JUCE/modules/juce_gui_basics/native/juce_ios_FileChooser.mm

/*
  ==============================================================================

   This file is part of the JUCE library.
   Copyright (c) 2017 - ROLI Ltd.

   JUCE is an open source library subject to commercial or open-source
   licensing.

   By using JUCE, you agree to the terms of both the JUCE 5 End-User License
   Agreement and JUCE 5 Privacy Policy (both updated and effective as of the
   27th April 2017).

   End User License Agreement: www.juce.com/juce-5-licence
   Privacy Policy: www.juce.com/juce-5-privacy-policy

   Or: You may also use this code under the terms of the GPL v3 (see
   www.gnu.org/licenses).

   JUCE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL WARRANTIES, WHETHER
   EXPRESSED OR IMPLIED, INCLUDING MERCHANTABILITY AND FITNESS FOR PURPOSE, ARE
   DISCLAIMED.

  ==============================================================================
*/

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]; } };

class FileChooser::Native    : private Component, public FileChooser::Pimpl
{
public:
    Native (FileChooser& fileChooser, int flags)
        : owner (fileChooser)
    {
        static FileChooserDelegateClass cls;
        delegate = [cls.createInstance() init];
        FileChooserDelegateClass::setOwner (delegate, this);

        auto utTypeArray = createNSArrayFromStringArray (getUTTypesForWildcards (owner.filters));

        if ((flags & FileBrowserComponent::saveMode) != 0)
        {
            // You must specify the fileWhichShouldBeSaved parameter when using
            // the native save dialog on iOS!
            jassert (owner.fileToSave.existsAsFile());

            auto url = [[NSURL alloc] initFileURLWithPath:juceStringToNS (owner.fileToSave.getFullPathName())];

            controller = [[UIDocumentPickerViewController alloc] initWithURL:url
                                                                      inMode:UIDocumentPickerModeExportToService];
            [url release];
        }
        else
        {
            controller = [[UIDocumentPickerViewController alloc] initWithDocumentTypes:utTypeArray
                                                                                inMode:UIDocumentPickerModeOpen];
        }

        [controller setDelegate:delegate];
        [controller setModalTransitionStyle:UIModalTransitionStyleCrossDissolve];

        setOpaque (false);

        auto chooserBounds = Desktop::getInstance().getDisplays().getMainDisplay().userArea;
        setBounds (chooserBounds);

        setAlwaysOnTop (true);
        addToDesktop (0);
    }

    ~Native()
    {
        exitModalState (0);
    }

    void launch() override
    {
        enterModalState (true, nullptr, true);
    }

    void runModally() override
    {
       #if JUCE_MODAL_LOOPS_PERMITTED
        runModalLoop();
       #endif
    }

private:
    //==============================================================================
    void parentHierarchyChanged() override
    {
        auto* newPeer = dynamic_cast<UIViewComponentPeer*> (getPeer());

        if (peer != newPeer)
        {
            peer = newPeer;

            if (auto* parentController = peer->controller)
                [parentController showViewController:controller sender:parentController];

            if (peer->view.window != nil)
                peer->view.window.autoresizesSubviews = YES;
        }
    }

    //==============================================================================
    static StringArray getUTTypesForWildcards (const String& filterWildcards)
    {
        auto filters = StringArray::fromTokens (filterWildcards, ";", "");
        StringArray result;

        if (! filters.contains ("*") && filters.size() > 0)
        {
            for (auto filter : filters)
            {
                // iOS only supports file extension wild cards
                jassert (filter.upToLastOccurrenceOf (".", true, false) == "*.");

                auto fileExtension = filter.fromLastOccurrenceOf (".", false, false);
                auto fileExtensionCF = fileExtension.toCFString();

                auto tag = UTTypeCreatePreferredIdentifierForTag (kUTTagClassFilenameExtension, fileExtensionCF, nullptr);

                if (tag != nullptr)
                {
                    result.add (String::fromCFString (tag));
                    CFRelease (tag);
                }

                CFRelease (fileExtensionCF);
            }
        }
        else
            result.add ("public.data");

        return result;
    }

    //==============================================================================
    void didPickDocumentAtURL (NSURL* url)
    {
        Array<URL> chooserResults;
        chooserResults.add (URL (nsStringToJuce ([url absoluteString])));

        owner.finished (chooserResults, false);
        exitModalState (1);
    }

    void pickerWasCancelled()
    {
        Array<URL> chooserResults;

        owner.finished (chooserResults, false);
        exitModalState (0);
    }

    //==============================================================================
    struct FileChooserDelegateClass  : public ObjCClass<NSObject<UIDocumentPickerDelegate>>
    {
        FileChooserDelegateClass()  : ObjCClass<NSObject<UIDocumentPickerDelegate>> ("FileChooserDelegate_")
        {
            addIvar<Native*> ("owner");

            addMethod (@selector (documentPicker:didPickDocumentAtURL:), didPickDocumentAtURL,       "v@:@@");
            addMethod (@selector (documentPickerWasCancelled:),          documentPickerWasCancelled, "v@:@");

            addProtocol (@protocol (UIDocumentPickerDelegate));

            registerClass();
        }

        static void setOwner (id self, Native* owner)   { object_setInstanceVariable         (self, "owner", owner); }
        static Native* getOwner (id self)               { return getIvar<Native*> (self, "owner"); }

        //==============================================================================
        static void didPickDocumentAtURL (id self, SEL, UIDocumentPickerViewController*, NSURL* url)
        {
            auto picker = getOwner (self);

            if (picker != nullptr)
                picker->didPickDocumentAtURL (url);
        }

        static void documentPickerWasCancelled (id self, SEL, UIDocumentPickerViewController*)
        {
            auto picker = getOwner (self);

            if (picker != nullptr)
                picker->pickerWasCancelled();
        }
    };

    //==============================================================================
    FileChooser& owner;
    ScopedPointer<NSObject<UIDocumentPickerDelegate>> delegate;
    ScopedPointer<UIDocumentPickerViewController> controller;
    UIViewComponentPeer* peer = nullptr;

    static FileChooserDelegateClass fileChooserDelegateClass;

    //==============================================================================
    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (Native)
};

//==============================================================================
bool FileChooser::isPlatformDialogAvailable()
{
   #if JUCE_DISABLE_NATIVE_FILECHOOSERS
    return false;
   #else
    return [[NSFileManager defaultManager] ubiquityIdentityToken] != nil;
   #endif
}

FileChooser::Pimpl* FileChooser::showPlatformDialog (FileChooser& owner, int flags,
                                                     FilePreviewComponent*)
{
    return new FileChooser::Native (owner, flags);
}

} // namespace juce