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 "Gui/MailBoxTreeView.h"
  29 #include "Gui/Util.h"
  30 #include "Imap/Model/ItemRoles.h"
  31 #include "Imap/Model/MailboxFinder.h"
  32 #include "Imap/Model/DragAndDrop.h"
  33 #include "UiUtils/IconLoader.h"
  34
  35 namespace Gui {
  36
  37 MailBoxTreeView::MailBoxTreeView(QWidget *parent)
  38     : QTreeView(parent)
  39     , m_mailboxFinder(nullptr)
  40 {
  41     setUniformRowHeights(true);
  42     setContextMenuPolicy(Qt::CustomContextMenu);
  43     setSelectionMode(QAbstractItemView::SingleSelection);
  44     setAllColumnsShowFocus(true);
  45     setAcceptDrops(true);
  46     setDropIndicatorShown(true);
  47     setHeaderHidden(true);
  48     // I wonder what's the best value to use here. Unfortunately, the default is to disable auto expanding.
  49     setAutoExpandDelay(800);
  50
  51     // Track expansion/collapsing so that we remember this state despite the asynchronous nature of mailbox loading
  52     connect(this, &QTreeView::expanded, this, [this](const QModelIndex &what) {
  53         auto name = what.data(Imap::Mailbox::RoleMailboxName).toString();
  54         if (!m_desiredExpansionState.contains(name)) {
  55             m_desiredExpansionState.insert(name);
  56             emit mailboxExpansionChanged(m_desiredExpansionState.toList());
  57         }
  58     });
  59     connect(this, &QTreeView::collapsed, this, [this](const QModelIndex &what) {
  60         auto name = what.data(Imap::Mailbox::RoleMailboxName).toString();
  61         if (m_desiredExpansionState.remove(name)) {
  62             emit mailboxExpansionChanged(m_desiredExpansionState.toList());
  63         }
  64     });
  65 }
  66
  67 /** \reimp
  68
  69 The MailboxFinder has to be kept up-to-speed about these changes.
  70 */
  71 void MailBoxTreeView::setModel(QAbstractItemModel *model)
  72 {
  73     delete m_mailboxFinder;
  74     m_mailboxFinder = nullptr;
  75
  76     if (model) {
  77         m_mailboxFinder = new Imap::Mailbox::MailboxFinder(this, model);
  78         connect(m_mailboxFinder, &Imap::Mailbox::MailboxFinder::mailboxFound,
  79                 this, [this](const QString &, const QModelIndex &index) {
  80             expand(index);
  81         });
  82         connect(model, &QAbstractItemModel::layoutChanged, this, &MailBoxTreeView::resetWatchedMailboxes);
  83         connect(model, &QAbstractItemModel::rowsRemoved, this, &MailBoxTreeView::resetWatchedMailboxes);
  84         connect(model, &QAbstractItemModel::modelReset, this, &MailBoxTreeView::resetWatchedMailboxes);
  85     }
  86     QTreeView::setModel(model);
  87     resetWatchedMailboxes();
  88 }
  89
  90 /** @short Reimplemented for more consistent handling of modifiers
  91
  92   Qt's default behaviour is odd here:
  93   If you selected the move-action by pressing shift and you release the shift
  94   key while moving the mouse, the action does not change back to copy. But if you
  95   then move the mouse over a widget border - i.e. cause dragLeaveEvent, the action
  96   WILL change back to copy.
  97   This implementation immitates KDE's behaviour: react to a change in modifiers
  98   immediately.
  99 */
 100 void MailBoxTreeView::dragMoveEvent(QDragMoveEvent *event)
 101 {
 102     QTreeView::dragMoveEvent(event);
 103     if (!event->isAccepted())
 104         return;
 105     if (event->keyboardModifiers() == Qt::ShiftModifier)
 106         event->setDropAction(Qt::MoveAction);
 107     else
 108         event->setDropAction(Qt::CopyAction);
 109 }
 110
 111 /** @short Reimplemented to present the user with a menu to choose between copy or move.
 112
 113   Does not show the menu if either ctrl (copy messages) or shift (move messages)
 114   is pressed
 115 */
 116 void MailBoxTreeView::dropEvent(QDropEvent *event)
 117 {
 118     if (Gui::Util::isFromDistinctImapAccount(event)) {
 119         event->ignore();
 120         return;
 121     }
 122     if (event->keyboardModifiers() == Qt::ControlModifier) {
 123         event->setDropAction(Qt::CopyAction);
 124     } else if (event->keyboardModifiers() == Qt::ShiftModifier) {
 125         event->setDropAction(Qt::MoveAction);
 126     } else {
 127         QMenu menu;
 128         QAction *moveAction = menu.addAction(UiUtils::loadIcon(QStringLiteral("go-jump")), tr("Move here\tShift"));
 129         menu.addAction(UiUtils::loadIcon(QStringLiteral("edit-copy")), tr("Copy here\tCtrl"));
 130         QAction *cancelAction = menu.addAction(UiUtils::loadIcon(QStringLiteral("process-stop")), tr("Cancel"));
 131
 132         QAction *selectedAction = menu.exec(QCursor::pos());
 133
 134         // if user closes the menu or selects cancel, ignore the event
 135         if (!selectedAction || selectedAction == cancelAction) {
 136             event->ignore();
 137             return;
 138         }
 139
 140         event->setDropAction(selectedAction == moveAction ? Qt::MoveAction : Qt::CopyAction);
 141     }
 142
 143     QTreeView::dropEvent(event);
 144 }
 145
 146 void MailBoxTreeView::dragEnterEvent(QDragEnterEvent *event)
 147 {
 148     if (Gui::Util::isFromDistinctImapAccount(event)) {
 149         event->ignore();
 150         return;
 151     }
 152     QTreeView::dragEnterEvent(event);
 153 }
 154
 155 /** @short Specify which mailboxes should be expanded
 156
 157 The mailboxes might appear and disappear at any time, so let's make sure that
 158 they are properly expanded/collapsed once they pop in.
 159 */
 160 void MailBoxTreeView::setDesiredExpansion(const QStringList &mailboxNames)
 161 {
 162     m_desiredExpansionState = mailboxNames.toSet();
 163     resetWatchedMailboxes();
 164 }
 165
 166 /** @short Ensure that we watch stuff that we need to watch */
 167 void MailBoxTreeView::resetWatchedMailboxes()
 168 {
 169     if (m_mailboxFinder) {
 170         for (const auto &mailbox: m_desiredExpansionState) {
 171             m_mailboxFinder->addMailbox(mailbox);
 172         }
 173     }
 174 }
 175
 176 }