src/views/folderexpander.cpp

   1 /***************************************************************************
   2  *   Copyright (C) 2008 by Simon St James <kdedevel@etotheipiplusone.com>  *
   3  *                                                                         *
   4  *   This program is free software; you can redistribute it and/or modify  *
   5  *   it under the terms of the GNU General Public License as published by  *
   6  *   the Free Software Foundation; either version 2 of the License, or     *
   7  *   (at your option) any later version.                                   *
   8  *                                                                         *
   9  *   This program is distributed in the hope that it will be useful,       *
  10  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
  11  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
  12  *   GNU General Public License for more details.                          *
  13  *                                                                         *
  14  *   You should have received a copy of the GNU General Public License     *
  15  *   along with this program; if not, write to the                         *
  16  *   Free Software Foundation, Inc.,                                       *
  17  *   51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA            *
  18  ***************************************************************************/
  19
  20 #include "folderexpander.h"
  21
  22 #include <QtCore/QTimer>
  23 #include <QtGui/QAbstractItemView>
  24 #include <QtGui/QTreeView>
  25 #include <QtGui/QScrollBar>
  26
  27 #include <QtCore/QEvent>
  28 #include <QtGui/QDragMoveEvent>
  29
  30 #include <QtGui/QSortFilterProxyModel>
  31
  32 #include <kdirmodel.h>
  33
  34 FolderExpander::FolderExpander(QAbstractItemView *view, QSortFilterProxyModel *proxyModel) :
  35     QObject(view),
  36     m_enabled(true),
  37     m_view(view),
  38     m_proxyModel(proxyModel),
  39     m_autoExpandTriggerTimer(0),
  40     m_autoExpandPos()
  41 {
  42     if (m_view == 0)  {
  43         return;
  44     }
  45     if (m_proxyModel == 0)  {
  46         return;
  47     }
  48     KDirModel *m_dirModel = qobject_cast<KDirModel*>(m_proxyModel->sourceModel());
  49     if (m_dirModel == 0) {
  50         return;
  51     }
  52
  53     // Initialise auto-expand timer.
  54     m_autoExpandTriggerTimer = new QTimer(this);
  55     m_autoExpandTriggerTimer->setSingleShot(true);
  56     connect(m_autoExpandTriggerTimer, SIGNAL(timeout()),
  57             this, SLOT(autoExpandTimeout()));
  58
  59     // The view scrolling complicates matters, so we want to
  60     // be informed if they occur.
  61     connect(m_view->horizontalScrollBar(), SIGNAL(valueChanged(int)),
  62             this, SLOT(viewScrolled()));
  63     connect(m_view->verticalScrollBar(), SIGNAL(valueChanged(int)),
  64             this, SLOT(viewScrolled()));
  65
  66     // "Dragging" events are sent to the QAbstractItemView's viewport.
  67     m_view->viewport()->installEventFilter(this);
  68 }
  69
  70 void FolderExpander::setEnabled(bool enabled)
  71 {
  72     m_enabled = enabled;
  73 }
  74
  75 bool FolderExpander::enabled() const
  76 {
  77     return m_enabled;
  78 }
  79
  80 FolderExpander::~FolderExpander()
  81 {
  82 }
  83
  84 void FolderExpander::viewScrolled()
  85 {
  86     if (m_autoExpandTriggerTimer->isActive())  {
  87         m_autoExpandTriggerTimer->start(AUTO_EXPAND_DELAY);
  88     }
  89 }
  90
  91 void FolderExpander::autoExpandTimeout()
  92 {
  93     if (!m_enabled) {
  94         return;
  95     }
  96
  97     // We want to find whether the file currently being hovered over is a
  98     // directory. TODO - is there a simpler way, preferably without
  99     // needing to pass in m_proxyModel that has a KDirModel as its sourceModel() ... ?
 100     QModelIndex proxyIndexToExpand = m_view->indexAt(m_autoExpandPos);
 101     QModelIndex indexToExpand = m_proxyModel->mapToSource(proxyIndexToExpand);
 102     KDirModel* m_dirModel = qobject_cast< KDirModel* >(m_proxyModel->sourceModel());
 103     Q_ASSERT(m_dirModel != 0);
 104     KFileItem itemToExpand = m_dirModel->itemForIndex(indexToExpand);
 105
 106     if (itemToExpand.isNull() || itemToExpand == m_dirModel->itemForIndex(QModelIndex())) {
 107         // The second clause occurs when we are expanding the folder represented
 108         // by the view, which is a case we should ignore (#182618).
 109         return;
 110     }
 111
 112     if (itemToExpand.isDir()) {
 113         QTreeView* treeView = qobject_cast<QTreeView*>(m_view);
 114         if ((treeView != 0) && treeView->itemsExpandable()) {
 115             // Toggle expanded state of this directory.
 116             treeView->setExpanded(proxyIndexToExpand, !treeView->isExpanded(proxyIndexToExpand));
 117         }
 118         else {
 119             emit enterDir(proxyIndexToExpand);
 120         }
 121     }
 122 }
 123
 124 bool FolderExpander::eventFilter(QObject* watched, QEvent* event)
 125 {
 126     Q_UNUSED(watched);
 127     // We're interested in reading Drag* events, but not filtering them,
 128     // so always return false.
 129     // We just store the position of the hover, here; actually working out
 130     // what the hovered item is and whether it is expandable is done in
 131     // autoExpandTimeout.
 132     if (event->type() == QEvent::DragMove) {
 133         QDragMoveEvent *dragMoveEvent = static_cast<QDragMoveEvent*>(event);
 134         // (Re-)set the timer while we're still moving and dragging.
 135         m_autoExpandTriggerTimer->start(AUTO_EXPAND_DELAY);
 136         m_autoExpandPos = dragMoveEvent->pos();
 137     } else if (event->type() == QEvent::DragLeave || event->type() == QEvent::Drop) {
 138         m_autoExpandTriggerTimer->stop();
 139     }
 140     return false;
 141 }