Add a 'spinning' indicator to the toolbar when the program runs.

src/QProgressIndicator.cpp

@@ -0,0 +1,208 @@
+#include "QProgressIndicator.h"
+
+#include <QDebug>
+#include <QtGlobal>
+#include <QPoint>
+
+#define SPIN_INTERVAL   60
+
+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()));
+}
+
+QProgressIndicator::~QProgressIndicator() {
+
+    stop();
+
+    delete _timer;
+}
+
+void QProgressIndicator::paintEvent(QPaintEvent* e) {
+
+    Q_UNUSED(e)
+
+    if (!_timer->isActive()) {
+        return;
+    }
+
+    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;
+    }
+}
+
+void QProgressIndicator::start() {
+
+    _timer->start(_interval);
+}
+
+void QProgressIndicator::stop() {
+
+    _timer->stop();
+
+    update(); // Force an update to erate the indicator from the view.
+}
+
+int QProgressIndicator::type () {
+
+    return _type;
+}
+
+void QProgressIndicator::setType (int type) {
+
+    _type = type;
+}
+
+const QColor& QProgressIndicator::color () {
+
+    return _color;
+}
+
+void QProgressIndicator::setColor (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 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();
+    }
+}
+