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 "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 #include <kdebug.h>
  38
  39 FolderExpander::FolderExpander(QAbstractItemView *view, QSortFilterProxyModel *proxyModel) :
  40     QObject(view),
  41     m_enabled(true),
  42     m_view(view),
  43     m_proxyModel(proxyModel),
  44     m_autoExpandTriggerTimer(0),
  45     m_autoExpandPos()
  46 {
  47     // Validation.  If these fail, the event filter is never
  48     // installed on the view and the FolderExpander is inactive.
  49     if (m_view == 0)  {
  50         kWarning() << "Need a view!";
  51         return; // Not valid.
  52     }
  53     if (m_proxyModel == 0)  {
  54         kWarning() << "Need a proxyModel!";
  55         return; // Not valid.
  56     }
  57     KDirModel *m_dirModel = qobject_cast< KDirModel* >( m_proxyModel->sourceModel() );
  58     if (m_dirModel == 0) {
  59         kWarning() << "Expected m_proxyModel's sourceModel() to be a KDirModel!";
  60         return; // Not valid.
  61     }
  62
  63     // Initialise auto-expand timer.
  64     m_autoExpandTriggerTimer = new QTimer(this);
  65     m_autoExpandTriggerTimer->setSingleShot(true);
  66     connect(m_autoExpandTriggerTimer, SIGNAL(timeout()),
  67             this, SLOT(autoExpandTimeout()));
  68
  69     // The view scrolling complicates matters, so we want to
  70     // be informed if they occur.
  71     connect(m_view->horizontalScrollBar(), SIGNAL(valueChanged(int)),
  72             this, SLOT(viewScrolled()));
  73     connect(m_view->verticalScrollBar(), SIGNAL(valueChanged(int)),
  74             this, SLOT(viewScrolled()));
  75
  76     // "Dragging" events are sent to the QAbstractItemView's viewport.
  77     m_view->viewport()->installEventFilter(this);
  78 }
  79
  80 void FolderExpander::setEnabled(bool enabled)
  81 {
  82     m_enabled = enabled;
  83 }
  84
  85 bool FolderExpander::enabled() const
  86 {
  87     return m_enabled;
  88 }
  89
  90 FolderExpander::~FolderExpander()
  91 {
  92 }
  93
  94 void FolderExpander::viewScrolled()
  95 {
  96     if (m_autoExpandTriggerTimer->isActive())  {
  97         kDebug() << "Resetting time due to scrolling!";
  98         // (Re-)set the timer while we're scrolling the view
  99         // (or it's being scrolled by some external mechanism).
 100         // TODO - experiment with this.  Cancelling the timer,
 101         // or adding a "penalty" on top of AUTO_EXPAND_DELAY
 102         // might work more nicely when drilling down through the sidebar
 103         // tree.
 104         m_autoExpandTriggerTimer->start(AUTO_EXPAND_DELAY);
 105     }
 106 }
 107
 108 void FolderExpander::autoExpandTimeout()
 109 {
 110     if (!m_enabled) {
 111         return;
 112     }
 113
 114     // We want to find whether the file currently being hovered over is a
 115     // directory. TODO - is there a simpler way, preferably without
 116     // needing to pass in m_proxyModel that has a KDirModel as its sourceModel() ... ?
 117     QModelIndex proxyIndexToExpand = m_view->indexAt(m_autoExpandPos);
 118     QModelIndex indexToExpand = m_proxyModel->mapToSource(proxyIndexToExpand);
 119     KDirModel* m_dirModel = qobject_cast< KDirModel* >(m_proxyModel->sourceModel());
 120     Q_ASSERT(m_dirModel != 0);
 121     KFileItem itemToExpand = m_dirModel->itemForIndex(indexToExpand );
 122
 123     if (itemToExpand.isNull()) {
 124         return;
 125     }
 126
 127     kDebug() << "Need to expand: " << itemToExpand.targetUrl() << " isDir? = " << itemToExpand.isDir();
 128
 129     if (itemToExpand.isDir()) {
 130         QTreeView *viewAsTreeView = qobject_cast<QTreeView*>(m_view);
 131         if (viewAsTreeView != 0) {
 132             // Toggle expanded state of this directory.
 133             viewAsTreeView->setExpanded(proxyIndexToExpand, !viewAsTreeView->isExpanded(proxyIndexToExpand));
 134         }
 135         else {
 136             // Enter this directory.
 137             emit enterDir(proxyIndexToExpand);
 138         }
 139     }
 140 }
 141
 142 bool FolderExpander::eventFilter(QObject* watched, QEvent* event)
 143 {
 144     Q_UNUSED(watched);
 145     // We're interested in reading Drag* events, but not filtering them,
 146     // so always return false.
 147     // We just store the position of the hover, here; actually working out
 148     // what the hovered item is and whether it is expandable is done in
 149     // autoExpandTimeout.
 150     if (event->type() == QEvent::DragMove) {
 151         QDragMoveEvent *dragMoveEvent = static_cast<QDragMoveEvent*>(event);
 152         // (Re-)set the timer while we're still moving and dragging.
 153         m_autoExpandTriggerTimer->start(AUTO_EXPAND_DELAY);
 154         m_autoExpandPos = dragMoveEvent->pos();
 155     } else if (event->type() == QEvent::DragLeave || event->type() == QEvent::Drop) {
 156         m_autoExpandTriggerTimer->stop();
 157     }
 158     return false;
 159 }