seer/src/QProgressIndicator.cpp

// SPDX-FileCopyrightText: 2021 Ernie Pasveer <epasveer@att.net>
//
// SPDX-License-Identifier: MIT

#include "QProgressIndicator.h"

#include <QDebug>
#include <QtGlobal>
#include <QPoint>
#include <limits>
#include <cmath>

#define SPIN_INTERVAL 100 // Set timer to wake up every 100ms.

QProgressIndicator::QProgressIndicator(QWidget* parent) : QWidget(parent) {

    _type     = QProgressIndicator::line_rotate;
    _interval = SPIN_INTERVAL;
    _angle    = 0;
    _scale    = 0.0f;
    _color    = Qt::black;

    setSizePolicy(QSizePolicy::Fixed, QSizePolicy::Fixed);
    setFocusPolicy(Qt::NoFocus);

    _timer = new QTimer();

    connect(_timer, SIGNAL(timeout()), this, SLOT(onTimeout()));

    update();
}

QProgressIndicator::~QProgressIndicator() {

    stop();

    delete _timer;
}

void QProgressIndicator::paintEvent(QPaintEvent* e) {

    Q_UNUSED(e)

    if (!_timer->isActive()) {
        _angle = 0;
        _scale = 0.0f;
        return; // Draw nothing when stopped. stop() expects the indicator to be erased from the view.
    }

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

    switch (_type) {
        case QProgressIndicator::line_rotate:
            drawRotateLine(&painter);
            break;
        case QProgressIndicator::line_scale:
            drawScaleLine((&painter));
            break;
        case QProgressIndicator::ball_rotate:
            drawRotateBall(&painter);
            break;
        case QProgressIndicator::circle_rotate:
            drawRotateCircle(&painter);
            break;
    }
}

void QProgressIndicator::start() {

    _timer->start(_interval);
}

void QProgressIndicator::stop() {

    _timer->stop();

    update(); // Force an update to erase the indicator from the view.
}

int QProgressIndicator::type () const {

    return _type;
}

QString QProgressIndicator::typeName () const {

    if (_type == line_rotate) {
        return "LineRotate";
    }else if (_type == line_scale) {
        return "LineScale";
    }else if (_type == ball_rotate) {
        return "BallRotate";
    }else if (_type == circle_rotate) {
        return "CircleRotate";
    }

    return "BallRotate";
}

void QProgressIndicator::setType (int type) {

    _type = type;
}

void QProgressIndicator::setType (const QString& type) {

    if (type == "LineRotate") {
        setType(line_rotate);
    }else if (type == "LineScale") {
        setType(line_scale);
    }else if (type == "BallRotate") {
        setType(ball_rotate);
    }else if (type == "CircleRotate") {
        setType(circle_rotate);
    }else{
        setType(line_rotate);
    }

    update();
}

QStringList QProgressIndicator::types () const {

    QStringList list = {"LineRotate", "LineScale", "BallRotate", "CircleRotate"};

    return list;
}

const QColor& QProgressIndicator::color () {

    return _color;
}

void QProgressIndicator::setColor (const QColor& color) {

    _color = color;
}

int QProgressIndicator::interval () {

    return _interval;
}

void QProgressIndicator::setInterval (int interval) {

    _interval = interval;
}

void QProgressIndicator::onTimeout() {

    switch (_type) {
        case line_rotate:
        case ball_rotate:
            _angle = (_angle + 45) % 360;
            break;
        case circle_rotate:
            _angle = (_angle + 45) % 360;
            break;
        case line_scale:
            _scale += 0.1f;
            _scale = _scale > .5f ? 0.0f : _scale;
            break;
    }

    update();
}

void QProgressIndicator::drawRotateLine(QPainter* painter) {

    int width = qMin(this->width(), this->height());

    int outerRadius = (width - 4) * 0.5f;
    int innerRadius = outerRadius * 0.42f;

    int capsuleHeight = outerRadius - innerRadius;
    int capsuleWidth  = (width > 32 ) ? capsuleHeight * .32f : capsuleHeight * .40f;
    int capsuleRadius = capsuleWidth / 2;

    for (int i = 0; i < 8; i++) {

        QColor color = _color;

        color.setAlphaF(1.0f - (i / 8.0f));
        painter->setPen(Qt::NoPen);
        painter->setBrush(color);

        painter->save();

        painter->translate(rect().center());
        painter->rotate(_angle - i * 45.0f);

        painter->drawRoundedRect(-capsuleWidth * 0.5, -(innerRadius + capsuleHeight), capsuleWidth, capsuleHeight, capsuleRadius, capsuleRadius);

        painter->restore();
    }
}

void QProgressIndicator::drawScaleLine(QPainter* painter) {

    int height = qMin(this->width(), this->height());

    qreal lineWidth  = height * 0.15f;
    qreal lineHeight = height * 0.9f;
    qreal lineRadius = lineWidth / 2.0f;
    qreal lineGap    = lineWidth;
    qreal margin     = (this->width() - lineWidth * 5 - lineGap * 4) / 2.0f;

    for (int i = 0; i < 5; i++) {

        painter->setPen(Qt::NoPen);
        painter->setBrush(_color);

        int tmp = _scale * 10 + i + 1;
        if (tmp > 5) {
            tmp = 5 - tmp % 5;
        }

        qreal scale = 0.5f + tmp * 0.1f;
        qreal h = lineHeight * scale;

        painter->save();

        painter->translate(QPointF(margin + (lineWidth + lineGap) * i, this->height() / 2));

        painter->drawRoundedRect(0, -h / 2.0f, lineWidth, h, lineRadius, lineRadius);

        painter->restore();
    }
}

void QProgressIndicator::drawRotateBall(QPainter* painter) {

    int width = qMin(this->width(), this->height());

    int outerRadius = (width - 4) * 0.5f;
    int innerRadius = outerRadius * 0.78f;

    int capsuleRadius = (outerRadius - innerRadius) / 2;

    for (int i = 0; i < 8; i++) {

        QColor color = _color;

        color.setAlphaF(1.0f - (i / 8.0f));

        painter->setPen(Qt::NoPen);
        painter->setBrush(color);

        qreal radius = capsuleRadius * (1.0f - (i / 16.0f));

        painter->save();

        painter->translate(rect().center());
        painter->rotate(_angle - i * 45.0f);

        QPointF centre = QPointF(-capsuleRadius, -(innerRadius + capsuleRadius));
        painter->drawEllipse(centre, radius * 2, radius * 2);

        painter->restore();
    }
}

void QProgressIndicator::drawRotateCircle(QPainter* painter) {

    // My version is based on ProgressInfiniteBar from : https://github.com/przemek83/wble

    int width    = qMin(this->width(), this->height());
    int offset   = qAbs(this->width() - this->height()) / 2;
    int penwidth = 3;

    QRectF r = QRect(offset+penwidth,0+penwidth, width-(2*penwidth),width-(2*penwidth));

    QPen pen(_color);
    pen.setWidth(penwidth);
    pen.setCapStyle(Qt::RoundCap);

    painter->setPen(pen);
    painter->setBrush(_color);

    int startAngle = 0.0;
    int spanAngle  = 45 * 16;

    startAngle = (0.0 + _angle) * 16;
    painter->drawArc(r, -startAngle, -spanAngle);

    startAngle = (120.0 + _angle) * 16;
    painter->drawArc(r, -startAngle, -spanAngle);

    startAngle = (240.0 + _angle) * 16;
    painter->drawArc(r, -startAngle, -spanAngle);
}