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 <KConfigGroup>
  24 #include <KIcon>
  25 #include <KIO/PreviewJob>
  26 #include <KSharedConfig>
  27
  28 #include <QApplication>
  29 #include <QDesktopWidget>
  30 #include <QScrollArea>
  31 #include <QScrollBar>
  32 #include <QTimer>
  33
  34 #include <views/dolphinmodel.h>
  35 #include <views/dolphinsortfilterproxymodel.h>
  36
  37 ToolTipManager::ToolTipManager(QAbstractItemView* parent,
  38                                DolphinSortFilterProxyModel* model) :
  39     QObject(parent),
  40     m_view(parent),
  41     m_dolphinModel(0),
  42     m_proxyModel(model),
  43     m_showToolTipTimer(0),
  44     m_contentRetrievalTimer(0),
  45     m_fileMetaDataToolTip(0),
  46     m_toolTipRequested(false),
  47     m_metaDataRequested(false),
  48     m_appliedWaitCursor(false),
  49     m_item(),
  50     m_itemRect(),
  51     m_enabledPlugins()
  52 {
  53     static FileMetaDataToolTip* sharedToolTip = 0;
  54     if (sharedToolTip == 0) {
  55         sharedToolTip = new FileMetaDataToolTip();
  56         // TODO: Using K_GLOBAL_STATIC would be preferable to maintain the
  57         // instance, but the cleanup of KFileMetaDataWidget at this stage does
  58         // not work.
  59     }
  60     m_fileMetaDataToolTip = sharedToolTip;
  61     connect(m_fileMetaDataToolTip, SIGNAL(metaDataRequestFinished(KFileItemList)),
  62             this, SLOT(slotMetaDataRequestFinished()));
  63
  64     m_dolphinModel = static_cast<DolphinModel*>(m_proxyModel->sourceModel());
  65     connect(parent, SIGNAL(entered(const QModelIndex&)),
  66             this, SLOT(requestToolTip(const QModelIndex&)));
  67     connect(parent, SIGNAL(viewportEntered()),
  68             this, SLOT(hideToolTip()));
  69
  70     // Initialize timers
  71     m_showToolTipTimer = new QTimer(this);
  72     m_showToolTipTimer->setSingleShot(true);
  73     m_showToolTipTimer->setInterval(500);
  74     connect(m_showToolTipTimer, SIGNAL(timeout()), this, SLOT(showToolTip()));
  75
  76     m_contentRetrievalTimer = new QTimer(this);
  77     m_contentRetrievalTimer->setSingleShot(true);
  78     m_contentRetrievalTimer->setInterval(200);
  79     connect(m_contentRetrievalTimer, SIGNAL(timeout()), this, SLOT(startContentRetrieval()));
  80
  81     Q_ASSERT(m_contentRetrievalTimer->interval() < m_showToolTipTimer->interval());
  82
  83     // When the mousewheel is used, the items don't get a hovered indication
  84     // (Qt-issue #200665). To assure that the tooltip still gets hidden,
  85     // the scrollbars are observed.
  86     connect(parent->horizontalScrollBar(), SIGNAL(valueChanged(int)),
  87             this, SLOT(hideToolTip()));
  88     connect(parent->verticalScrollBar(), SIGNAL(valueChanged(int)),
  89             this, SLOT(hideToolTip()));
  90
  91     m_view->viewport()->installEventFilter(this);
  92     m_view->installEventFilter(this);
  93 }
  94
  95 ToolTipManager::~ToolTipManager()
  96 {
  97 }
  98
  99 void ToolTipManager::hideToolTip()
 100 {
 101     if (m_appliedWaitCursor) {
 102         QApplication::restoreOverrideCursor();
 103         m_appliedWaitCursor = false;
 104     }
 105
 106     m_toolTipRequested = false;
 107     m_metaDataRequested = false;
 108     m_showToolTipTimer->stop();
 109     m_contentRetrievalTimer->stop();
 110
 111     m_fileMetaDataToolTip->setItems(KFileItemList());
 112     m_fileMetaDataToolTip->hide();
 113 }
 114
 115 bool ToolTipManager::eventFilter(QObject* watched, QEvent* event)
 116 {
 117     if (watched == m_view->viewport()) {
 118         switch (event->type()) {
 119         case QEvent::Leave:
 120         case QEvent::MouseButtonPress:
 121             hideToolTip();
 122             break;
 123         default:
 124             break;
 125         }
 126     } else if ((watched == m_view) && (event->type() == QEvent::KeyPress)) {
 127         hideToolTip();
 128     }
 129
 130     return QObject::eventFilter(watched, event);
 131 }
 132
 133 void ToolTipManager::requestToolTip(const QModelIndex& index)
 134 {
 135     hideToolTip();
 136
 137     // Only request a tooltip for the name column and when no selection or
 138     // drag & drop operation is done (indicated by the left mouse button)
 139     if ((index.column() == DolphinModel::Name) && !(QApplication::mouseButtons() & Qt::LeftButton)) {
 140         m_itemRect = m_view->visualRect(index);
 141         const QPoint pos = m_view->viewport()->mapToGlobal(m_itemRect.topLeft());
 142         m_itemRect.moveTo(pos);
 143
 144         const QModelIndex dirIndex = m_proxyModel->mapToSource(index);
 145         m_item = m_dolphinModel->itemForIndex(dirIndex);
 146
 147         // Only start the retrieving of the content, when the mouse has been over this
 148         // item for 200 milliseconds. This prevents a lot of useless preview jobs and
 149         // meta data retrieval, when passing rapidly over a lot of items.
 150         m_contentRetrievalTimer->start();
 151         m_showToolTipTimer->start();
 152         m_toolTipRequested = true;
 153         Q_ASSERT(!m_metaDataRequested);
 154     }
 155 }
 156
 157 void ToolTipManager::startContentRetrieval()
 158 {
 159     if (!m_toolTipRequested) {
 160         return;
 161     }
 162
 163     m_fileMetaDataToolTip->setName(m_item.text());
 164
 165     // Request the retrieval of meta-data. The slot
 166     // slotMetaDataRequestFinished() is invoked after the
 167     // meta-data have been received.
 168     m_metaDataRequested = true;
 169     m_fileMetaDataToolTip->setItems(KFileItemList() << m_item);
 170
 171     // Request a preview of the item
 172     m_fileMetaDataToolTip->setPreview(QPixmap());
 173
 174     if (m_enabledPlugins.isEmpty()) {
 175         const KConfigGroup globalConfig(KGlobal::config(), "PreviewSettings");
 176         m_enabledPlugins = globalConfig.readEntry("Plugins", QStringList()
 177                                                              << "directorythumbnail"
 178                                                              << "imagethumbnail"
 179                                                              << "jpegthumbnail");
 180     }
 181     KIO::PreviewJob* job = KIO::filePreview(KFileItemList() << m_item, 256, 256, true, true, &m_enabledPlugins);
 182
 183     connect(job, SIGNAL(gotPreview(const KFileItem&, const QPixmap&)),
 184             this, SLOT(setPreviewPix(const KFileItem&, const QPixmap&)));
 185     connect(job, SIGNAL(failed(const KFileItem&)),
 186             this, SLOT(previewFailed()));
 187 }
 188
 189
 190 void ToolTipManager::setPreviewPix(const KFileItem& item,
 191                                    const QPixmap& pixmap)
 192 {
 193     if (!m_toolTipRequested || (m_item.url() != item.url())) {
 194         // No tooltip is requested anymore or an old preview has been received
 195         return;
 196     }
 197
 198     if (pixmap.isNull()) {
 199         previewFailed();
 200     } else {
 201         m_fileMetaDataToolTip->setPreview(pixmap);
 202         if (!m_showToolTipTimer->isActive()) {
 203             showToolTip();
 204         }
 205     }
 206 }
 207
 208 void ToolTipManager::previewFailed()
 209 {
 210     if (!m_toolTipRequested) {
 211         return;
 212     }
 213
 214     const QPixmap pixmap = KIcon(m_item.iconName()).pixmap(128, 128);
 215     m_fileMetaDataToolTip->setPreview(pixmap);
 216     if (!m_showToolTipTimer->isActive()) {
 217         showToolTip();
 218     }
 219 }
 220
 221 void ToolTipManager::slotMetaDataRequestFinished()
 222 {
 223     if (!m_toolTipRequested) {
 224         return;
 225     }
 226
 227     m_metaDataRequested = false;
 228     if (!m_showToolTipTimer->isActive()) {
 229         showToolTip();
 230     }
 231 }
 232
 233 void ToolTipManager::showToolTip()
 234 {
 235     Q_ASSERT(m_toolTipRequested);
 236     if (m_appliedWaitCursor) {
 237         QApplication::restoreOverrideCursor();
 238         m_appliedWaitCursor = false;
 239     }
 240
 241     if (QApplication::mouseButtons() & Qt::LeftButton) {
 242         return;
 243     }
 244
 245     if (m_fileMetaDataToolTip->preview().isNull() || m_metaDataRequested) {
 246         Q_ASSERT(!m_appliedWaitCursor);
 247         QApplication::setOverrideCursor(QCursor(Qt::WaitCursor));
 248         m_appliedWaitCursor = true;
 249         return;
 250     }
 251
 252     const QRect screen = QApplication::desktop()->screenGeometry(QCursor::pos());
 253
 254     // Restrict tooltip size to current screen size when needed.
 255     // Because layout controlling widget doesn't respect widget's maximumSize property
 256     // (correct me if I'm wrong), we need to let layout do its work, then manually change
 257     // geometry if resulting widget doesn't fit the screen.
 258
 259     // Step #1 - make sizeHint return calculated tooltip size
 260     m_fileMetaDataToolTip->layout()->setSizeConstraint(QLayout::SetFixedSize);
 261     m_fileMetaDataToolTip->adjustSize();
 262     QSize size = m_fileMetaDataToolTip->sizeHint();
 263
 264     // Step #2 - correct tooltip size when needed
 265     if (size.width() > screen.width()) {
 266         size.setWidth(screen.width());
 267     }
 268     if (size.height() > screen.height()) {
 269         size.setHeight(screen.height());
 270     }
 271
 272     // m_itemRect defines the area of the item, where the tooltip should be
 273     // shown. Per default the tooltip is shown in the bottom right corner.
 274     // It must be assured that:
 275     // - the content is fully visible
 276     // - the content is not drawn inside m_itemRect
 277     const bool hasRoomToLeft  = (m_itemRect.left()   - size.width()  >= screen.left());
 278     const bool hasRoomToRight = (m_itemRect.right()  + size.width()  <= screen.right());
 279     const bool hasRoomAbove   = (m_itemRect.top()    - size.height() >= screen.top());
 280     const bool hasRoomBelow   = (m_itemRect.bottom() + size.height() <= screen.bottom());
 281     if (!hasRoomAbove && !hasRoomBelow && !hasRoomToLeft && !hasRoomToRight) {
 282         return;
 283     }
 284
 285     int x, y;
 286     if (hasRoomBelow || hasRoomAbove) {
 287         x = QCursor::pos().x() + 16; // TODO: use mouse pointer width instead of the magic value of 16
 288         if (x + size.width() >= screen.right()) {
 289             x = screen.right() - size.width() + 1;
 290         }
 291         if (hasRoomBelow) {
 292             y = m_itemRect.bottom() + 1;
 293         } else {
 294             y = m_itemRect.top() - size.height();
 295         }
 296     } else {
 297         Q_ASSERT(hasRoomToLeft || hasRoomToRight);
 298         if (hasRoomToRight) {
 299             x = m_itemRect.right() + 1;
 300         } else {
 301             x = m_itemRect.left() - size.width();
 302         }
 303         // Put the tooltip at the bottom of the screen. The x-coordinate has already
 304         // been adjusted, so that no overlapping with m_itemRect occurs.
 305         y = screen.bottom() - size.height() + 1;
 306     }
 307
 308     // Step #3 - Alter tooltip geometry
 309     m_fileMetaDataToolTip->setFixedSize(size);
 310     m_fileMetaDataToolTip->layout()->setSizeConstraint(QLayout::SetNoConstraint);
 311     m_fileMetaDataToolTip->setGeometry(x, y, size.width(), size.height());
 312     m_fileMetaDataToolTip->show();
 313
 314     m_toolTipRequested = false;
 315 }
 316
 317 #include "tooltipmanager.moc"