apps/dolphin/src/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 #include "dolphinview.h"
  22
  23 #include "settings/dolphinsettings.h"
  24 #include "dolphin_generalsettings.h"
  25
  26 #include <QtCore/QTimer>
  27 #include <QtGui/QAbstractItemView>
  28 #include <QtGui/QTreeView>
  29 #include <QtGui/QScrollBar>
  30
  31 #include <QtCore/QEvent>
  32 #include <QtGui/QDragMoveEvent>
  33
  34 #include <QtGui/QSortFilterProxyModel>
  35
  36 #include <kdirmodel.h>
  37
  38 FolderExpander::FolderExpander(QAbstractItemView *view, QSortFilterProxyModel *proxyModel) :
  39     QObject(view),
  40     m_enabled(true),
  41     m_view(view),
  42     m_proxyModel(proxyModel),
  43     m_autoExpandTriggerTimer(0),
  44     m_autoExpandPos()
  45 {
  46     // Validation.  If these fail, the event filter is never
  47     // installed on the view and the FolderExpander is inactive.
  48     if (m_view == 0)  {
  49         kWarning() << "Need a view!";
  50         return; // Not valid.
  51     }
  52     if (m_proxyModel == 0)  {
  53         kWarning() << "Need a proxyModel!";
  54         return; // Not valid.
  55     }
  56     KDirModel *m_dirModel = qobject_cast< KDirModel* >( m_proxyModel->sourceModel() );
  57     if (m_dirModel == 0) {
  58         kWarning() << "Expected m_proxyModel's sourceModel() to be a KDirModel!";
  59         return; // Not valid.
  60     }
  61
  62     // Initialise auto-expand timer.
  63     m_autoExpandTriggerTimer = new QTimer(this);
  64     m_autoExpandTriggerTimer->setSingleShot(true);
  65     connect(m_autoExpandTriggerTimer, SIGNAL(timeout()),
  66             this, SLOT(autoExpandTimeout()));
  67
  68     // The view scrolling complicates matters, so we want to
  69     // be informed if they occur.
  70     connect(m_view->horizontalScrollBar(), SIGNAL(valueChanged(int)),
  71             this, SLOT(viewScrolled()));
  72     connect(m_view->verticalScrollBar(), SIGNAL(valueChanged(int)),
  73             this, SLOT(viewScrolled()));
  74
  75     // "Dragging" events are sent to the QAbstractItemView's viewport.
  76     m_view->viewport()->installEventFilter(this);
  77 }
  78
  79 void FolderExpander::setEnabled(bool enabled)
  80 {
  81     m_enabled = enabled;
  82 }
  83
  84 bool FolderExpander::enabled() const
  85 {
  86     return m_enabled;
  87 }
  88
  89 FolderExpander::~FolderExpander()
  90 {
  91 }
  92
  93 void FolderExpander::viewScrolled()
  94 {
  95     if (m_autoExpandTriggerTimer->isActive())  {
  96         m_autoExpandTriggerTimer->start(AUTO_EXPAND_DELAY);
  97     }
  98 }
  99
 100 void FolderExpander::autoExpandTimeout()
 101 {
 102     if (!m_enabled) {
 103         return;
 104     }
 105
 106     // We want to find whether the file currently being hovered over is a
 107     // directory. TODO - is there a simpler way, preferably without
 108     // needing to pass in m_proxyModel that has a KDirModel as its sourceModel() ... ?
 109     QModelIndex proxyIndexToExpand = m_view->indexAt(m_autoExpandPos);
 110     QModelIndex indexToExpand = m_proxyModel->mapToSource(proxyIndexToExpand);
 111     KDirModel* m_dirModel = qobject_cast< KDirModel* >(m_proxyModel->sourceModel());
 112     Q_ASSERT(m_dirModel != 0);
 113     KFileItem itemToExpand = m_dirModel->itemForIndex(indexToExpand);
 114
 115     if (itemToExpand.isNull()) {
 116         return;
 117     }
 118
 119     if (itemToExpand.isDir()) {
 120         QTreeView* treeView = qobject_cast<QTreeView*>(m_view);
 121         if ((treeView != 0) && treeView->itemsExpandable()) {
 122             // Toggle expanded state of this directory.
 123             treeView->setExpanded(proxyIndexToExpand, !treeView->isExpanded(proxyIndexToExpand));
 124         }
 125         else {
 126             emit enterDir(proxyIndexToExpand, m_view);
 127         }
 128     }
 129 }
 130
 131 bool FolderExpander::eventFilter(QObject* watched, QEvent* event)
 132 {
 133     Q_UNUSED(watched);
 134     // We're interested in reading Drag* events, but not filtering them,
 135     // so always return false.
 136     // We just store the position of the hover, here; actually working out
 137     // what the hovered item is and whether it is expandable is done in
 138     // autoExpandTimeout.
 139     if (event->type() == QEvent::DragMove) {
 140         QDragMoveEvent *dragMoveEvent = static_cast<QDragMoveEvent*>(event);
 141         // (Re-)set the timer while we're still moving and dragging.
 142         m_autoExpandTriggerTimer->start(AUTO_EXPAND_DELAY);
 143         m_autoExpandPos = dragMoveEvent->pos();
 144     } else if (event->type() == QEvent::DragLeave || event->type() == QEvent::Drop) {
 145         m_autoExpandTriggerTimer->stop();
 146     }
 147     return false;
 148 }