JUCE/modules/juce_gui_basics/native/juce_mac_FileChooser.mm

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

   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
{

//==============================================================================
static NSMutableArray* createAllowedTypesArray (const StringArray& filters)
{
    if (filters.size() == 0)
        return nil;

    NSMutableArray* filterArray = [[[NSMutableArray alloc] init] autorelease];

    for (int i = 0; i < filters.size(); ++i)
    {
        // From OS X 10.6 you can only specify allowed extensions, so any filters containing wildcards
        // must be of the form "*.extension"
        jassert (filters[i] == "*"
                 || (filters[i].startsWith ("*.") && filters[i].lastIndexOfChar ('*') == 0));
        const String f (filters[i].replace ("*.", ""));

        if (f == "*")
            return nil;

        [filterArray addObject: juceStringToNS (f)];
    }

    return filterArray;
}

//==============================================================================
class FileChooser::Native     : public Component,
                                public FileChooser::Pimpl
{
public:
    Native (FileChooser& fileChooser, int flags, FilePreviewComponent* previewComponent)
        : owner (fileChooser), preview (previewComponent),
          selectsDirectories ((flags & FileBrowserComponent::canSelectDirectories)   != 0),
          selectsFiles       ((flags & FileBrowserComponent::canSelectFiles)         != 0),
          isSave             ((flags & FileBrowserComponent::saveMode)               != 0),
          selectMultiple     ((flags & FileBrowserComponent::canSelectMultipleItems) != 0),
          panel (isSave ? [[NSSavePanel alloc] init] : [[NSOpenPanel alloc] init])
    {
        setBounds (0, 0, 0, 0);
        setOpaque (true);

        static DelegateClass cls;

        delegate = [cls.createInstance() init];
        object_setInstanceVariable (delegate, "cppObject", this);

        [panel setDelegate: delegate];

        filters.addTokens (owner.filters.replaceCharacters (",:", ";;"), ";", String());
        filters.trim();
        filters.removeEmptyStrings();

        [panel setTitle: juceStringToNS (owner.title)];
        [panel setAllowedFileTypes: createAllowedTypesArray (filters)];

        if (! isSave)
        {
            NSOpenPanel* openPanel = (NSOpenPanel*) panel;

            [openPanel setCanChooseDirectories: selectsDirectories];
            [openPanel setCanChooseFiles: selectsFiles];
            [openPanel setAllowsMultipleSelection: selectMultiple];
            [openPanel setResolvesAliases: YES];

            if (owner.treatFilePackagesAsDirs)
                [openPanel setTreatsFilePackagesAsDirectories: YES];
        }

        if (preview != nullptr)
        {
            nsViewPreview = [[NSView alloc] initWithFrame: makeNSRect (preview->getLocalBounds())];
            preview->addToDesktop (0, (void*) nsViewPreview);
            preview->setVisible (true);

            [panel setAccessoryView: nsViewPreview];
        }

        if (isSave || selectsDirectories)
            [panel setCanCreateDirectories: YES];

        [panel setLevel:NSModalPanelWindowLevel];

        if (owner.startingFile.isDirectory())
        {
            startingDirectory = owner.startingFile.getFullPathName();
        }
        else
        {
            startingDirectory = owner.startingFile.getParentDirectory().getFullPathName();
            filename = owner.startingFile.getFileName();
        }

        [panel setDirectoryURL: createNSURLFromFile (startingDirectory)];
        [panel setNameFieldStringValue: juceStringToNS (filename)];
    }

    ~Native() override
    {
        exitModalState (0);
        removeFromDesktop();

        if (panel != nil)
        {
            [panel setDelegate: nil];

            if (nsViewPreview != nil)
            {
                [panel setAccessoryView: nil];

                [nsViewPreview release];

                nsViewPreview = nil;
                preview = nullptr;
            }

            [panel close];
            [panel release];
        }

        if (delegate != nil)
        {
            [delegate release];
            delegate = nil;
        }
    }

    void launch() override
    {
        if (panel != nil)
        {
            setAlwaysOnTop (juce_areThereAnyAlwaysOnTopWindows());
            addToDesktop (0);

            enterModalState (true);
            [panel beginWithCompletionHandler:CreateObjCBlock (this, &Native::finished)];
        }
    }

    void runModally() override
    {
        std::unique_ptr<TemporaryMainMenuWithStandardCommands> tempMenu;

        if (JUCEApplicationBase::isStandaloneApp())
            tempMenu.reset (new TemporaryMainMenuWithStandardCommands());

        jassert (panel != nil);
        auto result = [panel runModal];
        finished (result);
    }

    bool canModalEventBeSentToComponent (const Component* targetComponent) override
    {
        if (targetComponent == nullptr)
            return false;

        return targetComponent->findParentComponentOfClass<FilePreviewComponent>() != nullptr;
    }

private:
    //==============================================================================
    typedef NSObject<NSOpenSavePanelDelegate> DelegateType;

    void finished (NSInteger result)
    {
        Array<URL> chooserResults;

        exitModalState (0);

        if (panel != nil && result ==
                             #if defined (MAC_OS_X_VERSION_10_9) && MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_9
                               NSModalResponseOK)
                             #else
                               NSFileHandlingPanelOKButton)
                             #endif
        {
            auto addURLResult = [&chooserResults] (NSURL* urlToAdd)
            {
                auto scheme = nsStringToJuce ([urlToAdd scheme]);
                auto pathComponents = StringArray::fromTokens (nsStringToJuce ([urlToAdd path]), "/", {});

                for (auto& component : pathComponents)
                    component = URL::addEscapeChars (component, false);

                chooserResults.add (URL (scheme + "://" + pathComponents.joinIntoString ("/")));
            };

            if (isSave)
            {
                addURLResult ([panel URL]);
            }
            else
            {
                auto* openPanel = (NSOpenPanel*) panel;
                auto urls = [openPanel URLs];

                for (unsigned int i = 0; i < [urls count]; ++i)
                    addURLResult ([urls objectAtIndex: i]);
            }
        }

        owner.finished (chooserResults);
    }

    bool shouldShowFilename (const String& filenameToTest)
    {
        const File f (filenameToTest);
        auto nsFilename = juceStringToNS (filenameToTest);

        for (int i = filters.size(); --i >= 0;)
            if (f.getFileName().matchesWildcard (filters[i], true))
                return true;

        return f.isDirectory()
                 && ! [[NSWorkspace sharedWorkspace] isFilePackageAtPath: nsFilename];
    }

    void panelSelectionDidChange (id sender)
    {
        // NB: would need to extend FilePreviewComponent to handle the full list rather than just the first one
        if (preview != nullptr)
            preview->selectedFileChanged (File (getSelectedPaths (sender)[0]));
    }

    static StringArray getSelectedPaths (id sender)
    {
        StringArray paths;

        if ([sender isKindOfClass: [NSOpenPanel class]])
        {
            NSArray* urls = [(NSOpenPanel*) sender URLs];

            for (NSUInteger i = 0; i < [urls count]; ++i)
                paths.add (nsStringToJuce ([[urls objectAtIndex: i] path]));
        }
        else if ([sender isKindOfClass: [NSSavePanel class]])
        {
            paths.add (nsStringToJuce ([[(NSSavePanel*) sender URL] path]));
        }

        return paths;
    }

    //==============================================================================
    FileChooser& owner;
    FilePreviewComponent* preview;
    NSView* nsViewPreview = nullptr;
    bool selectsDirectories, selectsFiles, isSave, selectMultiple;

    NSSavePanel* panel;
    DelegateType* delegate;

    StringArray filters;
    String startingDirectory, filename;

    //==============================================================================
    struct DelegateClass : ObjCClass<DelegateType>
    {
        DelegateClass()  : ObjCClass <DelegateType> ("JUCEFileChooser_")
        {
            addIvar<Native*> ("cppObject");

            addMethod (@selector (panel:shouldShowFilename:), shouldShowFilename,      "c@:@@");
            addMethod (@selector (panelSelectionDidChange:),  panelSelectionDidChange, "c@");

            addProtocol (@protocol (NSOpenSavePanelDelegate));

            registerClass();
        }

    private:
        static BOOL shouldShowFilename (id self, SEL, id /*sender*/, NSString* filename)
        {
            auto* _this = getIvar<Native*> (self, "cppObject");

            return _this->shouldShowFilename (nsStringToJuce (filename)) ? YES : NO;
        }

        static void panelSelectionDidChange (id self, SEL, id sender)
        {
            auto* _this = getIvar<Native*> (self, "cppObject");

            _this->panelSelectionDidChange (sender);
        }
    };

    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (Native)
};

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

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

}