src/views/tooltips/tooltipmanager.cpp

   1 /*******************************************************************************
   2  *   Copyright (C) 2008 by Konstantin Heil <konst.heil@stud.uni-heidelberg.de> *
   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 "tooltipmanager.h"
  21
  22 #include "filemetadatatooltip.h"
  23 #include <KIcon>
  24 #include <KIO/PreviewJob>
  25 #include <KSharedConfig>
  26
  27 #include <QApplication>
  28 #include <QDesktopWidget>
  29 #include <QScrollArea>
  30 #include <QScrollBar>
  31 #include <QTimer>
  32
  33 #include <views/dolphinmodel.h>
  34 #include <views/dolphinsortfilterproxymodel.h>
  35
  36 ToolTipManager::ToolTipManager(QAbstractItemView* parent,
  37                                DolphinSortFilterProxyModel* model) :
  38     QObject(parent),
  39     m_view(parent),
  40     m_dolphinModel(0),
  41     m_proxyModel(model),
  42     m_showToolTipTimer(0),
  43     m_contentRetrievalTimer(0),
  44     m_fileMetaDataToolTip(0),
  45     m_toolTipRequested(false),
  46     m_metaDataRequested(false),
  47     m_appliedWaitCursor(false),
  48     m_item(),
  49     m_itemRect()
  50 {
  51     m_dolphinModel = static_cast<DolphinModel*>(m_proxyModel->sourceModel());
  52     connect(parent, SIGNAL(entered(const QModelIndex&)),
  53             this, SLOT(requestToolTip(const QModelIndex&)));
  54     connect(parent, SIGNAL(viewportEntered()),
  55             this, SLOT(hideToolTip()));
  56
  57     // Initialize timers
  58     m_showToolTipTimer = new QTimer(this);
  59     m_showToolTipTimer->setSingleShot(true);
  60     m_showToolTipTimer->setInterval(500);
  61     connect(m_showToolTipTimer, SIGNAL(timeout()), this, SLOT(showToolTip()));
  62
  63     m_contentRetrievalTimer = new QTimer(this);
  64     m_contentRetrievalTimer->setSingleShot(true);
  65     m_contentRetrievalTimer->setInterval(200);
  66     connect(m_contentRetrievalTimer, SIGNAL(timeout()), this, SLOT(startContentRetrieval()));
  67
  68     Q_ASSERT(m_contentRetrievalTimer->interval() < m_showToolTipTimer->interval());
  69
  70     // When the mousewheel is used, the items don't get a hovered indication
  71     // (Qt-issue #200665). To assure that the tooltip still gets hidden,
  72     // the scrollbars are observed.
  73     connect(parent->horizontalScrollBar(), SIGNAL(valueChanged(int)),
  74             this, SLOT(hideToolTip()));
  75     connect(parent->verticalScrollBar(), SIGNAL(valueChanged(int)),
  76             this, SLOT(hideToolTip()));
  77
  78     Q_ASSERT(m_view);
  79     m_view->viewport()->installEventFilter(this);
  80     m_view->installEventFilter(this);
  81 }
  82
  83 ToolTipManager::~ToolTipManager()
  84 {
  85 }
  86
  87 void ToolTipManager::hideToolTip()
  88 {
  89     if (m_appliedWaitCursor) {
  90         QApplication::restoreOverrideCursor();
  91         m_appliedWaitCursor = false;
  92     }
  93
  94     m_toolTipRequested = false;
  95     m_metaDataRequested = false;
  96     m_showToolTipTimer->stop();
  97     m_contentRetrievalTimer->stop();
  98
  99     delete m_fileMetaDataToolTip;
 100     m_fileMetaDataToolTip = 0;
 101 }
 102
 103
 104 bool ToolTipManager::eventFilter(QObject* watched, QEvent* event)
 105 {
 106     if (watched == m_view->viewport()) {
 107         switch (event->type()) {
 108         case QEvent::Leave:
 109         case QEvent::MouseButtonPress:
 110             hideToolTip();
 111             break;
 112         default:
 113             break;
 114         }
 115     } else if ((watched == m_view) && (event->type() == QEvent::KeyPress)) {
 116         hideToolTip();
 117     }
 118
 119     return QObject::eventFilter(watched, event);
 120 }
 121
 122 void ToolTipManager::requestToolTip(const QModelIndex& index)
 123 {
 124     hideToolTip();
 125
 126     // Only request a tooltip for the name column and when no selection or
 127     // drag & drop operation is done (indicated by the left mouse button)
 128     if ((index.column() == DolphinModel::Name) && !(QApplication::mouseButtons() & Qt::LeftButton)) {
 129         m_itemRect = m_view->visualRect(index);
 130         const QPoint pos = m_view->viewport()->mapToGlobal(m_itemRect.topLeft());
 131         m_itemRect.moveTo(pos);
 132
 133         const QModelIndex dirIndex = m_proxyModel->mapToSource(index);
 134         m_item = m_dolphinModel->itemForIndex(dirIndex);
 135
 136         // Only start the retrieving of the content, when the mouse has been over this
 137         // item for 200 milliseconds. This prevents a lot of useless preview jobs and
 138         // meta data retrieval, when passing rapidly over a lot of items.
 139         Q_ASSERT(!m_fileMetaDataToolTip);
 140         m_fileMetaDataToolTip = new FileMetaDataToolTip(m_view);
 141         connect(m_fileMetaDataToolTip, SIGNAL(metaDataRequestFinished(KFileItemList)),
 142                 this, SLOT(slotMetaDataRequestFinished()));
 143
 144         m_contentRetrievalTimer->start();
 145         m_showToolTipTimer->start();
 146         m_toolTipRequested = true;
 147         Q_ASSERT(!m_metaDataRequested);
 148     }
 149 }
 150
 151 void ToolTipManager::startContentRetrieval()
 152 {
 153     if (!m_toolTipRequested) {
 154         return;
 155     }
 156
 157     m_fileMetaDataToolTip->setName(m_item.text());
 158
 159     // Request the retrieval of meta-data. The slot
 160     // slotMetaDataRequestFinished() is invoked after the
 161     // meta-data have been received.
 162     m_metaDataRequested = true;
 163     m_fileMetaDataToolTip->setItems(KFileItemList() << m_item);
 164     m_fileMetaDataToolTip->adjustSize();
 165
 166     // Request a preview of the item
 167     m_fileMetaDataToolTip->setPreview(QPixmap());
 168
 169     KIO::PreviewJob* job = KIO::filePreview(KFileItemList() << m_item, QSize(256, 256));
 170
 171     connect(job, SIGNAL(gotPreview(const KFileItem&, const QPixmap&)),
 172             this, SLOT(setPreviewPix(const KFileItem&, const QPixmap&)));
 173     connect(job, SIGNAL(failed(const KFileItem&)),
 174             this, SLOT(previewFailed()));
 175 }
 176
 177
 178 void ToolTipManager::setPreviewPix(const KFileItem& item,
 179                                    const QPixmap& pixmap)
 180 {
 181     if (!m_toolTipRequested || (m_item.url() != item.url())) {
 182         // No tooltip is requested anymore or an old preview has been received
 183         return;
 184     }
 185
 186     if (pixmap.isNull()) {
 187         previewFailed();
 188     } else {
 189         m_fileMetaDataToolTip->setPreview(pixmap);
 190         if (!m_showToolTipTimer->isActive()) {
 191             showToolTip();
 192         }
 193     }
 194 }
 195
 196 void ToolTipManager::previewFailed()
 197 {
 198     if (!m_toolTipRequested) {
 199         return;
 200     }
 201
 202     const QPixmap pixmap = KIcon(m_item.iconName()).pixmap(128, 128);
 203     m_fileMetaDataToolTip->setPreview(pixmap);
 204     if (!m_showToolTipTimer->isActive()) {
 205         showToolTip();
 206     }
 207 }
 208
 209 void ToolTipManager::slotMetaDataRequestFinished()
 210 {
 211     if (!m_toolTipRequested) {
 212         return;
 213     }
 214
 215     m_metaDataRequested = false;
 216
 217     if (!m_showToolTipTimer->isActive()) {
 218         showToolTip();
 219     }
 220 }
 221
 222 void ToolTipManager::showToolTip()
 223 {
 224     Q_ASSERT(m_toolTipRequested);
 225     if (m_appliedWaitCursor) {
 226         QApplication::restoreOverrideCursor();
 227         m_appliedWaitCursor = false;
 228     }
 229
 230     if (QApplication::mouseButtons() & Qt::LeftButton) {
 231         return;
 232     }
 233
 234     if (m_fileMetaDataToolTip->preview().isNull() || m_metaDataRequested) {
 235         Q_ASSERT(!m_appliedWaitCursor);
 236         QApplication::setOverrideCursor(QCursor(Qt::WaitCursor));
 237         m_appliedWaitCursor = true;
 238         return;
 239     }
 240
 241     const QRect screen = QApplication::desktop()->screenGeometry(QCursor::pos());
 242
 243     // Restrict tooltip size to current screen size when needed.
 244     // Because layout controlling widget doesn't respect widget's maximumSize property
 245     // (correct me if I'm wrong), we need to let layout do its work, then manually change
 246     // geometry if resulting widget doesn't fit the screen.
 247
 248     // Step #1 - make sizeHint return calculated tooltip size
 249     m_fileMetaDataToolTip->layout()->setSizeConstraint(QLayout::SetFixedSize);
 250     m_fileMetaDataToolTip->adjustSize();
 251     QSize size = m_fileMetaDataToolTip->sizeHint();
 252
 253     // Step #2 - correct tooltip size when needed
 254     if (size.width() > screen.width()) {
 255         size.setWidth(screen.width());
 256     }
 257     if (size.height() > screen.height()) {
 258         size.setHeight(screen.height());
 259     }
 260
 261     // m_itemRect defines the area of the item, where the tooltip should be
 262     // shown. Per default the tooltip is shown centered at the bottom.
 263     // It must be assured that:
 264     // - the content is fully visible
 265     // - the content is not drawn inside m_itemRect
 266     const int margin = 3;
 267     const bool hasRoomToLeft  = (m_itemRect.left()   - size.width()  - margin >= screen.left());
 268     const bool hasRoomToRight = (m_itemRect.right()  + size.width()  + margin <= screen.right());
 269     const bool hasRoomAbove   = (m_itemRect.top()    - size.height() - margin >= screen.top());
 270     const bool hasRoomBelow   = (m_itemRect.bottom() + size.height() + margin <= screen.bottom());
 271     if (!hasRoomAbove && !hasRoomBelow && !hasRoomToLeft && !hasRoomToRight) {
 272         return;
 273     }
 274
 275     int x, y;
 276     if (hasRoomBelow || hasRoomAbove) {
 277         x = qMax(screen.left(), m_itemRect.center().x() - size.width() / 2);
 278         if (x + size.width() >= screen.right()) {
 279             x = screen.right() - size.width() + 1;
 280         }
 281         if (hasRoomBelow) {
 282             y = m_itemRect.bottom() + margin;
 283         } else {
 284             y = m_itemRect.top() - size.height() - margin;
 285         }
 286     } else {
 287         Q_ASSERT(hasRoomToLeft || hasRoomToRight);
 288         if (hasRoomToRight) {
 289             x = m_itemRect.right() + margin;
 290         } else {
 291             x = m_itemRect.left() - size.width() - margin;
 292         }
 293         // Put the tooltip at the bottom of the screen. The x-coordinate has already
 294         // been adjusted, so that no overlapping with m_itemRect occurs.
 295         y = screen.bottom() - size.height() + 1;
 296     }
 297
 298     // Step #3 - Alter tooltip geometry
 299     m_fileMetaDataToolTip->setFixedSize(size);
 300     m_fileMetaDataToolTip->layout()->setSizeConstraint(QLayout::SetNoConstraint);
 301     m_fileMetaDataToolTip->move(QPoint(x, y));
 302     m_fileMetaDataToolTip->show();
 303
 304     m_toolTipRequested = false;
 305 }
 306
 307 #include "tooltipmanager.moc"