plasma-framework/widgets/scrollwidget.cpp
Wang Kai ec7651c5e1 Scroll fix:
If scroll widget is wider/taller than the internal widget,
then the internal widget should be positioned to scroll widget's top left, not bottom right.


svn path=/trunk/KDE/kdelibs/; revision=951376
2009-04-09 04:52:38 +00:00

281 lines
7.6 KiB
C++

/*
* Copyright 2009 Marco Martin <notmart@gmail.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU Library General Public License as
* published by the Free Software Foundation; either version 2, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details
*
* You should have received a copy of the GNU Library General Public
* License along with this program; if not, write to the
* Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
#include "scrollwidget.h"
//Qt
#include <QGraphicsSceneResizeEvent>
#include <QGraphicsGridLayout>
#include <QApplication>
#include <QWidget>
//KDE
#include <kmimetype.h>
#include <kdebug.h>
//Plasma
#include <plasma/widgets/scrollbar.h>
namespace Plasma
{
class ScrollWidgetPrivate
{
public:
ScrollWidgetPrivate(ScrollWidget *parent)
: q(parent),
widget(0),
dragging(false)
{
}
~ScrollWidgetPrivate()
{
}
void adjustScrollbars()
{
verticalScrollBar->nativeWidget()->setMaximum(qMax(0, int((widget->size().height() - scrollingWidget->size().height())/10)));
if (verticalScrollBarPolicy == Qt::ScrollBarAlwaysOff ||
verticalScrollBar->nativeWidget()->maximum() == 0) {
if (layout->itemAt(2) == verticalScrollBar) {
layout->removeAt(2);
} else if (layout->itemAt(1) == verticalScrollBar) {
layout->removeAt(1);
}
verticalScrollBar->hide();
} else if (!verticalScrollBar->isVisible()) {
layout->addItem(verticalScrollBar, 0, 1);
verticalScrollBar->show();
}
horizontalScrollBar->nativeWidget()->setMaximum(qMax(0, int((widget->size().width() - scrollingWidget->size().width())/10)));
if (horizontalScrollBarPolicy == Qt::ScrollBarAlwaysOff ||
horizontalScrollBar->nativeWidget()->maximum() == 0) {
if (layout->itemAt(2) == horizontalScrollBar) {
layout->removeAt(2);
} else if (layout->itemAt(1) == horizontalScrollBar) {
layout->removeAt(1);
}
horizontalScrollBar->hide();
} else if (!horizontalScrollBar->isVisible()) {
layout->addItem(horizontalScrollBar, 1, 0);
horizontalScrollBar->show();
}
}
void verticalScroll(int value)
{
if (!dragging) {
widget->setPos(QPoint(0, -value*10));
}
}
void horizontalScroll(int value)
{
if (!dragging) {
widget->setPos(QPoint(-value*10, 0));
}
}
void adjustClipping()
{
const bool clip = widget->size().width() > scrollingWidget->size().width() ||
widget->size().height() > scrollingWidget->size().height();
scrollingWidget->setFlag(QGraphicsItem::ItemClipsChildrenToShape, clip);
}
ScrollWidget *q;
QGraphicsWidget *scrollingWidget;
QGraphicsWidget *widget;
QGraphicsGridLayout *layout;
ScrollBar *verticalScrollBar;
Qt::ScrollBarPolicy verticalScrollBarPolicy;
ScrollBar *horizontalScrollBar;
Qt::ScrollBarPolicy horizontalScrollBarPolicy;
QString styleSheet;
bool dragging;
};
ScrollWidget::ScrollWidget(QGraphicsWidget *parent)
: QGraphicsWidget(parent),
d(new ScrollWidgetPrivate(this))
{
setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);
d->layout = new QGraphicsGridLayout(this);
d->scrollingWidget = new QGraphicsWidget(this);
d->layout->addItem(d->scrollingWidget, 0, 0);
d->verticalScrollBarPolicy = Qt::ScrollBarAsNeeded;
d->verticalScrollBar = new Plasma::ScrollBar(this);
d->layout->addItem(d->verticalScrollBar, 0, 1);
d->verticalScrollBar->nativeWidget()->setMinimum(0);
d->verticalScrollBar->nativeWidget()->setMaximum(100);
connect(d->verticalScrollBar, SIGNAL(valueChanged(int)), this, SLOT(verticalScroll(int)));
d->horizontalScrollBarPolicy = Qt::ScrollBarAsNeeded;
d->horizontalScrollBar = new Plasma::ScrollBar(this);
d->horizontalScrollBar->setOrientation(Qt::Horizontal);
d->layout->addItem(d->horizontalScrollBar, 1, 0);
d->horizontalScrollBar->nativeWidget()->setMinimum(0);
d->horizontalScrollBar->nativeWidget()->setMaximum(100);
connect(d->horizontalScrollBar, SIGNAL(valueChanged(int)), this, SLOT(horizontalScroll(int)));
}
ScrollWidget::~ScrollWidget()
{
delete d;
}
void ScrollWidget::setWidget(QGraphicsWidget *widget)
{
if (d->widget && d->widget != widget) {
d->widget->removeEventFilter(this);
delete d->widget;
}
d->widget = widget;
widget->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Fixed);
widget->setParentItem(d->scrollingWidget);
widget->setPos(QPoint(0,0));
widget->installEventFilter(this);
d->adjustScrollbars();
}
QGraphicsWidget *ScrollWidget::widget() const
{
return d->widget;
}
void ScrollWidget::setHorizontalScrollBarPolicy(const Qt::ScrollBarPolicy policy)
{
d->horizontalScrollBarPolicy = policy;
}
Qt::ScrollBarPolicy ScrollWidget::horizontalScrollBarPolicy() const
{
return d->horizontalScrollBarPolicy;
}
void ScrollWidget::setVerticalScrollBarPolicy(const Qt::ScrollBarPolicy policy)
{
d->verticalScrollBarPolicy = policy;
}
Qt::ScrollBarPolicy ScrollWidget::verticalScrollBarPolicy() const
{
return d->verticalScrollBarPolicy;
}
void ScrollWidget::setStyleSheet(const QString &styleSheet)
{
d->styleSheet = styleSheet;
d->verticalScrollBar->setStyleSheet(styleSheet);
d->horizontalScrollBar->setStyleSheet(styleSheet);
}
QString ScrollWidget::styleSheet() const
{
return d->styleSheet;
}
QWidget *ScrollWidget::nativeWidget() const
{
return 0;
}
void ScrollWidget::resizeEvent(QGraphicsSceneResizeEvent *event)
{
if (!d->widget) {
return;
}
d->widget->resize(d->scrollingWidget->size());
d->adjustScrollbars();
d->adjustClipping();
QGraphicsWidget::resizeEvent(event);
}
void ScrollWidget::mouseMoveEvent(QGraphicsSceneMouseEvent *event)
{
if (!d->widget) {
return;
}
QPointF deltaPos = event->pos() - event->lastPos();
d->widget->setPos(qBound(qMin((qreal)0,-d->widget->size().width()+d->scrollingWidget->size().width()), d->widget->pos().x()+deltaPos.x(), (qreal)0),
qBound(qMin((qreal)0,-d->widget->size().height()+d->scrollingWidget->size().height()), d->widget->pos().y()+deltaPos.y(), (qreal)0));
d->dragging = true;
d->horizontalScrollBar->setValue(-d->widget->pos().x()/10);
d->verticalScrollBar->setValue(-d->widget->pos().y()/10);
d->dragging = false;
QGraphicsWidget::mouseMoveEvent(event);
}
void ScrollWidget::mousePressEvent(QGraphicsSceneMouseEvent *event)
{
event->accept();
}
void ScrollWidget::wheelEvent(QGraphicsSceneWheelEvent *event)
{
if (event->delta() < 0) {
d->verticalScrollBar->setValue(d->verticalScrollBar->value()+10);
} else {
d->verticalScrollBar->setValue(d->verticalScrollBar->value()-10);
}
QGraphicsWidget::wheelEvent(event);
}
bool ScrollWidget::eventFilter(QObject *watched, QEvent *event)
{
if (!d->widget) {
return false;
}
if (watched == d->widget && event->type() == QEvent::GraphicsSceneResize) {
d->adjustScrollbars();
d->adjustClipping();
}
return false;
}
} // namespace Plasma
#include <scrollwidget.moc>