JUCE/modules/juce_gui_basics/native/juce_android_FileChooser.cpp

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

   This file is part of the JUCE 6 technical preview.
   Copyright (c) 2020 - Raw Material Software Limited

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

   For this technical preview, this file is not subject to commercial licensing.

   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
{

class FileChooser::Native     : public FileChooser::Pimpl
{
public:
    //==============================================================================
    Native (FileChooser& fileChooser, int flags)    : owner (fileChooser)
    {
        if (currentFileChooser == nullptr)
        {
            currentFileChooser = this;
            auto* env = getEnv();

            auto sdkVersion         = getAndroidSDKVersion();
            auto saveMode           = ((flags & FileBrowserComponent::saveMode) != 0);
            auto selectsDirectories = ((flags & FileBrowserComponent::canSelectDirectories) != 0);

            // You cannot save a directory
            jassert (! (saveMode && selectsDirectories));

            if (sdkVersion < 19)
            {
                // native save dialogs are only supported in Android versions >= 19
                jassert (! saveMode);
                saveMode = false;
            }

            if (sdkVersion < 21)
            {
                // native directory chooser dialogs are only supported in Android versions >= 21
                jassert (! selectsDirectories);
                selectsDirectories = false;
            }

            const char* action = (selectsDirectories ? "android.intent.action.OPEN_DOCUMENT_TREE"
                                                     : (saveMode ? "android.intent.action.CREATE_DOCUMENT"
                                                     : (sdkVersion >= 19 ? "android.intent.action.OPEN_DOCUMENT"
                                                     : "android.intent.action.GET_CONTENT")));


            intent = GlobalRef (LocalRef<jobject> (env->NewObject (AndroidIntent, AndroidIntent.constructWithString,
                                                                   javaString (action).get())));

            if (owner.startingFile != File())
            {
                if (saveMode && (! owner.startingFile.isDirectory()))
                    env->CallObjectMethod (intent.get(), AndroidIntent.putExtraString,
                                           javaString ("android.intent.extra.TITLE").get(),
                                           javaString (owner.startingFile.getFileName()).get());


                URL url (owner.startingFile);
                LocalRef<jobject> uri (env->CallStaticObjectMethod (AndroidUri, AndroidUri.parse,
                                                                    javaString (url.toString (true)).get()));

                if (uri)
                    env->CallObjectMethod (intent.get(), AndroidIntent.putExtraParcelable,
                                           javaString ("android.provider.extra.INITIAL_URI").get(),
                                           uri.get());
            }


            if (! selectsDirectories)
            {
                env->CallObjectMethod (intent.get(), AndroidIntent.addCategory,
                                       javaString ("android.intent.category.OPENABLE").get());

                auto mimeTypes = convertFiltersToMimeTypes (owner.filters);

                if (mimeTypes.size() == 1)
                {
                    env->CallObjectMethod (intent.get(), AndroidIntent.setType, javaString (mimeTypes[0]).get());
                }
                else
                {
                    String mimeGroup = "*";

                    if (mimeTypes.size() > 0)
                    {
                        mimeGroup = mimeTypes[0].upToFirstOccurrenceOf ("/", false, false);
                        auto allMimeTypesHaveSameGroup = true;

                        LocalRef<jobjectArray> jMimeTypes (env->NewObjectArray (mimeTypes.size(), JavaString,
                                                                                javaString("").get()));

                        for (int i = 0; i < mimeTypes.size(); ++i)
                        {
                            env->SetObjectArrayElement (jMimeTypes.get(), i, javaString (mimeTypes[i]).get());

                            if (mimeGroup != mimeTypes[i].upToFirstOccurrenceOf ("/", false, false))
                                allMimeTypesHaveSameGroup = false;
                        }

                        env->CallObjectMethod (intent.get(), AndroidIntent.putExtraStrings,
                                               javaString ("android.intent.extra.MIME_TYPES").get(),
                                               jMimeTypes.get());

                        if (! allMimeTypesHaveSameGroup)
                            mimeGroup = "*";
                    }

                    env->CallObjectMethod (intent.get(), AndroidIntent.setType, javaString (mimeGroup + "/*").get());
                }
            }
        }
        else
            jassertfalse; // there can only be a single file chooser
    }

    ~Native() override
    {
        masterReference.clear();
        currentFileChooser = nullptr;
    }

    void runModally() override
    {
        // Android does not support modal file choosers
        jassertfalse;
    }

    void launch() override
    {
        auto* env = getEnv();

        if (currentFileChooser != nullptr)
        {
            WeakReference<Native> myself (this);

            startAndroidActivityForResult (LocalRef<jobject> (env->NewLocalRef (intent.get())), /*READ_REQUEST_CODE*/ 42,
                                           [myself] (int requestCode, int resultCode, LocalRef<jobject> intentData) mutable
                                           {
                                               if (myself != nullptr)
                                                   myself->onActivityResult (requestCode, resultCode, intentData);
                                           });
        }
        else
        {
            jassertfalse; // There is already a file chooser running
        }
    }

    void onActivityResult (int /*requestCode*/, int resultCode, const LocalRef<jobject>& intentData)
    {
        currentFileChooser = nullptr;
        auto* env = getEnv();

        Array<URL> chosenURLs;

        if (resultCode == /*Activity.RESULT_OK*/ -1 && intentData != nullptr)
        {
            LocalRef<jobject> uri (env->CallObjectMethod (intentData.get(), AndroidIntent.getData));

            if (uri != nullptr)
            {
                auto jStr = (jstring) env->CallObjectMethod (uri, JavaObject.toString);

                if (jStr != nullptr)
                    chosenURLs.add (URL (juceString (env, jStr)));
            }
        }

        owner.finished (chosenURLs);
    }

    static Native* currentFileChooser;

    static StringArray convertFiltersToMimeTypes (const String& fileFilters)
    {
        StringArray result;
        auto wildcards = StringArray::fromTokens (fileFilters, ";", "");

        for (auto wildcard : wildcards)
        {
            if (wildcard.upToLastOccurrenceOf (".", false, false) == "*")
            {
                auto extension = wildcard.fromLastOccurrenceOf (".", false, false);

                result.addArray (getMimeTypesForFileExtension (extension));
            }
        }

        result.removeDuplicates (false);
        return result;
    }

private:
    JUCE_DECLARE_WEAK_REFERENCEABLE (Native)

    FileChooser& owner;
    GlobalRef intent;
};

FileChooser::Native* FileChooser::Native::currentFileChooser = nullptr;

FileChooser::Pimpl* FileChooser::showPlatformDialog (FileChooser& owner, int flags,
                                                     FilePreviewComponent*)
{
    if (FileChooser::Native::currentFileChooser == nullptr)
        return new FileChooser::Native (owner, flags);

    // there can only be one file chooser on Android at a once
    jassertfalse;
    return nullptr;
}

bool FileChooser::isPlatformDialogAvailable()
{
   #if JUCE_DISABLE_NATIVE_FILECHOOSERS
    return false;
   #else
    return true;
   #endif
}

} // namespace juce