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.h>
  24 #include <kio/previewjob.h>
  25 #include <kwindowsystem.h>
  26
  27 #include <QApplication>
  28 #include <QDesktopWidget>
  29 #include <QScrollArea>
  30 #include <QScrollBar>
  31 #include <QTimer>
  32
  33 #include <views/dolphinmodel.h>
  34 #include <views/dolphinsortfilterproxymodel.h>
  35
  36 ToolTipManager::ToolTipManager(QAbstractItemView* parent,
  37                                DolphinSortFilterProxyModel* model) :
  38     QObject(parent),
  39     m_view(parent),
  40     m_dolphinModel(0),
  41     m_proxyModel(model),
  42     m_prepareToolTipTimer(0),
  43     m_startPreviewJobTimer(0),
  44     m_waitOnPreviewTimer(0),
  45     m_showToolTipDelayedTimer(0),
  46     m_fileMetaDataToolTip(0),
  47     m_item(),
  48     m_itemRect(),
  49     m_generatingPreview(false),
  50     m_hasDefaultIcon(false),
  51     m_previewPixmap()
  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
  62     m_dolphinModel = static_cast<DolphinModel*>(m_proxyModel->sourceModel());
  63     connect(parent, SIGNAL(entered(const QModelIndex&)),
  64             this, SLOT(requestToolTip(const QModelIndex&)));
  65     connect(parent, SIGNAL(viewportEntered()),
  66             this, SLOT(hideToolTip()));
  67
  68     // Initialize timers
  69     m_prepareToolTipTimer = new QTimer(this);
  70     m_prepareToolTipTimer->setSingleShot(true);
  71     m_prepareToolTipTimer->setInterval(500);
  72     connect(m_prepareToolTipTimer, SIGNAL(timeout()), this, SLOT(prepareToolTip()));
  73
  74     m_startPreviewJobTimer = new QTimer(this);
  75     m_startPreviewJobTimer->setSingleShot(true);
  76     m_startPreviewJobTimer->setInterval(200);
  77     connect(m_startPreviewJobTimer, SIGNAL(timeout()), this, SLOT(startPreviewJob()));
  78
  79     m_waitOnPreviewTimer = new QTimer(this);
  80     m_waitOnPreviewTimer->setSingleShot(true);
  81     m_waitOnPreviewTimer->setInterval(250);
  82     connect(m_waitOnPreviewTimer, SIGNAL(timeout()), this, SLOT(prepareToolTip()));
  83
  84     m_showToolTipDelayedTimer = new QTimer(this);
  85     m_showToolTipDelayedTimer->setSingleShot(true);
  86     m_showToolTipDelayedTimer->setInterval(100);
  87     connect(m_showToolTipDelayedTimer, SIGNAL(timeout()), this, SLOT(showToolTip()));
  88
  89     // When the mousewheel is used, the items don't get a hovered indication
  90     // (Qt-issue #200665). To assure that the tooltip still gets hidden,
  91     // the scrollbars are observed.
  92     connect(parent->horizontalScrollBar(), SIGNAL(valueChanged(int)),
  93             this, SLOT(hideTip()));
  94     connect(parent->verticalScrollBar(), SIGNAL(valueChanged(int)),
  95             this, SLOT(hideTip()));
  96
  97     m_view->viewport()->installEventFilter(this);
  98     m_view->installEventFilter(this);
  99 }
 100
 101 ToolTipManager::~ToolTipManager()
 102 {
 103 }
 104
 105 void ToolTipManager::hideTip()
 106 {
 107     hideToolTip();
 108 }
 109
 110 bool ToolTipManager::eventFilter(QObject* watched, QEvent* event)
 111 {
 112     if (watched == m_view->viewport()) {
 113         switch (event->type()) {
 114         case QEvent::Leave:
 115         case QEvent::MouseButtonPress:
 116             hideToolTip();
 117             break;
 118         default:
 119             break;
 120         }
 121     } else if ((watched == m_view) && (event->type() == QEvent::KeyPress)) {
 122         hideToolTip();
 123     }
 124
 125     return QObject::eventFilter(watched, event);
 126 }
 127
 128 void ToolTipManager::requestToolTip(const QModelIndex& index)
 129 {
 130     hideToolTip();
 131
 132     // Only request a tooltip for the name column and when no selection or
 133     // drag & drop operation is done (indicated by the left mouse button)
 134     if ((index.column() == DolphinModel::Name) && !(QApplication::mouseButtons() & Qt::LeftButton)) {
 135         m_itemRect = m_view->visualRect(index);
 136         const QPoint pos = m_view->viewport()->mapToGlobal(m_itemRect.topLeft());
 137         m_itemRect.moveTo(pos);
 138
 139         const QModelIndex dirIndex = m_proxyModel->mapToSource(index);
 140         m_item = m_dolphinModel->itemForIndex(dirIndex);
 141
 142         // Only start the previewJob when the mouse has been over this item for 200 milliseconds.
 143         // This prevents a lot of useless preview jobs when passing rapidly over a lot of items.
 144         m_startPreviewJobTimer->start();
 145         m_previewPixmap = QPixmap();
 146         m_hasDefaultIcon = false;
 147
 148         m_prepareToolTipTimer->start();
 149     }
 150 }
 151
 152 void ToolTipManager::hideToolTip()
 153 {
 154     m_prepareToolTipTimer->stop();
 155     m_startPreviewJobTimer->stop();
 156     m_waitOnPreviewTimer->stop();
 157     m_showToolTipDelayedTimer->stop();
 158
 159     m_fileMetaDataToolTip->hide();
 160 }
 161
 162 void ToolTipManager::prepareToolTip()
 163 {
 164     if (m_generatingPreview) {
 165         m_waitOnPreviewTimer->start();
 166     }
 167
 168     if (!m_previewPixmap.isNull()) {
 169         showToolTipDelayed(m_previewPixmap);
 170     } else if (!m_hasDefaultIcon) {
 171         const QPixmap image(KIcon(m_item.iconName()).pixmap(128, 128));
 172         showToolTipDelayed(image);
 173         m_hasDefaultIcon = true;
 174     }
 175 }
 176
 177 void ToolTipManager::startPreviewJob()
 178 {
 179     m_generatingPreview = true;
 180     KIO::PreviewJob* job = KIO::filePreview(KFileItemList() << m_item, 256, 256);
 181
 182     connect(job, SIGNAL(gotPreview(const KFileItem&, const QPixmap&)),
 183             this, SLOT(setPreviewPix(const KFileItem&, const QPixmap&)));
 184     connect(job, SIGNAL(failed(const KFileItem&)),
 185             this, SLOT(previewFailed()));
 186 }
 187
 188
 189 void ToolTipManager::setPreviewPix(const KFileItem& item,
 190                                    const QPixmap& pixmap)
 191 {
 192     if ((m_item.url() != item.url()) || pixmap.isNull()) {
 193         // An old preview or an invalid preview has been received
 194         previewFailed();
 195     } else {
 196         m_previewPixmap = pixmap;
 197         m_generatingPreview = false;
 198     }
 199 }
 200
 201 void ToolTipManager::previewFailed()
 202 {
 203     m_generatingPreview = false;
 204 }
 205
 206 void ToolTipManager::showToolTip()
 207 {
 208     const QRect desktop = QApplication::desktop()->screenGeometry(m_itemRect.bottomRight());
 209     const QSize size = m_fileMetaDataToolTip->sizeHint();
 210
 211     // m_itemRect defines the area of the item, where the tooltip should be
 212     // shown. Per default the tooltip is shown in the bottom right corner.
 213     // If the tooltip content exceeds the desktop borders, it must be assured that:
 214     // - the content is fully visible
 215     // - the content is not drawn inside m_itemRect
 216     const bool hasRoomToLeft  = (m_itemRect.left()   - size.width()  >= desktop.left());
 217     const bool hasRoomToRight = (m_itemRect.right()  + size.width()  <= desktop.right());
 218     const bool hasRoomAbove   = (m_itemRect.top()    - size.height() >= desktop.top());
 219     const bool hasRoomBelow   = (m_itemRect.bottom() + size.height() <= desktop.bottom());
 220     if (!hasRoomAbove && !hasRoomBelow && !hasRoomToLeft && !hasRoomToRight) {
 221         return;
 222     }
 223
 224     int x = 0;
 225     int y = 0;
 226     if (hasRoomBelow || hasRoomAbove) {
 227         x = QCursor::pos().x() + 16; // TODO: use mouse pointer width instead of the magic value of 16
 228         if (x + size.width() >= desktop.right()) {
 229             x = desktop.right() - size.width();
 230         }
 231         if (hasRoomBelow) {
 232             y = m_itemRect.bottom() + 1;
 233         } else {
 234             y = m_itemRect.top() - size.height();
 235         }
 236     } else {
 237         Q_ASSERT(hasRoomToLeft || hasRoomToRight);
 238         if (hasRoomToRight) {
 239             x = m_itemRect.right() + 1;
 240         } else {
 241             x = m_itemRect.left() - size.width();
 242         }
 243
 244         // Put the tooltip at the bottom of the screen. The x-coordinate has already
 245         // been adjusted, so that no overlapping with m_itemRect occurs.
 246         y = desktop.bottom() - size.height();
 247     }
 248
 249     m_fileMetaDataToolTip->move(qMax(x, 0), qMax(y, 0));
 250     m_fileMetaDataToolTip->show();
 251 }
 252
 253 void ToolTipManager::showToolTipDelayed(const QPixmap& pixmap)
 254 {
 255     if (QApplication::mouseButtons() & Qt::LeftButton) {
 256         return;
 257     }
 258
 259     m_fileMetaDataToolTip->setPreview(pixmap);
 260     m_fileMetaDataToolTip->setName(m_item.text());
 261     m_fileMetaDataToolTip->setItems(KFileItemList() << m_item);
 262
 263     // Because one tooltip instance is reused, the size hint always depends on the previous
 264     // content (QWidgets don't update their layout geometry if they are invisible). To
 265     // assure having a consistent size without relayout flickering, the tooltip is opened
 266     // on an invisible position first. This gives the layout system some time to asynchronously
 267     // update the content. Sadly this only works with compositing enabled.
 268     if (KWindowSystem::compositingActive()) {
 269         const QRect desktop = QApplication::desktop()->screenGeometry(m_itemRect.bottomRight());
 270         m_fileMetaDataToolTip->move(desktop.bottomRight());
 271         m_fileMetaDataToolTip->show();
 272     }
 273
 274     m_showToolTipDelayedTimer->start(); // Calls ToolTipManager::showToolTip()
 275 }
 276
 277 #include "tooltipmanager.moc"