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     static FileMetaDataToolTip* sharedToolTip = 0;
  52     if (!sharedToolTip) {
  53         sharedToolTip = new FileMetaDataToolTip();
  54         // TODO: Using K_GLOBAL_STATIC would be preferable to maintain the
  55         // instance, but the cleanup of KFileMetaDataWidget at this stage does
  56         // not work.
  57     }
  58     m_fileMetaDataToolTip = sharedToolTip;
  59     connect(m_fileMetaDataToolTip, SIGNAL(metaDataRequestFinished(KFileItemList)),
  60             this, SLOT(slotMetaDataRequestFinished()));
  61
  62     m_dolphinModel = static_cast<DolphinModel*>(m_proxyModel->sourceModel());
  63     connect(parent, SIGNAL(entered(const QModelIndex&)),
  64             this, SLOT(requestToolTip(const QModelIndex&)));
  65     connect(parent, SIGNAL(viewportEntered()),
  66             this, SLOT(hideToolTip()));
  67
  68     // Initialize timers
  69     m_showToolTipTimer = new QTimer(this);
  70     m_showToolTipTimer->setSingleShot(true);
  71     m_showToolTipTimer->setInterval(500);
  72     connect(m_showToolTipTimer, SIGNAL(timeout()), this, SLOT(showToolTip()));
  73
  74     m_contentRetrievalTimer = new QTimer(this);
  75     m_contentRetrievalTimer->setSingleShot(true);
  76     m_contentRetrievalTimer->setInterval(200);
  77     connect(m_contentRetrievalTimer, SIGNAL(timeout()), this, SLOT(startContentRetrieval()));
  78
  79     Q_ASSERT(m_contentRetrievalTimer->interval() < m_showToolTipTimer->interval());
  80
  81     // When the mousewheel is used, the items don't get a hovered indication
  82     // (Qt-issue #200665). To assure that the tooltip still gets hidden,
  83     // the scrollbars are observed.
  84     connect(parent->horizontalScrollBar(), SIGNAL(valueChanged(int)),
  85             this, SLOT(hideToolTip()));
  86     connect(parent->verticalScrollBar(), SIGNAL(valueChanged(int)),
  87             this, SLOT(hideToolTip()));
  88
  89     m_view->viewport()->installEventFilter(this);
  90     m_view->installEventFilter(this);
  91 }
  92
  93 ToolTipManager::~ToolTipManager()
  94 {
  95 }
  96
  97 void ToolTipManager::hideToolTip()
  98 {
  99     if (m_appliedWaitCursor) {
 100         QApplication::restoreOverrideCursor();
 101         m_appliedWaitCursor = false;
 102     }
 103
 104     m_toolTipRequested = false;
 105     m_metaDataRequested = false;
 106     m_showToolTipTimer->stop();
 107     m_contentRetrievalTimer->stop();
 108
 109     m_fileMetaDataToolTip->setItems(KFileItemList());
 110     m_fileMetaDataToolTip->hide();
 111 }
 112
 113 bool ToolTipManager::eventFilter(QObject* watched, QEvent* event)
 114 {
 115     if (watched == m_view->viewport()) {
 116         switch (event->type()) {
 117         case QEvent::Leave:
 118         case QEvent::MouseButtonPress:
 119             hideToolTip();
 120             break;
 121         default:
 122             break;
 123         }
 124     } else if ((watched == m_view) && (event->type() == QEvent::KeyPress)) {
 125         hideToolTip();
 126     }
 127
 128     return QObject::eventFilter(watched, event);
 129 }
 130
 131 void ToolTipManager::requestToolTip(const QModelIndex& index)
 132 {
 133     hideToolTip();
 134
 135     // Only request a tooltip for the name column and when no selection or
 136     // drag & drop operation is done (indicated by the left mouse button)
 137     if ((index.column() == DolphinModel::Name) && !(QApplication::mouseButtons() & Qt::LeftButton)) {
 138         m_itemRect = m_view->visualRect(index);
 139         const QPoint pos = m_view->viewport()->mapToGlobal(m_itemRect.topLeft());
 140         m_itemRect.moveTo(pos);
 141
 142         const QModelIndex dirIndex = m_proxyModel->mapToSource(index);
 143         m_item = m_dolphinModel->itemForIndex(dirIndex);
 144
 145         // Only start the retrieving of the content, when the mouse has been over this
 146         // item for 200 milliseconds. This prevents a lot of useless preview jobs and
 147         // meta data retrieval, when passing rapidly over a lot of items.
 148         m_contentRetrievalTimer->start();
 149         m_showToolTipTimer->start();
 150         m_toolTipRequested = true;
 151         Q_ASSERT(!m_metaDataRequested);
 152     }
 153 }
 154
 155 void ToolTipManager::startContentRetrieval()
 156 {
 157     if (!m_toolTipRequested) {
 158         return;
 159     }
 160
 161     m_fileMetaDataToolTip->setName(m_item.text());
 162
 163     // Request the retrieval of meta-data. The slot
 164     // slotMetaDataRequestFinished() is invoked after the
 165     // meta-data have been received.
 166     m_metaDataRequested = true;
 167     m_fileMetaDataToolTip->setItems(KFileItemList() << m_item);
 168
 169     // Request a preview of the item
 170     m_fileMetaDataToolTip->setPreview(QPixmap());
 171
 172     KIO::PreviewJob* job = KIO::filePreview(KFileItemList() << m_item, QSize(256, 256));
 173
 174     connect(job, SIGNAL(gotPreview(const KFileItem&, const QPixmap&)),
 175             this, SLOT(setPreviewPix(const KFileItem&, const QPixmap&)));
 176     connect(job, SIGNAL(failed(const KFileItem&)),
 177             this, SLOT(previewFailed()));
 178 }
 179
 180
 181 void ToolTipManager::setPreviewPix(const KFileItem& item,
 182                                    const QPixmap& pixmap)
 183 {
 184     if (!m_toolTipRequested || (m_item.url() != item.url())) {
 185         // No tooltip is requested anymore or an old preview has been received
 186         return;
 187     }
 188
 189     if (pixmap.isNull()) {
 190         previewFailed();
 191     } else {
 192         m_fileMetaDataToolTip->setPreview(pixmap);
 193         if (!m_showToolTipTimer->isActive()) {
 194             showToolTip();
 195         }
 196     }
 197 }
 198
 199 void ToolTipManager::previewFailed()
 200 {
 201     if (!m_toolTipRequested) {
 202         return;
 203     }
 204
 205     const QPixmap pixmap = KIcon(m_item.iconName()).pixmap(128, 128);
 206     m_fileMetaDataToolTip->setPreview(pixmap);
 207     if (!m_showToolTipTimer->isActive()) {
 208         showToolTip();
 209     }
 210 }
 211
 212 void ToolTipManager::slotMetaDataRequestFinished()
 213 {
 214     if (!m_toolTipRequested) {
 215         return;
 216     }
 217
 218     m_metaDataRequested = false;
 219     if (!m_showToolTipTimer->isActive()) {
 220         showToolTip();
 221     }
 222 }
 223
 224 void ToolTipManager::showToolTip()
 225 {
 226     Q_ASSERT(m_toolTipRequested);
 227     if (m_appliedWaitCursor) {
 228         QApplication::restoreOverrideCursor();
 229         m_appliedWaitCursor = false;
 230     }
 231
 232     if (QApplication::mouseButtons() & Qt::LeftButton) {
 233         return;
 234     }
 235
 236     if (m_fileMetaDataToolTip->preview().isNull() || m_metaDataRequested) {
 237         Q_ASSERT(!m_appliedWaitCursor);
 238         QApplication::setOverrideCursor(QCursor(Qt::WaitCursor));
 239         m_appliedWaitCursor = true;
 240         return;
 241     }
 242
 243     const QRect screen = QApplication::desktop()->screenGeometry(QCursor::pos());
 244
 245     // Restrict tooltip size to current screen size when needed.
 246     // Because layout controlling widget doesn't respect widget's maximumSize property
 247     // (correct me if I'm wrong), we need to let layout do its work, then manually change
 248     // geometry if resulting widget doesn't fit the screen.
 249
 250     // Step #1 - make sizeHint return calculated tooltip size
 251     m_fileMetaDataToolTip->layout()->setSizeConstraint(QLayout::SetFixedSize);
 252     m_fileMetaDataToolTip->adjustSize();
 253     QSize size = m_fileMetaDataToolTip->sizeHint();
 254
 255     // Step #2 - correct tooltip size when needed
 256     if (size.width() > screen.width()) {
 257         size.setWidth(screen.width());
 258     }
 259     if (size.height() > screen.height()) {
 260         size.setHeight(screen.height());
 261     }
 262
 263     // m_itemRect defines the area of the item, where the tooltip should be
 264     // shown. Per default the tooltip is shown in the bottom right corner.
 265     // It must be assured that:
 266     // - the content is fully visible
 267     // - the content is not drawn inside m_itemRect
 268     const bool hasRoomToLeft  = (m_itemRect.left()   - size.width()  >= screen.left());
 269     const bool hasRoomToRight = (m_itemRect.right()  + size.width()  <= screen.right());
 270     const bool hasRoomAbove   = (m_itemRect.top()    - size.height() >= screen.top());
 271     const bool hasRoomBelow   = (m_itemRect.bottom() + size.height() <= screen.bottom());
 272     if (!hasRoomAbove && !hasRoomBelow && !hasRoomToLeft && !hasRoomToRight) {
 273         return;
 274     }
 275
 276     int x, y;
 277     if (hasRoomBelow || hasRoomAbove) {
 278         x = QCursor::pos().x() + 16; // TODO: use mouse pointer width instead of the magic value of 16
 279         if (x + size.width() >= screen.right()) {
 280             x = screen.right() - size.width() + 1;
 281         }
 282         if (hasRoomBelow) {
 283             y = m_itemRect.bottom() + 1;
 284         } else {
 285             y = m_itemRect.top() - size.height();
 286         }
 287     } else {
 288         Q_ASSERT(hasRoomToLeft || hasRoomToRight);
 289         if (hasRoomToRight) {
 290             x = m_itemRect.right() + 1;
 291         } else {
 292             x = m_itemRect.left() - size.width();
 293         }
 294         // Put the tooltip at the bottom of the screen. The x-coordinate has already
 295         // been adjusted, so that no overlapping with m_itemRect occurs.
 296         y = screen.bottom() - size.height() + 1;
 297     }
 298
 299     // Step #3 - Alter tooltip geometry
 300     m_fileMetaDataToolTip->setFixedSize(size);
 301     m_fileMetaDataToolTip->layout()->setSizeConstraint(QLayout::SetNoConstraint);
 302     m_fileMetaDataToolTip->setGeometry(x, y, size.width(), size.height());
 303     m_fileMetaDataToolTip->show();
 304
 305     m_toolTipRequested = false;
 306 }
 307
 308 #include "tooltipmanager.moc"