##// END OF EJS Templates
HG_REPOSITORIES » LPP » SciQLOP_Repos » SciQLop
RSS
simple graph unit test: simple scroll implemented...
simple graph unit test: simple scroll implemented Test does the scroll but shows that GUI scroll may change also Delta T while this shouldn't. Signed-off-by: Alexis Jeandet <alexis.jeandet@member.fsf.org>
trabillard - - Load All Authors

File last commit:

r885:dd73a5040007
r1361:d94394edced5
Show More
DragDropScroller.cpp
125 lines | 4.4 KiB | text/x-c | CppLexer
/ gui / src / DragAndDrop / DragDropScroller.cpp
History | Source | Raw |Copy content |Copy permalink
trabillard
Moves the class DragDropScroller in its own file
 r885 #include "DragAndDrop/DragDropScroller.h"
#include <QDragEnterEvent>
#include <QDragMoveEvent>
#include <QScrollBar>
#include <QTimer>
const int SCROLL_SPEED = 5;
const int SCROLL_ZONE_SIZE = 50;
struct DragDropScroller::DragDropScrollerPrivate {
QList<QScrollArea *> m_ScrollAreas;
QScrollArea *m_CurrentScrollArea = nullptr;
std::unique_ptr<QTimer> m_Timer = nullptr;
enum class ScrollDirection { up, down, unknown };
ScrollDirection m_Direction = ScrollDirection::unknown;
explicit DragDropScrollerPrivate() : m_Timer{std::make_unique<QTimer>()}
{
m_Timer->setInterval(0);
}
};
DragDropScroller::DragDropScroller(QObject *parent)
: QObject{parent}, impl{spimpl::make_unique_impl<DragDropScrollerPrivate>()}
{
connect(impl->m_Timer.get(), &QTimer::timeout, this, &DragDropScroller::onTimer);
}
void DragDropScroller::addScrollArea(QScrollArea *scrollArea)
{
impl->m_ScrollAreas << scrollArea;
scrollArea->viewport()->setAcceptDrops(true);
}
void DragDropScroller::removeScrollArea(QScrollArea *scrollArea)
{
impl->m_ScrollAreas.removeAll(scrollArea);
scrollArea->viewport()->setAcceptDrops(false);
}
bool DragDropScroller::eventFilter(QObject *obj, QEvent *event)
{
if (event->type() == QEvent::DragMove) {
auto w = static_cast<QWidget *>(obj);
if (impl->m_CurrentScrollArea && impl->m_CurrentScrollArea->isAncestorOf(w)) {
auto moveEvent = static_cast<QDragMoveEvent *>(event);
auto pos = moveEvent->pos();
if (impl->m_CurrentScrollArea->viewport() != w) {
auto globalPos = w->mapToGlobal(moveEvent->pos());
pos = impl->m_CurrentScrollArea->viewport()->mapFromGlobal(globalPos);
}
auto isInTopZone = pos.y() > impl->m_CurrentScrollArea->viewport()->size().height()
- SCROLL_ZONE_SIZE;
auto isInBottomZone = pos.y() < SCROLL_ZONE_SIZE;
if (!isInTopZone && !isInBottomZone) {
impl->m_Direction = DragDropScrollerPrivate::ScrollDirection::unknown;
impl->m_Timer->stop();
}
else if (!impl->m_Timer->isActive()) {
impl->m_Direction = isInTopZone ? DragDropScrollerPrivate::ScrollDirection::up
: DragDropScrollerPrivate::ScrollDirection::down;
impl->m_Timer->start();
}
}
}
else if (event->type() == QEvent::DragEnter) {
auto w = static_cast<QWidget *>(obj);
for (auto scrollArea : impl->m_ScrollAreas) {
if (impl->m_CurrentScrollArea != scrollArea && scrollArea->isAncestorOf(w)) {
auto enterEvent = static_cast<QDragEnterEvent *>(event);
enterEvent->acceptProposedAction();
enterEvent->setDropAction(Qt::IgnoreAction);
impl->m_CurrentScrollArea = scrollArea;
break;
}
}
}
else if (event->type() == QEvent::DragLeave) {
if (impl->m_CurrentScrollArea) {
if (!QRect(QPoint(), impl->m_CurrentScrollArea->size())
.contains(impl->m_CurrentScrollArea->mapFromGlobal(QCursor::pos()))) {
impl->m_CurrentScrollArea = nullptr;
impl->m_Direction = DragDropScrollerPrivate::ScrollDirection::unknown;
impl->m_Timer->stop();
}
}
}
else if (event->type() == QEvent::Drop) {
if (impl->m_CurrentScrollArea) {
impl->m_CurrentScrollArea = nullptr;
impl->m_Direction = DragDropScrollerPrivate::ScrollDirection::unknown;
impl->m_Timer->stop();
}
}
return false;
}
void DragDropScroller::onTimer()
{
if (impl->m_CurrentScrollArea) {
auto mvt = 0;
switch (impl->m_Direction) {
case DragDropScrollerPrivate::ScrollDirection::up:
mvt = SCROLL_SPEED;
break;
case DragDropScrollerPrivate::ScrollDirection::down:
mvt = -SCROLL_SPEED;
break;
default:
break;
}
impl->m_CurrentScrollArea->verticalScrollBar()->setValue(
impl->m_CurrentScrollArea->verticalScrollBar()->value() + mvt);
}
}