src/Gui/MailBoxTreeView.cpp

   1 /* Copyright (C) 2012 Thomas Gahr <thomas.gahr@physik.uni-muenchen.de>
   2    Copyright (C) 2006 - 2016 Jan Kundrát <jkt@kde.org>
   3
   4    This file is part of the Trojita Qt IMAP e-mail client,
   5    http://trojita.flaska.net/
   6
   7    This program is free software; you can redistribute it and/or
   8    modify it under the terms of the GNU General Public License as
   9    published by the Free Software Foundation; either version 2 of
  10    the License or (at your option) version 3 or any later version
  11    accepted by the membership of KDE e.V. (or its successor approved
  12    by the membership of KDE e.V.), which shall act as a proxy
  13    defined in Section 14 of version 3 of the license.
  14
  15    This program is distributed in the hope that it will be useful,
  16    but WITHOUT ANY WARRANTY; without even the implied warranty of
  17    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18    GNU General Public License for more details.
  19
  20    You should have received a copy of the GNU General Public License
  21    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  22 */
  23
  24 #include <QDragMoveEvent>
  25 #include <QDropEvent>
  26 #include <QMenu>
  27 #include <QMimeData>
  28 #include "Common/SettingsNames.h"
  29 #include "Gui/MailBoxTreeView.h"
  30 #include "Gui/Util.h"
  31 #include "Imap/Model/ItemRoles.h"
  32 #include "Imap/Model/MailboxFinder.h"
  33 #include "Imap/Model/DragAndDrop.h"
  34 #include "UiUtils/IconLoader.h"
  35
  36 namespace Gui {
  37
  38 MailBoxTreeView::MailBoxTreeView(QWidget *parent, QSettings *settings)
  39     : QTreeView(parent)
  40     , m_mailboxFinder(nullptr), m_settings(settings)
  41 {
  42     setUniformRowHeights(true);
  43     setContextMenuPolicy(Qt::CustomContextMenu);
  44     setSelectionMode(QAbstractItemView::SingleSelection);
  45     setAllColumnsShowFocus(true);
  46     setAcceptDrops(true);
  47     setDropIndicatorShown(true);
  48     setHeaderHidden(true);
  49     // I wonder what's the best value to use here. Unfortunately, the default is to disable auto expanding.
  50     setAutoExpandDelay(800);
  51
  52     // Track expansion/collapsing so that we remember this state despite the asynchronous nature of mailbox loading
  53     connect(this, &QTreeView::expanded, this, [this](const QModelIndex &what) {
  54         auto name = what.data(Imap::Mailbox::RoleMailboxName).toString();
  55         if (!m_desiredExpansionState.contains(name)) {
  56             m_desiredExpansionState.insert(name);
  57             emit mailboxExpansionChanged(m_desiredExpansionState.toList());
  58         }
  59     });
  60     connect(this, &QTreeView::collapsed, this, [this](const QModelIndex &what) {
  61         auto name = what.data(Imap::Mailbox::RoleMailboxName).toString();
  62         if (m_desiredExpansionState.remove(name)) {
  63             emit mailboxExpansionChanged(m_desiredExpansionState.toList());
  64         }
  65     });
  66 }
  67
  68 /** \reimp
  69
  70 The MailboxFinder has to be kept up-to-speed about these changes.
  71 */
  72 void MailBoxTreeView::setModel(QAbstractItemModel *model)
  73 {
  74     delete m_mailboxFinder;
  75     m_mailboxFinder = nullptr;
  76
  77     if (model) {
  78         m_mailboxFinder = new Imap::Mailbox::MailboxFinder(this, model);
  79         connect(m_mailboxFinder, &Imap::Mailbox::MailboxFinder::mailboxFound,
  80                 this, [this](const QString &, const QModelIndex &index) {
  81             expand(index);
  82         });
  83         connect(model, &QAbstractItemModel::layoutChanged, this, &MailBoxTreeView::resetWatchedMailboxes);
  84         connect(model, &QAbstractItemModel::rowsRemoved, this, &MailBoxTreeView::resetWatchedMailboxes);
  85         connect(model, &QAbstractItemModel::modelReset, this, &MailBoxTreeView::resetWatchedMailboxes);
  86     }
  87     QTreeView::setModel(model);
  88     resetWatchedMailboxes();
  89 }
  90 /** @short Returns the user's default action from Qt::DropAction or Qt::IgnoreAction if not set */
  91 Qt::DropAction MailBoxTreeView::defaultDropAction()
  92 {
  93     auto mboxDropAction = m_settings->value(Common::SettingsNames::mboxDropAction, QVariant(QStringLiteral("ask"))).toString();
  94     if (mboxDropAction == QStringLiteral("move")) {
  95         return Qt::MoveAction;
  96     } else if (mboxDropAction == QStringLiteral("copy")) {
  97         return Qt::CopyAction;
  98     } else {
  99         return Qt::IgnoreAction;
 100     }
 101 }
 102
 103 /** @short Reimplemented for more consistent handling of modifiers
 104
 105   Qt's default behaviour is odd here:
 106   If you selected the move-action by pressing shift and you release the shift
 107   key while moving the mouse, the action does not change back to copy. But if you
 108   then move the mouse over a widget border - i.e. cause dragLeaveEvent, the action
 109   WILL change back to copy.
 110   This implementation immitates KDE's behaviour: react to a change in modifiers
 111   immediately.
 112 */
 113 void MailBoxTreeView::dragMoveEvent(QDragMoveEvent *event)
 114 {
 115     QTreeView::dragMoveEvent(event);
 116     if (!event->isAccepted())
 117         return;
 118     if (event->keyboardModifiers() == Qt::ShiftModifier)
 119         event->setDropAction(Qt::MoveAction);
 120     else
 121         event->setDropAction(Qt::CopyAction);
 122 }
 123
 124 /** @short Reimplemented to present the user with a menu to choose between copy or move.
 125
 126   Does not show the menu if either ctrl (copy messages) or shift (move messages)
 127   is pressed
 128 */
 129 void MailBoxTreeView::dropEvent(QDropEvent *event)
 130 {
 131     if (Gui::Util::isFromDistinctImapAccount(event)) {
 132         event->ignore();
 133         return;
 134     }
 135     if (event->keyboardModifiers() == Qt::ControlModifier) {
 136         event->setDropAction(Qt::CopyAction);
 137     } else if (event->keyboardModifiers() == Qt::ShiftModifier) {
 138         event->setDropAction(Qt::MoveAction);
 139     } else if (defaultDropAction() != Qt::IgnoreAction) {
 140         event->setDropAction(defaultDropAction());
 141     } else {
 142         QMenu menu(this);
 143         QAction *moveAction = menu.addAction(UiUtils::loadIcon(QStringLiteral("go-jump")), tr("Move here\tShift"));
 144         menu.addAction(UiUtils::loadIcon(QStringLiteral("edit-copy")), tr("Copy here\tCtrl"));
 145         QAction *cancelAction = menu.addAction(UiUtils::loadIcon(QStringLiteral("process-stop")), tr("Cancel"));
 146
 147         QAction *selectedAction = menu.exec(mapToGlobal(event->pos()));
 148
 149         // if user closes the menu or selects cancel, ignore the event
 150         if (!selectedAction || selectedAction == cancelAction) {
 151             event->ignore();
 152             return;
 153         }
 154
 155         event->setDropAction(selectedAction == moveAction ? Qt::MoveAction : Qt::CopyAction);
 156     }
 157
 158     QTreeView::dropEvent(event);
 159 }
 160
 161 void MailBoxTreeView::dragEnterEvent(QDragEnterEvent *event)
 162 {
 163     if (Gui::Util::isFromDistinctImapAccount(event)) {
 164         event->ignore();
 165         return;
 166     }
 167     QTreeView::dragEnterEvent(event);
 168 }
 169
 170 /** @short Specify which mailboxes should be expanded
 171
 172 The mailboxes might appear and disappear at any time, so let's make sure that
 173 they are properly expanded/collapsed once they pop in.
 174 */
 175 void MailBoxTreeView::setDesiredExpansion(const QStringList &mailboxNames)
 176 {
 177     m_desiredExpansionState = mailboxNames.toSet();
 178     resetWatchedMailboxes();
 179 }
 180
 181 /** @short Ensure that we watch stuff that we need to watch */
 182 void MailBoxTreeView::resetWatchedMailboxes()
 183 {
 184     if (m_mailboxFinder) {
 185         for (const auto &mailbox: m_desiredExpansionState) {
 186             m_mailboxFinder->addMailbox(mailbox);
 187         }
 188     }
 189 }
 190
 191 }