src/views/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>
  23 #include <KIcon>
  24 #include <KIconLoader>
  25 #include <KIconEffect>
  26 #include <KLocale>
  27
  28 #include <QApplication>
  29 #include <QPainter>
  30 #include <QPaintEvent>
  31 #include <QRect>
  32 #include <QTimer>
  33 #include <QTimeLine>
  34
  35 #include <KDebug>
  36
  37 SelectionToggle::SelectionToggle(QWidget* parent) :
  38     QAbstractButton(parent),
  39     m_isHovered(false),
  40     m_leftMouseButtonPressed(false),
  41     m_fadingValue(0),
  42     m_margin(0),
  43     m_icon(),
  44     m_fadingTimeLine(0)
  45 {
  46     setFocusPolicy(Qt::NoFocus);
  47     parent->installEventFilter(this);
  48     resize(sizeHint());
  49     setIconOverlay(isChecked());
  50     connect(this, SIGNAL(toggled(bool)),
  51             this, SLOT(setIconOverlay(bool)));
  52     connect(KGlobalSettings::self(), SIGNAL(iconChanged(int)),
  53             this, SLOT(refreshIcon()));
  54 }
  55
  56 SelectionToggle::~SelectionToggle()
  57 {
  58 }
  59
  60 QSize SelectionToggle::sizeHint() const
  61 {
  62     return QSize(16, 16);
  63 }
  64
  65 void SelectionToggle::reset()
  66 {
  67     m_url = KUrl();
  68     hide();
  69 }
  70
  71 void SelectionToggle::setUrl(const KUrl& url)
  72 {
  73     m_url = url;
  74     if (!url.isEmpty()) {
  75         startFading();
  76     }
  77 }
  78
  79 void SelectionToggle::setMargin(int margin)
  80 {
  81     if (margin != m_margin) {
  82         m_margin = margin;
  83         update();
  84     }
  85 }
  86
  87 int SelectionToggle::margin() const
  88 {
  89     return m_margin;
  90 }
  91
  92 KUrl SelectionToggle::url() const
  93 {
  94     return m_url;
  95 }
  96
  97 void SelectionToggle::setVisible(bool visible)
  98 {
  99     QAbstractButton::setVisible(visible);
 100
 101     stopFading();
 102     if (visible) {
 103         startFading();
 104     }
 105
 106 }
 107
 108 bool SelectionToggle::eventFilter(QObject* obj, QEvent* event)
 109 {
 110     if ((obj == parent()) && (event->type() == QEvent::MouseMove) && m_leftMouseButtonPressed) {
 111         // Don't forward mouse move events to the viewport,
 112         // otherwise a rubberband selection will be shown when
 113         // clicking on the selection toggle and moving the mouse
 114         // above the viewport.
 115         return true;
 116     }
 117
 118     return QAbstractButton::eventFilter(obj, event);
 119 }
 120
 121 void SelectionToggle::enterEvent(QEvent* event)
 122 {
 123     QAbstractButton::enterEvent(event);
 124
 125     // if the mouse cursor is above the selection toggle, display
 126     // it immediately without fading timer
 127     m_isHovered = true;
 128     if (m_fadingTimeLine != 0) {
 129         m_fadingTimeLine->stop();
 130     }
 131     m_fadingValue = 255;
 132     setToolTip(isChecked() ? i18nc("@info:tooltip", "Deselect Item") :
 133                              i18nc("@info:tooltip", "Select Item"));
 134     update();
 135 }
 136
 137 void SelectionToggle::leaveEvent(QEvent* event)
 138 {
 139     QAbstractButton::leaveEvent(event);
 140
 141     m_isHovered = false;
 142     update();
 143 }
 144
 145 void SelectionToggle::mousePressEvent(QMouseEvent* event)
 146 {
 147     QAbstractButton::mousePressEvent(event);
 148     m_leftMouseButtonPressed = (event->buttons() & Qt::LeftButton);
 149 }
 150
 151 void SelectionToggle::mouseReleaseEvent(QMouseEvent* event)
 152 {
 153     QAbstractButton::mouseReleaseEvent(event);
 154     m_leftMouseButtonPressed = (event->buttons() & Qt::LeftButton);
 155 }
 156
 157 void SelectionToggle::resizeEvent(QResizeEvent* event)
 158 {
 159     QAbstractButton::resizeEvent(event);
 160     setIconOverlay(isChecked());
 161 }
 162
 163 void SelectionToggle::paintEvent(QPaintEvent* event)
 164 {
 165     QPainter painter(this);
 166     painter.setClipRect(event->rect());
 167
 168     // draw the icon overlay
 169     const QPoint pos(m_margin, m_margin);
 170     if (m_isHovered) {
 171         KIconEffect *iconEffect = KIconLoader::global()->iconEffect();
 172         QPixmap activeIcon = iconEffect->apply(m_icon, KIconLoader::Desktop, KIconLoader::ActiveState);
 173         painter.drawPixmap(pos, activeIcon);
 174     } else {
 175         if (m_fadingValue < 255) {
 176             // apply an alpha mask respecting the fading value to the icon
 177             QPixmap icon = m_icon;
 178             QPixmap alphaMask(icon.width(), icon.height());
 179             const QColor color(m_fadingValue, m_fadingValue, m_fadingValue);
 180             alphaMask.fill(color);
 181             icon.setAlphaChannel(alphaMask);
 182             painter.drawPixmap(pos, icon);
 183         } else {
 184             // no fading is required
 185             painter.drawPixmap(pos, m_icon);
 186         }
 187     }
 188
 189 }
 190
 191 void SelectionToggle::setFadingValue(int value)
 192 {
 193     m_fadingValue = value;
 194     if (m_fadingValue >= 255) {
 195         Q_ASSERT(m_fadingTimeLine != 0);
 196         m_fadingTimeLine->stop();
 197     }
 198     update();
 199 }
 200
 201 void SelectionToggle::setIconOverlay(bool checked)
 202 {
 203     const char* icon = checked ? "list-remove" : "list-add";
 204     const int size = qMin(width() - 2 * m_margin, height() - 2 * m_margin);
 205     m_icon = KIconLoader::global()->loadIcon(icon,
 206                                              KIconLoader::NoGroup,
 207                                              size);
 208     update();
 209 }
 210
 211 void SelectionToggle::refreshIcon()
 212 {
 213     setIconOverlay(isChecked());
 214 }
 215
 216 void SelectionToggle::startFading()
 217 {
 218     Q_ASSERT(m_fadingTimeLine == 0);
 219
 220     const bool animate = KGlobalSettings::graphicEffectsLevel() & KGlobalSettings::SimpleAnimationEffects;
 221     const int duration = animate ? 600 : 1;
 222
 223     m_fadingTimeLine = new QTimeLine(duration, this);
 224     connect(m_fadingTimeLine, SIGNAL(frameChanged(int)),
 225             this, SLOT(setFadingValue(int)));
 226     m_fadingTimeLine->setFrameRange(0, 255);
 227     m_fadingTimeLine->start();
 228     m_fadingValue = 0;
 229 }
 230
 231 void SelectionToggle::stopFading()
 232 {
 233     if (m_fadingTimeLine != 0) {
 234         m_fadingTimeLine->stop();
 235         delete m_fadingTimeLine;
 236         m_fadingTimeLine = 0;
 237     }
 238     m_fadingValue = 0;
 239 }
 240
 241 #include "selectiontoggle.moc"