view src/panned.cpp @ 571:012ba1b83328

Show cancel button with progress bar only when running an operation that it makes sense to cancel (we don't really want people cancelling e.g. initial folder scan because it would leave things in an inconsistent state)

/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */

/*
    EasyMercurial

    Based on HgExplorer by Jari Korhonen
    Copyright (c) 2010 Jari Korhonen
    Copyright (c) 2012 Chris Cannam
    Copyright (c) 2012 Queen Mary, University of London
    
    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.  See the file
    COPYING included with this distribution for more information.
*/

#include "panned.h"
#include "debug.h"

#include <QScrollBar>
#include <QWheelEvent>
#include <QTimer>

#include <cmath>

#include <iostream>

Panned::Panned() :
    m_dragging(false)
{
    m_dragTimer = new QTimer(this);
    m_dragTimerMs = 50;
    connect(m_dragTimer, SIGNAL(timeout()), this, SLOT(dragTimerTimeout()));
    setRenderHints(QPainter::Antialiasing |
                   QPainter::TextAntialiasing);
}

void
Panned::resizeEvent(QResizeEvent *ev)
{
    DEBUG << "Panned::resizeEvent()" << endl;

    QPointF nearpt = mapToScene(0, 0);
    QPointF farpt = mapToScene(width(), height());
    QSizeF sz(farpt.x()-nearpt.x(), farpt.y()-nearpt.y());
    QRectF pr(nearpt, sz);

    QGraphicsView::resizeEvent(ev);

    if (pr != m_pannedRect) {
        DEBUG << "Panned: setting panned rect to " << pr << endl;
        m_pannedRect = pr;
        centerOn(pr.center());
        emit pannedRectChanged(pr);
    }
}

void
Panned::setScene(QGraphicsScene *s)
{
    if (!scene()) {
        QGraphicsView::setScene(s);
        return;
    }

    QPointF nearpt = mapToScene(0, 0);
    QPointF farpt = mapToScene(width(), height());
    QSizeF sz(farpt.x()-nearpt.x(), farpt.y()-nearpt.y());
    QRectF pr(nearpt, sz);

    QGraphicsView::setScene(s);

    DEBUG << "Panned::setScene: pr = " << pr << ", sceneRect = " << sceneRect() << endl;

    if (scene() && sceneRect().intersects(pr)) {
        DEBUG << "Panned::setScene: restoring old rect " << pr << endl;
        m_pannedRect = pr;
        centerOn(pr.center());
        emit pannedRectChanged(pr);
    }
}

void
Panned::paintEvent(QPaintEvent *e)
{
    QGraphicsView::paintEvent(e);
}

void
Panned::drawForeground(QPainter *paint, const QRectF &)
{
    QPointF nearpt = mapToScene(0, 0);
    QPointF farpt = mapToScene(width(), height());
    QSizeF sz(farpt.x()-nearpt.x(), farpt.y()-nearpt.y());
    QRectF pr(nearpt, sz);

    if (pr != m_pannedRect) {
        DEBUG << "Panned::drawForeground: visible rect " << pr << " differs from panned rect " << m_pannedRect << ", updating panned rect" <<endl;
        if (pr.x() != m_pannedRect.x()) emit pannedContentsScrolled();
        m_pannedRect = pr;
        emit pannedRectChanged(pr);
    }
}

void
Panned::zoomIn()
{
    QMatrix m = matrix();
    m.scale(1.0 / 1.1, 1.0 / 1.1);
    setMatrix(m);
}

void
Panned::zoomOut()
{
    QMatrix m = matrix();
    m.scale(1.1, 1.1);
    setMatrix(m);
}

void
Panned::slotSetPannedRect(QRectF pr)
{
    centerOn(pr.center());
//	setSceneRect(pr);
//	m_pannedRect = pr;
}

void
Panned::wheelEvent(QWheelEvent *ev)
{
    if (ev->modifiers() & Qt::ControlModifier) {
        int d = ev->delta();
        if (d > 0) {
            while (d > 0) {
                zoomOut();
                d -= 120;
            }
        } else {
            while (d < 0) {
                zoomIn();
                d += 120;
            }
        }
    } else {
        emit wheelEventReceived(ev);
        QGraphicsView::wheelEvent(ev);
    }
}

void
Panned::slotEmulateWheelEvent(QWheelEvent *ev)
{
    QGraphicsView::wheelEvent(ev);
}

void
Panned::mousePressEvent(QMouseEvent *ev)
{
    if (dragMode() != QGraphicsView::ScrollHandDrag ||
        ev->button() != Qt::LeftButton) {
        QGraphicsView::mousePressEvent(ev);
        return;
    }

    DEBUG << "Panned::mousePressEvent: have left button in drag mode" << endl;

    setDragMode(QGraphicsView::NoDrag);
    QGraphicsView::mousePressEvent(ev);
    setDragMode(QGraphicsView::ScrollHandDrag);

    if (!ev->isAccepted()) {
        ev->accept();
        m_dragging = true;
        m_lastDragPos = ev->pos();
        m_lastDragStart = ev->pos();
        m_lastOrigin = QPoint(horizontalScrollBar()->value(),
                              verticalScrollBar()->value());
        m_velocity = QPointF(0, 0);
        m_dragTimer->start(m_dragTimerMs);
        m_dragDirection = UnknownDrag;
    }
}

void
Panned::updateDragDirection(QPoint pos)
{
    if (m_dragDirection == FreeDrag) {
        return;
    }

    QPoint overall = pos - m_lastDragStart;

    int smallThreshold = 10;
    int largeThreshold = 30;
    int dx = qAbs(overall.x());
    int dy = qAbs(overall.y());

    switch (m_dragDirection) {

    case UnknownDrag:
        if (dx > smallThreshold) {
            if (dy > smallThreshold) {
                m_dragDirection = FreeDrag;
            } else {
                m_dragDirection = HorizontalDrag;
            }
        } else if (dy > smallThreshold) {
            m_dragDirection = VerticalDrag;
        }
        break;

    case HorizontalDrag:
        if (dy > largeThreshold) {
            m_dragDirection = FreeDrag;
        }
        break;

    case VerticalDrag:
        if (dx > largeThreshold) {
            m_dragDirection = FreeDrag;
        }
        break;
    };
}

void
Panned::mouseMoveEvent(QMouseEvent *ev)
{
    if (!m_dragging) {
        QGraphicsView::mouseMoveEvent(ev);
        return;
    }
    DEBUG << "Panned::mouseMoveEvent: dragging" << endl;
    ev->accept();
    updateDragDirection(ev->pos());
    QScrollBar *hBar = horizontalScrollBar();
    QScrollBar *vBar = verticalScrollBar();
    QPoint delta = ev->pos() - m_lastDragPos;
    if (m_dragDirection != VerticalDrag) {
        hBar->setValue(hBar->value() +
                       (isRightToLeft() ? delta.x() : -delta.x()));
    }
    if (m_dragDirection != HorizontalDrag) {
        vBar->setValue(vBar->value() - delta.y());
    }
    m_lastDragPos = ev->pos();
}

void
Panned::mouseReleaseEvent(QMouseEvent *ev)
{
    if (!m_dragging) {
        QGraphicsView::mouseReleaseEvent(ev);
        return;
    }
    DEBUG << "Panned::mouseReleaseEvent: dragging" << endl;
    ev->accept();
    m_dragging = false;
}

void
Panned::dragTimerTimeout()
{
    QPoint origin = QPoint(horizontalScrollBar()->value(),
                           verticalScrollBar()->value());
    if (m_dragging) {
        m_velocity = QPointF
            (float(origin.x() - m_lastOrigin.x()) / m_dragTimerMs,
             float(origin.y() - m_lastOrigin.y()) / m_dragTimerMs);
        m_lastOrigin = origin;
        DEBUG << "Panned::dragTimerTimeout: velocity = " << m_velocity << endl;
    } else {
        if (origin == m_lastOrigin) {
            m_dragTimer->stop();
        }
        float x = m_velocity.x(), y = m_velocity.y();
        if (fabsf(x) > 1.0/m_dragTimerMs) x = x * 0.9f;
        else x = 0.f;
        if (fabsf(y) > 1.0/m_dragTimerMs) y = y * 0.9f;
        else y = 0.f;
        m_velocity = QPointF(x, y);
        DEBUG << "Panned::dragTimerTimeout: velocity adjusted to " << m_velocity << endl;
        m_lastOrigin = origin;
        //!!! need to store origin in floats
        if (m_dragDirection != VerticalDrag) {
            horizontalScrollBar()->setValue(m_lastOrigin.x() +
                                            m_velocity.x() * m_dragTimerMs);
        }
        if (m_dragDirection != HorizontalDrag) {
            verticalScrollBar()->setValue(m_lastOrigin.y() +
                                          m_velocity.y() * m_dragTimerMs);
        }
    }
}

void
Panned::leaveEvent(QEvent *)
{
    emit mouseLeaves();
}