Empty initial drag/drop support.

src/core/feedsmodel.cpp

@@ -204,6 +204,122 @@ DatabaseCleaner *FeedsModel::databaseCleaner() {
   return m_dbCleaner;
 }
 
+QMimeData *FeedsModel::mimeData(const QModelIndexList &indexes) const {
+  QMimeData *mime_data = new QMimeData();
+  QByteArray encoded_data;
+  QDataStream stream(&encoded_data, QIODevice::WriteOnly);
+
+  foreach (const QModelIndex &index, indexes) {
+    if (index.column() != 0) {
+      continue;
+    }
+
+    RootItem *item_for_index = itemForIndex(index);
+
+    if (item_for_index->kind() != RootItemKind::Root) {
+      stream << (quintptr) item_for_index;
+    }
+  }
+
+  mime_data->setData(MIME_TYPE_ITEM_POINTER, encoded_data);
+  return mime_data;
+}
+
+QStringList FeedsModel::mimeTypes() const {
+  return QStringList() << MIME_TYPE_ITEM_POINTER;
+}
+
+bool FeedsModel::dropMimeData(const QMimeData *data, Qt::DropAction action, int row, int column, const QModelIndex &parent) {
+  Q_UNUSED(row)
+  Q_UNUSED(column)
+
+  if (action == Qt::IgnoreAction) {
+    return true;
+  }
+  else if (action != Qt::MoveAction) {
+    return false;
+  }
+
+  QByteArray dragged_items_data = data->data(MIME_TYPE_ITEM_POINTER);
+
+  if (dragged_items_data.isEmpty()) {
+    return false;
+  }
+  else {
+    QDataStream stream(&dragged_items_data, QIODevice::ReadOnly);
+
+    while (!stream.atEnd()) {
+      quintptr pointer_to_item;
+      stream >> pointer_to_item;
+
+      // We have item we want to drag, we also determine the target item.
+      RootItem *dragged_item = (RootItem*) pointer_to_item;
+      RootItem *target_item = itemForIndex(parent);
+      ServiceRoot *dragged_item_root = dragged_item->getParentServiceRoot();
+      ServiceRoot *target_item_root = target_item->getParentServiceRoot();
+
+      if (dragged_item == target_item || dragged_item->parent() == target_item) {
+        qDebug("Dragged item is equal to target item or its parent is equal to target item. Cancelling drag-drop action.");
+        return false;
+      }
+
+      if (dragged_item_root != target_item_root) {
+        // Transferring of items between different accounts is not possible.
+        qApp->showGuiMessage(tr("Cannot perform drag \& drop operation."),
+                             tr("You can't transfer dragged item into different account, this is not supported."),
+                             QSystemTrayIcon::Warning,
+                             qApp->mainForm(),
+                             true);
+
+        qDebug("Dragged item cannot be dragged into different account. Cancelling drag-drop action.");
+        return false;
+      }
+
+      /*
+      if (dragged_item->kind() == RootItem::Feeed) {
+        qDebug("Drag-drop action for feed '%s' detected, editing the feed.", qPrintable(dragged_item->title()));
+
+        Feed *actual_feed = dragged_item->toFeed();
+        Feed *feed_new = new Feed(*actual_feed);
+
+        feed_new->setParent(target_item);
+        editFeed(actual_feed, feed_new);
+
+        emit requireItemValidationAfterDragDrop(indexForItem(actual_feed));
+      }
+      else if (dragged_item->kind() == RootItem::Cattegory) {
+        qDebug("Drag-drop action for category '%s' detected, editing the feed.", qPrintable(dragged_item->title()));
+
+        Category *actual_category = dragged_item->toCategory();
+        Category *category_new = new Category(*actual_category);
+
+        category_new->clearChildren();
+        category_new->setParent(target_item);
+        editCategory(actual_category, category_new);
+
+        emit requireItemValidationAfterDragDrop(indexForItem(actual_category));
+      }
+      */
+    }
+
+    return true;
+  }
+
+  return false;
+}
+
+Qt::DropActions FeedsModel::supportedDropActions() const {
+  return Qt::MoveAction;
+}
+
+Qt::ItemFlags FeedsModel::flags(const QModelIndex &index) const {
+  Qt::ItemFlags base_flags = QAbstractItemModel::flags(index);
+  RootItem *item_for_index = itemForIndex(index);
+  Qt::ItemFlags additional_flags = item_for_index->additionalFlags();
+
+  return base_flags | additional_flags;
+}
+
 void FeedsModel::executeNextAutoUpdate() {
   if (!qApp->feedUpdateLock()->tryLock()) {
     qDebug("Delaying scheduled feed auto-updates for one minute due to another running update.");

src/core/feedsmodel.h

@@ -47,6 +47,13 @@ class FeedsModel : public QAbstractItemModel {
       return itemForIndex(index)->data(index.column(), role);
     }
 
+    // Drag & drop.
+    QMimeData *mimeData(const QModelIndexList &indexes) const;
+    QStringList mimeTypes() const;
+    bool dropMimeData(const QMimeData *data, Qt::DropAction action, int row, int column, const QModelIndex &parent);
+    Qt::DropActions supportedDropActions() const;
+    Qt::ItemFlags flags(const QModelIndex &index) const;
+
     QVariant headerData(int section, Qt::Orientation orientation, int role) const;
     QModelIndex index(int row, int column, const QModelIndex &parent) const;
     QModelIndex parent(const QModelIndex &child) const;
@@ -181,8 +188,11 @@ class FeedsModel : public QAbstractItemModel {
     void onFeedUpdatesFinished(FeedDownloadResults results);
 
   signals:
+    // Update of feeds is finished.
     void feedsUpdateFinished();
 
+    // Counts of unread messages are changed in some feeds,
+    // notify view about this shit.
     void readFeedsFilterInvalidationRequested();
 
     // Emitted when model requests update of some feeds.
@@ -194,6 +204,10 @@ class FeedsModel : public QAbstractItemModel {
     // Emitted when there is a need of reloading of displayed messages.
     void reloadMessageListRequested(bool mark_selected_messages_read);
 
+    // There was some drag/drop operation, notify view about this.
+    // NOTE: View will probably expand dropped index.
+    void requireItemValidationAfterDragDrop(const QModelIndex &source_index);
+
   private:
     // Returns converted ids of given feeds
     // which are suitable as IN clause for SQL queries.

src/core/feedsproxymodel.cpp

@@ -206,7 +206,9 @@ bool FeedsProxyModel::filterAcceptsRow(int source_row, const QModelIndex &source
     return true;
   }
   else {
-    return item->countOfUnreadMessages() > 0;
+    // NOTE: If item has < 0 of unread message it may mean, that the count
+    // of unread messages is not (yet) known, display that item too.
+    return item->countOfUnreadMessages() != 0;
   }
 }
 

src/core/rootitem.cpp

@@ -166,6 +166,10 @@ QVariant RootItem::data(int column, int role) const {
   }
 }
 
+Qt::ItemFlags RootItem::additionalFlags() const {
+  return Qt::NoItemFlags;
+}
+
 int RootItem::countOfAllMessages() const {
   int total_count = 0;
 

src/core/rootitem.h

@@ -74,8 +74,7 @@ class RootItem : public QObject {
     /////////////////////////////////////////
 
     // Returns list of specific actions which can be done with the item.
-    // Do not include general actions here like actions:
-    //  Mark as read, Update, ...
+    // Do not include general actions here like actions: Mark as read, Update, ...
     // NOTE: Ownership of returned actions is not switched to caller, free them when needed.
     virtual QList<QAction*> contextMenuActions();
 
@@ -113,6 +112,7 @@ class RootItem : public QObject {
 
     virtual int row() const;
     virtual QVariant data(int column, int role) const;
+    virtual Qt::ItemFlags additionalFlags() const;
 
     // Each item offers "counts" of messages.
     // Returns counts of messages of all child items summed up.

src/gui/feedsview.cpp

@@ -54,6 +54,7 @@ FeedsView::FeedsView(QWidget *parent)
   m_sourceModel = m_proxyModel->sourceModel();
 
   // Connections.
+  connect(m_sourceModel, SIGNAL(requireItemValidationAfterDragDrop(QModelIndex)), this, SLOT(validateItemAfterDragDrop(QModelIndex)));
   connect(header(), SIGNAL(sortIndicatorChanged(int,Qt::SortOrder)), this, SLOT(saveSortState(int,Qt::SortOrder)));
 
   setModel(m_proxyModel);

src/services/standard/standardcategory.cpp

@@ -90,6 +90,10 @@ QVariant StandardCategory::data(int column, int role) const {
   }
 }
 
+Qt::ItemFlags StandardCategory::additionalFlags() const {
+  return Qt::ItemIsDragEnabled | Qt::ItemIsDropEnabled;
+}
+
 bool StandardCategory::editViaGui() {
   QPointer<FormStandardCategoryDetails> form_pointer = new FormStandardCategoryDetails(serviceRoot(), qApp->mainForm());
 

src/services/standard/standardcategory.h

@@ -44,6 +44,7 @@ class StandardCategory : public Category {
 
     // Returns the actual data representation of standard category.
     QVariant data(int column, int role) const;
+    Qt::ItemFlags additionalFlags() const;
 
     bool canBeEdited() {
       return true;

src/services/standard/standardfeed.cpp

@@ -436,6 +436,10 @@ QVariant StandardFeed::data(int column, int role) const {
   }
 }
 
+Qt::ItemFlags StandardFeed::additionalFlags() const {
+  return Qt::ItemIsDragEnabled;
+}
+
 int StandardFeed::update() {
   QByteArray feed_contents;
   int download_timeout = qApp->settings()->value(GROUP(Feeds), SETTING(Feeds::UpdateTimeout)).toInt();

src/services/standard/standardfeed.h

@@ -81,6 +81,7 @@ class StandardFeed : public Feed {
 
     // Obtains data related to this feed.
     QVariant data(int column, int role) const;
+    Qt::ItemFlags additionalFlags() const;
 
     // Perform fetching of new messages. Returns number of newly updated messages.
     int update();

src/services/standard/standardserviceroot.cpp

@@ -128,6 +128,10 @@ QVariant StandardServiceRoot::data(int column, int role) const {
   }
 }
 
+Qt::ItemFlags StandardServiceRoot::additionalFlags() const {
+  return Qt::ItemIsDropEnabled;
+}
+
 RecycleBin *StandardServiceRoot::recycleBin() {
   return m_recycleBin;
 }

src/services/standard/standardserviceroot.h

@@ -50,6 +50,7 @@ class StandardServiceRoot : public ServiceRoot {
     bool canBeEdited();
     bool canBeDeleted();
     QVariant data(int column, int role) const;
+    Qt::ItemFlags additionalFlags() const;
 
     RecycleBin *recycleBin();