JUCE/modules/juce_gui_basics/filebrowser/juce_FileListComponent.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
{

Image juce_createIconForFile (const File& file);


//==============================================================================
FileListComponent::FileListComponent (DirectoryContentsList& listToShow)
    : ListBox ({}, nullptr),
      DirectoryContentsDisplayComponent (listToShow),
      lastDirectory (listToShow.getDirectory())
{
    setModel (this);
    directoryContentsList.addChangeListener (this);
}

FileListComponent::~FileListComponent()
{
    directoryContentsList.removeChangeListener (this);
}

int FileListComponent::getNumSelectedFiles() const
{
    return getNumSelectedRows();
}

File FileListComponent::getSelectedFile (int index) const
{
    return directoryContentsList.getFile (getSelectedRow (index));
}

void FileListComponent::deselectAllFiles()
{
    deselectAllRows();
}

void FileListComponent::scrollToTop()
{
    getVerticalScrollBar().setCurrentRangeStart (0);
}

void FileListComponent::setSelectedFile (const File& f)
{
    for (int i = directoryContentsList.getNumFiles(); --i >= 0;)
    {
        if (directoryContentsList.getFile(i) == f)
        {
            fileWaitingToBeSelected = File();

            selectRow (i);
            return;
        }
    }

    deselectAllRows();
    fileWaitingToBeSelected = f;
}

//==============================================================================
void FileListComponent::changeListenerCallback (ChangeBroadcaster*)
{
    updateContent();

    if (lastDirectory != directoryContentsList.getDirectory())
    {
        fileWaitingToBeSelected = File();
        lastDirectory = directoryContentsList.getDirectory();
        deselectAllRows();
    }

    if (fileWaitingToBeSelected != File())
        setSelectedFile (fileWaitingToBeSelected);
}

//==============================================================================
class FileListComponent::ItemComponent  : public Component,
                                          private TimeSliceClient,
                                          private AsyncUpdater
{
public:
    ItemComponent (FileListComponent& fc, TimeSliceThread& t)
        : owner (fc), thread (t)
    {
    }

    ~ItemComponent() override
    {
        thread.removeTimeSliceClient (this);
    }

    //==============================================================================
    void paint (Graphics& g) override
    {
        getLookAndFeel().drawFileBrowserRow (g, getWidth(), getHeight(),
                                             file, file.getFileName(),
                                             &icon, fileSize, modTime,
                                             isDirectory, highlighted,
                                             index, owner);
    }

    void mouseDown (const MouseEvent& e) override
    {
        owner.selectRowsBasedOnModifierKeys (index, e.mods, true);
        owner.sendMouseClickMessage (file, e);
    }

    void mouseDoubleClick (const MouseEvent&) override
    {
        owner.sendDoubleClickMessage (file);
    }

    void update (const File& root, const DirectoryContentsList::FileInfo* fileInfo,
                 int newIndex, bool nowHighlighted)
    {
        thread.removeTimeSliceClient (this);

        if (nowHighlighted != highlighted || newIndex != index)
        {
            index = newIndex;
            highlighted = nowHighlighted;
            repaint();
        }

        File newFile;
        String newFileSize, newModTime;

        if (fileInfo != nullptr)
        {
            newFile = root.getChildFile (fileInfo->filename);
            newFileSize = File::descriptionOfSizeInBytes (fileInfo->fileSize);
            newModTime = fileInfo->modificationTime.formatted ("%d %b '%y %H:%M");
        }

        if (newFile != file
             || fileSize != newFileSize
             || modTime != newModTime)
        {
            file = newFile;
            fileSize = newFileSize;
            modTime = newModTime;
            icon = Image();
            isDirectory = fileInfo != nullptr && fileInfo->isDirectory;

            repaint();
        }

        if (file != File() && icon.isNull() && ! isDirectory)
        {
            updateIcon (true);

            if (! icon.isValid())
                thread.addTimeSliceClient (this);
        }
    }

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

    void handleAsyncUpdate() override
    {
        repaint();
    }

private:
    //==============================================================================
    FileListComponent& owner;
    TimeSliceThread& thread;
    File file;
    String fileSize, modTime;
    Image icon;
    int index = 0;
    bool highlighted = false, isDirectory = false;

    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())
            {
                icon = im;
                triggerAsyncUpdate();
            }
        }
    }

    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (ItemComponent)
};

//==============================================================================
int FileListComponent::getNumRows()
{
    return directoryContentsList.getNumFiles();
}

void FileListComponent::paintListBoxItem (int, Graphics&, int, int, bool)
{
}

Component* FileListComponent::refreshComponentForRow (int row, bool isSelected, Component* existingComponentToUpdate)
{
    jassert (existingComponentToUpdate == nullptr || dynamic_cast<ItemComponent*> (existingComponentToUpdate) != nullptr);

    auto comp = static_cast<ItemComponent*> (existingComponentToUpdate);

    if (comp == nullptr)
        comp = new ItemComponent (*this, directoryContentsList.getTimeSliceThread());

    DirectoryContentsList::FileInfo fileInfo;
    comp->update (directoryContentsList.getDirectory(),
                  directoryContentsList.getFileInfo (row, fileInfo) ? &fileInfo : nullptr,
                  row, isSelected);

    return comp;
}

void FileListComponent::selectedRowsChanged (int /*lastRowSelected*/)
{
    sendSelectionChangeMessage();
}

void FileListComponent::deleteKeyPressed (int /*currentSelectedRow*/)
{
}

void FileListComponent::returnKeyPressed (int currentSelectedRow)
{
    sendDoubleClickMessage (directoryContentsList.getFile (currentSelectedRow));
}

} // namespace juce