Files
cantata/support/flickcharm.cpp

384 lines
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C++

/****************************************************************************
**
** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
** Contact: Qt Software Information (qt-info@nokia.com)
**
** This file is part of the Graphics Dojo project on Qt Labs.
**
** This file may be used under the terms of the GNU General Public
** License version 2.0 or 3.0 as published by the Free Software Foundation
** and appearing in the file LICENSE.GPL included in the packaging of
** this file. Please review the following information to ensure GNU
** General Public Licensing requirements will be met:
** http://www.fsf.org/licensing/licenses/info/GPLv2.html and
** http://www.gnu.org/copyleft/gpl.html.
**
** If you are unsure which license is appropriate for your use, please
** contact the sales department at qt-sales@nokia.com.
**
** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
**
****************************************************************************/
#include "flickcharm.h"
#include "globalstatic.h"
#include "utils.h"
#include <QAbstractScrollArea>
#include <QAbstractItemView>
#include <QApplication>
#include <QBasicTimer>
#include <QTimer>
#include <QEvent>
#include <QHash>
#include <QList>
#include <QMouseEvent>
#include <QScrollBar>
//#include <QWebFrame>
//#include <QWebView>
//#include <QDebug>
GLOBAL_STATIC(FlickCharm, instance)
int FlickCharm::dragArea()
{
static int area=-1;
if (-1==area) {
area=Utils::scaleForDpi(32);
}
return area;
}
struct FlickData {
typedef enum { Steady, Pressed, ManualScroll, AutoScroll, Stop } State;
State state;
QWidget *widget;
QPoint pressPos;
QPoint offset;
QPoint dragPos;
QPoint speed;
QList<QEvent*> ignored;
};
class FlickCharmPrivate
{
public:
QHash<QWidget*, FlickData*> flickData;
QBasicTimer ticker;
};
FlickCharm::FlickCharm(QObject *parent): QObject(parent)
{
d = Utils::touchFriendly() ? new FlickCharmPrivate : 0;
}
FlickCharm::~FlickCharm()
{
delete d;
}
void FlickCharm::activateOn(QWidget *widget)
{
if (!enabled()) {
return;
}
QAbstractScrollArea *scrollArea = dynamic_cast<QAbstractScrollArea*>(widget);
if (scrollArea && !d->flickData.contains(scrollArea)) {
// scrollArea->setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
// scrollArea->setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
QWidget *viewport = scrollArea->viewport();
viewport->installEventFilter(this);
scrollArea->installEventFilter(this);
d->flickData.remove(viewport);
d->flickData[viewport] = new FlickData;
d->flickData[viewport]->widget = widget;
d->flickData[viewport]->state = FlickData::Steady;
QAbstractItemView *view = dynamic_cast<QAbstractItemView*>(widget);
if (view) {
view->setVerticalScrollMode(QAbstractItemView::ScrollPerPixel);
view->setHorizontalScrollMode(QAbstractItemView::ScrollPerPixel);
}
return;
}
// QWebView *webView = dynamic_cast<QWebView*>(widget);
// if (webView) {
// QWebFrame *frame = webView->page()->mainFrame();
// frame->setScrollBarPolicy(Qt::Vertical, Qt::ScrollBarAlwaysOff);
// frame->setScrollBarPolicy(Qt::Horizontal, Qt::ScrollBarAlwaysOff);
// webView->installEventFilter(this);
// d->flickData.remove(webView);
// d->flickData[webView] = new FlickData;
// d->flickData[webView]->widget = webView;
// d->flickData[webView]->state = FlickData::Steady;
// return;
// }
// qWarning() << "FlickCharm only works on QAbstractScrollArea (and derived classes)";
// qWarning() << "or QWebView (and derived classes)";
}
void FlickCharm::deactivateFrom(QWidget *widget)
{
if (!enabled()) {
return;
}
QAbstractScrollArea *scrollArea = dynamic_cast<QAbstractScrollArea*>(widget);
if (scrollArea && d->flickData.contains(scrollArea)) {
QWidget *viewport = scrollArea->viewport();
viewport->removeEventFilter(this);
scrollArea->removeEventFilter(this);
delete d->flickData[viewport];
d->flickData.remove(viewport);
return;
}
// QWebView *webView = dynamic_cast<QWebView*>(widget);
// if (webView) {
// webView->removeEventFilter(this);
// delete d->flickData[webView];
// d->flickData.remove(webView);
// return;
// }
}
static QPoint scrollOffset(QWidget *widget)
{
int x = 0, y = 0;
QAbstractScrollArea *scrollArea = dynamic_cast<QAbstractScrollArea*>(widget);
if (scrollArea) {
x = scrollArea->horizontalScrollBar()->value();
y = scrollArea->verticalScrollBar()->value();
}
// QWebView *webView = dynamic_cast<QWebView*>(widget);
// if (webView) {
// QWebFrame *frame = webView->page()->mainFrame();
// x = frame->evaluateJavaScript("window.scrollX").toInt();
// y = frame->evaluateJavaScript("window.scrollY").toInt();
// }
return QPoint(x, y);
}
static void setScrollOffset(QWidget *widget, const QPoint &p)
{
QAbstractScrollArea *scrollArea = dynamic_cast<QAbstractScrollArea*>(widget);
if (scrollArea) {
scrollArea->horizontalScrollBar()->setValue(p.x());
scrollArea->verticalScrollBar()->setValue(p.y());
}
// QWebView *webView = dynamic_cast<QWebView*>(widget);
// QWebFrame *frame = webView ? webView->page()->mainFrame() : 0;
// if (frame)
// frame->evaluateJavaScript(QString("window.scrollTo(%1,%2);").arg(p.x()).arg(p.y()));
}
static QPoint deaccelerate(const QPoint &speed, int a = 1, int max = 64)
{
int x = qBound(-max, speed.x(), max);
int y = qBound(-max, speed.y(), max);
x = (x == 0) ? x : (x > 0) ? qMax(0, x - a) : qMin(0, x + a);
y = (y == 0) ? y : (y > 0) ? qMax(0, y - a) : qMin(0, y + a);
return QPoint(x, y);
}
class QAbstractItemViewHack : public QAbstractItemView
{
public:
void doDrag(Qt::DropActions supportedActions) { startDrag(supportedActions); }
};
static QAbstractItemViewHack *dragView=0;
void FlickCharm::startDrag()
{
dragView->doDrag(Qt::CopyAction);
dragView=0;
}
bool FlickCharm::eventFilter(QObject *object, QEvent *event)
{
if (!enabled() || !object->isWidgetType())
return false;
QEvent::Type type = event->type();
if (type != QEvent::MouseButtonPress &&
type != QEvent::MouseButtonRelease &&
type != QEvent::MouseMove)
return false;
QMouseEvent *mouseEvent = dynamic_cast<QMouseEvent*>(event);
if (!mouseEvent || mouseEvent->modifiers() != Qt::NoModifier)
return false;
QWidget *viewport = dynamic_cast<QWidget*>(object);
FlickData *data = d->flickData.value(viewport);
if (!viewport || !data || data->ignored.removeAll(event))
return false;
bool consumed = false;
switch (data->state) {
case FlickData::Steady:
if (mouseEvent->type() == QEvent::MouseButtonPress)
if (mouseEvent->buttons() == Qt::LeftButton) {
// Drag?
if (qobject_cast<QAbstractItemView *>(data->widget)) {
QAbstractItemView *view=static_cast<QAbstractItemView *>(data->widget);
QModelIndex index=view->indexAt(mouseEvent->pos());
if (index.isValid() && 0==index.column() && index.model()) {
int flags=index.model()->flags(index);
if (flags&Qt::ItemIsDragEnabled && !(flags&Qt::ItemIsUserCheckable)) {
QRect r=view->visualRect(index);
if (view->isRightToLeft()) {
r=QRect(r.x()+r.width()-(1+dragArea()), r.y(), qMin(dragArea(), r.width()), qMin(dragArea(), r.height()));
} else {
r=QRect(r.x(), r.y(), qMin(dragArea(), r.width()), qMin(dragArea(), r.height()));
}
if (r.contains(mouseEvent->pos())) {
QMouseEvent *event1 = new QMouseEvent(QEvent::MouseButtonPress,
mouseEvent->pos(), Qt::LeftButton,
Qt::LeftButton, Qt::NoModifier);
QMouseEvent *event2 = new QMouseEvent(*mouseEvent);
data->ignored << event1;
data->ignored << event2;
QApplication::postEvent(object, event1);
QApplication::postEvent(object, event2);
dragView=((QAbstractItemViewHack *)view);
QTimer::singleShot(0, this, SLOT(startDrag()));
break;
}
}
}
}
consumed = true;
data->state = FlickData::Pressed;
data->pressPos = mouseEvent->pos();
data->offset = scrollOffset(data->widget);
}
break;
case FlickData::Pressed:
if (mouseEvent->type() == QEvent::MouseButtonRelease) {
consumed = true;
data->state = FlickData::Steady;
QMouseEvent *event1 = new QMouseEvent(QEvent::MouseButtonPress,
data->pressPos, Qt::LeftButton,
Qt::LeftButton, Qt::NoModifier);
QMouseEvent *event2 = new QMouseEvent(*mouseEvent);
data->ignored << event1;
data->ignored << event2;
QApplication::postEvent(object, event1);
QApplication::postEvent(object, event2);
}
if (mouseEvent->type() == QEvent::MouseMove) {
consumed = true;
data->state = FlickData::ManualScroll;
data->dragPos = QCursor::pos();
if (!d->ticker.isActive())
d->ticker.start(20, this);
}
break;
case FlickData::ManualScroll:
if (mouseEvent->type() == QEvent::MouseMove) {
consumed = true;
QPoint delta = mouseEvent->pos() - data->pressPos;
setScrollOffset(data->widget, data->offset - delta);
}
if (mouseEvent->type() == QEvent::MouseButtonRelease) {
consumed = true;
data->state = FlickData::AutoScroll;
}
break;
case FlickData::AutoScroll:
if (mouseEvent->type() == QEvent::MouseButtonPress) {
consumed = true;
data->state = FlickData::Stop;
data->speed = QPoint(0, 0);
data->pressPos = mouseEvent->pos();
data->offset = scrollOffset(data->widget);
}
if (mouseEvent->type() == QEvent::MouseButtonRelease) {
consumed = true;
data->state = FlickData::Steady;
data->speed = QPoint(0, 0);
}
break;
case FlickData::Stop:
if (mouseEvent->type() == QEvent::MouseButtonRelease) {
consumed = true;
data->state = FlickData::Steady;
}
if (mouseEvent->type() == QEvent::MouseMove) {
consumed = true;
data->state = FlickData::ManualScroll;
data->dragPos = QCursor::pos();
if (!d->ticker.isActive())
d->ticker.start(20, this);
}
break;
default:
break;
}
return consumed;
}
void FlickCharm::timerEvent(QTimerEvent *event)
{
if (!enabled()) {
return;
}
int count = 0;
QHashIterator<QWidget*, FlickData*> item(d->flickData);
while (item.hasNext()) {
item.next();
FlickData *data = item.value();
if (data->state == FlickData::ManualScroll) {
count++;
data->speed = QCursor::pos() - data->dragPos;
data->dragPos = QCursor::pos();
}
if (data->state == FlickData::AutoScroll) {
count++;
data->speed = deaccelerate(data->speed);
QPoint p = scrollOffset(data->widget);
setScrollOffset(data->widget, p - data->speed);
if (data->speed == QPoint(0, 0))
data->state = FlickData::Steady;
}
}
if (!count)
d->ticker.stop();
QObject::timerEvent(event);
}