src/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 "dolphinmodel.h"
  23 #include "dolphinsortfilterproxymodel.h"
  24
  25 #include "filemetadatatooltip.h"
  26 #include <kicon.h>
  27 #include <kio/previewjob.h>
  28
  29 #include <QApplication>
  30 #include <QDesktopWidget>
  31 #include <QScrollArea>
  32 #include <QScrollBar>
  33 #include <QTimer>
  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_prepareToolTipTimer(0),
  42     m_startPreviewJobTimer(0),
  43     m_waitOnPreviewTimer(0),
  44     m_showToolTipDelayedTimer(0),
  45     m_fileMetaDataToolTip(0),
  46     m_item(),
  47     m_itemRect(),
  48     m_generatingPreview(false),
  49     m_hasDefaultIcon(false),
  50     m_previewPixmap()
  51 {
  52     static FileMetaDataToolTip* sharedToolTip = 0;
  53     if (sharedToolTip == 0) {
  54         sharedToolTip = new FileMetaDataToolTip();
  55         // TODO: Using K_GLOBAL_STATIC would be preferable to maintain the
  56         // instance, but the cleanup of KFileMetaDataWidget at this stage does
  57         // not work.
  58     }
  59     m_fileMetaDataToolTip = sharedToolTip;
  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_prepareToolTipTimer = new QTimer(this);
  69     m_prepareToolTipTimer->setSingleShot(true);
  70     m_prepareToolTipTimer->setInterval(500);
  71     connect(m_prepareToolTipTimer, SIGNAL(timeout()), this, SLOT(prepareToolTip()));
  72
  73     m_startPreviewJobTimer = new QTimer(this);
  74     m_startPreviewJobTimer->setSingleShot(true);
  75     m_startPreviewJobTimer->setInterval(200);
  76     connect(m_startPreviewJobTimer, SIGNAL(timeout()), this, SLOT(startPreviewJob()));
  77
  78     m_waitOnPreviewTimer = new QTimer(this);
  79     m_waitOnPreviewTimer->setSingleShot(true);
  80     m_waitOnPreviewTimer->setInterval(250);
  81     connect(m_waitOnPreviewTimer, SIGNAL(timeout()), this, SLOT(prepareToolTip()));
  82
  83     m_showToolTipDelayedTimer = new QTimer(this);
  84     m_showToolTipDelayedTimer->setSingleShot(true);
  85     m_showToolTipDelayedTimer->setInterval(100);
  86     connect(m_showToolTipDelayedTimer, SIGNAL(timeout()), this, SLOT(showToolTip()));
  87
  88     // When the mousewheel is used, the items don't get a hovered indication
  89     // (Qt-issue #200665). To assure that the tooltip still gets hidden,
  90     // the scrollbars are observed.
  91     connect(parent->horizontalScrollBar(), SIGNAL(valueChanged(int)),
  92             this, SLOT(hideTip()));
  93     connect(parent->verticalScrollBar(), SIGNAL(valueChanged(int)),
  94             this, SLOT(hideTip()));
  95
  96     m_view->viewport()->installEventFilter(this);
  97     m_view->installEventFilter(this);
  98 }
  99
 100 ToolTipManager::~ToolTipManager()
 101 {
 102 }
 103
 104 void ToolTipManager::hideTip()
 105 {
 106     hideToolTip();
 107 }
 108
 109 bool ToolTipManager::eventFilter(QObject* watched, QEvent* event)
 110 {
 111     if (watched == m_view->viewport()) {
 112         switch (event->type()) {
 113         case QEvent::Leave:
 114         case QEvent::MouseButtonPress:
 115             hideToolTip();
 116             break;
 117         default:
 118             break;
 119         }
 120     } else if ((watched == m_view) && (event->type() == QEvent::KeyPress)) {
 121         hideToolTip();
 122     }
 123
 124     return QObject::eventFilter(watched, event);
 125 }
 126
 127 void ToolTipManager::requestToolTip(const QModelIndex& index)
 128 {
 129     hideToolTip();
 130
 131     // Only request a tooltip for the name column and when no selection or
 132     // drag & drop operation is done (indicated by the left mouse button)
 133     if ((index.column() == DolphinModel::Name) && !(QApplication::mouseButtons() & Qt::LeftButton)) {
 134         m_itemRect = m_view->visualRect(index);
 135         const QPoint pos = m_view->viewport()->mapToGlobal(m_itemRect.topLeft());
 136         m_itemRect.moveTo(pos);
 137
 138         const QModelIndex dirIndex = m_proxyModel->mapToSource(index);
 139         m_item = m_dolphinModel->itemForIndex(dirIndex);
 140
 141         // Only start the previewJob when the mouse has been over this item for 200 milliseconds.
 142         // This prevents a lot of useless preview jobs when passing rapidly over a lot of items.
 143         m_startPreviewJobTimer->start();
 144         m_previewPixmap = QPixmap();
 145         m_hasDefaultIcon = false;
 146
 147         m_prepareToolTipTimer->start();
 148     }
 149 }
 150
 151 void ToolTipManager::hideToolTip()
 152 {
 153     m_prepareToolTipTimer->stop();
 154     m_startPreviewJobTimer->stop();
 155     m_waitOnPreviewTimer->stop();
 156     m_showToolTipDelayedTimer->stop();
 157
 158     m_fileMetaDataToolTip->hide();
 159 }
 160
 161 void ToolTipManager::prepareToolTip()
 162 {
 163     if (m_generatingPreview) {
 164         m_waitOnPreviewTimer->start();
 165     }
 166
 167     if (!m_previewPixmap.isNull()) {
 168         showToolTipDelayed(m_previewPixmap);
 169     } else if (!m_hasDefaultIcon) {
 170         const QPixmap image(KIcon(m_item.iconName()).pixmap(128, 128));
 171         showToolTipDelayed(image);
 172         m_hasDefaultIcon = true;
 173     }
 174 }
 175
 176 void ToolTipManager::startPreviewJob()
 177 {
 178     m_generatingPreview = true;
 179     KIO::PreviewJob* job = KIO::filePreview(KFileItemList() << m_item, 256, 256);
 180
 181     connect(job, SIGNAL(gotPreview(const KFileItem&, const QPixmap&)),
 182             this, SLOT(setPreviewPix(const KFileItem&, const QPixmap&)));
 183     connect(job, SIGNAL(failed(const KFileItem&)),
 184             this, SLOT(previewFailed()));
 185 }
 186
 187
 188 void ToolTipManager::setPreviewPix(const KFileItem& item,
 189                                    const QPixmap& pixmap)
 190 {
 191     if ((m_item.url() != item.url()) || pixmap.isNull()) {
 192         // An old preview or an invalid preview has been received
 193         previewFailed();
 194     } else {
 195         m_previewPixmap = pixmap;
 196         m_generatingPreview = false;
 197     }
 198 }
 199
 200 void ToolTipManager::previewFailed()
 201 {
 202     m_generatingPreview = false;
 203 }
 204
 205 void ToolTipManager::showToolTip()
 206 {
 207     const QRect desktop = QApplication::desktop()->screenGeometry(m_itemRect.bottomRight());
 208     const QSize size = m_fileMetaDataToolTip->sizeHint();
 209
 210     // m_itemRect defines the area of the item, where the tooltip should be
 211     // shown. Per default the tooltip is shown in the bottom right corner.
 212     // If the tooltip content exceeds the desktop borders, it must be assured that:
 213     // - the content is fully visible
 214     // - the content is not drawn inside m_itemRect
 215     const bool hasRoomToLeft  = (m_itemRect.left()   - size.width()  >= desktop.left());
 216     const bool hasRoomToRight = (m_itemRect.right()  + size.width()  <= desktop.right());
 217     const bool hasRoomAbove   = (m_itemRect.top()    - size.height() >= desktop.top());
 218     const bool hasRoomBelow   = (m_itemRect.bottom() + size.height() <= desktop.bottom());
 219     if (!hasRoomAbove && !hasRoomBelow && !hasRoomToLeft && !hasRoomToRight) {
 220         return;
 221     }
 222
 223     int x = 0;
 224     int y = 0;
 225     if (hasRoomBelow || hasRoomAbove) {
 226         x = QCursor::pos().x() + 16; // TODO: use mouse pointer width instead of the magic value of 16
 227         if (x + size.width() >= desktop.right()) {
 228             x = desktop.right() - size.width();
 229         }
 230         if (hasRoomBelow) {
 231             y = m_itemRect.bottom();
 232         } else {
 233             y = m_itemRect.top() - size.height();
 234         }
 235     } else {
 236         Q_ASSERT(hasRoomToLeft || hasRoomToRight);
 237         if (hasRoomToRight) {
 238             x = m_itemRect.right();
 239         } else {
 240             x = m_itemRect.left() - size.width();
 241         }
 242
 243         // Put the tooltip at the bottom of the screen. The x-coordinate has already
 244         // been adjusted, so that no overlapping with m_itemRect occurs.
 245         y = desktop.bottom() - size.height();
 246     }
 247
 248     m_fileMetaDataToolTip->move(qMax(x, 0), qMax(y, 0));
 249     m_fileMetaDataToolTip->show();
 250 }
 251
 252 void ToolTipManager::showToolTipDelayed(const QPixmap& pixmap)
 253 {
 254     if (QApplication::mouseButtons() & Qt::LeftButton) {
 255         return;
 256     }
 257
 258     m_fileMetaDataToolTip->setPreview(pixmap);
 259     m_fileMetaDataToolTip->setName(m_item.text());
 260     m_fileMetaDataToolTip->setItems(KFileItemList() << m_item);
 261
 262     // Because one tooltip instance is reused, the size hint always depends on the previous
 263     // content (QWidgets don't update their layout geometry if they are invisible). To
 264     // assure having a consistent size without relayout flickering, the tooltip is opened
 265     // on an invisible position first. This gives the layout system some time to asynchronously
 266     // update the content.
 267     const QRect desktop = QApplication::desktop()->screenGeometry(m_itemRect.bottomRight());
 268     m_fileMetaDataToolTip->move(desktop.bottomRight());
 269     m_fileMetaDataToolTip->show();
 270
 271     m_showToolTipDelayedTimer->start(); // Calls ToolTipManager::showToolTip()
 272 }
 273
 274 #include "tooltipmanager.moc"