-/***************************************************************************
- * Copyright (C) 2008 by Peter Penz <peter.penz19@gmail.com> *
- * *
- * This program is free software; you can redistribute it and/or modify *
- * it under the terms of the GNU General Public License as published by *
- * the Free Software Foundation; either version 2 of the License, 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 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 "dolphinviewautoscroller.h"
-
-#include <QAbstractItemView>
-#include <QApplication>
-#include <QCursor>
-#include <QEvent>
-#include <QMouseEvent>
-#include <QScrollBar>
-#include <QTimer>
-#include <math.h>
-
-DolphinViewAutoScroller::DolphinViewAutoScroller(QAbstractItemView* parent) :
- QObject(parent),
- m_rubberBandSelection(false),
- m_keyPressed(false),
- m_initializedTimestamp(false),
- m_horizontalScrollInc(0),
- m_verticalScrollInc(0),
- m_itemView(parent),
- m_timer(0),
- m_timestamp()
-{
- m_itemView->setAutoScroll(false);
- m_itemView->viewport()->installEventFilter(this);
- m_itemView->installEventFilter(this);
-
- m_timer = new QTimer(this);
- m_timer->setSingleShot(false);
- m_timer->setInterval(1000 / 25); // 25 frames per second
- connect(m_timer, SIGNAL(timeout()), this, SLOT(scrollViewport()));
-}
-
-DolphinViewAutoScroller::~DolphinViewAutoScroller()
-{
-}
-
-bool DolphinViewAutoScroller::isActive() const
-{
- return m_timer->isActive();
-}
-
-void DolphinViewAutoScroller::handleCurrentIndexChange(const QModelIndex& current,
- const QModelIndex& previous)
-{
- // When the autoscroller is inactive and a key has been pressed, it must be
- // assured that the current item stays visible. The check whether the previous
- // item is valid is important because of #197951. The keypress check is done
- // because of #199833.
- if (current.isValid() && (previous.isValid() || m_keyPressed) && !isActive()) {
- m_itemView->scrollTo(current);
- }
-}
-
-bool DolphinViewAutoScroller::eventFilter(QObject* watched, QEvent* event)
-{
- if (watched == m_itemView->viewport()) {
- switch (event->type()) {
- case QEvent::MouseButtonPress:
- if (static_cast<QMouseEvent*>(event)->button() == Qt::LeftButton) {
- m_rubberBandSelection = true;
- }
- break;
-
- case QEvent::MouseMove:
- if (m_rubberBandSelection) {
- triggerAutoScroll();
- }
- break;
-
- case QEvent::MouseButtonRelease:
- m_rubberBandSelection = false;
- stopAutoScroll();
- break;
-
- case QEvent::DragEnter:
- case QEvent::DragMove:
- m_rubberBandSelection = false;
- triggerAutoScroll();
- break;
-
- case QEvent::Drop:
- case QEvent::DragLeave:
- m_rubberBandSelection = false;
- stopAutoScroll();
- break;
-
- default:
- break;
- }
- } else if (watched == m_itemView) {
- switch (event->type()) {
- case QEvent::KeyPress:
- m_keyPressed = true;
- break;
-
- case QEvent::KeyRelease:
- m_keyPressed = false;
- break;
-
- default:
- break;
- }
- }
-
- return QObject::eventFilter(watched, event);
-}
-
-void DolphinViewAutoScroller::scrollViewport()
-{
- if (m_timestamp.elapsed() < QApplication::startDragTime()) {
- return;
- }
-
- QScrollBar* verticalScrollBar = m_itemView->verticalScrollBar();
- if (verticalScrollBar) {
- const int value = verticalScrollBar->value();
- verticalScrollBar->setValue(value + m_verticalScrollInc);
-
- }
- QScrollBar* horizontalScrollBar = m_itemView->horizontalScrollBar();
- if (horizontalScrollBar) {
- const int value = horizontalScrollBar->value();
- horizontalScrollBar->setValue(value + m_horizontalScrollInc);
-
- }
-
- if (m_rubberBandSelection) {
- // The scrolling does not lead to an update of the rubberband
- // selection. Fake a mouse move event to let the QAbstractItemView
- // update the rubberband.
- QWidget* viewport = m_itemView->viewport();
- const QPoint pos = viewport->mapFromGlobal(QCursor::pos());
- QMouseEvent event(QEvent::MouseMove, pos, Qt::LeftButton, Qt::LeftButton, QApplication::keyboardModifiers());
- QCoreApplication::sendEvent(viewport, &event);
- }
-}
-
-void DolphinViewAutoScroller::triggerAutoScroll()
-{
- const bool verticalScrolling = m_itemView->verticalScrollBar() &&
- m_itemView->verticalScrollBar()->isVisible();
- const bool horizontalScrolling = m_itemView->horizontalScrollBar() &&
- m_itemView->horizontalScrollBar()->isVisible();
- if (!verticalScrolling && !horizontalScrolling) {
- // no scrollbars are shown at all, so no autoscrolling is necessary
- stopAutoScroll();
- return;
- }
-
- QWidget* viewport = m_itemView->viewport();
- const QPoint pos = viewport->mapFromGlobal(QCursor::pos());
- if (verticalScrolling) {
- m_verticalScrollInc = calculateScrollIncrement(pos.y(), viewport->height());
- }
- if (horizontalScrolling) {
- m_horizontalScrollInc = calculateScrollIncrement(pos.x(), viewport->width());
- }
-
- if (m_timer->isActive()) {
- if ((m_horizontalScrollInc == 0) && (m_verticalScrollInc == 0)) {
- stopAutoScroll();
- }
- } else if ((m_horizontalScrollInc != 0) || (m_verticalScrollInc != 0)) {
- if (!m_initializedTimestamp) {
- m_initializedTimestamp = true;
- m_timestamp.start();
- }
- m_timer->start();
- }
-}
-
-void DolphinViewAutoScroller::stopAutoScroll()
-{
- m_timer->stop();
- m_horizontalScrollInc = 0;
- m_verticalScrollInc = 0;
- m_initializedTimestamp = false;
-}
-
-int DolphinViewAutoScroller::calculateScrollIncrement(int cursorPos, int rangeSize) const
-{
- int inc = 0;
-
- const int minSpeed = 4;
- const int maxSpeed = 768;
- const int speedLimiter = 48;
- const int autoScrollBorder = 64;
-
- if (cursorPos < autoScrollBorder) {
- inc = -minSpeed + qAbs(cursorPos - autoScrollBorder) * (cursorPos - autoScrollBorder) / speedLimiter;
- if (inc < -maxSpeed) {
- inc = -maxSpeed;
- }
- } else if (cursorPos > rangeSize - autoScrollBorder) {
- inc = minSpeed + qAbs(cursorPos - rangeSize + autoScrollBorder) * (cursorPos - rangeSize + autoScrollBorder) / speedLimiter;
- if (inc > maxSpeed) {
- inc = maxSpeed;
- }
- }
-
- return inc;
-}
-
-#include "dolphinviewautoscroller.moc"
projects / dolphin.git / commitdiff