JUCE/modules/juce_gui_basics/filebrowser/juce_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::NonNative    : public FileChooser::Pimpl
{
public:
    NonNative (FileChooser& fileChooser, int flags, FilePreviewComponent* preview)
        : owner (fileChooser),
          selectsDirectories ((flags & FileBrowserComponent::canSelectDirectories)   != 0),
          selectsFiles       ((flags & FileBrowserComponent::canSelectFiles)         != 0),
          warnAboutOverwrite ((flags & FileBrowserComponent::warnAboutOverwriting)   != 0),

          filter (selectsFiles ? owner.filters : String(), selectsDirectories ? "*" : String(), {}),
          browserComponent (flags, owner.startingFile, &filter, preview),
          dialogBox (owner.title, {}, browserComponent, warnAboutOverwrite,
                     browserComponent.findColour (AlertWindow::backgroundColourId), owner.parent)
    {}

    ~NonNative() override
    {
        dialogBox.exitModalState (0);
    }

    void launch() override
    {
        dialogBox.centreWithDefaultSize (nullptr);
        dialogBox.enterModalState (true, ModalCallbackFunction::create ([this] (int r) { modalStateFinished (r); }), true);
    }

    void runModally() override
    {
       #if JUCE_MODAL_LOOPS_PERMITTED
        modalStateFinished (dialogBox.show() ? 1 : 0);
       #else
        jassertfalse;
       #endif
    }

private:
    void modalStateFinished (int returnValue)
    {
        Array<URL> result;

        if (returnValue != 0)
        {
            for (int i = 0; i < browserComponent.getNumSelectedFiles(); ++i)
                result.add (URL (browserComponent.getSelectedFile (i)));
        }

        owner.finished (result);
    }

    //==============================================================================
    FileChooser& owner;
    bool selectsDirectories, selectsFiles, warnAboutOverwrite;

    WildcardFileFilter filter;
    FileBrowserComponent browserComponent;
    FileChooserDialogBox dialogBox;

    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (NonNative)
};

//==============================================================================
FileChooser::FileChooser (const String& chooserBoxTitle,
                          const File& currentFileOrDirectory,
                          const String& fileFilters,
                          const bool useNativeBox,
                          const bool treatFilePackagesAsDirectories,
                          Component* parentComponentToUse)
    : title (chooserBoxTitle),
      filters (fileFilters),
      startingFile (currentFileOrDirectory),
      parent (parentComponentToUse),
      useNativeDialogBox (useNativeBox && isPlatformDialogAvailable()),
      treatFilePackagesAsDirs (treatFilePackagesAsDirectories)
{
   #ifndef JUCE_MAC
    ignoreUnused (treatFilePackagesAsDirs);
   #endif

    if (! fileFilters.containsNonWhitespaceChars())
        filters = "*";
}

FileChooser::~FileChooser()
{
    asyncCallback = nullptr;
}

#if JUCE_MODAL_LOOPS_PERMITTED
bool FileChooser::browseForFileToOpen (FilePreviewComponent* previewComp)
{
    return showDialog (FileBrowserComponent::openMode
                        | FileBrowserComponent::canSelectFiles,
                       previewComp);
}

bool FileChooser::browseForMultipleFilesToOpen (FilePreviewComponent* previewComp)
{
    return showDialog (FileBrowserComponent::openMode
                        | FileBrowserComponent::canSelectFiles
                        | FileBrowserComponent::canSelectMultipleItems,
                       previewComp);
}

bool FileChooser::browseForMultipleFilesOrDirectories (FilePreviewComponent* previewComp)
{
    return showDialog (FileBrowserComponent::openMode
                        | FileBrowserComponent::canSelectFiles
                        | FileBrowserComponent::canSelectDirectories
                        | FileBrowserComponent::canSelectMultipleItems,
                       previewComp);
}

bool FileChooser::browseForFileToSave (const bool warnAboutOverwrite)
{
    return showDialog (FileBrowserComponent::saveMode
                        | FileBrowserComponent::canSelectFiles
                        | (warnAboutOverwrite ? FileBrowserComponent::warnAboutOverwriting : 0),
                       nullptr);
}

bool FileChooser::browseForDirectory()
{
    return showDialog (FileBrowserComponent::openMode
                        | FileBrowserComponent::canSelectDirectories,
                       nullptr);
}

bool FileChooser::showDialog (const int flags, FilePreviewComponent* const previewComp)
{
    FocusRestorer focusRestorer;

    pimpl.reset (createPimpl (flags, previewComp));
    pimpl->runModally();

    // ensure that the finished function was invoked
    jassert (pimpl == nullptr);

    return (results.size() > 0);
}
#endif

void FileChooser::launchAsync (int flags, std::function<void(const FileChooser&)> callback,
                               FilePreviewComponent* previewComp)
{
    // You must specify a callback when using launchAsync
    jassert (callback);

    // you cannot run two file chooser dialog boxes at the same time
    jassert (asyncCallback == nullptr);

    asyncCallback = std::move (callback);

    pimpl.reset (createPimpl (flags, previewComp));
    pimpl->launch();
}


FileChooser::Pimpl* FileChooser::createPimpl (int flags, FilePreviewComponent* previewComp)
{
    results.clear();

    // the preview component needs to be the right size before you pass it in here..
    jassert (previewComp == nullptr || (previewComp->getWidth() > 10
                                         && previewComp->getHeight() > 10));

    if (pimpl != nullptr)
    {
        // you cannot run two file chooser dialog boxes at the same time
        jassertfalse;
        pimpl.reset();
    }

    // You've set the flags for both saveMode and openMode!
    jassert (! (((flags & FileBrowserComponent::saveMode) != 0)
                && ((flags & FileBrowserComponent::openMode) != 0)));

   #if JUCE_WINDOWS
    const bool selectsFiles       = (flags & FileBrowserComponent::canSelectFiles) != 0;
    const bool selectsDirectories = (flags & FileBrowserComponent::canSelectDirectories) != 0;

    if (useNativeDialogBox && ! (selectsFiles && selectsDirectories))
   #else
    if (useNativeDialogBox)
   #endif
    {
        return showPlatformDialog (*this, flags, previewComp);
    }
    else
    {
        return new NonNative (*this, flags, previewComp);
    }
}

Array<File> FileChooser::getResults() const noexcept
{
    Array<File> files;

    for (auto url : getURLResults())
        if (url.isLocalFile())
            files.add (url.getLocalFile());

    return files;
}

File FileChooser::getResult() const
{
    auto fileResults = getResults();

    // if you've used a multiple-file select, you should use the getResults() method
    // to retrieve all the files that were chosen.
    jassert (fileResults.size() <= 1);

    return fileResults.getFirst();
}

URL FileChooser::getURLResult() const
{
    // if you've used a multiple-file select, you should use the getResults() method
    // to retrieve all the files that were chosen.
    jassert (results.size() <= 1);

    return results.getFirst();
}

void FileChooser::finished (const Array<URL>& asyncResults)
{
     std::function<void(const FileChooser&)> callback;
     std::swap (callback, asyncCallback);

     results = asyncResults;

     pimpl.reset();

     if (callback)
         callback (*this);
}

//==============================================================================
FilePreviewComponent::FilePreviewComponent() {}
FilePreviewComponent::~FilePreviewComponent() {}

} // namespace juce