cursorpair.cpp

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/*
 * This file is part of the PulseView project.
 *
 * Copyright (C) 2013 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 <QColor>
#include <QMenu>
#include <QToolTip>

#include "cursorpair.hpp"

#include "pv/globalsettings.hpp"
#include "pv/util.hpp"
#include "ruler.hpp"
#include "view.hpp"

using std::max;
using std::make_pair;
using std::min;
using std::shared_ptr;
using std::pair;

namespace pv {
namespace views {
namespace trace {

const int CursorPair::DeltaPadding = 8;

CursorPair::CursorPair(View &view) :
    TimeItem(view),
    first_(new Cursor(view, 0.0)),
    second_(new Cursor(view, 1.0)),
    label_incomplete_(true)
{
    GlobalSettings::add_change_handler(this);

    GlobalSettings settings;
    fill_color_ = QColor::fromRgba(settings.value(
        GlobalSettings::Key_View_CursorFillColor).value<uint32_t>());
    show_frequency_ = settings.value(
        GlobalSettings::Key_View_CursorShowFrequency).value<bool>();
    show_interval_ = settings.value(
        GlobalSettings::Key_View_CursorShowInterval).value<bool>();
    show_samples_ = settings.value(
        GlobalSettings::Key_View_CursorShowSamples).value<bool>();

    connect(&view_, SIGNAL(hover_point_changed(const QWidget*, QPoint)),
        this, SLOT(on_hover_point_changed(const QWidget*, QPoint)));
}

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

bool CursorPair::enabled() const
{
    return view_.cursors_shown();
}

shared_ptr<Cursor> CursorPair::first() const
{
    return first_;
}

shared_ptr<Cursor> CursorPair::second() const
{
    return second_;
}

void CursorPair::set_time(const pv::util::Timestamp& time)
{
    const pv::util::Timestamp delta = second_->time() - first_->time();
    first_->set_time(time);
    second_->set_time(time + delta);
}

const pv::util::Timestamp CursorPair::time() const
{
    return 0;
}

float CursorPair::get_x() const
{
    return (first_->get_x() + second_->get_x()) / 2.0f;
}

const pv::util::Timestamp CursorPair::delta(const pv::util::Timestamp& other) const
{
    if (other < second_->time())
        return other - first_->time();
    else
        return other - second_->time();
}

QPoint CursorPair::drag_point(const QRect &rect) const
{
    return first_->drag_point(rect);
}

pv::widgets::Popup* CursorPair::create_popup(QWidget *parent)
{
    (void)parent;
    return nullptr;
}

QMenu *CursorPair::create_header_context_menu(QWidget *parent)
{
    QMenu *menu = new QMenu(parent);

    QAction *displayIntervalAction = new QAction(tr("Display interval"), this);
    displayIntervalAction->setCheckable(true);
    displayIntervalAction->setChecked(show_interval_);
    menu->addAction(displayIntervalAction);

    connect(displayIntervalAction, &QAction::toggled, displayIntervalAction,
        [=]{
            GlobalSettings settings;
            settings.setValue(GlobalSettings::Key_View_CursorShowInterval,
                !settings.value(GlobalSettings::Key_View_CursorShowInterval).value<bool>());
        });

    QAction *displayFrequencyAction = new QAction(tr("Display frequency"), this);
    displayFrequencyAction->setCheckable(true);
    displayFrequencyAction->setChecked(show_frequency_);
    menu->addAction(displayFrequencyAction);

    connect(displayFrequencyAction, &QAction::toggled, displayFrequencyAction,
        [=]{
            GlobalSettings settings;
            settings.setValue(GlobalSettings::Key_View_CursorShowFrequency,
                !settings.value(GlobalSettings::Key_View_CursorShowFrequency).value<bool>());
        });

    QAction *displaySamplesAction = new QAction(tr("Display samples"), this);
    displaySamplesAction->setCheckable(true);
    displaySamplesAction->setChecked(show_samples_);
    menu->addAction(displaySamplesAction);

    connect(displaySamplesAction, &QAction::toggled, displaySamplesAction,
        [=]{
            GlobalSettings settings;
            settings.setValue(GlobalSettings::Key_View_CursorShowSamples,
                !settings.value(GlobalSettings::Key_View_CursorShowSamples).value<bool>());
        });

    return menu;
}

QRectF CursorPair::label_rect(const QRectF &rect) const
{
    const QSizeF label_size(text_size_ + LabelPadding * 2);
    const pair<float, float> offsets(get_cursor_offsets());
    const pair<float, float> normal_offsets(
        (offsets.first < offsets.second) ? offsets :
        make_pair(offsets.second, offsets.first));

    const float height = label_size.height();
    const float left = max(normal_offsets.first + DeltaPadding, -height);
    const float right = min(normal_offsets.second - DeltaPadding,
        (float)rect.width() + height);

    return QRectF(left, rect.height() - label_size.height() -
        TimeMarker::ArrowSize - 0.5f,
        right - left, height);
}

void CursorPair::paint_label(QPainter &p, const QRect &rect, bool hover)
{
    assert(first_);
    assert(second_);

    if (!enabled())
        return;

    const QColor text_color = ViewItem::select_text_color(Cursor::FillColor);
    p.setPen(text_color);

    QRectF delta_rect(label_rect(rect));
    const int radius = delta_rect.height() / 2;
    QRectF text_rect(delta_rect.intersected(rect).adjusted(radius, 0, -radius, 0));

    QString text = format_string(text_rect.width(),
        [&p](const QString& s) -> double { return p.boundingRect(QRectF(), 0, s).width(); });

    text_size_ = p.boundingRect(QRectF(), 0, text).size();

    /* Currently, selecting the middle section between two cursors doesn't do
     * anything, so don't highlight it when selected
    if (selected()) {
        p.setBrush(Qt::transparent);
        p.setPen(highlight_pen());
        p.drawRoundedRect(delta_rect, radius, radius);
    } */

    p.setBrush(hover ? Cursor::FillColor.lighter() : Cursor::FillColor);
    p.setPen(Cursor::FillColor.darker());
    p.drawRoundedRect(delta_rect, radius, radius);

    delta_rect.adjust(1, 1, -1, -1);
    p.setPen(Cursor::FillColor.lighter());
    const int highlight_radius = delta_rect.height() / 2 - 2;
    p.drawRoundedRect(delta_rect, highlight_radius, highlight_radius);
    label_area_ = delta_rect;

    p.setPen(text_color);
    p.drawText(text_rect, Qt::AlignCenter | Qt::AlignVCenter, text);
}

void CursorPair::paint_back(QPainter &p, ViewItemPaintParams &pp)
{
    if (!enabled())
        return;

    p.setPen(Qt::NoPen);
    p.setBrush(fill_color_);

    const pair<float, float> offsets(get_cursor_offsets());
    const int l = (int)max(min(offsets.first, offsets.second), 0.0f);
    const int r = (int)min(max(offsets.first, offsets.second), (float)pp.width());

    p.drawRect(l, pp.top(), r - l, pp.height());
}

QString CursorPair::format_string(int max_width, std::function<double(const QString&)> query_size)
{
    int time_precision = 12;
    int freq_precision = 12;

    QString s = format_string_sub(time_precision, freq_precision);

    // Try full "{time} s / {freq} Hz" format
    if ((max_width <= 0) || (query_size(s) <= max_width)) {
        label_incomplete_ = false;
        return s;
    }

    label_incomplete_ = true;

    // Gradually reduce time precision to match frequency precision
    while (time_precision > freq_precision) {
        time_precision--;

        s = format_string_sub(time_precision, freq_precision);
        if (query_size(s) <= max_width)
            return s;
    }

    // Gradually reduce both precisions down to zero
    while (time_precision > 0) {
        time_precision--;
        freq_precision--;

        s = format_string_sub(time_precision, freq_precision);
        if (query_size(s) <= max_width)
            return s;
    }

    // Try no trailing digits and drop the unit to at least display something
    s = format_string_sub(0, 0, false);

    if (query_size(s) <= max_width)
        return s;

    // Give up
    return "...";
}

pair<float, float> CursorPair::get_cursor_offsets() const
{
    assert(first_);
    assert(second_);

    return pair<float, float>(first_->get_x(), second_->get_x());
}

void CursorPair::on_setting_changed(const QString &key, const QVariant &value)
{
    if (key == GlobalSettings::Key_View_CursorFillColor)
        fill_color_ = QColor::fromRgba(value.value<uint32_t>());

    if (key == GlobalSettings::Key_View_CursorShowFrequency)
        show_frequency_ = value.value<bool>();

    if (key == GlobalSettings::Key_View_CursorShowInterval)
        show_interval_ = value.value<bool>();

    if (key == GlobalSettings::Key_View_CursorShowSamples)
        show_samples_ = value.value<bool>();
}

void CursorPair::on_hover_point_changed(const QWidget* widget, const QPoint& hp)
{
    if (widget != view_.ruler())
        return;

    if (!label_incomplete_)
        return;

    if (label_area_.contains(hp))
        QToolTip::showText(view_.mapToGlobal(hp), format_string());
    else
        QToolTip::hideText();  // TODO Will break other tooltips when there can be others
}

QString CursorPair::format_string_sub(int time_precision, int freq_precision, bool show_unit)
{
    QString s = " ";

    const pv::util::SIPrefix prefix = view_.tick_prefix();
    const pv::util::Timestamp diff = abs(second_->time() - first_->time());

    const QString time = Ruler::format_time_with_distance(
        diff, diff, prefix, (show_unit ? view_.time_unit() : pv::util::TimeUnit::None),
        time_precision, false);

    // We can only show a frequency when there's a time base
    if (view_.time_unit() == pv::util::TimeUnit::Time) {
        int items = 0;

        if (show_frequency_) {
            const QString freq = util::format_value_si(
                1 / diff.convert_to<double>(), pv::util::SIPrefix::unspecified,
                freq_precision, (show_unit ? "Hz" : nullptr), false);
            s = QString("%1").arg(freq);
            items++;
        }

        if (show_interval_) {
            if (items > 0)
                s = QString("%1 / %2").arg(s, time);
            else
                s = QString("%1").arg(time);
            items++;
        }

        if (show_samples_) {
            const QString samples = QString::number(
                (diff * view_.session().get_samplerate()).convert_to<uint64_t>());
            if (items > 0)
                s = QString("%1 / %2").arg(s, samples);
            else
                s = QString("%1").arg(samples);
        }
    } else
        // In this case, we return the number of samples, really
        s = time;

    return s;
}

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