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