src/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 "dolphintooltip.h"
  23 #include "dolphinmodel.h"
  24 #include "dolphinsortfilterproxymodel.h"
  25
  26 #include <kicon.h>
  27 #include <ktooltip.h>
  28 #include <kio/previewjob.h>
  29
  30 #include <QApplication>
  31 #include <QDesktopWidget>
  32 #include <QScrollBar>
  33 #include <QTimer>
  34 #include <QToolTip>
  35
  36 const int PREVIEW_WIDTH = 256;
  37 const int PREVIEW_HEIGHT = 256;
  38 const int ICON_WIDTH = 128;
  39 const int ICON_HEIGHT = 128;
  40 const int PREVIEW_DELAY = 250;
  41
  42 K_GLOBAL_STATIC(DolphinBalloonTooltipDelegate, g_delegate)
  43
  44 ToolTipManager::ToolTipManager(QAbstractItemView* parent,
  45                                DolphinSortFilterProxyModel* model) :
  46     QObject(parent),
  47     m_view(parent),
  48     m_dolphinModel(0),
  49     m_proxyModel(model),
  50     m_timer(0),
  51     m_previewTimer(0),
  52     m_waitOnPreviewTimer(0),
  53     m_item(),
  54     m_itemRect(),
  55     m_preview(false),
  56     m_generatingPreview(false),
  57     m_previewIsLate(false),
  58     m_previewPass(0),
  59     m_emptyRenderedKToolTipItem(0),
  60     m_pix()
  61 {
  62     KToolTip::setToolTipDelegate(g_delegate);
  63
  64     m_dolphinModel = static_cast<DolphinModel*>(m_proxyModel->sourceModel());
  65     connect(parent, SIGNAL(entered(const QModelIndex&)),
  66             this, SLOT(requestToolTip(const QModelIndex&)));
  67     connect(parent, SIGNAL(viewportEntered()),
  68             this, SLOT(hideToolTip()));
  69
  70     m_timer = new QTimer(this);
  71     m_timer->setSingleShot(true);
  72     connect(m_timer, SIGNAL(timeout()),
  73             this, SLOT(prepareToolTip()));
  74
  75     m_previewTimer = new QTimer(this);
  76     m_previewTimer->setSingleShot(true);
  77     connect(m_previewTimer, SIGNAL(timeout()),
  78             this, SLOT(startPreviewJob()));
  79
  80     m_waitOnPreviewTimer = new QTimer(this);
  81     m_waitOnPreviewTimer->setSingleShot(true);
  82     connect(m_waitOnPreviewTimer, SIGNAL(timeout()),
  83             this, SLOT(prepareToolTip()));
  84
  85     // When the mousewheel is used, the items don't get a hovered indication
  86     // (Qt-issue #200665). To assure that the tooltip still gets hidden,
  87     // the scrollbars are observed.
  88     connect(parent->horizontalScrollBar(), SIGNAL(valueChanged(int)),
  89             this, SLOT(hideTip()));
  90     connect(parent->verticalScrollBar(), SIGNAL(valueChanged(int)),
  91             this, SLOT(hideTip()));
  92
  93     m_view->viewport()->installEventFilter(this);
  94 }
  95
  96 ToolTipManager::~ToolTipManager()
  97 {
  98 }
  99
 100 void ToolTipManager::hideTip()
 101 {
 102     hideToolTip();
 103 }
 104
 105 bool ToolTipManager::eventFilter(QObject* watched, QEvent* event)
 106 {
 107     if ((watched == m_view->viewport()) && (event->type() == QEvent::Leave)) {
 108         hideToolTip();
 109     }
 110
 111     return QObject::eventFilter(watched, event);
 112 }
 113
 114 void ToolTipManager::requestToolTip(const QModelIndex& index)
 115 {
 116     // only request a tooltip for the name column and when no selection or
 117     // drag & drop operation is done (indicated by the left mouse button)
 118     if ((index.column() == DolphinModel::Name) && !(QApplication::mouseButtons() & Qt::LeftButton)) {
 119         m_waitOnPreviewTimer->stop();
 120         KToolTip::hideTip();
 121
 122         m_itemRect = m_view->visualRect(index);
 123         const QPoint pos = m_view->viewport()->mapToGlobal(m_itemRect.topLeft());
 124         m_itemRect.moveTo(pos);
 125
 126         const QModelIndex dirIndex = m_proxyModel->mapToSource(index);
 127         m_item = m_dolphinModel->itemForIndex(dirIndex);
 128
 129         // only start the previewJob when the mouse has been over this item for 200 milliseconds,
 130         // this prevents a lot of useless preview jobs when passing rapidly over a lot of items
 131         m_previewTimer->start(200);
 132         m_preview = false;
 133         m_previewIsLate = false;
 134         m_previewPass = 0;
 135
 136         m_timer->start(500);
 137     } else {
 138         hideToolTip();
 139     }
 140 }
 141
 142 void ToolTipManager::hideToolTip()
 143 {
 144     m_timer->stop();
 145     m_previewTimer->stop();
 146     m_waitOnPreviewTimer->stop();
 147     m_previewIsLate = false;
 148     KToolTip::hideTip();
 149 }
 150
 151 void ToolTipManager::prepareToolTip()
 152 {
 153     if (m_generatingPreview) {
 154         if (m_previewPass == 1) {
 155             // We waited 250msec and the preview is still not finished,
 156             // so show the toolTip with a transparent image of maximal width.
 157             // When the preview finishes, m_previewIsLate will cause
 158             // a direct update of the tooltip, via m_emptyRenderedKToolTipItem.
 159             QPixmap paddedImage(QSize(PREVIEW_WIDTH, 32));
 160             m_previewIsLate = true;
 161             paddedImage.fill(Qt::transparent);
 162             KToolTipItem* toolTip = new KToolTipItem(paddedImage, m_item.getToolTipText());
 163             m_emptyRenderedKToolTipItem = toolTip; // make toolTip accessible everywhere
 164             showToolTip(toolTip);
 165         }
 166
 167         ++m_previewPass;
 168         m_waitOnPreviewTimer->start(250);
 169     } else {
 170         // The preview generation has finished, find out under which circumstances.
 171         if (m_preview && m_previewIsLate) {
 172             // We got a preview, but it is late, the tooltip has already been shown.
 173             // So update the tooltip directly.
 174             if (m_emptyRenderedKToolTipItem != 0) {
 175                 m_emptyRenderedKToolTipItem->setData(Qt::DecorationRole, KIcon(m_pix));
 176             }
 177             return;
 178         }
 179
 180         KIcon icon;
 181         if (m_preview) {
 182             // We got a preview.
 183             icon = KIcon(m_pix);
 184         } else {
 185             // No preview, so use an icon.
 186             // Force a 128x128 icon, a 256x256 one is far too big.
 187             icon = KIcon(KIcon(m_item.iconName()).pixmap(ICON_WIDTH, ICON_HEIGHT));
 188         }
 189
 190         KToolTipItem* toolTip = new KToolTipItem(icon, m_item.getToolTipText());
 191         showToolTip(toolTip);
 192     }
 193 }
 194
 195 void ToolTipManager::showToolTip(KToolTipItem* tip)
 196 {
 197     if (QApplication::mouseButtons() & Qt::LeftButton) {
 198         delete tip;
 199         tip = 0;
 200         // m_emptyRenderedKToolTipItem is an alias for tip.
 201         m_emptyRenderedKToolTipItem = 0;
 202         return;
 203     }
 204
 205     KStyleOptionToolTip option;
 206     // TODO: get option content from KToolTip or add KToolTip::sizeHint() method
 207     option.direction      = QApplication::layoutDirection();
 208     option.fontMetrics    = QFontMetrics(QToolTip::font());
 209     option.activeCorner   = KStyleOptionToolTip::TopLeftCorner;
 210     option.palette        = QToolTip::palette();
 211     option.font           = QToolTip::font();
 212     option.rect           = QRect();
 213     option.state          = QStyle::State_None;
 214     option.decorationSize = QSize(32, 32);
 215
 216     QSize size;
 217     if (m_previewIsLate) {
 218         QPixmap paddedImage(QSize(PREVIEW_WIDTH, PREVIEW_HEIGHT));
 219         KToolTipItem* maxiTip = new KToolTipItem(paddedImage, m_item.getToolTipText());
 220         size = g_delegate->sizeHint(&option, maxiTip);
 221         delete maxiTip;
 222         maxiTip = 0;
 223     }
 224     else {
 225         size = g_delegate->sizeHint(&option, tip);
 226     }
 227     const QRect desktop = QApplication::desktop()->screenGeometry(m_itemRect.bottomRight());
 228
 229     // m_itemRect defines the area of the item, where the tooltip should be
 230     // shown. Per default the tooltip is shown in the bottom right corner.
 231     // If the tooltip content exceeds the desktop borders, it must be assured that:
 232     // - the content is fully visible
 233     // - the content is not drawn inside m_itemRect
 234     const bool hasRoomToLeft  = (m_itemRect.left()   - size.width()  >= desktop.left());
 235     const bool hasRoomToRight = (m_itemRect.right()  + size.width()  <= desktop.right());
 236     const bool hasRoomAbove   = (m_itemRect.top()    - size.height() >= desktop.top());
 237     const bool hasRoomBelow   = (m_itemRect.bottom() + size.height() <= desktop.bottom());
 238     if (!hasRoomAbove && !hasRoomBelow && !hasRoomToLeft && !hasRoomToRight) {
 239         delete tip;
 240         tip = 0;
 241         return;
 242     }
 243
 244     int x = 0;
 245     int y = 0;
 246     if (hasRoomBelow || hasRoomAbove) {
 247         x = QCursor::pos().x() + 16; // TODO: use mouse pointer width instead of the magic value of 16
 248         if (x + size.width() >= desktop.right()) {
 249             x = desktop.right() - size.width();
 250         }
 251         y = hasRoomBelow ? m_itemRect.bottom() : m_itemRect.top() - size.height();
 252     } else {
 253         Q_ASSERT(hasRoomToLeft || hasRoomToRight);
 254         x = hasRoomToRight ? m_itemRect.right() : m_itemRect.left() - size.width();
 255
 256         // Put the tooltip at the bottom of the screen. The x-coordinate has already
 257         // been adjusted, so that no overlapping with m_itemRect occurs.
 258         y = desktop.bottom() - size.height();
 259     }
 260
 261     KToolTip::showTip(QPoint(x, y), tip);
 262 }
 263
 264
 265
 266 void ToolTipManager::startPreviewJob()
 267 {
 268     m_generatingPreview = true;
 269     KIO::PreviewJob* job = KIO::filePreview(KUrl::List() << m_item.url(),
 270                                             PREVIEW_WIDTH,
 271                                             PREVIEW_HEIGHT);
 272     job->setIgnoreMaximumSize(true);
 273
 274     connect(job, SIGNAL(gotPreview(const KFileItem&, const QPixmap&)),
 275             this, SLOT(setPreviewPix(const KFileItem&, const QPixmap&)));
 276     connect(job, SIGNAL(failed(const KFileItem&)),
 277             this, SLOT(previewFailed(const KFileItem&)));
 278 }
 279
 280
 281 void ToolTipManager::setPreviewPix(const KFileItem& item,
 282                                    const QPixmap& pixmap)
 283 {
 284     if (m_item.url() != item.url()) {
 285         m_generatingPreview = false;
 286         return;
 287     }
 288
 289     if (m_previewIsLate) {
 290         // always use the maximal width
 291         QPixmap paddedImage(QSize(PREVIEW_WIDTH, pixmap.height()));
 292         paddedImage.fill(Qt::transparent);
 293         QPainter painter(&paddedImage);
 294         painter.drawPixmap((PREVIEW_WIDTH - pixmap.width()) / 2, 0, pixmap);
 295         m_pix = paddedImage;
 296     } else {
 297         m_pix = pixmap;
 298     }
 299     m_preview = true;
 300     m_generatingPreview = false;
 301 }
 302
 303 void ToolTipManager::previewFailed(const KFileItem& item)
 304 {
 305     Q_UNUSED(item);
 306     m_generatingPreview = false;
 307 }
 308
 309 #include "tooltipmanager.moc"