src/views/draganddrophelper.h

   1 /*
   2  * SPDX-FileCopyrightText: 2007-2011 Peter Penz <peter.penz19@gmail.com>
   3  * SPDX-FileCopyrightText: 2007 David Faure <faure@kde.org>
   4  *
   5  * SPDX-License-Identifier: GPL-2.0-or-later
   6  */
   7
   8 #ifndef DRAGANDDROPHELPER_H
   9 #define DRAGANDDROPHELPER_H
  10
  11 #include "dolphin_export.h"
  12
  13 #include <KFileItem>
  14 #include <KIO/StatJob>
  15
  16 #include <QList>
  17 #include <QString>
  18 #include <QTimer>
  19 #include <QUrl>
  20
  21 class QDropEvent;
  22 class QMimeData;
  23 class QWidget;
  24 namespace KIO
  25 {
  26 class DropJob;
  27 }
  28
  29 class DOLPHIN_EXPORT DragAndDropHelper : public QObject
  30 {
  31 public:
  32     /**
  33      * Handles the dropping of URLs to the given destination. A context menu
  34      * with the options 'Move Here', 'Copy Here', 'Link Here' and 'Cancel' is
  35      * offered to the user. The drag destination must represent a directory or
  36      * a desktop-file, otherwise the dropping gets ignored.
  37      *
  38      * @param destUrl   URL of the item destination. Is used only if destItem::isNull()
  39      *                  is true.
  40      * @param event     Drop event.
  41      * @param window    Widget where the drop happened, will be used as parent of the drop menu.
  42      * @return          KIO::DropJob pointer or null in case the destUrl is contained
  43      *                  in the mimeData url list.
  44      */
  45     static KIO::DropJob *dropUrls(const QUrl &destUrl, QDropEvent *event, QWidget *window);
  46
  47     /**
  48      * Checks if the destination supports dropping.
  49      *
  50      * @param destItem  The item destination.
  51      * @return          True if the destination is a directory and is writable, or it's a desktop file.
  52      *                  False otherwise.
  53      */
  54     static bool supportsDropping(const KFileItem &destItem);
  55
  56     /**
  57      * @return True if destUrl is contained in the urls parameter.
  58      */
  59     static bool urlListMatchesUrl(const QList<QUrl> &urls, const QUrl &destUrl);
  60
  61     /**
  62      * @return True if mimeData contains Ark's drag and drop mime types.
  63      */
  64     static bool isArkDndMimeType(const QMimeData *mimeData);
  65     static QString arkDndServiceMimeType()
  66     {
  67         return QStringLiteral("application/x-kde-ark-dndextract-service");
  68     }
  69     static QString arkDndPathMimeType()
  70     {
  71         return QStringLiteral("application/x-kde-ark-dndextract-path");
  72     }
  73
  74     /**
  75      * clear the internal cache.
  76      */
  77     static void clearUrlListMatchesUrlCache();
  78
  79     DragAndDropHelper(QObject *parent);
  80
  81     /**
  82      * Updates the drop action according to whether the destination supports dropping.
  83      * If supportsDropping(destUrl), set dropAction = proposedAction. Otherwise, set
  84      * dropAction = Qt::IgnoreAction.
  85      *
  86      * @param event     Drop event.
  87      * @param destUrl   Destination URL.
  88      */
  89     void updateDropAction(QDropEvent *event, const QUrl &destUrl);
  90
  91 private:
  92     /**
  93      * Stores the results of the expensive checks made in urlListMatchesUrl.
  94      */
  95     static QHash<QUrl, bool> m_urlListMatchesUrlCache;
  96
  97     /**
  98      * When updateDropAction() is called with a remote URL, we create a StatJob to
  99      * check if the destination is a directory or a desktop file. We cache the result
 100      * here to avoid doing the stat again on subsequent calls to updateDropAction().
 101      */
 102     KFileItem m_destItemCache;
 103
 104     /**
 105      * Only keep the cache for 30 seconds, because the stat of the destUrl might change.
 106      */
 107     QTimer m_destItemCacheInvalidationTimer;
 108
 109     /**
 110      * A StatJob on-fly to fill the cache for a remote URL. We shouldn't create more
 111      * than one StatJob at a time, so we keep a pointer to the current one.
 112      */
 113     KIO::StatJob *m_statJob = nullptr;
 114
 115     /**
 116      * The URL for which the StatJob is running.
 117      * Note: We can't use m_statJob->url() because StatJob might resolve the URL to be
 118      *       different from what we passed into stat(). E.g. "mtp:<bus-name>" is resolved
 119      *       to "mtp:<phone name>"
 120      */
 121     QUrl m_statJobUrl;
 122
 123     /**
 124      * The last event we received in updateDropAction(), but can't react to yet,
 125      * because a StatJob is on-fly.
 126      */
 127     QDropEvent *m_lastUndecidedEvent = nullptr;
 128 };
 129
 130 #endif