Implement sane behavior of space key in torrent content list. Closes #140.

Definitions:

Selection in QTreeView consist of two things:

   currentIndex -- is a (dotted) cell where user clicked last time. Note
                   that it is a cell
   selectedIndexes -- is a set of cells (blue) of current selection.

Checkboxes in torrent content lists are belong to COL_NAME column.

Problem:

The problem is that spacebar toggled checkbox only in currentIndex
index. This has two consequences:

  1. It is impossible to toggle checkboxes on multiple rows
     simultaneously.
  2. If currentIndex is not in COL_NAME column a space key doesn't work
     at all. This problem is amplifyed by the fact that SelectionBehavior
     is set to SelectRows. So visually it is impossible to tell which
     column does it belong to. For end user it looks like "space doesn't
     work sometimes".

This patch addresses the problem by implementing TorrentContentTreeView
derived from QTreeView and overridding keyPressEvent(QKeyEvent*).

The code of TorrentContentTreeView::keyPressEvent is written under
inspiration from QAbstractItemView::keyPressEvent and
QItemDelegate::editorEvent.

src/addnewtorrentdialog.ui

@@ -166,7 +166,7 @@
        </layout>
       </item>
       <item>
-       <widget class="QTreeView" name="content_tree">
+       <widget class="TorrentContentTreeView" name="content_tree">
         <property name="contextMenuPolicy">
          <enum>Qt::CustomContextMenu</enum>
         </property>
@@ -262,6 +262,13 @@
    </property>
   </action>
  </widget>
+ <customwidgets>
+  <customwidget>
+   <class>TorrentContentTreeView</class>
+   <extends>QTreeView</extends>
+   <header>torrentcontenttreeview.h</header>
+  </customwidget>
+ </customwidgets>
  <resources/>
  <connections>
   <connection>

src/properties/propertieswidget.ui

@@ -685,7 +685,7 @@
         </layout>
        </item>
        <item>
-        <widget class="QTreeView" name="filesList">
+        <widget class="TorrentContentTreeView" name="filesList">
          <property name="contextMenuPolicy">
           <enum>Qt::CustomContextMenu</enum>
          </property>
@@ -780,6 +780,13 @@
    </property>
   </action>
  </widget>
+ <customwidgets>
+  <customwidget>
+   <class>TorrentContentTreeView</class>
+   <extends>QTreeView</extends>
+   <header location="global">torrentcontenttreeview.h</header>
+  </customwidget>
+ </customwidgets>
  <resources/>
  <connections/>
 </ui>

src/src.pro

@@ -133,6 +133,7 @@ nox {
               torrentcontentmodelfolder.h \
               torrentcontentmodelfile.h \
               torrentcontentfiltermodel.h \
+              torrentcontenttreeview.h \
               deletionconfirmationdlg.h \
               statusbar.h \
               reverseresolution.h \
@@ -167,6 +168,7 @@ nox {
              torrentcontentmodelfolder.cpp \
              torrentcontentmodelfile.cpp \
              torrentcontentfiltermodel.cpp \
+             torrentcontenttreeview.cpp \
              sessionapplication.cpp \
              torrentimportdlg.cpp \
              executionlog.cpp \

src/torrentcontenttreeview.cpp

@@ -0,0 +1,78 @@
+/*
+ * Bittorrent Client using Qt4 and libtorrent.
+ * Copyright (C) 2014  Ivan Sorokin
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ *
+ * In addition, as a special exception, the copyright holders give permission to
+ * link this program with the OpenSSL project's "OpenSSL" library (or with
+ * modified versions of it that use the same license as the "OpenSSL" library),
+ * and distribute the linked executables. You must obey the GNU General Public
+ * License in all respects for all of the code used other than "OpenSSL".  If you
+ * modify file(s), you may extend this exception to your version of the file(s),
+ * but you are not obligated to do so. If you do not wish to do so, delete this
+ * exception statement from your version.
+ *
+ * Contact : vanyacpp@gmail.com
+ */
+
+#include "torrentcontenttreeview.h"
+
+#include <QKeyEvent>
+#include <QModelIndexList>
+
+#include "torrentcontentmodelitem.h"
+
+TorrentContentTreeView::TorrentContentTreeView(QWidget* parent)
+  : QTreeView(parent)
+{}
+
+void TorrentContentTreeView::keyPressEvent(QKeyEvent *event) {
+  if (event->key() != Qt::Key_Space && event->key() != Qt::Key_Select) {
+    QTreeView::keyPressEvent(event);
+    return;
+  }
+
+  event->accept();
+
+  QModelIndex current = currentNameCell();
+
+  QVariant value = current.data(Qt::CheckStateRole);
+  if (!value.isValid()) {
+    Q_ASSERT(false);
+    return;
+  }
+
+  Qt::CheckState state = (static_cast<Qt::CheckState>(value.toInt()) == Qt::Checked
+                       ? Qt::Unchecked : Qt::Checked);
+
+  QModelIndexList selection = selectionModel()->selectedRows(TorrentContentModelItem::COL_NAME);
+
+  for (QModelIndexList::const_iterator i = selection.begin(); i != selection.end(); ++i) {
+    QModelIndex index = *i;
+    Q_ASSERT(i->column() == TorrentContentModelItem::COL_NAME);
+    model()->setData(index, state, Qt::CheckStateRole);
+  }
+}
+
+QModelIndex TorrentContentTreeView::currentNameCell() {
+  QModelIndex current = currentIndex();
+  if (!current.isValid()) {
+    Q_ASSERT(false);
+    return QModelIndex();
+  }
+
+  return model()->index(current.row(), TorrentContentModelItem::COL_NAME, current.parent());
+}

src/torrentcontenttreeview.h

@@ -0,0 +1,47 @@
+/*
+ * Bittorrent Client using Qt4 and libtorrent.
+ * Copyright (C) 2014  Ivan Sorokin
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ *
+ * In addition, as a special exception, the copyright holders give permission to
+ * link this program with the OpenSSL project's "OpenSSL" library (or with
+ * modified versions of it that use the same license as the "OpenSSL" library),
+ * and distribute the linked executables. You must obey the GNU General Public
+ * License in all respects for all of the code used other than "OpenSSL".  If you
+ * modify file(s), you may extend this exception to your version of the file(s),
+ * but you are not obligated to do so. If you do not wish to do so, delete this
+ * exception statement from your version.
+ *
+ * Contact : vanyacpp@gmail.com
+ */
+
+#ifndef TORRENTCONTENTTREEVIEW_H
+#define TORRENTCONTENTTREEVIEW_H
+
+#include <QTreeView>
+
+class TorrentContentTreeView : public QTreeView {
+  Q_OBJECT
+
+public:
+  explicit TorrentContentTreeView(QWidget *parent = 0);
+  void keyPressEvent(QKeyEvent *event);
+
+private:
+  QModelIndex currentNameCell();
+};
+
+#endif