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