src/kitemviews/kitemlistcontainer.cpp

   1 /***************************************************************************
   2  *   Copyright (C) 2011 by Peter Penz <peter.penz19@gmail.com>             *
   3  *                                                                         *
   4  *   Based on the Itemviews NG project from Trolltech Labs:                *
   5  *   http://qt.gitorious.org/qt-labs/itemviews-ng                          *
   6  *                                                                         *
   7  *   This program is free software; you can redistribute it and/or modify  *
   8  *   it under the terms of the GNU General Public License as published by  *
   9  *   the Free Software Foundation; either version 2 of the License, or     *
  10  *   (at your option) any later version.                                   *
  11  *                                                                         *
  12  *   This program is distributed in the hope that it will be useful,       *
  13  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
  14  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
  15  *   GNU General Public License for more details.                          *
  16  *                                                                         *
  17  *   You should have received a copy of the GNU General Public License     *
  18  *   along with this program; if not, write to the                         *
  19  *   Free Software Foundation, Inc.,                                       *
  20  *   51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA            *
  21  ***************************************************************************/
  22
  23 #include "kitemlistcontainer.h"
  24
  25 #include "kitemlistcontroller.h"
  26 #include "kitemlistview.h"
  27 #include "kitemmodelbase.h"
  28
  29 #include <QGraphicsScene>
  30 #include <QGraphicsView>
  31 #include <QScrollBar>
  32 #include <QStyle>
  33
  34 #include <KDebug>
  35
  36 class KItemListContainerViewport : public QGraphicsView
  37 {
  38 public:
  39     KItemListContainerViewport(QGraphicsScene* scene, QWidget* parent)
  40         : QGraphicsView(scene, parent)
  41     {
  42         setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
  43         setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
  44         setViewportMargins(0, 0, 0, 0);
  45         setFrameShape(QFrame::NoFrame);
  46     }
  47
  48     void scrollContentsBy(int dx, int dy)
  49     {
  50         Q_UNUSED(dx);
  51         Q_UNUSED(dy);
  52         // Do nothing. This prevents that e.g. the wheel-event
  53         // results in a moving of the scene items.
  54     }
  55 };
  56
  57 KItemListContainer::KItemListContainer(KItemListController* controller, QWidget* parent) :
  58     QAbstractScrollArea(parent),
  59     m_controller(controller)
  60 {
  61     Q_ASSERT(controller);
  62     controller->setParent(this);
  63     initialize();
  64 }
  65
  66 KItemListContainer::KItemListContainer(QWidget* parent) :
  67     QAbstractScrollArea(parent),
  68     m_controller(0)
  69 {
  70     initialize();
  71 }
  72
  73 KItemListContainer::~KItemListContainer()
  74 {
  75 }
  76
  77 KItemListController* KItemListContainer::controller() const
  78 {
  79     return m_controller;
  80 }
  81
  82 void KItemListContainer::showEvent(QShowEvent* event)
  83 {
  84     QAbstractScrollArea::showEvent(event);
  85     updateGeometries();
  86 }
  87
  88 void KItemListContainer::resizeEvent(QResizeEvent* event)
  89 {
  90     QAbstractScrollArea::resizeEvent(event);
  91     updateGeometries();
  92 }
  93
  94 void KItemListContainer::scrollContentsBy(int dx, int dy)
  95 {
  96     KItemListView* view = m_controller->view();
  97     if (!view) {
  98         return;
  99     }
 100
 101     const qreal currentOffset = view->offset();
 102     const qreal offsetDiff = (view->scrollOrientation() == Qt::Vertical) ? dy : dx;
 103     view->setOffset(currentOffset - offsetDiff);
 104 }
 105
 106 void KItemListContainer::slotModelChanged(KItemModelBase* current, KItemModelBase* previous)
 107 {
 108     Q_UNUSED(current);
 109     Q_UNUSED(previous);
 110 }
 111
 112 void KItemListContainer::slotViewChanged(KItemListView* current, KItemListView* previous)
 113 {
 114     QGraphicsScene* scene = static_cast<QGraphicsView*>(viewport())->scene();
 115     if (previous) {
 116         scene->removeItem(previous);
 117         disconnect(previous, SIGNAL(offsetChanged(int,int)), this, SLOT(updateScrollBars()));
 118         disconnect(previous, SIGNAL(maximumOffsetChanged(int,int)), this, SLOT(updateScrollBars()));
 119     }
 120     if (current) {
 121         scene->addItem(current);
 122         connect(previous, SIGNAL(offsetChanged(int,int)), this, SLOT(updateScrollBars()));
 123         connect(current, SIGNAL(maximumOffsetChanged(int,int)), this, SLOT(updateScrollBars()));
 124     }
 125 }
 126
 127 void KItemListContainer::updateScrollBars()
 128 {
 129     const QSizeF size = m_controller->view()->size();
 130
 131     if (m_controller->view()->scrollOrientation() == Qt::Vertical) {
 132         QScrollBar* scrollBar = verticalScrollBar();
 133         const int value = m_controller->view()->offset();
 134         const int maximum = qMax(0, int(m_controller->view()->maximumOffset() - size.height()));
 135         scrollBar->setPageStep(size.height());
 136         scrollBar->setMinimum(0);
 137         scrollBar->setMaximum(maximum);
 138         scrollBar->setValue(value);
 139         horizontalScrollBar()->setMaximum(0);
 140     } else {
 141         QScrollBar* scrollBar = horizontalScrollBar();
 142         const int value = m_controller->view()->offset();
 143         const int maximum = qMax(0, int(m_controller->view()->maximumOffset() - size.width()));
 144         scrollBar->setPageStep(size.width());
 145         scrollBar->setMinimum(0);
 146         scrollBar->setMaximum(maximum);
 147         scrollBar->setValue(value);
 148         verticalScrollBar()->setMaximum(0);
 149     }
 150 }
 151
 152 void KItemListContainer::updateGeometries()
 153 {
 154     QRect rect = geometry();
 155
 156     int widthDec = frameWidth() * 2;
 157     if (verticalScrollBar()->isVisible()) {
 158         widthDec += style()->pixelMetric(QStyle::PM_ScrollBarExtent);
 159     }
 160
 161     int heightDec = frameWidth() * 2;
 162     if (horizontalScrollBar()->isVisible()) {
 163         heightDec += style()->pixelMetric(QStyle::PM_ScrollBarExtent);
 164     }
 165
 166     rect.adjust(0, 0, -widthDec, -heightDec);
 167
 168     m_controller->view()->setGeometry(QRect(0, 0, rect.width(), rect.height()));
 169
 170     static_cast<KItemListContainerViewport*>(viewport())->scene()->setSceneRect(0, 0, rect.width(), rect.height());
 171     static_cast<KItemListContainerViewport*>(viewport())->viewport()->setGeometry(QRect(0, 0, rect.width(), rect.height()));
 172
 173     updateScrollBars();
 174 }
 175
 176 void KItemListContainer::initialize()
 177 {
 178     if (!m_controller) {
 179         m_controller = new KItemListController(this);
 180     }
 181
 182     connect(m_controller, SIGNAL(modelChanged(KItemModelBase*,KItemModelBase*)),
 183             this, SLOT(slotModelChanged(KItemModelBase*,KItemModelBase*)));
 184     connect(m_controller, SIGNAL(viewChanged(KItemListView*,KItemListView*)),
 185             this, SLOT(slotViewChanged(KItemListView*,KItemListView*)));
 186
 187     QGraphicsView* graphicsView = new KItemListContainerViewport(new QGraphicsScene(this), this);
 188     setViewport(graphicsView);
 189 }
 190
 191 #include "kitemlistcontainer.moc"