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_timer(0),
  42     m_previewTimer(0),
  43     m_waitOnPreviewTimer(0),
  44     m_fileMetaDataToolTip(0),
  45     m_item(),
  46     m_itemRect(),
  47     m_generatingPreview(false),
  48     m_hasDefaultIcon(false),
  49     m_previewPixmap()
  50 {
  51     m_dolphinModel = static_cast<DolphinModel*>(m_proxyModel->sourceModel());
  52     connect(parent, SIGNAL(entered(const QModelIndex&)),
  53             this, SLOT(requestToolTip(const QModelIndex&)));
  54     connect(parent, SIGNAL(viewportEntered()),
  55             this, SLOT(hideToolTip()));
  56
  57     m_timer = new QTimer(this);
  58     m_timer->setSingleShot(true);
  59     connect(m_timer, SIGNAL(timeout()),
  60             this, SLOT(prepareToolTip()));
  61
  62     m_previewTimer = new QTimer(this);
  63     m_previewTimer->setSingleShot(true);
  64     connect(m_previewTimer, SIGNAL(timeout()),
  65             this, SLOT(startPreviewJob()));
  66
  67     m_waitOnPreviewTimer = new QTimer(this);
  68     m_waitOnPreviewTimer->setSingleShot(true);
  69     connect(m_waitOnPreviewTimer, SIGNAL(timeout()),
  70             this, SLOT(prepareToolTip()));
  71
  72     // When the mousewheel is used, the items don't get a hovered indication
  73     // (Qt-issue #200665). To assure that the tooltip still gets hidden,
  74     // the scrollbars are observed.
  75     connect(parent->horizontalScrollBar(), SIGNAL(valueChanged(int)),
  76             this, SLOT(hideTip()));
  77     connect(parent->verticalScrollBar(), SIGNAL(valueChanged(int)),
  78             this, SLOT(hideTip()));
  79
  80     m_view->viewport()->installEventFilter(this);
  81     m_view->installEventFilter(this);
  82
  83     static FileMetaDataToolTip* sharedToolTip = 0;
  84     if (sharedToolTip == 0) {
  85         sharedToolTip = new FileMetaDataToolTip();
  86         // TODO: Using K_GLOBAL_STATIC would be preferable to maintain the
  87         // instance, but the cleanup of KMetaDataWidget at this stage does
  88         // not work.
  89     }
  90     m_fileMetaDataToolTip = sharedToolTip;
  91 }
  92
  93 ToolTipManager::~ToolTipManager()
  94 {
  95 }
  96
  97 void ToolTipManager::hideTip()
  98 {
  99     hideToolTip();
 100 }
 101
 102 bool ToolTipManager::eventFilter(QObject* watched, QEvent* event)
 103 {
 104     if (watched == m_view->viewport()) {
 105         switch (event->type()) {
 106         case QEvent::Leave:
 107         case QEvent::MouseButtonPress:
 108             hideToolTip();
 109             break;
 110         default:
 111             break;
 112         }
 113     } else if ((watched == m_view) && (event->type() == QEvent::KeyPress)) {
 114         hideToolTip();
 115     }
 116
 117     return QObject::eventFilter(watched, event);
 118 }
 119
 120 void ToolTipManager::requestToolTip(const QModelIndex& index)
 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 ((index.column() == DolphinModel::Name) && !(QApplication::mouseButtons() & Qt::LeftButton)) {
 125         m_waitOnPreviewTimer->stop();
 126         hideToolTip();
 127
 128         m_itemRect = m_view->visualRect(index);
 129         const QPoint pos = m_view->viewport()->mapToGlobal(m_itemRect.topLeft());
 130         m_itemRect.moveTo(pos);
 131
 132         const QModelIndex dirIndex = m_proxyModel->mapToSource(index);
 133         m_item = m_dolphinModel->itemForIndex(dirIndex);
 134
 135         // Only start the previewJob when the mouse has been over this item for 200 milliseconds.
 136         // This prevents a lot of useless preview jobs when passing rapidly over a lot of items.
 137         m_previewTimer->start(200);
 138         m_previewPixmap = QPixmap();
 139         m_hasDefaultIcon = false;
 140
 141         m_timer->start(500);
 142     } else {
 143         hideToolTip();
 144     }
 145 }
 146
 147 void ToolTipManager::hideToolTip()
 148 {
 149     m_timer->stop();
 150     m_previewTimer->stop();
 151     m_waitOnPreviewTimer->stop();
 152
 153     m_fileMetaDataToolTip->hide();
 154     m_fileMetaDataToolTip->setItems(KFileItemList());
 155 }
 156
 157 void ToolTipManager::prepareToolTip()
 158 {
 159     if (m_generatingPreview) {
 160         m_waitOnPreviewTimer->start(250);
 161     }
 162
 163     if (!m_previewPixmap.isNull()) {
 164         showToolTip(m_previewPixmap);
 165     } else if (!m_hasDefaultIcon) {
 166         const QPixmap image(KIcon(m_item.iconName()).pixmap(128, 128));
 167         showToolTip(image);
 168         m_hasDefaultIcon = true;
 169     }
 170 }
 171
 172 void ToolTipManager::startPreviewJob()
 173 {
 174     m_generatingPreview = true;
 175     KIO::PreviewJob* job = KIO::filePreview(KFileItemList() << m_item, 256, 256);
 176
 177     connect(job, SIGNAL(gotPreview(const KFileItem&, const QPixmap&)),
 178             this, SLOT(setPreviewPix(const KFileItem&, const QPixmap&)));
 179     connect(job, SIGNAL(failed(const KFileItem&)),
 180             this, SLOT(previewFailed()));
 181 }
 182
 183
 184 void ToolTipManager::setPreviewPix(const KFileItem& item,
 185                                    const QPixmap& pixmap)
 186 {
 187     if ((m_item.url() != item.url()) || pixmap.isNull()) {
 188         // An old preview or an invalid preview has been received
 189         previewFailed();
 190     } else {
 191         m_previewPixmap = pixmap;
 192         m_generatingPreview = false;
 193     }
 194 }
 195
 196 void ToolTipManager::previewFailed()
 197 {
 198     m_generatingPreview = false;
 199 }
 200
 201
 202 void ToolTipManager::showToolTip(const QPixmap& pixmap)
 203 {
 204     if (QApplication::mouseButtons() & Qt::LeftButton) {
 205         return;
 206     }
 207
 208     m_fileMetaDataToolTip->setPreview(pixmap);
 209     m_fileMetaDataToolTip->setName(m_item.text());
 210     m_fileMetaDataToolTip->setItems(KFileItemList() << m_item);
 211
 212     // Calculate the x- and y-position of the tooltip
 213     const QSize size = m_fileMetaDataToolTip->sizeHint();
 214     const QRect desktop = QApplication::desktop()->screenGeometry(m_itemRect.bottomRight());
 215
 216     // m_itemRect defines the area of the item, where the tooltip should be
 217     // shown. Per default the tooltip is shown in the bottom right corner.
 218     // If the tooltip content exceeds the desktop borders, it must be assured that:
 219     // - the content is fully visible
 220     // - the content is not drawn inside m_itemRect
 221     const bool hasRoomToLeft  = (m_itemRect.left()   - size.width()  >= desktop.left());
 222     const bool hasRoomToRight = (m_itemRect.right()  + size.width()  <= desktop.right());
 223     const bool hasRoomAbove   = (m_itemRect.top()    - size.height() >= desktop.top());
 224     const bool hasRoomBelow   = (m_itemRect.bottom() + size.height() <= desktop.bottom());
 225     if (!hasRoomAbove && !hasRoomBelow && !hasRoomToLeft && !hasRoomToRight) {
 226         return;
 227     }
 228
 229     // The size hint provided by the tooltip is not necessarily equal to the
 230     // real size of the tooltip after showing it. As long as the tooltip is aligned
 231     // on the upper-left edge, this is no problem. If the tooltip is aligned at
 232     // another edge, the real size must be respected and the position
 233     // corrected. Whether a correction must be done, is indicated by the variables
 234     // updateWidth and updateHeight:
 235     bool updateWidth = false;
 236     bool updateHeight = false;
 237
 238     int x = 0;
 239     int y = 0;
 240     if (hasRoomBelow || hasRoomAbove) {
 241         x = QCursor::pos().x() + 16; // TODO: use mouse pointer width instead of the magic value of 16
 242         if (x + size.width() >= desktop.right()) {
 243             x = desktop.right() - size.width();
 244         }
 245         if (hasRoomBelow) {
 246             y = m_itemRect.bottom();
 247         } else {
 248             y = m_itemRect.top() - size.height();
 249             updateHeight = true;
 250         }
 251     } else {
 252         Q_ASSERT(hasRoomToLeft || hasRoomToRight);
 253         if (hasRoomToRight) {
 254             x = m_itemRect.right();
 255         } else {
 256             x = m_itemRect.left() - size.width();
 257             updateWidth = true;
 258         }
 259
 260         // Put the tooltip at the bottom of the screen. The x-coordinate has already
 261         // been adjusted, so that no overlapping with m_itemRect occurs.
 262         y = desktop.bottom() - size.height();
 263         updateHeight = true;
 264     }
 265
 266     if (!updateWidth && !updateHeight) {
 267         // Default case: There is enough room below and right of the mouse
 268         // pointer and the tooltip can be positioned there.
 269         m_fileMetaDataToolTip->move(x, y);
 270         m_fileMetaDataToolTip->show();
 271     } else {
 272         // There is not enough room to show the tooltip at the default position and
 273         // it must be moved left or upwards. In this case the size hint of the
 274         // tooltip is not sufficient and the real size must be respected.
 275         // To prevent a flickering, the tooltip is first opened outside the visible
 276         // desktop area and moved afterwards.
 277         m_fileMetaDataToolTip->move(desktop.right() + 1, desktop.bottom() + 1);
 278         m_fileMetaDataToolTip->show();
 279
 280         const QSize shownSize = m_fileMetaDataToolTip->size();
 281         const int xDiff = updateWidth ? shownSize.width() - size.width() : 0;
 282         const int yDiff = updateHeight ? shownSize.height() - size.height() : 0;
 283         m_fileMetaDataToolTip->move(x - xDiff, y - yDiff);
 284     }
 285 }
 286
 287 #include "tooltipmanager.moc"