galleryviews.cpp

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#include "galleryviews.h"
 
#include <algorithm> // std::shuffle, upper_bound
#include <cmath>     // std::pow
#include <cstdint>
#include <iterator>  // std::distance
#include <random>
#include <vector>
 
#include "libmythbase/mythrandom.h"
 
#define LOC QString("Galleryviews: ")
 
const static int   kMaxFolderThumbnails = 4;
 
const double LEADING_BETA_SHAPE  = 0.175;
const double TRAILING_BETA_SHAPE = 0.31;
 
const double DEFAULT_WEIGHT = std::pow(0.5, TRAILING_BETA_SHAPE - 1) *
                              std::pow(0.5, LEADING_BETA_SHAPE - 1);
static constexpr qint64 BETA_CLIP { 24LL * 60 * 60 };
 
void MarkedFiles::Add(const ImageIdList& newIds)
{
    for (int newid : newIds)
        insert(newid);
}
 
void MarkedFiles::Invert(const ImageIdList &all)
{
    QSet tmp;
    for (int tmpint : all)
        tmp.insert(tmpint);
    for (int tmpint : qAsConst(*this))
        tmp.remove(tmpint);
    swap(tmp);
}
 
ImageListK FlatView::GetAllNodes() const
{
    ImageListK files;
    for (int id : qAsConst(m_sequence))
        files.append(m_images.value(id));
    return files;
}
 
 
ImagePtrK FlatView::GetSelected() const
{
    return m_active < 0 || m_active >= m_sequence.size()
            ? ImagePtrK() : m_images.value(m_sequence.at(m_active));
}
 
 
QString FlatView::GetPosition() const
{
    return QString("%1/%2").arg(m_active + 1).arg(m_sequence.size());
}
 
 
bool FlatView::Update(int id)
{
    ImagePtrK im = m_images.value(id);
    if (!im)
        return false;
 
    // Get updated image
    ImageList files;
    ImageList dirs;
    ImageIdList ids = ImageIdList() << id;
    if (m_mgr.GetImages(ids, files, dirs) != 1 || files.size() != 1)
        return false;
 
    bool active = (im == GetSelected());
 
    // Replace image
    m_images.insert(id, files.at(0));
 
    LOG(VB_FILE, LOG_DEBUG, LOC + QString("Modified id %1").arg(id));
 
    return active;
}
 
 
bool FlatView::Select(int id, int fallback)
{
    // Select first appearance of image
    int index = m_sequence.indexOf(id);
    if (index >= 0)
    {
        m_active = index;
        return true;
    }
 
    if (fallback >= 0)
        m_active = fallback;
 
    return false;
}
 
 
void FlatView::Clear(bool resetParent)
{
    m_images.clear();
    m_sequence.clear();
    m_active = -1;
    if (resetParent)
        m_parentId = GALLERY_DB_ID;
}
 
 
ImagePtrK FlatView::HasNext(int inc) const
{
    return m_sequence.isEmpty() || m_active + inc >= m_sequence.size()
            ? ImagePtrK() : m_images.value(m_sequence.at(m_active + inc));
}
 
 
ImagePtrK FlatView::Next(int inc)
{
    if (m_sequence.isEmpty())
        return {};
 
    // Preserve index as it may be reset when wrapping
    int next = m_active + inc;
 
    // Regenerate unordered views when wrapping
    if (next >= m_sequence.size() && m_order != kOrdered && !LoadFromDb(m_parentId))
        // Images have disappeared
        return {};
 
    m_active = next % m_sequence.size();
    return m_images.value(m_sequence.at(m_active));
}
 
 
ImagePtrK FlatView::HasPrev(int inc) const
{
    return m_sequence.isEmpty() || m_active < inc
            ? ImagePtrK() : m_images.value(m_sequence.at(m_active - inc));
}
 
 
ImagePtrK FlatView::Prev(int inc)
{
    if (m_sequence.isEmpty())
        return {};
 
    // Wrap avoiding modulo of negative uncertainty
    m_active -= inc % m_sequence.size();
    if (m_active < 0)
        m_active += m_sequence.size();
 
    return m_images.value(m_sequence.at(m_active));
}
 
 
void FlatView::Populate(ImageList &files)
{
    // Do not reset parent
    Clear(false);
 
    if (files.isEmpty())
        return;
 
    for (const QSharedPointer<ImageItem> & im : qAsConst(files))
    {
        // Add image to view
        m_images.insert(im->m_id, im);
 
        // Cache all displayed images
        if (im->IsFile())
            Cache(im->m_id, im->m_parentId, im->m_url, im->m_thumbNails.at(0).second);
    }
 
    if (files.size() == 1 || m_order == kOrdered || m_order == kShuffle)
    {
        // Default sequence is ordered
        for (const QSharedPointer<ImageItem> & im : qAsConst(files))
            m_sequence.append(im->m_id);
    }
 
    if (files.size() > 1)
    {
        // Modify viewing sequence
        if (m_order == kShuffle)
        {
            std::shuffle(m_sequence.begin(), m_sequence.end(),
                         std::mt19937(std::random_device()()));
        }
        else if (m_order == kRandom)
        {
            // An image is not a valid candidate for its successor
            // add files.size() elements from files in a random order
            // to m_sequence allowing non-consecutive repetition
            int size  = files.size();
            int range = files.size() - 1;
            int last  = size; // outside of the random interval [0, size)
            int count = 0;
            while (count < size)
            {
                int rand = MythRandom(0, range);
 
                // Avoid consecutive repeats
                if (last == rand)
                {
                    continue;
                }
                last = rand;
                m_sequence.append(files.at(rand)->m_id);
                count++;
            }
        }
        else if (m_order == kSeasonal)
        {
            WeightList cdf = CalculateSeasonalWeights(files); // not normalized to 1.0
            std::vector<uint32_t> weights;
            weights.reserve(cdf.size());
            for (int i = 0; i < cdf.size(); i++)
            {
                weights.emplace_back(lround(cdf[i] / cdf.back() * UINT32_MAX));
            }
            // exclude the last value so the past the end iterator is not returned
            // by std::upper_bound
            uint32_t maxWeight = weights.back() - 1;
 
            for (int count = 0; count < files.size(); ++count)
            {
                uint32_t randWeight = MythRandom(0, maxWeight);
                auto it = std::upper_bound(weights.begin(), weights.end(), randWeight);
                int    index      = std::distance(weights.begin(), it);
                m_sequence.append(files.at(index)->m_id);
            }
        }
    }
}
 
 
WeightList FlatView::CalculateSeasonalWeights(ImageList &files)
{
    WeightList weights(files.size());
    double     totalWeight = 0;
    QDateTime  now         = QDateTime::currentDateTime();
 
    for (int i = 0; i < files.size(); ++i)
    {
        ImagePtrK im = files.at(i);
        double weight = 0;
 
        if (im->m_date == 0s)
            weight = DEFAULT_WEIGHT;
        else
        {
            QDateTime timestamp = QDateTime::fromSecsSinceEpoch(im->m_date.count());
            QDateTime curYearAnniversary =
                    QDateTime(QDate(now.date().year(),
                                    timestamp.date().month(),
                                    timestamp.date().day()),
                              timestamp.time());
 
            bool isAnniversaryPast = curYearAnniversary < now;
 
            QDateTime adjacentYearAnniversary =
                    QDateTime(QDate(now.date().year() +
                                    (isAnniversaryPast ? 1 : -1),
                                    timestamp.date().month(),
                                    timestamp.date().day()),
                              timestamp.time());
 
            double range = llabs(curYearAnniversary.secsTo(
                                   adjacentYearAnniversary)) + BETA_CLIP;
 
            // This calculation is not normalized, because that would require the
            // beta function, which isn't part of the C++98 libraries. Weights
            // that aren't normalized work just as well relative to each other.
            QDateTime d1(isAnniversaryPast ? curYearAnniversary
                                           : adjacentYearAnniversary);
            QDateTime d2(isAnniversaryPast ? adjacentYearAnniversary
                                           : curYearAnniversary);
            weight = std::pow(llabs(now.secsTo(d1) + BETA_CLIP) / range,
                              TRAILING_BETA_SHAPE - 1)
                    * std::pow(llabs(now.secsTo(d2) + BETA_CLIP) / range,
                               LEADING_BETA_SHAPE - 1);
        }
        totalWeight += weight;
        weights[i]   = totalWeight;
    }
    return weights;
}
 
 
bool FlatView::LoadFromDb(int parentId)
{
    m_parentId = parentId;
 
    // Load child images of the parent
    ImageList files;
    ImageList dirs;
    m_mgr.GetChildren(m_parentId, files, dirs);
 
    // Load gallery datastore with current dir
    Populate(files);
 
    return !files.isEmpty();
}
 
 
void FlatView::ClearCache()
{
    LOG(VB_FILE, LOG_DEBUG, LOC + "Cleared File cache");
    m_fileCache.clear();
}
 
 
QStringList FlatView::ClearImage(int id, bool remove)
{
    if (remove)
    {
        m_sequence.removeAll(id);
        m_images.remove(id);
    }
 
    QStringList urls;
    FileCacheEntry file = m_fileCache.take(id);
 
    if (!file.m_url.isEmpty())
        urls << file.m_url;
 
    if (!file.m_thumbUrl.isEmpty())
        urls << file.m_thumbUrl;
 
    LOG(VB_FILE, LOG_DEBUG, LOC + QString("Cleared %1 from file cache (%2)")
        .arg(id).arg(urls.join(",")));
    return urls;
}
 
 
void FlatView::Rotate(int id)
{
    // Rotate sequence so that (first appearance of) specified image is
    // at offset from front
    int index = m_sequence.indexOf(id);
    if (index >= 0)
    {
        int first = index % m_sequence.size();
        if (first > 0)
            m_sequence = m_sequence.mid(first) + m_sequence.mid(0, first);
    }
}
 
 
void FlatView::Cache(int id, int parent, const QString &url, const QString &thumb)
{
    // Cache parent dir so that dir thumbs are updated when a child changes.
    // Also store urls for image cache cleanup
    FileCacheEntry cached(parent, url, thumb);
    m_fileCache.insert(id, cached);
    LOG(VB_FILE, LOG_DEBUG, LOC + "Caching " + cached.ToString(id));
}
 
 
QString DirCacheEntry::ToString(int id) const
{
    QStringList ids;
    for (const auto & thumb : qAsConst(m_thumbs))
        ids << QString::number(thumb.first);
    return QString("Dir %1 (%2, %3) Thumbs %4 (%5) Parent %6")
            .arg(id).arg(m_fileCount).arg(m_dirCount).arg(ids.join(","))
            .arg(m_thumbCount).arg(m_parent);
}
 
 
DirectoryView::DirectoryView(SlideOrderType order)
    : FlatView(order)
{
    m_marked.Clear();
    m_prevMarked.Clear();
}
 
 
QString DirectoryView::GetPosition() const
{
    return QString("%1/%2").arg(m_active).arg(m_sequence.size() - 1);
}
 
 
bool DirectoryView::LoadFromDb(int parentId)
{
    // Determine parent (defaulting to ancestor) & get initial children
    ImageList files;
    ImageList dirs;
    ImagePtr parent;
    int count = 0;
    // Root is guaranteed to return at least 1 item
    while ((count = m_mgr.GetDirectory(parentId, parent, files, dirs)) == 0)
    {
        // Fallback if dir no longer exists
        // Ascend to Gallery for gallery subdirs, Root for device dirs & Gallery
        parentId = parentId > PHOTO_DB_ID ? PHOTO_DB_ID : GALLERY_DB_ID;
    }
 
    SetDirectory(parentId);
    m_parentId = parentId;
 
    // No SG & no devices uses special 'empty' screen
    if (!parent || (parentId == GALLERY_DB_ID && count == 1))
    {
        parent.clear();
        return false;
    }
 
    // Populate all subdirs
    for (const ImagePtr & im : qAsConst(dirs))
    {
        if (im)
            // Load sufficient thumbs from each dir as subsequent dirs may be empty
            LoadDirThumbs(*im, kMaxFolderThumbnails);
    }
 
    // Populate parent
    if (!PopulateFromCache(*parent, kMaxFolderThumbnails))
        PopulateThumbs(*parent, kMaxFolderThumbnails, files, dirs);
 
    // Dirs shown before images
    ImageList images = dirs + files;
 
    // Validate marked images
    if (!m_marked.isEmpty())
    {
        QSet<int> ids;
        for (const QSharedPointer<ImageItem> & im : qAsConst(images))
            ids.insert(im->m_id);
        m_marked.intersect(ids);
    }
 
    // Parent is always first (for navigating up).
    images.prepend(parent);
 
    // Preserve current selection before view is destroyed
    ImagePtrK selected = GetSelected();
    int activeId = selected ? selected->m_id : 0;
 
    // Construct view
    Populate(images);
 
    // Reinstate selection, falling back to parent
    Select(activeId);
 
    return true;
}
 
 
void DirectoryView::LoadDirThumbs(ImageItem &parent, int thumbsNeeded, int level)
{
    // Use cached data, if available
    if (PopulateFromCache(parent, thumbsNeeded))
        return;
 
    // Load child images & dirs
    ImageList files;
    ImageList dirs;
    m_mgr.GetChildren(parent.m_id, files, dirs);
 
    PopulateThumbs(parent, thumbsNeeded, files, dirs, level);
}
 
 
void DirectoryView::PopulateThumbs(ImageItem &parent, int thumbsNeeded,
                                   const ImageList &files, const ImageList &dirs,
                                   int level)
{
    // Set parent stats
    parent.m_fileCount = files.size();
    parent.m_dirCount  = dirs.size();
 
    // Locate user assigned thumb amongst children, if defined
    ImagePtr userIm;
    if (parent.m_userThumbnail != 0)
    {
        ImageList images = files + dirs;
        // ImageItem has been explicitly marked Q_DISABLE_COPY
        for (const ImagePtr & im : qAsConst(images))
        {
            if (im && im->m_id == parent.m_userThumbnail)
            { // cppcheck-suppress useStlAlgorithm
                userIm = im;
                break;
            }
        }
    }
 
    // Children to use as thumbnails
    ImageList thumbFiles;
    ImageList thumbDirs;
 
    if (!userIm)
    {
        // Construct multi-thumbnail from all children
        thumbFiles = files;
        thumbDirs  = dirs;
    }
    else if (userIm->IsFile())
    {
        thumbFiles.append(userIm);
        thumbsNeeded = 1;
    }
    else
        thumbDirs.append(userIm);
 
    // Fill parent thumbs from child files first
    // Whilst they're available fill as many as possible for cache
    for (int i = 0; i < std::min(kMaxFolderThumbnails, static_cast<int>(thumbFiles.size())); ++i)
    {
        parent.m_thumbNails.append(thumbFiles.at(i)->m_thumbNails.at(0));
        --thumbsNeeded;
    }
 
    // Only recurse if necessary
    if (thumbsNeeded > 0)
    {
        // Prevent lengthy/infinite recursion due to deep/cyclic folder
        // structures
        if (++level > 10)
        {
            LOG(VB_GENERAL, LOG_NOTICE, LOC +
                "Directory thumbnails are more than 10 levels deep");
        }
        else
        {
            // Recursively load subdir thumbs to try to get 1 thumb from each
            for (const ImagePtr & im : qAsConst(thumbDirs))
            {
                if (!im)
                    continue;
 
                // Load sufficient thumbs from each dir as subsequent dirs may
                // be empty
                LoadDirThumbs(*im, thumbsNeeded, level);
 
                if (!im->m_thumbNails.empty())
                {
                    // Add first thumbnail to parent thumb
                    parent.m_thumbNails.append(im->m_thumbNails.at(0));
 
                    // Quit when we have sufficient thumbs
                    if (--thumbsNeeded == 0)
                        break;
                }
            }
 
            // If insufficient dirs to supply 1 thumb per dir, use other dir
            // thumbs (indices 1-3) as well
            int i = 0;
            while (thumbsNeeded > 0 && ++i < kMaxFolderThumbnails)
            {
                for (const QSharedPointer<ImageItem> & im : qAsConst(thumbDirs))
                {
                    if (i < im->m_thumbNails.size())
                    {
                        parent.m_thumbNails.append(im->m_thumbNails.at(i));
                        if (--thumbsNeeded == 0)
                            break;
                    }
                }
            }
        }
    }
 
    // Flag the cached entry with number of thumbs loaded. If future uses require
    // more, then the dir must be reloaded.
    // For user thumbs and dirs with insufficient child images, the cache is always valid
    int scanned = (userIm || thumbsNeeded > 0)
            ? kMaxFolderThumbnails
            : parent.m_thumbNails.size();
 
    // Cache result to optimize navigation
    Cache(parent, scanned);
}
 
 
void DirectoryView::Clear(bool /*resetParent*/)
{
    ClearMarked();
    ClearCache();
    FlatView::Clear();
}
 
 
void DirectoryView::MarkAll()
{
    // Any marking clears previous marks
    m_prevMarked.Clear();
    m_marked.Add(GetChildren());
}
 
 
void DirectoryView::Mark(int id, bool mark)
{
    if (mark)
    {
        // Any marking clears previous marks
        m_prevMarked.Clear();
        m_marked.Add(id);
    }
    else
    {
        m_prevMarked.remove(id);
        m_marked.remove(id);
    }
}
 
 
void DirectoryView::InvertMarked()
{
    // Any marking clears previous marks
    m_prevMarked.Clear();
    m_marked.Invert(GetChildren());
}
 
 
void DirectoryView::ClearMarked()
{
    m_marked.Clear();
    m_prevMarked.Clear();
}
 
 
void DirectoryView::SetDirectory(int newParent)
{
    if (m_marked.IsFor(newParent))
        // Directory hasn't changed
        return;
 
    // Markings are cleared on every dir change
    // Any current markings become previous markings
    // Only 1 set of previous markings are preserved
    if (m_prevMarked.IsFor(newParent))
    {
        // Returned to dir of previous markings: reinstate them
        m_marked = m_prevMarked;
        m_prevMarked.Clear();
        return;
    }
 
    if (!m_marked.isEmpty())
        // Preserve current markings
        m_prevMarked = m_marked;
 
    // Initialise current markings for new dir
    m_marked.Initialise(newParent);
}
 
 
MenuSubjects DirectoryView::GetMenuSubjects()
{
    // hiddenMarked is true if 1 or more marked items are hidden
    // unhiddenMarked is true if 1 or more marked items are not hidden
    bool hiddenMarked   = false;
    bool unhiddenMarked = false;
    for (int id : qAsConst(m_marked))
    {
        ImagePtrK im = m_images.value(id);
        if (!im)
            continue;
 
        if (im->m_isHidden)
            hiddenMarked = true;
        else
            unhiddenMarked = true;
 
        if (hiddenMarked && unhiddenMarked)
            break;
    }
 
    return {GetSelected(), m_sequence.size() - 1,
            m_marked,      m_prevMarked,
            hiddenMarked,  unhiddenMarked};
}
 
 
bool DirectoryView::PopulateFromCache(ImageItem &dir, int required)
{
    DirCacheEntry cached(m_dirCache.value(dir.m_id));
    if (cached.m_dirCount == -1 || cached.m_thumbCount < required)
        return false;
 
    dir.m_fileCount  = cached.m_fileCount;
    dir.m_dirCount   = cached.m_dirCount;
    dir.m_thumbNails = cached.m_thumbs;
 
    LOG(VB_FILE, LOG_DEBUG, LOC + "Using cached " + cached.ToString(dir.m_id));
    return true;
}
 
 
void DirectoryView::Cache(ImageItemK &dir, int thumbCount)
{
    // Cache counts & thumbnails for each dir so that we don't need to reload its
    // children from Db each time it's displayed
    DirCacheEntry cacheEntry(dir.m_parentId, dir.m_dirCount, dir.m_fileCount,
                             dir.m_thumbNails, thumbCount);
 
    m_dirCache.insert(dir.m_id, cacheEntry);
 
    // Cache images used by dir thumbnails
    for (const ThumbPair & thumb : qAsConst(dir.m_thumbNails))
    {
        // Do not overwrite any existing image url nor parent.
        // Image url is cached when image is displayed as a child, but not as a
        // ancestor dir thumbnail
        // First cache attempt will be by parent. Subsequent attempts may be
        // by ancestor dirs.
        if (!m_fileCache.contains(thumb.first))
            FlatView::Cache(thumb.first, dir.m_id, "", thumb.second);
    }
    LOG(VB_FILE, LOG_DEBUG, LOC + "Caching " + cacheEntry.ToString(dir.m_id));
}
 
 
void DirectoryView::ClearCache()
{
    LOG(VB_FILE, LOG_DEBUG, LOC + "Cleared Dir cache");
    m_dirCache.clear();
    FlatView::ClearCache();
}
 
 
QStringList DirectoryView::RemoveImage(int id, bool deleted)
{
    QStringList urls;
    int dirId = id;
 
    if (deleted)
    {
        m_marked.remove(id);
        m_prevMarked.remove(id);
    }
 
    // If id is a file then start with its parent
    if (m_fileCache.contains(id))
    {
        // Clear file cache & start from its parent dir
        dirId = m_fileCache.value(id).m_parent;
        urls = FlatView::ClearImage(id, deleted);
    }
 
    // Clear ancestor dirs
    while (m_dirCache.contains(dirId))
    {
        LOG(VB_FILE, LOG_DEBUG, LOC + QString("Cleared %1 from dir cache").arg(dirId));
        DirCacheEntry dir = m_dirCache.take(dirId);
        dirId = dir.m_parent;
    }
    return urls;
}
 
 
bool TreeView::LoadFromDb(int parentId)
{
    m_parentId = parentId;
 
    // Load visible subtree of the parent
    // Ordered images of parent first, then breadth-first recursion of ordered dirs
    ImageList files;
    m_mgr.GetImageTree(m_parentId, files);
 
    // Load view
    Populate(files);
 
    return !files.isEmpty();
}