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 #include <klocale.h>
  27
  28 #include <QPainter>
  29 #include <QPaintEvent>
  30 #include <QRect>
  31 #include <QTimer>
  32 #include <QTimeLine>
  33
  34 SelectionToggle::SelectionToggle(QWidget* parent) :
  35     QAbstractButton(parent),
  36     m_isHovered(false),
  37     m_fadingValue(0),
  38     m_icon(),
  39     m_fadingTimeLine(0)
  40 {
  41     setFocusPolicy(Qt::NoFocus);
  42     parent->installEventFilter(this);
  43     resize(sizeHint());
  44     setIconOverlay(isChecked());
  45     connect(this, SIGNAL(toggled(bool)),
  46             this, SLOT(setIconOverlay(bool)));
  47     connect(KGlobalSettings::self(), SIGNAL(iconChanged(int)),
  48             this, SLOT(refreshIcon()));
  49 }
  50
  51 SelectionToggle::~SelectionToggle()
  52 {
  53 }
  54
  55 QSize SelectionToggle::sizeHint() const
  56 {
  57     return QSize(16, 16);
  58 }
  59
  60 void SelectionToggle::reset()
  61 {
  62     m_url = KUrl();
  63     hide();
  64 }
  65
  66 void SelectionToggle::setUrl(const KUrl& url)
  67 {
  68     m_url = url;
  69     if (!url.isEmpty()) {
  70         startFading();
  71     }
  72 }
  73
  74 KUrl SelectionToggle::url() const
  75 {
  76     return m_url;
  77 }
  78
  79 void SelectionToggle::setVisible(bool visible)
  80 {
  81     QAbstractButton::setVisible(visible);
  82
  83     stopFading();
  84     if (visible) {
  85         startFading();
  86     }
  87
  88 }
  89
  90 bool SelectionToggle::eventFilter(QObject* obj, QEvent* event)
  91 {
  92     if ((obj == parent()) && (event->type() == QEvent::Leave)) {
  93         hide();
  94     }
  95     return QAbstractButton::eventFilter(obj, event);
  96 }
  97
  98 void SelectionToggle::enterEvent(QEvent* event)
  99 {
 100     QAbstractButton::enterEvent(event);
 101
 102     // if the mouse cursor is above the selection toggle, display
 103     // it immediately without fading timer
 104     m_isHovered = true;
 105     if (m_fadingTimeLine != 0) {
 106         m_fadingTimeLine->stop();
 107     }
 108     m_fadingValue = 255;
 109     setToolTip(isChecked() ? i18nc("@info:tooltip", "Deselect Item") :
 110                              i18nc("@info:tooltip", "Select Item"));
 111     update();
 112 }
 113
 114 void SelectionToggle::leaveEvent(QEvent* event)
 115 {
 116     QAbstractButton::leaveEvent(event);
 117     m_isHovered = false;
 118     update();
 119 }
 120
 121 void SelectionToggle::paintEvent(QPaintEvent* event)
 122 {
 123     QPainter painter(this);
 124     painter.setClipRect(event->rect());
 125     painter.setRenderHint(QPainter::Antialiasing);
 126
 127     // draw an alpha blended circle as background
 128     const QPalette& palette = parentWidget()->palette();
 129
 130     const QBrush& backgroundBrush = palette.brush(QPalette::Normal, QPalette::Window);
 131     QColor background = backgroundBrush.color();
 132     background.setAlpha(m_fadingValue / 2);
 133     painter.setBrush(background);
 134
 135     const QBrush& foregroundBrush = palette.brush(QPalette::Normal, QPalette::WindowText);
 136     QColor foreground = foregroundBrush.color();
 137     foreground.setAlpha(m_fadingValue / 4);
 138     painter.setPen(foreground);
 139
 140     painter.drawEllipse(0, 0, width(), height());
 141
 142     // draw the icon overlay
 143     if (m_isHovered) {
 144         KIconEffect iconEffect;
 145         QPixmap activeIcon = iconEffect.apply(m_icon, KIconLoader::Desktop, KIconLoader::ActiveState);
 146         painter.drawPixmap(0, 0, activeIcon);
 147     } else {
 148         if (m_fadingValue < 255) {
 149             // apply an alpha mask respecting the fading value to the icon
 150             QPixmap icon = m_icon;
 151             QPixmap alphaMask(icon.width(), icon.height());
 152             const QColor color(m_fadingValue, m_fadingValue, m_fadingValue);
 153             alphaMask.fill(color);
 154             icon.setAlphaChannel(alphaMask);
 155             painter.drawPixmap(0, 0, icon);
 156         } else {
 157             // no fading is required
 158             painter.drawPixmap(0, 0, m_icon);
 159         }
 160     }
 161 }
 162
 163 void SelectionToggle::setFadingValue(int value)
 164 {
 165     m_fadingValue = value;
 166     if (m_fadingValue >= 255) {
 167         Q_ASSERT(m_fadingTimeLine != 0);
 168         m_fadingTimeLine->stop();
 169     }
 170     update();
 171 }
 172
 173 void SelectionToggle::setIconOverlay(bool checked)
 174 {
 175     const char* icon = checked ? "list-remove" : "list-add";
 176     m_icon = KIconLoader::global()->loadIcon(icon,
 177                                              KIconLoader::NoGroup,
 178                                              KIconLoader::SizeSmall);
 179     update();
 180 }
 181
 182 void SelectionToggle::refreshIcon()
 183 {
 184     setIconOverlay(isChecked());
 185 }
 186
 187 void SelectionToggle::startFading()
 188 {
 189     Q_ASSERT(m_fadingTimeLine == 0);
 190
 191     const bool animate = KGlobalSettings::graphicEffectsLevel() & KGlobalSettings::SimpleAnimationEffects;
 192     const int duration = animate ? 600 : 1;
 193
 194     m_fadingTimeLine = new QTimeLine(duration, this);
 195     connect(m_fadingTimeLine, SIGNAL(frameChanged(int)),
 196             this, SLOT(setFadingValue(int)));
 197     m_fadingTimeLine->setFrameRange(0, 255);
 198     m_fadingTimeLine->start();
 199     m_fadingValue = 0;
 200 }
 201
 202 void SelectionToggle::stopFading()
 203 {
 204     if (m_fadingTimeLine != 0) {
 205         m_fadingTimeLine->stop();
 206         delete m_fadingTimeLine;
 207         m_fadingTimeLine = 0;
 208     }
 209     m_fadingValue = 0;
 210 }
 211
 212 #include "selectiontoggle.moc"