Add a new class, QtWaitingSpinner, MIT Licensed.

from https://github.com/snowwlex/QtWaitingSpinner

Signed-off-by: Tomaz Canabrava <tomaz.canabrava@gmail.com>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>

1 files changed, 288 insertions, 0 deletions

diff --git a/qt-ui/qtwaitingspinner.cpp b/qt-ui/qtwaitingspinner.cpp
new file mode 100644
index 000000000..14e8669b0
--- /dev/null
+++ b/qt-ui/qtwaitingspinner.cpp
@@ -0,0 +1,288 @@
+
+/* Original Work Copyright (c) 2012-2014 Alexander Turkin
+   Modified 2014 by William Hallatt
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the "Software"), to deal in
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+the Software, and to permit persons to whom the Software is furnished to do so,
+subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+*/
+#include <cmath>
+#include <algorithm>
+
+#include <QPainter>
+#include <QTimer>
+
+#include "qtwaitingspinner.h"
+
+/*----------------------------------------------------------------------------*/
+
+// Defaults
+const QColor c_color(Qt::black);
+const qreal c_roundness(70.0);
+const qreal c_minTrailOpacity(15.0);
+const qreal c_trailFadePercentage(70.0);
+const int c_lines(12);
+const int c_lineLength(10);
+const int c_lineWidth(5);
+const int c_innerRadius(10);
+const int c_revPerSec(1);
+
+/*----------------------------------------------------------------------------*/
+
+QtWaitingSpinner::QtWaitingSpinner(QWidget *parent)
+	: QWidget(parent),
+
+	  // Configurable settings.
+	  m_color(c_color), m_roundness(c_roundness),
+	  m_minTrailOpacity(c_minTrailOpacity),
+	  m_trailFadePercentage(c_trailFadePercentage), m_revPerSec(c_revPerSec),
+	  m_numberOfLines(c_lines), m_lineLength(c_lineLength + c_lineWidth),
+	  m_lineWidth(c_lineWidth), m_innerRadius(c_innerRadius),
+
+	  // Other
+	  m_timer(NULL), m_parent(parent), m_centreOnParent(false),
+	  m_currentCounter(0), m_isSpinning(false) {
+  initialise();
+}
+
+/*----------------------------------------------------------------------------*/
+
+QtWaitingSpinner::QtWaitingSpinner(Qt::WindowModality modality, QWidget *parent,
+								   bool centreOnParent)
+	: QWidget(parent, Qt::Dialog | Qt::FramelessWindowHint),
+
+	  // Configurable settings.
+	  m_color(c_color), m_roundness(c_roundness),
+	  m_minTrailOpacity(c_minTrailOpacity),
+	  m_trailFadePercentage(c_trailFadePercentage), m_revPerSec(c_revPerSec),
+	  m_numberOfLines(c_lines), m_lineLength(c_lineLength + c_lineWidth),
+	  m_lineWidth(c_lineWidth), m_innerRadius(c_innerRadius),
+
+	  // Other
+	  m_timer(NULL), m_parent(parent), m_centreOnParent(centreOnParent),
+	  m_currentCounter(0) {
+  initialise();
+
+  // We need to set the window modality AFTER we've hidden the
+  // widget for the first time since changing this property while
+  // the widget is visible has no effect.
+  this->setWindowModality(modality);
+  this->setAttribute(Qt::WA_TranslucentBackground);
+}
+
+/*----------------------------------------------------------------------------*/
+
+void QtWaitingSpinner::initialise() {
+  m_timer = new QTimer(this);
+  connect(m_timer, SIGNAL(timeout()), this, SLOT(rotate()));
+  updateSize();
+  updateTimer();
+  this->hide();
+}
+
+/*----------------------------------------------------------------------------*/
+
+void QtWaitingSpinner::paintEvent(QPaintEvent * /*ev*/) {
+  QPainter painter(this);
+  painter.fillRect(this->rect(), Qt::transparent);
+  painter.setRenderHint(QPainter::Antialiasing, true);
+
+  if (m_currentCounter >= m_numberOfLines) {
+	m_currentCounter = 0;
+  }
+  painter.setPen(Qt::NoPen);
+  for (int i = 0; i < m_numberOfLines; ++i) {
+	painter.save();
+	painter.translate(m_innerRadius + m_lineLength,
+					  m_innerRadius + m_lineLength);
+	qreal rotateAngle =
+		static_cast<qreal>(360 * i) / static_cast<qreal>(m_numberOfLines);
+	painter.rotate(rotateAngle);
+	painter.translate(m_innerRadius, 0);
+	int distance =
+		lineCountDistanceFromPrimary(i, m_currentCounter, m_numberOfLines);
+	QColor color =
+		currentLineColor(distance, m_numberOfLines, m_trailFadePercentage,
+						 m_minTrailOpacity, m_color);
+	painter.setBrush(color);
+	// TODO improve the way rounded rect is painted
+	painter.drawRoundedRect(
+		QRect(0, -m_lineWidth / 2, m_lineLength, m_lineWidth), m_roundness,
+		m_roundness, Qt::RelativeSize);
+	painter.restore();
+  }
+}
+
+/*----------------------------------------------------------------------------*/
+
+void QtWaitingSpinner::start() {
+  updatePosition();
+  m_isSpinning = true;
+  this->show();
+  if (!m_timer->isActive()) {
+	m_timer->start();
+	m_currentCounter = 0;
+  }
+}
+
+/*----------------------------------------------------------------------------*/
+
+void QtWaitingSpinner::stop() {
+  m_isSpinning = false;
+  this->hide();
+  if (m_timer->isActive()) {
+	m_timer->stop();
+	m_currentCounter = 0;
+  }
+}
+
+/*----------------------------------------------------------------------------*/
+
+void QtWaitingSpinner::setNumberOfLines(int lines) {
+  m_numberOfLines = lines;
+  m_currentCounter = 0;
+  updateTimer();
+}
+
+/*----------------------------------------------------------------------------*/
+
+void QtWaitingSpinner::setLineLength(int length) {
+  m_lineLength = length;
+  updateSize();
+}
+
+/*----------------------------------------------------------------------------*/
+
+void QtWaitingSpinner::setLineWidth(int width) {
+  m_lineWidth = width;
+  updateSize();
+}
+
+/*----------------------------------------------------------------------------*/
+
+void QtWaitingSpinner::setInnerRadius(int radius) {
+  m_innerRadius = radius;
+  updateSize();
+}
+
+/*----------------------------------------------------------------------------*/
+
+bool QtWaitingSpinner::isSpinning() const { return m_isSpinning; }
+
+/*----------------------------------------------------------------------------*/
+
+void QtWaitingSpinner::setRoundness(qreal roundness) {
+  m_roundness = std::max(0.0, std::min(100.0, roundness));
+}
+
+/*----------------------------------------------------------------------------*/
+
+void QtWaitingSpinner::setColor(QColor color) { m_color = color; }
+
+/*----------------------------------------------------------------------------*/
+
+void QtWaitingSpinner::setRevolutionsPerSecond(int rps) {
+  m_revPerSec = rps;
+  updateTimer();
+}
+
+/*----------------------------------------------------------------------------*/
+
+void QtWaitingSpinner::setTrailFadePercentage(qreal trail) {
+  m_trailFadePercentage = trail;
+}
+
+/*----------------------------------------------------------------------------*/
+
+void QtWaitingSpinner::setMinimumTrailOpacity(qreal minOpacity) {
+  m_minTrailOpacity = minOpacity;
+}
+
+/*----------------------------------------------------------------------------*/
+
+void QtWaitingSpinner::rotate() {
+  ++m_currentCounter;
+  if (m_currentCounter >= m_numberOfLines) {
+	m_currentCounter = 0;
+  }
+  update();
+}
+
+/*----------------------------------------------------------------------------*/
+
+void QtWaitingSpinner::updateSize() {
+  int size = (m_innerRadius + m_lineLength) * 2;
+  setFixedSize(size, size);
+}
+
+/*----------------------------------------------------------------------------*/
+
+void QtWaitingSpinner::updateTimer() {
+  m_timer->setInterval(calculateTimerInterval(m_numberOfLines, m_revPerSec));
+}
+
+/*----------------------------------------------------------------------------*/
+
+void QtWaitingSpinner::updatePosition() {
+  if (m_parent && m_centreOnParent) {
+	this->move(m_parent->frameGeometry().topLeft() + m_parent->rect().center() -
+			   this->rect().center());
+  }
+}
+
+/*----------------------------------------------------------------------------*/
+
+int QtWaitingSpinner::calculateTimerInterval(int lines, int speed) {
+  return 1000 / (lines * speed);
+}
+
+/*----------------------------------------------------------------------------*/
+
+int QtWaitingSpinner::lineCountDistanceFromPrimary(int current, int primary,
+												   int totalNrOfLines) {
+  int distance = primary - current;
+  if (distance < 0) {
+	distance += totalNrOfLines;
+  }
+  return distance;
+}
+
+/*----------------------------------------------------------------------------*/
+
+QColor QtWaitingSpinner::currentLineColor(int countDistance, int totalNrOfLines,
+										  qreal trailFadePerc, qreal minOpacity,
+										  QColor color) {
+  if (countDistance == 0) {
+	return color;
+  }
+  const qreal minAlphaF = minOpacity / 100.0;
+  int distanceThreshold =
+	  static_cast<int>(ceil((totalNrOfLines - 1) * trailFadePerc / 100.0));
+  if (countDistance > distanceThreshold) {
+	color.setAlphaF(minAlphaF);
+  } else {
+	qreal alphaDiff = color.alphaF() - minAlphaF;
+	qreal gradient = alphaDiff / static_cast<qreal>(distanceThreshold + 1);
+	qreal resultAlpha = color.alphaF() - gradient * countDistance;
+
+	// If alpha is out of bounds, clip it.
+	resultAlpha = std::min(1.0, std::max(0.0, resultAlpha));
+	color.setAlphaF(resultAlpha);
+  }
+  return color;
+}
+
+/*----------------------------------------------------------------------------*/