JUCE/modules/juce_gui_basics/filebrowser/juce_FileTreeComponent.cpp

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

   This file is part of the JUCE library.
   Copyright (c) 2022 - Raw Material Software Limited

   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 7 End-User License
   Agreement and JUCE Privacy Policy.

   End User License Agreement: www.juce.com/juce-7-licence
   Privacy Policy: www.juce.com/juce-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
{

//==============================================================================
class FileListTreeItem   : public TreeViewItem,
                           private TimeSliceClient,
                           private AsyncUpdater,
                           private ChangeListener
{
public:
    FileListTreeItem (FileTreeComponent& treeComp,
                      DirectoryContentsList* parentContents,
                      int indexInContents,
                      const File& f,
                      TimeSliceThread& t)
        : file (f),
          owner (treeComp),
          parentContentsList (parentContents),
          indexInContentsList (indexInContents),
          subContentsList (nullptr, false),
          thread (t)
    {
        DirectoryContentsList::FileInfo fileInfo;

        if (parentContents != nullptr
             && parentContents->getFileInfo (indexInContents, fileInfo))
        {
            fileSize = File::descriptionOfSizeInBytes (fileInfo.fileSize);
            modTime = fileInfo.modificationTime.formatted ("%d %b '%y %H:%M");
            isDirectory = fileInfo.isDirectory;
        }
        else
        {
            isDirectory = true;
        }
    }

    ~FileListTreeItem() override
    {
        thread.removeTimeSliceClient (this);
        clearSubItems();
        removeSubContentsList();
    }

    //==============================================================================
    bool mightContainSubItems() override                 { return isDirectory; }
    String getUniqueName() const override                { return file.getFullPathName(); }
    int getItemHeight() const override                   { return owner.getItemHeight(); }

    var getDragSourceDescription() override              { return owner.getDragAndDropDescription(); }

    void itemOpennessChanged (bool isNowOpen) override
    {
        if (isNowOpen)
        {
            clearSubItems();

            isDirectory = file.isDirectory();

            if (isDirectory)
            {
                if (subContentsList == nullptr && parentContentsList != nullptr)
                {
                    auto l = new DirectoryContentsList (parentContentsList->getFilter(), thread);

                    l->setDirectory (file,
                                     parentContentsList->isFindingDirectories(),
                                     parentContentsList->isFindingFiles());

                    setSubContentsList (l, true);
                }

                changeListenerCallback (nullptr);
            }
        }
    }

    void removeSubContentsList()
    {
        if (subContentsList != nullptr)
        {
            subContentsList->removeChangeListener (this);
            subContentsList.reset();
        }
    }

    void setSubContentsList (DirectoryContentsList* newList, const bool canDeleteList)
    {
        removeSubContentsList();

        subContentsList = OptionalScopedPointer<DirectoryContentsList> (newList, canDeleteList);
        newList->addChangeListener (this);
    }

    void selectFile (const File& target)
    {
        if (file == target)
        {
            setSelected (true, true);
            return;
        }

        if (subContentsList != nullptr && subContentsList->isStillLoading())
        {
            pendingFileSelection.emplace (*this, target);
            return;
        }

        pendingFileSelection.reset();

        if (! target.isAChildOf (file))
            return;

        setOpen (true);

        for (int i = 0; i < getNumSubItems(); ++i)
            if (auto* f = dynamic_cast<FileListTreeItem*> (getSubItem (i)))
                f->selectFile (target);
    }

    void changeListenerCallback (ChangeBroadcaster*) override
    {
        rebuildItemsFromContentList();
    }

    void rebuildItemsFromContentList()
    {
        clearSubItems();

        if (isOpen() && subContentsList != nullptr)
        {
            for (int i = 0; i < subContentsList->getNumFiles(); ++i)
                addSubItem (new FileListTreeItem (owner, subContentsList, i,
                                                  subContentsList->getFile(i), thread));
        }
    }

    void paintItem (Graphics& g, int width, int height) override
    {
        ScopedLock lock (iconUpdate);

        if (file != File())
        {
            updateIcon (true);

            if (icon.isNull())
                thread.addTimeSliceClient (this);
        }

        owner.getLookAndFeel().drawFileBrowserRow (g, width, height,
                                                   file, file.getFileName(),
                                                   &icon, fileSize, modTime,
                                                   isDirectory, isSelected(),
                                                   indexInContentsList, owner);
    }

    String getAccessibilityName() override
    {
        return file.getFileName();
    }

    void itemClicked (const MouseEvent& e) override
    {
        owner.sendMouseClickMessage (file, e);
    }

    void itemDoubleClicked (const MouseEvent& e) override
    {
        TreeViewItem::itemDoubleClicked (e);

        owner.sendDoubleClickMessage (file);
    }

    void itemSelectionChanged (bool) override
    {
        owner.sendSelectionChangeMessage();
    }

    int useTimeSlice() override
    {
        updateIcon (false);
        return -1;
    }

    void handleAsyncUpdate() override
    {
        owner.repaint();
    }

    const File file;

private:
    class PendingFileSelection   : private Timer
    {
    public:
        PendingFileSelection (FileListTreeItem& item, const File& f)
            : owner (item), fileToSelect (f)
        {
            startTimer (10);
        }

        ~PendingFileSelection() override
        {
            stopTimer();
        }

    private:
        void timerCallback() override
        {
            // Take a copy of the file here, in case this PendingFileSelection
            // object is destroyed during the call to selectFile.
            owner.selectFile (File { fileToSelect });
        }

        FileListTreeItem& owner;
        File fileToSelect;
    };

    Optional<PendingFileSelection> pendingFileSelection;
    FileTreeComponent& owner;
    DirectoryContentsList* parentContentsList;
    int indexInContentsList;
    OptionalScopedPointer<DirectoryContentsList> subContentsList;
    bool isDirectory;
    TimeSliceThread& thread;
    CriticalSection iconUpdate;
    Image icon;
    String fileSize, modTime;

    void updateIcon (const bool onlyUpdateIfCached)
    {
        if (icon.isNull())
        {
            auto hashCode = (file.getFullPathName() + "_iconCacheSalt").hashCode();
            auto im = ImageCache::getFromHashCode (hashCode);

            if (im.isNull() && ! onlyUpdateIfCached)
            {
                im = juce_createIconForFile (file);

                if (im.isValid())
                    ImageCache::addImageToCache (im, hashCode);
            }

            if (im.isValid())
            {
                {
                    ScopedLock lock (iconUpdate);
                    icon = im;
                }

                triggerAsyncUpdate();
            }
        }
    }

    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (FileListTreeItem)
};

//==============================================================================
FileTreeComponent::FileTreeComponent (DirectoryContentsList& listToShow)
    : DirectoryContentsDisplayComponent (listToShow),
      itemHeight (22)
{
    setRootItemVisible (false);
    refresh();
}

FileTreeComponent::~FileTreeComponent()
{
    deleteRootItem();
}

void FileTreeComponent::refresh()
{
    deleteRootItem();

    auto root = new FileListTreeItem (*this, nullptr, 0, directoryContentsList.getDirectory(),
                                      directoryContentsList.getTimeSliceThread());

    root->setSubContentsList (&directoryContentsList, false);
    setRootItem (root);
}

//==============================================================================
File FileTreeComponent::getSelectedFile (const int index) const
{
    if (auto* item = dynamic_cast<const FileListTreeItem*> (getSelectedItem (index)))
        return item->file;

    return {};
}

void FileTreeComponent::deselectAllFiles()
{
    clearSelectedItems();
}

void FileTreeComponent::scrollToTop()
{
    getViewport()->getVerticalScrollBar().setCurrentRangeStart (0);
}

void FileTreeComponent::setDragAndDropDescription (const String& description)
{
    dragAndDropDescription = description;
}

void FileTreeComponent::setSelectedFile (const File& target)
{
    if (auto* t = dynamic_cast<FileListTreeItem*> (getRootItem()))
        t->selectFile (target);
}

void FileTreeComponent::setItemHeight (int newHeight)
{
    if (itemHeight != newHeight)
    {
        itemHeight = newHeight;

        if (auto* root = getRootItem())
            root->treeHasChanged();
    }
}

} // namespace juce