diff --git a/src/scrollzoomer.cpp b/src/scrollzoomer.cpp
new file mode 100644
--- /dev/null
+++ b/src/scrollzoomer.cpp
@@ -0,0 +1,480 @@
+#include <qevent.h>
+#include <qwt_plot_canvas.h>
+#include <qwt_plot_layout.h>
+#include <qwt_scale_engine.h>
+#include <qwt_scale_widget.h>
+#include "scrollbar.h"
+#include "scrollzoomer.h"
+
+class ScrollData
+{
+public:
+    ScrollData():
+        scrollBar( NULL ),
+        position( ScrollZoomer::OppositeToScale ),
+        mode( Qt::ScrollBarAsNeeded )
+    {
+    }
+
+    ~ScrollData()
+    {
+        delete scrollBar;
+    }
+
+    ScrollBar *scrollBar;
+    ScrollZoomer::ScrollBarPosition position;
+    Qt::ScrollBarPolicy mode;
+};
+
+ScrollZoomer::ScrollZoomer( QWidget *canvas ):
+    QwtPlotZoomer( canvas ),
+    d_cornerWidget( NULL ),
+    d_hScrollData( NULL ),
+    d_vScrollData( NULL ),
+    d_inZoom( false )
+{
+    for ( int axis = 0; axis < QwtPlot::axisCnt; axis++ )
+        d_alignCanvasToScales[ axis ] = false;
+
+    if ( !canvas )
+        return;
+
+    d_hScrollData = new ScrollData;
+    d_vScrollData = new ScrollData;
+}
+
+ScrollZoomer::~ScrollZoomer()
+{
+    delete d_cornerWidget;
+    delete d_vScrollData;
+    delete d_hScrollData;
+}
+
+void ScrollZoomer::rescale()
+{
+    QwtScaleWidget *xScale = plot()->axisWidget( xAxis() );
+    QwtScaleWidget *yScale = plot()->axisWidget( yAxis() );
+
+    if ( zoomRectIndex() <= 0 )
+    {
+        if ( d_inZoom )
+        {
+            xScale->setMinBorderDist( 0, 0 );
+            yScale->setMinBorderDist( 0, 0 );
+
+            QwtPlotLayout *layout = plot()->plotLayout();
+
+            for ( int axis = 0; axis < QwtPlot::axisCnt; axis++ )
+                layout->setAlignCanvasToScale( axis, d_alignCanvasToScales[ axis ] );
+
+            d_inZoom = false;
+        }
+    }
+    else
+    {
+        if ( !d_inZoom )
+        {
+            /*
+             We set a minimum border distance.
+             Otherwise the canvas size changes when scrolling,
+             between situations where the major ticks are at
+             the canvas borders (requiring extra space for the label)
+             and situations where all labels can be painted below/top
+             or left/right of the canvas.
+             */
+            int start, end;
+
+            xScale->getBorderDistHint( start, end );
+            xScale->setMinBorderDist( start, end );
+
+            yScale->getBorderDistHint( start, end );
+            yScale->setMinBorderDist( start, end );
+
+            QwtPlotLayout *layout = plot()->plotLayout();
+            for ( int axis = 0; axis < QwtPlot::axisCnt; axis++ )
+            {
+                d_alignCanvasToScales[axis] = 
+                    layout->alignCanvasToScale( axis );
+            }
+
+            layout->setAlignCanvasToScales( false );
+
+            d_inZoom = true;
+        }
+    }
+
+    QwtPlotZoomer::rescale();
+    updateScrollBars();
+}
+
+ScrollBar *ScrollZoomer::scrollBar( Qt::Orientation orientation )
+{
+    ScrollBar *&sb = ( orientation == Qt::Vertical )
+        ? d_vScrollData->scrollBar : d_hScrollData->scrollBar;
+
+    if ( sb == NULL )
+    {
+        sb = new ScrollBar( orientation, canvas() );
+        sb->hide();
+        connect( sb,
+            SIGNAL( valueChanged( Qt::Orientation, double, double ) ),
+            SLOT( scrollBarMoved( Qt::Orientation, double, double ) ) );
+    }
+    return sb;
+}
+
+ScrollBar *ScrollZoomer::horizontalScrollBar() const
+{
+    return d_hScrollData->scrollBar;
+}
+
+ScrollBar *ScrollZoomer::verticalScrollBar() const
+{
+    return d_vScrollData->scrollBar;
+}
+
+void ScrollZoomer::setHScrollBarMode( Qt::ScrollBarPolicy mode )
+{
+    if ( hScrollBarMode() != mode )
+    {
+        d_hScrollData->mode = mode;
+        updateScrollBars();
+    }
+}
+
+void ScrollZoomer::setVScrollBarMode( Qt::ScrollBarPolicy mode )
+{
+    if ( vScrollBarMode() != mode )
+    {
+        d_vScrollData->mode = mode;
+        updateScrollBars();
+    }
+}
+
+Qt::ScrollBarPolicy ScrollZoomer::hScrollBarMode() const
+{
+    return d_hScrollData->mode;
+}
+
+Qt::ScrollBarPolicy ScrollZoomer::vScrollBarMode() const
+{
+    return d_vScrollData->mode;
+}
+
+void ScrollZoomer::setHScrollBarPosition( ScrollBarPosition pos )
+{
+    if ( d_hScrollData->position != pos )
+    {
+        d_hScrollData->position = pos;
+        updateScrollBars();
+    }
+}
+
+void ScrollZoomer::setVScrollBarPosition( ScrollBarPosition pos )
+{
+    if ( d_vScrollData->position != pos )
+    {
+        d_vScrollData->position = pos;
+        updateScrollBars();
+    }
+}
+
+ScrollZoomer::ScrollBarPosition ScrollZoomer::hScrollBarPosition() const
+{
+    return d_hScrollData->position;
+}
+
+ScrollZoomer::ScrollBarPosition ScrollZoomer::vScrollBarPosition() const
+{
+    return d_vScrollData->position;
+}
+
+void ScrollZoomer::setCornerWidget( QWidget *w )
+{
+    if ( w != d_cornerWidget )
+    {
+        if ( canvas() )
+        {
+            delete d_cornerWidget;
+            d_cornerWidget = w;
+            if ( d_cornerWidget->parent() != canvas() )
+                d_cornerWidget->setParent( canvas() );
+
+            updateScrollBars();
+        }
+    }
+}
+
+QWidget *ScrollZoomer::cornerWidget() const
+{
+    return d_cornerWidget;
+}
+
+bool ScrollZoomer::eventFilter( QObject *object, QEvent *event )
+{
+    if ( object == canvas() )
+    {
+        switch( event->type() )
+        {
+            case QEvent::Resize:
+            {
+                int left, top, right, bottom;
+                canvas()->getContentsMargins( &left, &top, &right, &bottom );
+
+                QRect rect;
+                rect.setSize( static_cast<QResizeEvent *>( event )->size() );
+                rect.adjust( left, top, -right, -bottom );
+
+                layoutScrollBars( rect );
+                break;
+            }
+            case QEvent::ChildRemoved:
+            {
+                const QObject *child =
+                    static_cast<QChildEvent *>( event )->child();
+
+                if ( child == d_cornerWidget )
+                    d_cornerWidget = NULL;
+                else if ( child == d_hScrollData->scrollBar )
+                    d_hScrollData->scrollBar = NULL;
+                else if ( child == d_vScrollData->scrollBar )
+                    d_vScrollData->scrollBar = NULL;
+                break;
+            }
+            default:
+                break;
+        }
+    }
+    return QwtPlotZoomer::eventFilter( object, event );
+}
+
+bool ScrollZoomer::needScrollBar( Qt::Orientation orientation ) const
+{
+    Qt::ScrollBarPolicy mode;
+    double zoomMin, zoomMax, baseMin, baseMax;
+
+    if ( orientation == Qt::Horizontal )
+    {
+        mode = d_hScrollData->mode;
+        baseMin = zoomBase().left();
+        baseMax = zoomBase().right();
+        zoomMin = zoomRect().left();
+        zoomMax = zoomRect().right();
+    }
+    else
+    {
+        mode = d_vScrollData->mode;
+        baseMin = zoomBase().top();
+        baseMax = zoomBase().bottom();
+        zoomMin = zoomRect().top();
+        zoomMax = zoomRect().bottom();
+    }
+
+    bool needed = false;
+    switch( mode )
+    {
+        case Qt::ScrollBarAlwaysOn:
+            needed = true;
+            break;
+        case Qt::ScrollBarAlwaysOff:
+            needed = false;
+            break;
+        default:
+        {
+            if ( baseMin < zoomMin || baseMax > zoomMax )
+                needed = true;
+            break;
+        }
+    }
+    return needed;
+}
+
+void ScrollZoomer::updateScrollBars()
+{
+    if ( !canvas() )
+        return;
+
+    const int xAxis = QwtPlotZoomer::xAxis();
+    const int yAxis = QwtPlotZoomer::yAxis();
+
+    int xScrollBarAxis = xAxis;
+    if ( hScrollBarPosition() == OppositeToScale )
+        xScrollBarAxis = oppositeAxis( xScrollBarAxis );
+
+    int yScrollBarAxis = yAxis;
+    if ( vScrollBarPosition() == OppositeToScale )
+        yScrollBarAxis = oppositeAxis( yScrollBarAxis );
+
+
+    QwtPlotLayout *layout = plot()->plotLayout();
+
+    bool showHScrollBar = needScrollBar( Qt::Horizontal );
+    if ( showHScrollBar )
+    {
+        ScrollBar *sb = scrollBar( Qt::Horizontal );
+        sb->setPalette( plot()->palette() );
+        sb->setInverted( !plot()->axisScaleDiv( xAxis ).isIncreasing() );
+        sb->setBase( zoomBase().left(), zoomBase().right() );
+        sb->moveSlider( zoomRect().left(), zoomRect().right() );
+
+        if ( !sb->isVisibleTo( canvas() ) )
+        {
+            sb->show();
+            layout->setCanvasMargin( layout->canvasMargin( xScrollBarAxis )
+                + sb->extent(), xScrollBarAxis );
+        }
+    }
+    else
+    {
+        if ( horizontalScrollBar() )
+        {
+            horizontalScrollBar()->hide();
+            layout->setCanvasMargin( layout->canvasMargin( xScrollBarAxis )
+                - horizontalScrollBar()->extent(), xScrollBarAxis );
+        }
+    }
+
+    bool showVScrollBar = needScrollBar( Qt::Vertical );
+    if ( showVScrollBar )
+    {
+        ScrollBar *sb = scrollBar( Qt::Vertical );
+        sb->setPalette( plot()->palette() );
+        sb->setInverted( !plot()->axisScaleDiv( yAxis ).isIncreasing() );
+        sb->setBase( zoomBase().top(), zoomBase().bottom() );
+        sb->moveSlider( zoomRect().top(), zoomRect().bottom() );
+
+        if ( !sb->isVisibleTo( canvas() ) )
+        {
+            sb->show();
+            layout->setCanvasMargin( layout->canvasMargin( yScrollBarAxis )
+                + sb->extent(), yScrollBarAxis );
+        }
+    }
+    else
+    {
+        if ( verticalScrollBar() )
+        {
+            verticalScrollBar()->hide();
+            layout->setCanvasMargin( layout->canvasMargin( yScrollBarAxis )
+                - verticalScrollBar()->extent(), yScrollBarAxis );
+        }
+    }
+
+    if ( showHScrollBar && showVScrollBar )
+    {
+        if ( d_cornerWidget == NULL )
+        {
+            d_cornerWidget = new QWidget( canvas() );
+            d_cornerWidget->setAutoFillBackground( true );
+            d_cornerWidget->setPalette( plot()->palette() );
+        }
+        d_cornerWidget->show();
+    }
+    else
+    {
+        if ( d_cornerWidget )
+            d_cornerWidget->hide();
+    }
+
+    layoutScrollBars( canvas()->contentsRect() );
+    plot()->updateLayout();
+}
+
+void ScrollZoomer::layoutScrollBars( const QRect &rect )
+{
+    int hPos = xAxis();
+    if ( hScrollBarPosition() == OppositeToScale )
+        hPos = oppositeAxis( hPos );
+
+    int vPos = yAxis();
+    if ( vScrollBarPosition() == OppositeToScale )
+        vPos = oppositeAxis( vPos );
+
+    ScrollBar *hScrollBar = horizontalScrollBar();
+    ScrollBar *vScrollBar = verticalScrollBar();
+
+    const int hdim = hScrollBar ? hScrollBar->extent() : 0;
+    const int vdim = vScrollBar ? vScrollBar->extent() : 0;
+
+    if ( hScrollBar && hScrollBar->isVisible() )
+    {
+        int x = rect.x();
+        int y = ( hPos == QwtPlot::xTop )
+            ? rect.top() : rect.bottom() - hdim + 1;
+        int w = rect.width();
+
+        if ( vScrollBar && vScrollBar->isVisible() )
+        {
+            if ( vPos == QwtPlot::yLeft )
+                x += vdim;
+            w -= vdim;
+        }
+
+        hScrollBar->setGeometry( x, y, w, hdim );
+    }
+    if ( vScrollBar && vScrollBar->isVisible() )
+    {
+        int pos = yAxis();
+        if ( vScrollBarPosition() == OppositeToScale )
+            pos = oppositeAxis( pos );
+
+        int x = ( vPos == QwtPlot::yLeft )
+            ? rect.left() : rect.right() - vdim + 1;
+        int y = rect.y();
+
+        int h = rect.height();
+
+        if ( hScrollBar && hScrollBar->isVisible() )
+        {
+            if ( hPos == QwtPlot::xTop )
+                y += hdim;
+
+            h -= hdim;
+        }
+
+        vScrollBar->setGeometry( x, y, vdim, h );
+    }
+    if ( hScrollBar && hScrollBar->isVisible() &&
+        vScrollBar && vScrollBar->isVisible() )
+    {
+        if ( d_cornerWidget )
+        {
+            QRect cornerRect(
+                vScrollBar->pos().x(), hScrollBar->pos().y(),
+                vdim, hdim );
+            d_cornerWidget->setGeometry( cornerRect );
+        }
+    }
+}
+
+void ScrollZoomer::scrollBarMoved(
+    Qt::Orientation o, double min, double max )
+{
+    Q_UNUSED( max );
+
+    if ( o == Qt::Horizontal )
+        moveTo( QPointF( min, zoomRect().top() ) );
+    else
+        moveTo( QPointF( zoomRect().left(), min ) );
+
+    Q_EMIT zoomed( zoomRect() );
+}
+
+int ScrollZoomer::oppositeAxis( int axis ) const
+{
+    switch( axis )
+    {
+        case QwtPlot::xBottom:
+            return QwtPlot::xTop;
+        case QwtPlot::xTop:
+            return QwtPlot::xBottom;
+        case QwtPlot::yLeft:
+            return QwtPlot::yRight;
+        case QwtPlot::yRight:
+            return QwtPlot::yLeft;
+        default:
+            break;
+    }
+
+    return axis;
+}