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
  26 #include <QApplication>
  27 #include <QDesktopWidget>
  28 #include <QScrollArea>
  29 #include <QScrollBar>
  30 #include <QTimer>
  31
  32 #include <views/dolphinmodel.h>
  33 #include <views/dolphinsortfilterproxymodel.h>
  34
  35 ToolTipManager::ToolTipManager(QAbstractItemView* parent,
  36                                DolphinSortFilterProxyModel* model) :
  37     QObject(parent),
  38     m_view(parent),
  39     m_dolphinModel(0),
  40     m_proxyModel(model),
  41     m_showToolTipTimer(0),
  42     m_contentRetrievalTimer(0),
  43     m_fileMetaDataToolTip(0),
  44     m_toolTipRequested(false),
  45     m_metaDataRequested(false),
  46     m_item(),
  47     m_itemRect()
  48 {
  49     static FileMetaDataToolTip* sharedToolTip = 0;
  50     if (sharedToolTip == 0) {
  51         sharedToolTip = new FileMetaDataToolTip();
  52         // TODO: Using K_GLOBAL_STATIC would be preferable to maintain the
  53         // instance, but the cleanup of KFileMetaDataWidget at this stage does
  54         // not work.
  55     }
  56     m_fileMetaDataToolTip = sharedToolTip;
  57     connect(m_fileMetaDataToolTip, SIGNAL(metaDataRequestFinished()),
  58             this, SLOT(slotMetaDataRequestFinished()));
  59
  60     m_dolphinModel = static_cast<DolphinModel*>(m_proxyModel->sourceModel());
  61     connect(parent, SIGNAL(entered(const QModelIndex&)),
  62             this, SLOT(requestToolTip(const QModelIndex&)));
  63     connect(parent, SIGNAL(viewportEntered()),
  64             this, SLOT(hideToolTip()));
  65
  66     // Initialize timers
  67     m_showToolTipTimer = new QTimer(this);
  68     m_showToolTipTimer->setSingleShot(true);
  69     m_showToolTipTimer->setInterval(500);
  70     connect(m_showToolTipTimer, SIGNAL(timeout()), this, SLOT(showToolTip()));
  71
  72     m_contentRetrievalTimer = new QTimer(this);
  73     m_contentRetrievalTimer->setSingleShot(true);
  74     m_contentRetrievalTimer->setInterval(200);
  75     connect(m_contentRetrievalTimer, SIGNAL(timeout()), this, SLOT(startContentRetrieval()));
  76
  77     Q_ASSERT(m_contentRetrievalTimer->interval() < m_showToolTipTimer->interval());
  78
  79     // When the mousewheel is used, the items don't get a hovered indication
  80     // (Qt-issue #200665). To assure that the tooltip still gets hidden,
  81     // the scrollbars are observed.
  82     connect(parent->horizontalScrollBar(), SIGNAL(valueChanged(int)),
  83             this, SLOT(hideToolTip()));
  84     connect(parent->verticalScrollBar(), SIGNAL(valueChanged(int)),
  85             this, SLOT(hideToolTip()));
  86
  87     m_view->viewport()->installEventFilter(this);
  88     m_view->installEventFilter(this);
  89 }
  90
  91 ToolTipManager::~ToolTipManager()
  92 {
  93 }
  94
  95 void ToolTipManager::hideToolTip()
  96 {
  97     QApplication::restoreOverrideCursor();
  98
  99     m_toolTipRequested = false;
 100     m_metaDataRequested = false;
 101     m_showToolTipTimer->stop();
 102     m_contentRetrievalTimer->stop();
 103
 104     m_fileMetaDataToolTip->setItems(KFileItemList());
 105     m_fileMetaDataToolTip->hide();
 106 }
 107
 108 bool ToolTipManager::eventFilter(QObject* watched, QEvent* event)
 109 {
 110     if (watched == m_view->viewport()) {
 111         switch (event->type()) {
 112         case QEvent::Leave:
 113         case QEvent::MouseButtonPress:
 114             hideToolTip();
 115             break;
 116         default:
 117             break;
 118         }
 119     } else if ((watched == m_view) && (event->type() == QEvent::KeyPress)) {
 120         hideToolTip();
 121     }
 122
 123     return QObject::eventFilter(watched, event);
 124 }
 125
 126 void ToolTipManager::requestToolTip(const QModelIndex& index)
 127 {
 128     hideToolTip();
 129
 130     // Only request a tooltip for the name column and when no selection or
 131     // drag & drop operation is done (indicated by the left mouse button)
 132     if ((index.column() == DolphinModel::Name) && !(QApplication::mouseButtons() & Qt::LeftButton)) {
 133         m_itemRect = m_view->visualRect(index);
 134         const QPoint pos = m_view->viewport()->mapToGlobal(m_itemRect.topLeft());
 135         m_itemRect.moveTo(pos);
 136
 137         const QModelIndex dirIndex = m_proxyModel->mapToSource(index);
 138         m_item = m_dolphinModel->itemForIndex(dirIndex);
 139
 140         // Only start the retrieving of the content, when the mouse has been over this
 141         // item for 200 milliseconds. This prevents a lot of useless preview jobs and
 142         // meta data retrieval, when passing rapidly over a lot of items.
 143         m_contentRetrievalTimer->start();
 144         m_showToolTipTimer->start();
 145         m_toolTipRequested = true;
 146         Q_ASSERT(!m_metaDataRequested);
 147     }
 148 }
 149
 150 void ToolTipManager::startContentRetrieval()
 151 {
 152     if (!m_toolTipRequested) {
 153         return;
 154     }
 155
 156     m_fileMetaDataToolTip->setName(m_item.text());
 157
 158     m_metaDataRequested = true;
 159     m_fileMetaDataToolTip->setItems(KFileItemList() << m_item);
 160
 161     KIO::PreviewJob* job = KIO::filePreview(KFileItemList() << m_item, 256, 256);
 162
 163     connect(job, SIGNAL(gotPreview(const KFileItem&, const QPixmap&)),
 164             this, SLOT(setPreviewPix(const KFileItem&, const QPixmap&)));
 165     connect(job, SIGNAL(failed(const KFileItem&)),
 166             this, SLOT(previewFailed()));
 167 }
 168
 169
 170 void ToolTipManager::setPreviewPix(const KFileItem& item,
 171                                    const QPixmap& pixmap)
 172 {
 173     if (!m_toolTipRequested || (m_item.url() != item.url())) {
 174         // No tooltip is requested anymore or an old preview has been received
 175         return;
 176     }
 177
 178     if (pixmap.isNull()) {
 179         previewFailed();
 180     } else {
 181         m_fileMetaDataToolTip->setPreview(pixmap);
 182         if (!m_showToolTipTimer->isActive()) {
 183             showToolTip();
 184         }
 185     }
 186 }
 187
 188 void ToolTipManager::previewFailed()
 189 {
 190     if (!m_toolTipRequested) {
 191         return;
 192     }
 193
 194     const QPixmap pixmap = KIcon(m_item.iconName()).pixmap(128, 128);
 195     m_fileMetaDataToolTip->setPreview(pixmap);
 196     if (!m_showToolTipTimer->isActive()) {
 197         showToolTip();
 198     }
 199 }
 200
 201 void ToolTipManager::slotMetaDataRequestFinished()
 202 {
 203     if (!m_toolTipRequested) {
 204         return;
 205     }
 206
 207     m_metaDataRequested = false;
 208     if (!m_showToolTipTimer->isActive()) {
 209         showToolTip();
 210     }
 211 }
 212
 213 void ToolTipManager::showToolTip()
 214 {
 215     Q_ASSERT(m_toolTipRequested);
 216     QApplication::restoreOverrideCursor();
 217
 218     if (QApplication::mouseButtons() & Qt::LeftButton) {
 219         return;
 220     }
 221
 222     if (m_fileMetaDataToolTip->preview().isNull() || m_metaDataRequested) {
 223         QApplication::setOverrideCursor(QCursor(Qt::WaitCursor));
 224         return;
 225     }
 226
 227     const QRect screen = QApplication::desktop()->screenGeometry(QCursor::pos());
 228
 229     // Restrict tooltip size to current screen size when needed.
 230     // Because layout controlling widget doesn't respect widget's maximumSize property
 231     // (correct me if I'm wrong), we need to let layout do its work, then manually change
 232     // geometry if resulting widget doesn't fit the screen.
 233
 234     // Step #1 - make sizeHint return calculated tooltip size
 235     m_fileMetaDataToolTip->layout()->setSizeConstraint(QLayout::SetFixedSize);
 236     m_fileMetaDataToolTip->adjustSize();
 237     QSize size = m_fileMetaDataToolTip->sizeHint();
 238
 239     // Step #2 - correct tooltip size when needed
 240     if (size.width() > screen.width()) {
 241         size.setWidth(screen.width());
 242     }
 243     if (size.height() > screen.height()) {
 244         size.setHeight(screen.height());
 245     }
 246
 247     // m_itemRect defines the area of the item, where the tooltip should be
 248     // shown. Per default the tooltip is shown in the bottom right corner.
 249     // It must be assured that:
 250     // - the content is fully visible
 251     // - the content is not drawn inside m_itemRect
 252     const bool hasRoomToLeft  = (m_itemRect.left()   - size.width()  >= screen.left());
 253     const bool hasRoomToRight = (m_itemRect.right()  + size.width()  <= screen.right());
 254     const bool hasRoomAbove   = (m_itemRect.top()    - size.height() >= screen.top());
 255     const bool hasRoomBelow   = (m_itemRect.bottom() + size.height() <= screen.bottom());
 256     if (!hasRoomAbove && !hasRoomBelow && !hasRoomToLeft && !hasRoomToRight) {
 257         return;
 258     }
 259
 260     int x, y;
 261     if (hasRoomBelow || hasRoomAbove) {
 262         x = QCursor::pos().x() + 16; // TODO: use mouse pointer width instead of the magic value of 16
 263         if (x + size.width() >= screen.right()) {
 264             x = screen.right() - size.width() + 1;
 265         }
 266         if (hasRoomBelow) {
 267             y = m_itemRect.bottom() + 1;
 268         } else {
 269             y = m_itemRect.top() - size.height();
 270         }
 271     } else {
 272         Q_ASSERT(hasRoomToLeft || hasRoomToRight);
 273         if (hasRoomToRight) {
 274             x = m_itemRect.right() + 1;
 275         } else {
 276             x = m_itemRect.left() - size.width();
 277         }
 278         // Put the tooltip at the bottom of the screen. The x-coordinate has already
 279         // been adjusted, so that no overlapping with m_itemRect occurs.
 280         y = screen.bottom() - size.height() + 1;
 281     }
 282
 283     // Step #3 - Alter tooltip geometry
 284     m_fileMetaDataToolTip->setFixedSize(size);
 285     m_fileMetaDataToolTip->layout()->setSizeConstraint(QLayout::SetNoConstraint);
 286     m_fileMetaDataToolTip->setGeometry(x, y, size.width(), size.height());
 287     m_fileMetaDataToolTip->show();
 288
 289     m_toolTipRequested = false;
 290 }
 291
 292 #include "tooltipmanager.moc"