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, see <http://www.gnu.org/licenses/>.
 */

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

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

#include <pv/session.hpp>

#include <QMouseEvent>
#include <QScreen>
#include <QWindow>

#include <QDebug>

using std::abs;
using std::back_inserter;
using std::copy;
using std::dynamic_pointer_cast;
using std::none_of; // NOLINT. Used in assert()s.
using std::shared_ptr;
using std::stable_sort;
using std::vector;

namespace pv {
namespace views {
namespace trace {

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

    // Set up settings and event handlers
    GlobalSettings settings;
    allow_vertical_dragging_ = settings.value(GlobalSettings::Key_View_AllowVerticalDragging).toBool();

    GlobalSettings::add_change_handler(this);
}

Viewport::~Viewport()
{
    GlobalSettings::remove_change_handler(this);
}

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, QPoint pos)
{
    if (item && item->is_draggable(pos))
        setCursor(dynamic_pointer_cast<ViewItem>(item) ?
            Qt::SizeHorCursor : Qt::SizeVerCursor);
    else
        unsetCursor();
}

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

    if (allow_vertical_dragging_)
        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()));

    if (allow_vertical_dragging_)
        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 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)
{
#if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
    QList<QEventPoint> touchPoints = event->points();
#else
    QList<QTouchEvent::TouchPoint> touchPoints = event->touchPoints();
#endif

    if (touchPoints.count() != 2) {
        pinch_zoom_active_ = false;
        return false;
    }
#if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
    if (event->device()->type() == QInputDevice::DeviceType::TouchPad) {
        return false;
    }

    const QEventPoint &touchPoint0 = touchPoints.first();
    const QEventPoint &touchPoint1 = touchPoints.last();

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

    double w = touchPoint1.position().x() - touchPoint0.position().x();
    if (abs(w) >= 1.0) {
        const double scale =
            fabs((pinch_offset1_ - pinch_offset0_) / w);
        double offset = pinch_offset0_ - touchPoint0.position().x() * scale;
        if (scale > 0)
            view_.set_scale_offset(scale, offset);
    }
#else
    if (event->device()->type() == QTouchDevice::TouchPad) {
        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);
    }
#endif

    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
#if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
            mouse_down_point_ = touchPoint0.position().toPoint();
#else
            mouse_down_point_ = touchPoint0.pos().toPoint();
#endif
            drag();
        }
    }

    return true;
}

void Viewport::paintEvent(QPaintEvent*)
{
    typedef void (ViewItem::*LayerPaintFunc)(
        QPainter &p, ViewItemPaintParams &pp);
    LayerPaintFunc layer_paint_funcs[] = {
        &ViewItem::paint_back, &ViewItem::paint_mid,
        &ViewItem::paint_fore, nullptr};

    vector< shared_ptr<ViewItem> > row_items(view_.list_by_type<ViewItem>());
    assert(none_of(row_items.begin(), row_items.end(),
        [](const shared_ptr<ViewItem> &r) { return !r; }));

    stable_sort(row_items.begin(), row_items.end(),
        [](const shared_ptr<ViewItem> &a, const shared_ptr<ViewItem> &b) {
            return a->drag_point(QRect()).y() < b->drag_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);

    // Disable antialiasing for high-DPI displays
    bool use_antialiasing =
        window()->windowHandle()->screen()->devicePixelRatio() < 2.0;
    p.setRenderHint(QPainter::Antialiasing, use_antialiasing);

    for (LayerPaintFunc *paint_func = layer_paint_funcs;
            *paint_func; paint_func++) {
        ViewItemPaintParams time_pp(rect(), view_.scale(), view_.offset());
        for (const shared_ptr<TimeItem>& t : time_items)
            (t.get()->*(*paint_func))(p, time_pp);

        ViewItemPaintParams row_pp(rect(), view_.scale(), view_.offset());
        for (const shared_ptr<ViewItem>& r : row_items)
            (r.get()->*(*paint_func))(p, row_pp);
    }

    p.end();
}

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

#if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
    if (event->buttons() & Qt::LeftButton)
        view_.zoom(2.0, event->position().x());
    else if (event->buttons() & Qt::RightButton)
        view_.zoom(-2.0, event->position().x());
#else
    if (event->buttons() & Qt::LeftButton)
        view_.zoom(2.0, event->x());
    else if (event->buttons() & Qt::RightButton)
        view_.zoom(-2.0, event->x());
#endif
}

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

#if QT_VERSION >= QT_VERSION_CHECK(5, 12, 0)
    int delta = (event->angleDelta().x() != 0) ? event->angleDelta().x() : event->angleDelta().y();
#else
    int delta = event->delta();
#endif

#if QT_VERSION >= QT_VERSION_CHECK(5, 12, 0)
    if (event->angleDelta().y() != 0) {
#else
    if (event->orientation() == Qt::Vertical) {
#endif
        if (event->modifiers() & Qt::ControlModifier) {
            // Vertical scrolling with the control key pressed
            // is intrepretted as vertical scrolling
            view_.set_v_offset(-view_.owner_visual_v_offset() -
                (delta * height()) / (8 * 120));
        } else if (event->modifiers() & Qt::ShiftModifier) {
            // Vertical scrolling with the shift key pressed
            // acts as horizontal scrolling like in Gimp
            // and Inkscape.
            view_.set_scale_offset(view_.scale(),
                - delta * view_.scale() + view_.offset());
        } else {
            // Vertical scrolling is interpreted as zooming in/out
#if QT_VERSION >= QT_VERSION_CHECK(5, 14, 0)
            view_.zoom(delta / 120.0, event->position().x());
#else
            view_.zoom(delta / 120.0, event->x());
#endif
        }
#if QT_VERSION >= QT_VERSION_CHECK(5, 12, 0)
    } else if (event->angleDelta().x() != 0) {
#else
    } else if (event->orientation() == Qt::Horizontal) {
#endif
        // Horizontal scrolling is interpreted as moving left/right
        view_.set_scale_offset(view_.scale(),
            delta * view_.scale() + view_.offset());
    }
}

void Viewport::on_setting_changed(const QString &key, const QVariant &value)
{
    if (key == GlobalSettings::Key_View_AllowVerticalDragging)
        allow_vertical_dragging_ = value.toBool();
}

} // namespace trace
} // namespace views
} // namespace pv