::warnAboutOverwriting : 0),
-                       nullptr, fileWhichShouldBeSaved);
+                       nullptr);
 }
 
 bool FileChooser::browseForDirectory()
@@ -153,11 +152,8 @@ bool FileChooser::browseForDirectory()
                        nullptr);
 }
 
-bool FileChooser::showDialog (const int flags, FilePreviewComponent* const previewComp,
-                              const File& fileWhichShouldBeSaved)
+bool FileChooser::showDialog (const int flags, FilePreviewComponent* const previewComp)
 {
-    fileToSave = (flags & FileBrowserComponent::saveMode) != 0 ? fileWhichShouldBeSaved : File();
-
     FocusRestorer focusRestorer;
 
     pimpl = createPimpl (flags, previewComp);
@@ -171,8 +167,7 @@ bool FileChooser::showDialog (const int flags, FilePreviewComponent* const previ
 #endif
 
 void FileChooser::launchAsync (int flags, std::function<void (const FileChooser&)> callback,
-                               FilePreviewComponent* previewComp,
-                               const File& fileWhichShouldBeSaved)
+                               FilePreviewComponent* previewComp)
 {
     // You must specify a callback when using launchAsync
     jassert (callback);
@@ -180,8 +175,6 @@ void FileChooser::launchAsync (int flags, std::function<void (const FileChooser&
     // you cannot run two file chooser dialog boxes at the same time
     jassert (asyncCallback == nullptr);
 
-    fileToSave = (flags & FileBrowserComponent::saveMode) != 0 ? fileWhichShouldBeSaved : File();
-
     asyncCallback = static_cast<std::function<void (const FileChooser&)>&&> (callback);
 
     pimpl = createPimpl (flags, previewComp);
@@ -256,30 +249,13 @@ URL FileChooser::getURLResult() const
     return results.getFirst();
 }
 
-void FileChooser::finished (const Array<URL>& asyncResults, bool shouldMove)
+void FileChooser::finished (const Array<URL>& asyncResults)
 {
      std::function<void (const FileChooser&)> callback;
      std::swap (callback, asyncCallback);
 
      results = asyncResults;
 
-     if (shouldMove && fileToSave.existsAsFile())
-     {
-         if (results.size() > 0)
-         {
-             // The user either selected multiple files or wants to save the file to a URL
-             // Both are not supported
-             jassert (results.size() == 1 && results.getReference (0).isLocalFile());
-
-             if (! fileToSave.moveFileTo (results.getReference (0).getLocalFile()))
-                 results.clear();
-         }
-         else
-         {
-             fileToSave.deleteFile();
-         }
-     }
-
      pimpl = nullptr;
 
      if (callback)

modules/juce_gui_basics/filebrowser/juce_FileChooser.h

@@ -66,8 +66,27 @@ public:
         @param initialFileOrDirectory         the file or directory that should be selected
                                               when the dialog box opens. If this parameter is
                                               set to File(), a sensible default directory will
-                                              be used instead. This parameter is ignored for native
-                                              iOS file choosers.
+                                              be used instead.
+
+                                              Note: on iOS when saving a file, a user will not
+                                              be able to change a file name, so it may be a good
+                                              idea to include at list a valid file name in
+                                              initialFileOrDirectory. When no filename is found,
+                                              "Untitled" will be used.
+
+                                              Also, if you pass an already existing file on iOS,
+                                              that file will be automatically copied to the
+                                              destination chosen by user and if it can be previewed,
+                                              its preview will be presented in the dialog too. You
+                                              will still be able to write into this file copy, since
+                                              its URL will be returned by getURLResult(). This can be
+                                              useful when you want to save e.g. an image, so that
+                                              you can pass a (temporary) file with low quality
+                                              preview and after the user picks the destination,
+                                              you can write a high quality image into the copied
+                                              file. If you create such a temporary file, you need
+                                              to delete it yourself, once it is not needed anymore.
+
         @param filePatternsAllowed            a set of file patterns to specify which files
                                               can be selected - each pattern should be
                                               separated by a comma or semi-colon, e.g. "*" or
@@ -123,22 +142,12 @@ public:
         @param warnAboutOverwritingExistingFiles     if true, the dialog box will ask
                     the user if they're sure they want to overwrite a file that already
                     exists
-        @param fileWhichShouldBeSaved     if this parameter is specified, then, if the the user
-                    selects a valid location to save the file, fileWhichShouldBeSaved will
-                    automaitcally be moved to the location selected by the user when the user
-                    clicks 'ok'. If you do not specify this parameter, then it is your
-                    responsibility to save your file at the location that is returned from this
-                    file chooser. Typically, when using this parameter, you already write the
-                    file you wish to save to a temporary location and then supply the path to
-                    this file to this parameter. This parameter is required on iOS when using
-                    native file save dialogs but can be used on all other platforms.
         @returns    true if the user chose a file and pressed 'ok', in which case, use
                     the getResult() method to find out what the file was. Returns false
                     if they cancelled instead.
         @see browseForFileToOpen, browseForDirectory
     */
-    bool browseForFileToSave (bool warnAboutOverwritingExistingFiles,
-                              const File& fileWhichShouldBeSaved = File());
+    bool browseForFileToSave (bool warnAboutOverwritingExistingFiles);
 
     /** Shows a dialog box to choose a directory.
 
@@ -163,24 +172,12 @@ public:
     /** Runs a dialog box for the given set of option flags.
         The flag values used are those in FileBrowserComponent::FileChooserFlags.
 
-        @param fileWhichShouldBeSaved     if this parameter is specified and saveMode is
-                    specified, then, if the the user selects a valid location to save the file,
-                    fileWhichShouldBeSaved will automaitcally be moved to the location selected
-                    by the user when the user clicks 'ok'. If you do not specify this parameter,
-                    then it is your responsibility to save your file at the location that is
-                    returned from this file chooser. Typically, when using this parameter,
-                    you already write the file you wish to save to a temporary location and
-                    then supply the path to this file to this parameter. This parameter is
-                    required on iOS when using native file save dialogs but can be used on all
-                    other platforms.
-
         @returns    true if the user chose a directory and pressed 'ok', in which case, use
                     the getResult() method to find out what they chose. Returns false
                     if they cancelled instead.
         @see FileBrowserComponent::FileChooserFlags
     */
-    bool showDialog (int flags, FilePreviewComponent* previewComponent,
-                     const File& fileWhichShouldBeSaved = File());
+    bool showDialog (int flags, FilePreviewComponent* previewComponent);
 
     /** Use this method to launch the file browser window asynchronously.
 
@@ -196,22 +193,10 @@ public:
 
         You must ensure that the lifetime of the callback object is longer than
         the lifetime of the file-chooser.
-
-        @param fileWhichShouldBeSaved     if this parameter is specified and saveMode is
-                    specified, then, if the the user selects a valid location to save the file,
-                    fileWhichShouldBeSaved will automaitcally be moved to the location selected
-                    by the user when the user clicks 'ok'. If you do not specify this parameter,
-                    then it is your responsibility to save your file at the location that is
-                    returned from this file chooser. Typically, when using this parameter,
-                    you already write the file you wish to save to a temporary location and
-                    then supply the path to this file to this parameter. This parameter is
-                    required on iOS when using native file save dialogs but can be used on all
-                    other platforms.
     */
     void launchAsync (int flags,
                       std::function<void (const FileChooser&)>,
-                      FilePreviewComponent* previewComponent = nullptr,
-                      const File& fileWhichShouldBeSaved = File());
+                      FilePreviewComponent* previewComponent = nullptr);
 
     //==============================================================================
     /** Returns the last file that was chosen by one of the browseFor methods.
@@ -252,6 +237,10 @@ public:
         may return a URL to a remote document. If a local file is chosen then you can
         convert this file to a JUCE File class via the URL::getLocalFile method.
 
+        Note: on iOS it is best to dispose any copies of returned URL as soon as
+        you finish dealing with the file. This is because URL might be security
+        scoped and a system allows only for a limited number of such URLs.
+
         @see getResult, URL::getLocalFile
     */
     URL getURLResult() const;
@@ -266,6 +255,10 @@ public:
         This array may be empty if no files were chosen, or can contain multiple entries
         if multiple files were chosen.
 
+        Note: on iOS it is best to dispose any copies of returned URLs as soon as
+        you finish dealing with the file. This is because URLs might be security
+        scoped and a system allows only for a limited number of such URLs.
+
         @see getResults, URL::getLocalFile
     */
     const Array<URL>& getURLResults() const noexcept      { return results; }
@@ -288,14 +281,14 @@ public:
 private:
     //==============================================================================
     String title, filters;
-    File startingFile, fileToSave;
+    File startingFile;
     Array<URL> results;
     const bool useNativeDialogBox;
     const bool treatFilePackagesAsDirs;
     std::function<void (const FileChooser&)> asyncCallback;
 
     //==============================================================================
-    void finished (const Array<URL>&, bool);
+    void finished (const Array<URL>&);
 
     //==============================================================================
     struct Pimpl
@@ -303,7 +296,7 @@ private:
         virtual ~Pimpl() {}
 
         virtual void launch()     = 0;
-        virtual void runModally()                                            = 0;
+        virtual void runModally() = 0;
     };
 
     ScopedPointer<Pimpl> pimpl;

modules/juce_gui_basics/native/juce_android_FileChooser.cpp

@@ -109,7 +109,7 @@ public:
                         {
                             env->SetObjectArrayElement (jMimeTypes.get(), i, javaString (mimeTypes[i]).get());
 
-                            if (mimeGroup != mimeTypes[0].upToFirstOccurrenceOf ("/", false, false))
+                            if (mimeGroup != mimeTypes[i].upToFirstOccurrenceOf ("/", false, false))
                                 allMimeTypesHaveSameGroup = false;
                         }
 
@@ -168,7 +168,7 @@ public:
             }
         }
 
-        owner.finished (chosenURLs, true);
+        owner.finished (chosenURLs);
     }
 
     static Native* currentFileChooser;

modules/juce_gui_basics/native/juce_ios_FileChooser.mm

@@ -28,8 +28,8 @@ namespace juce
 {
 
 //==============================================================================
-template <> struct ContainerDeletePolicy<UIDocumentPickerViewController>                   { static void destroy (NSObject* o) { [o release]; } };
-template <> struct ContainerDeletePolicy<NSObject<UIDocumentPickerDelegate>>               { static void destroy (NSObject* o) { [o release]; } };
+template <> struct ContainerDeletePolicy<UIDocumentPickerViewController>     { static void destroy (NSObject* o) { [o release]; } };
+template <> struct ContainerDeletePolicy<NSObject<UIDocumentPickerDelegate>> { static void destroy (NSObject* o) { [o release]; } };
 
 class FileChooser::Native    : private Component, public FileChooser::Pimpl
 {
@@ -37,32 +37,54 @@ public:
     Native (FileChooser& fileChooser, int flags)
         : owner (fileChooser)
     {
+        String firstFileExtension;
+
         static FileChooserDelegateClass cls;
         delegate = [cls.createInstance() init];
         FileChooserDelegateClass::setOwner (delegate, this);
 
-        auto utTypeArray = createNSArrayFromStringArray (getUTTypesForWildcards (owner.filters));
+        auto utTypeArray = createNSArrayFromStringArray (getUTTypesForWildcards (owner.filters, firstFileExtension));
 
         if ((flags & FileBrowserComponent::saveMode) != 0)
         {
-            // You must specify the fileWhichShouldBeSaved parameter when using
-            // the native save dialog on iOS!
-            jassert (owner.fileToSave.existsAsFile());
+            auto currentFileOrDirectory = owner.startingFile;
+
+            UIDocumentPickerMode pickerMode = currentFileOrDirectory.existsAsFile()
+                                            ? UIDocumentPickerModeExportToService
+                                            : UIDocumentPickerModeMoveToService;
 
-            auto url = [[NSURL alloc] initFileURLWithPath:juceStringToNS (owner.fileToSave.getFullPathName())];
+            if (! currentFileOrDirectory.existsAsFile())
+            {
+                auto filename = getFilename (currentFileOrDirectory, firstFileExtension);
+                auto tmpDirectory = File::createTempFile ("JUCE-filepath");
+
+                if (tmpDirectory.createDirectory().wasOk())
+                {
+                    currentFileOrDirectory = tmpDirectory.getChildFile (filename);
+                    currentFileOrDirectory.replaceWithText ("");
+                }
+                else
+                {
+                    // Temporary directory creation failed! You need to specify a
+                    // path you have write access to. Saving will not work for
+                    // current path.
+                    jassertfalse;
+                }
+            }
 
-            controller = [[UIDocumentPickerViewController alloc] initWithURL:url
-                                                                      inMode:UIDocumentPickerModeExportToService];
+            auto url = [[NSURL alloc] initFileURLWithPath: juceStringToNS (currentFileOrDirectory.getFullPathName())];
+            controller = [[UIDocumentPickerViewController alloc] initWithURL: url
+                                                                      inMode: pickerMode];
             [url release];
         }
         else
         {
-            controller = [[UIDocumentPickerViewController alloc] initWithDocumentTypes:utTypeArray
-                                                                                inMode:UIDocumentPickerModeOpen];
+            controller = [[UIDocumentPickerViewController alloc] initWithDocumentTypes: utTypeArray
+                                                                                inMode: UIDocumentPickerModeOpen];
         }
 
-        [controller setDelegate:delegate];
-        [controller setModalTransitionStyle:UIModalTransitionStyleCrossDissolve];
+        [controller setDelegate: delegate];
+        [controller setModalTransitionStyle: UIModalTransitionStyleCrossDissolve];
 
         setOpaque (false);
 
@@ -101,7 +123,7 @@ private:
             peer = newPeer;
 
             if (auto* parentController = peer->controller)
-                [parentController showViewController:controller sender:parentController];
+                [parentController showViewController: controller sender: parentController];
 
             if (peer->view.window != nil)
                 peer->view.window.autoresizesSubviews = YES;
@@ -109,11 +131,13 @@ private:
     }
 
     //==============================================================================
-    static StringArray getUTTypesForWildcards (const String& filterWildcards)
+    static StringArray getUTTypesForWildcards (const String& filterWildcards, String& firstExtension)
     {
         auto filters = StringArray::fromTokens (filterWildcards, ";", "");
         StringArray result;
 
+        firstExtension = {};
+
         if (! filters.contains ("*") && filters.size() > 0)
         {
             for (auto filter : filters)
@@ -124,6 +148,9 @@ private:
                 auto fileExtension = filter.fromLastOccurrenceOf (".", false, false);
                 auto fileExtensionCF = fileExtension.toCFString();
 
+                if (firstExtension.isEmpty())
+                    firstExtension = fileExtension;
+
                 auto tag = UTTypeCreatePreferredIdentifierForTag (kUTTagClassFilenameExtension, fileExtensionCF, nullptr);
 
                 if (tag != nullptr)
@@ -141,21 +168,87 @@ private:
         return result;
     }
 
+    static String getFilename (const File& path, const String& fallbackExtension)
+    {
+        auto filename  = path.getFileNameWithoutExtension();
+        auto extension = path.getFileExtension().substring (1);
+
+        if (filename.isEmpty())
+            filename = "Untitled";
+
+        if (extension.isEmpty())
+            extension = fallbackExtension;
+
+        if (extension.isNotEmpty())
+            filename += String (".") + extension;
+
+        return filename;
+    }
+
     //==============================================================================
     void didPickDocumentAtURL (NSURL* url)
     {
-        Array<URL> chooserResults;
-        chooserResults.add (URL (nsStringToJuce ([url absoluteString])));
+        bool isWriting = controller.get().documentPickerMode == UIDocumentPickerModeExportToService
+                       | controller.get().documentPickerMode == UIDocumentPickerModeMoveToService;
+
+        NSUInteger accessOptions = isWriting ? 0 : NSFileCoordinatorReadingWithoutChanges;
+
+        auto* fileAccessIntent = isWriting
+                               ? [NSFileAccessIntent writingIntentWithURL: url options: accessOptions]
+                               : [NSFileAccessIntent readingIntentWithURL: url options: accessOptions];
+
+        NSArray<NSFileAccessIntent*>* intents = @[fileAccessIntent];
+
+        auto* fileCoordinator = [[NSFileCoordinator alloc] initWithFilePresenter: nil];
+
+        [fileCoordinator coordinateAccessWithIntents: intents queue: [NSOperationQueue mainQueue] byAccessor: ^(NSError* err)
+        {
+            Array<URL> chooserResults;
+
+            if (err == nil)
+            {
+                [url startAccessingSecurityScopedResource];
+
+                NSError* error = nil;
+
+                NSData* bookmark = [url bookmarkDataWithOptions: 0
+                                 includingResourceValuesForKeys: nil
+                                                  relativeToURL: nil
+                                                          error: &error];
+
+                [url stopAccessingSecurityScopedResource];
+
+                URL juceUrl (nsStringToJuce ([url absoluteString]));
+
+                if (error == nil)
+                {
+                    setURLBookmark (juceUrl, (void*) bookmark);
+                }
+                else
+                {
+                    auto* desc = [error localizedDescription];
+                    ignoreUnused (desc);
+                    jassertfalse;
+                }
+
+                chooserResults.add (juceUrl);
+            }
+            else
+            {
+                auto* desc = [err localizedDescription];
+                ignoreUnused (desc);
+                jassertfalse;
+            }
 
-        owner.finished (chooserResults, false);
-        exitModalState (1);
+            owner.finished (chooserResults);
+        }];
     }
 
     void pickerWasCancelled()
     {
         Array<URL> chooserResults;
 
-        owner.finished (chooserResults, false);
+        owner.finished (chooserResults);
         exitModalState (0);
     }
 
@@ -174,7 +267,7 @@ private:
             registerClass();
         }
 
-        static void setOwner (id self, Native* owner)   { object_setInstanceVariable         (self, "owner", owner); }
+        static void setOwner (id self, Native* owner)   { object_setInstanceVariable (self, "owner", owner); }
         static Native* getOwner (id self)               { return getIvar<Native*> (self, "owner"); }
 
         //==============================================================================

modules/juce_gui_basics/native/juce_linux_FileChooser.cpp

@@ -122,7 +122,7 @@ private:
         if (! shouldKill)
         {
             child.waitForProcessToFinish (60 * 1000);
-            owner.finished (selection, true);
+            owner.finished (selection);
         }
     }
 

modules/juce_gui_basics/native/juce_mac_FileChooser.mm

@@ -213,7 +213,7 @@ private:
             }
         }
 
-        owner.finished (chooserResults, true);
+        owner.finished (chooserResults);
     }
 
     bool shouldShowFilename (const String& filenameToTest)

modules/juce_gui_basics/native/juce_win32_FileChooser.cpp

@@ -535,7 +535,7 @@ public:
                         [safeThis] (int)
                         {
                             if (safeThis != nullptr)
-                                safeThis->owner.finished (safeThis->nativeFileChooser->results, true);
+                                safeThis->owner.finished (safeThis->nativeFileChooser->results);
                         }));
 
         nativeFileChooser->open (true);
@@ -548,7 +548,7 @@ public:
         exitModalState (nativeFileChooser->results.size() > 0 ? 1 : 0);
         nativeFileChooser->cancel();
 
-        owner.finished (nativeFileChooser->results, true);
+        owner.finished (nativeFileChooser->results);
     }
 
 private: