src/selectiontoggle.cpp

   1 /***************************************************************************
   2  *   Copyright (C) 2008 by Peter Penz <peter.penz@gmx.at>                  *
   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 "selectiontoggle.h"
  21
  22 #include <kglobalsettings.h>
  23 #include <kicon.h>
  24 #include <kiconloader.h>
  25 #include <kiconeffect.h>
  26
  27 #include <QPainter>
  28 #include <QPaintEvent>
  29 #include <QRect>
  30 #include <QTimer>
  31 #include <QTimeLine>
  32
  33 SelectionToggle::SelectionToggle(QWidget* parent) :
  34     QAbstractButton(parent),
  35     m_isHovered(false),
  36     m_fadingValue(0),
  37     m_icon(),
  38     m_fadingTimeLine(0)
  39 {
  40     setFocusPolicy(Qt::NoFocus);
  41     parent->installEventFilter(this);
  42     resize(sizeHint());
  43     setIconOverlay(isChecked());
  44     connect(this, SIGNAL(toggled(bool)),
  45             this, SLOT(setIconOverlay(bool)));
  46 }
  47
  48 SelectionToggle::~SelectionToggle()
  49 {
  50 }
  51
  52 QSize SelectionToggle::sizeHint() const
  53 {
  54     return QSize(16, 16);
  55 }
  56
  57 void SelectionToggle::reset()
  58 {
  59     m_url = KUrl();
  60     hide();
  61 }
  62
  63 void SelectionToggle::setUrl(const KUrl& url)
  64 {
  65     m_url = url;
  66     if (!url.isEmpty()) {
  67         startFading();
  68     }
  69 }
  70
  71 KUrl SelectionToggle::url() const
  72 {
  73     return m_url;
  74 }
  75
  76 void SelectionToggle::setVisible(bool visible)
  77 {
  78     QAbstractButton::setVisible(visible);
  79
  80     stopFading();
  81     if (visible) {
  82         startFading();
  83     }
  84
  85 }
  86
  87 bool SelectionToggle::eventFilter(QObject* obj, QEvent* event)
  88 {
  89     if ((obj == parent()) && (event->type() == QEvent::Leave)) {
  90         hide();
  91     }
  92     return QAbstractButton::eventFilter(obj, event);
  93 }
  94
  95 void SelectionToggle::enterEvent(QEvent* event)
  96 {
  97     QAbstractButton::enterEvent(event);
  98
  99     // if the mouse cursor is above the selection toggle, display
 100     // it immediately without fading timer
 101     m_isHovered = true;
 102     if (m_fadingTimeLine != 0) {
 103         m_fadingTimeLine->stop();
 104     }
 105     m_fadingValue = 255;
 106     update();
 107 }
 108
 109 void SelectionToggle::leaveEvent(QEvent* event)
 110 {
 111     QAbstractButton::leaveEvent(event);
 112     m_isHovered = false;
 113     update();
 114 }
 115
 116 void SelectionToggle::paintEvent(QPaintEvent* event)
 117 {
 118     QPainter painter(this);
 119     painter.setClipRect(event->rect());
 120     painter.setRenderHint(QPainter::Antialiasing);
 121
 122     // draw an alpha blended circle as background
 123     const QPalette& palette = parentWidget()->palette();
 124
 125     const QBrush& backgroundBrush = palette.brush(QPalette::Normal, QPalette::Window);
 126     QColor background = backgroundBrush.color();
 127     background.setAlpha(m_fadingValue / 2);
 128     painter.setBrush(background);
 129
 130     const QBrush& foregroundBrush = palette.brush(QPalette::Normal, QPalette::WindowText);
 131     QColor foreground = foregroundBrush.color();
 132     foreground.setAlpha(m_fadingValue / 4);
 133     painter.setPen(foreground);
 134
 135     painter.drawEllipse(0, 0, width(), height());
 136
 137     // draw the icon overlay
 138     if (m_isHovered) {
 139         KIconEffect iconEffect;
 140         QPixmap activeIcon = iconEffect.apply(m_icon, KIconLoader::Desktop, KIconLoader::ActiveState);
 141         painter.drawPixmap(0, 0, activeIcon);
 142     } else {
 143         if (m_fadingValue < 255) {
 144             // apply an alpha mask respecting the fading value to the icon
 145             QPixmap icon = m_icon;
 146             QPixmap alphaMask(icon.width(), icon.height());
 147             const QColor color(m_fadingValue, m_fadingValue, m_fadingValue);
 148             alphaMask.fill(color);
 149             icon.setAlphaChannel(alphaMask);
 150             painter.drawPixmap(0, 0, icon);
 151         } else {
 152             // no fading is required
 153             painter.drawPixmap(0, 0, m_icon);
 154         }
 155     }
 156 }
 157
 158 void SelectionToggle::setFadingValue(int value)
 159 {
 160     m_fadingValue = value;
 161     if (m_fadingValue >= 255) {
 162         Q_ASSERT(m_fadingTimeLine != 0);
 163         m_fadingTimeLine->stop();
 164     }
 165     update();
 166 }
 167
 168 void SelectionToggle::setIconOverlay(bool checked)
 169 {
 170     const char* icon = checked ? "list-remove" : "list-add";
 171     m_icon = KIconLoader::global()->loadIcon(icon,
 172                                              KIconLoader::NoGroup,
 173                                              KIconLoader::SizeSmall);
 174     update();
 175 }
 176
 177 void SelectionToggle::startFading()
 178 {
 179     Q_ASSERT(m_fadingTimeLine == 0);
 180
 181     const bool animate = KGlobalSettings::graphicEffectsLevel() & KGlobalSettings::SimpleAnimationEffects;
 182     const int duration = animate ? 1500 : 1;
 183
 184     m_fadingTimeLine = new QTimeLine(duration, this);
 185     connect(m_fadingTimeLine, SIGNAL(frameChanged(int)),
 186             this, SLOT(setFadingValue(int)));
 187     m_fadingTimeLine->setFrameRange(0, 255);
 188     m_fadingTimeLine->start();
 189     m_fadingValue = 0;
 190 }
 191
 192 void SelectionToggle::stopFading()
 193 {
 194     if (m_fadingTimeLine != 0) {
 195         m_fadingTimeLine->stop();
 196         delete m_fadingTimeLine;
 197         m_fadingTimeLine = 0;
 198     }
 199     m_fadingValue = 0;
 200 }
 201
 202 #include "selectiontoggle.moc"