src/panels/information/pixmapviewer.cpp

   1 /***************************************************************************
   2  *   Copyright (C) 2006 by Peter Penz <peter.penz19@gmail.com>             *
   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 "pixmapviewer.h"
  21
  22 #include <KIconLoader>
  23
  24 #include <QPainter>
  25 #include <QPixmap>
  26 #include <QStyle>
  27
  28 PixmapViewer::PixmapViewer(QWidget* parent, Transition transition) :
  29     QWidget(parent),
  30     m_transition(transition),
  31     m_animationStep(0),
  32     m_sizeHint()
  33 {
  34     setMinimumWidth(KIconLoader::SizeEnormous);
  35     setMinimumHeight(KIconLoader::SizeEnormous);
  36
  37     m_animation.setDuration(150);
  38     m_animation.setCurveShape(QTimeLine::LinearCurve);
  39
  40     if (m_transition != NoTransition) {
  41         connect(&m_animation, &QTimeLine::valueChanged, this, static_cast<void(PixmapViewer::*)()>(&PixmapViewer::update));
  42         connect(&m_animation, &QTimeLine::finished, this, &PixmapViewer::checkPendingPixmaps);
  43     }
  44 }
  45
  46 PixmapViewer::~PixmapViewer()
  47 {
  48 }
  49
  50 void PixmapViewer::setPixmap(const QPixmap& pixmap)
  51 {
  52     if (pixmap.isNull()) {
  53         return;
  54     }
  55
  56     if ((m_transition != NoTransition) && (m_animation.state() == QTimeLine::Running)) {
  57         m_pendingPixmaps.enqueue(pixmap);
  58         if (m_pendingPixmaps.count() > 5) {
  59             // don't queue more than 5 pixmaps
  60             m_pendingPixmaps.takeFirst();
  61         }
  62         return;
  63     }
  64
  65     m_oldPixmap = m_pixmap.isNull() ? pixmap : m_pixmap;
  66     m_pixmap = pixmap;
  67     update();
  68
  69     const bool animate = (m_transition != NoTransition) &&
  70                          (m_pixmap.size() != m_oldPixmap.size());
  71     if (animate) {
  72         m_animation.start();
  73     }
  74 }
  75
  76 void PixmapViewer::setSizeHint(const QSize& size)
  77 {
  78     m_sizeHint = size;
  79     updateGeometry();
  80 }
  81
  82 QSize PixmapViewer::sizeHint() const
  83 {
  84     return m_sizeHint;
  85 }
  86
  87 void PixmapViewer::paintEvent(QPaintEvent* event)
  88 {
  89     QWidget::paintEvent(event);
  90
  91     QPainter painter(this);
  92
  93     if (m_transition != NoTransition) {
  94         const float value = m_animation.currentValue();
  95         const int scaledWidth  = static_cast<int>((m_oldPixmap.width()  * (1.0 - value)) + (m_pixmap.width()  * value));
  96         const int scaledHeight = static_cast<int>((m_oldPixmap.height() * (1.0 - value)) + (m_pixmap.height() * value));
  97
  98         const bool useOldPixmap = (m_transition == SizeTransition) &&
  99                                   (m_oldPixmap.width() > m_pixmap.width());
 100         const QPixmap& largePixmap = useOldPixmap ? m_oldPixmap : m_pixmap;
 101         if (!largePixmap.isNull()) {
 102             const QPixmap scaledPixmap = largePixmap.scaled(scaledWidth,
 103                                                             scaledHeight,
 104                                                             Qt::IgnoreAspectRatio,
 105                                                             Qt::FastTransformation);
 106
 107             style()->drawItemPixmap(&painter, rect(), Qt::AlignCenter, scaledPixmap);
 108         }
 109     } else {
 110         style()->drawItemPixmap(&painter, rect(), Qt::AlignCenter, m_pixmap);
 111     }
 112 }
 113
 114 void PixmapViewer::checkPendingPixmaps()
 115 {
 116     if (m_pendingPixmaps.count() > 0) {
 117         QPixmap pixmap = m_pendingPixmaps.dequeue();
 118         m_oldPixmap = m_pixmap.isNull() ? pixmap : m_pixmap;
 119         m_pixmap = pixmap;
 120         update();
 121         m_animation.start();
 122     } else {
 123         m_oldPixmap = m_pixmap;
 124     }
 125 }
 126