viewport.cpp

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/*
 * This file is part of the PulseView project.
 *
 * Copyright (C) 2012 Joel Holdsworth <joel@airwebreathe.org.uk>
 *
 * 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 St, Fifth Floor, Boston, MA  02110-1301 USA
 */

#include <cassert>
#include <cmath>
#include <algorithm>
#include <limits>

#include "signal.hpp"
#include "view.hpp"
#include "viewitempaintparams.hpp"
#include "viewport.hpp"

#include <pv/session.hpp>

#include <QMouseEvent>

using std::abs;
using std::back_inserter;
using std::copy;
using std::dynamic_pointer_cast;
using std::max;
using std::min;
using std::none_of;
using std::numeric_limits;
using std::shared_ptr;
using std::stable_sort;
using std::vector;

namespace pv {
namespace view {

Viewport::Viewport(View &parent) :
    ViewWidget(parent),
    pinch_zoom_active_(false)
{
    setAutoFillBackground(true);
    setBackgroundRole(QPalette::Base);
}

shared_ptr<ViewItem> Viewport::get_mouse_over_item(const QPoint &pt)
{
    const ViewItemPaintParams pp(rect(), view_.scale(), view_.offset());
    const vector< shared_ptr<ViewItem> > items(this->items());
    for (auto i = items.rbegin(); i != items.rend(); i++)
        if ((*i)->enabled() &&
            (*i)->hit_box_rect(pp).contains(pt))
            return *i;
    return nullptr;
}

void Viewport::item_hover(const shared_ptr<ViewItem> &item)
{
    if (item && item->is_draggable())
        setCursor(dynamic_pointer_cast<RowItem>(item) ?
            Qt::SizeVerCursor : Qt::SizeHorCursor);
    else
        unsetCursor();
}

void Viewport::drag()
{
    drag_offset_ = view_.offset();
    drag_v_offset_ = view_.owner_visual_v_offset();
}

void Viewport::drag_by(const QPoint &delta)
{
    if (drag_offset_ == boost::none)
        return;

    view_.set_scale_offset(view_.scale(),
        (*drag_offset_ - delta.x() * view_.scale()));

    view_.set_v_offset(-drag_v_offset_ - delta.y());
}

void Viewport::drag_release()
{
    drag_offset_ = boost::none;
}

vector< shared_ptr<ViewItem> > Viewport::items()
{
    vector< shared_ptr<ViewItem> > items;
    const std::vector< shared_ptr<ViewItem> > view_items(
        view_.list_by_type<ViewItem>());
    copy(view_items.begin(), view_items.end(), back_inserter(items));
    const vector< shared_ptr<TimeItem> > time_items(view_.time_items());
    copy(time_items.begin(), time_items.end(), back_inserter(items));
    return items;
}

bool Viewport::touch_event(QTouchEvent *event)
{
    QList<QTouchEvent::TouchPoint> touchPoints = event->touchPoints();

    if (touchPoints.count() != 2) {
        pinch_zoom_active_ = false;
        return false;
    }

    const QTouchEvent::TouchPoint &touchPoint0 = touchPoints.first();
    const QTouchEvent::TouchPoint &touchPoint1 = touchPoints.last();

    if (!pinch_zoom_active_ ||
        (event->touchPointStates() & Qt::TouchPointPressed)) {
        pinch_offset0_ = (view_.offset() + view_.scale() * touchPoint0.pos().x()).convert_to<double>();
        pinch_offset1_ = (view_.offset() + view_.scale() * touchPoint1.pos().x()).convert_to<double>();
        pinch_zoom_active_ = true;
    }

    double w = touchPoint1.pos().x() - touchPoint0.pos().x();
    if (abs(w) >= 1.0) {
        const double scale =
            fabs((pinch_offset1_ - pinch_offset0_) / w);
        double offset = pinch_offset0_ - touchPoint0.pos().x() * scale;
        if (scale > 0)
            view_.set_scale_offset(scale, offset);
    }

    if (event->touchPointStates() & Qt::TouchPointReleased) {
        pinch_zoom_active_ = false;

        if (touchPoint0.state() & Qt::TouchPointReleased) {
            // Primary touch released
            drag_release();
        } else {
            // Update the mouse down fields so that continued
            // dragging with the primary touch will work correctly
            mouse_down_point_ = touchPoint0.pos().toPoint();
            drag();
        }
    }

    return true;
}

void Viewport::paintEvent(QPaintEvent*)
{
    vector< shared_ptr<RowItem> > row_items(view_.list_by_type<RowItem>());
    assert(none_of(row_items.begin(), row_items.end(),
        [](const shared_ptr<RowItem> &r) { return !r; }));

    stable_sort(row_items.begin(), row_items.end(),
        [](const shared_ptr<RowItem> &a, const shared_ptr<RowItem> &b) {
            return a->point(QRect()).y() < b->point(QRect()).y(); });

    const vector< shared_ptr<TimeItem> > time_items(view_.time_items());
    assert(none_of(time_items.begin(), time_items.end(),
        [](const shared_ptr<TimeItem> &t) { return !t; }));

    QPainter p(this);
    p.setRenderHint(QPainter::Antialiasing);

    const ViewItemPaintParams pp(rect(), view_.scale(), view_.offset());

    for (const shared_ptr<TimeItem> t : time_items)
        t->paint_back(p, pp);
    for (const shared_ptr<RowItem> r : row_items)
        r->paint_back(p, pp);

    for (const shared_ptr<TimeItem> t : time_items)
        t->paint_mid(p, pp);
    for (const shared_ptr<RowItem> r : row_items)
        r->paint_mid(p, pp);

    for (const shared_ptr<RowItem> r : row_items)
        r->paint_fore(p, pp);

    p.setRenderHint(QPainter::Antialiasing, false);
    for (const shared_ptr<TimeItem> t : time_items)
        t->paint_fore(p, pp);

    p.end();
}

void Viewport::mouseDoubleClickEvent(QMouseEvent *event)
{
    assert(event);

    if (event->buttons() & Qt::LeftButton)
        view_.zoom(2.0, event->x());
    else if (event->buttons() & Qt::RightButton)
        view_.zoom(-2.0, event->x());
}

void Viewport::wheelEvent(QWheelEvent *e)
{
    assert(e);

    if (e->orientation() == Qt::Vertical) {
        if (e->modifiers() & Qt::ControlModifier) {
            // Vertical scrolling with the control key pressed
            // is intrepretted as vertical scrolling
            view_.set_v_offset(-view_.owner_visual_v_offset() -
                (e->delta() * height()) / (8 * 120));
        } else {
            // Vertical scrolling is interpreted as zooming in/out
            view_.zoom(e->delta() / 120, e->x());
        }
    } else if (e->orientation() == Qt::Horizontal) {
        // Horizontal scrolling is interpreted as moving left/right
        view_.set_scale_offset(view_.scale(),
            e->delta() * view_.scale() + view_.offset());
    }
}

} // namespace view
} // namespace pv