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>

qt-ui/qtwaitingspinner.h

@@ -0,0 +1,103 @@
+/* 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.
+*/
+#ifndef QTWAITINGSPINNER_H
+#define QTWAITINGSPINNER_H
+
+#include <QWidget>
+
+#include <QTimer>
+#include <QColor>
+
+class QtWaitingSpinner : public QWidget {
+  Q_OBJECT
+public:
+  /*! Constructor for "standard" widget behaviour - use this
+   * constructor if you wish to, e.g. embed your widget in another. */
+  QtWaitingSpinner(QWidget *parent = 0);
+
+  /*! Constructor - use this constructor to automatically create a modal
+   * ("blocking") spinner on top of the calling widget/window.  If a valid
+   * parent widget is provided, "centreOnParent" will ensure that
+   * QtWaitingSpinner automatically centres itself on it, if not,
+   * "centreOnParent" is ignored. */
+  QtWaitingSpinner(Qt::WindowModality modality, QWidget *parent = 0,
+				   bool centreOnParent = true);
+
+public Q_SLOTS:
+  void start();
+  void stop();
+
+public:
+  void setColor(QColor color);
+  void setRoundness(qreal roundness);
+  void setMinimumTrailOpacity(qreal minOpacity);
+  void setTrailFadePercentage(qreal trail);
+  void setRevolutionsPerSecond(int rps);
+  void setNumberOfLines(int lines);
+  void setLineLength(int length);
+  void setLineWidth(int width);
+  void setInnerRadius(int radius);
+
+  bool isSpinning() const;
+
+private Q_SLOTS:
+  void rotate();
+
+protected:
+  void paintEvent(QPaintEvent *ev);
+
+private:
+  static int calculateTimerInterval(int lines, int speed);
+  static int lineCountDistanceFromPrimary(int current, int primary,
+										  int totalNrOfLines);
+  static QColor currentLineColor(int distance, int totalNrOfLines,
+								 qreal trailFadePerc, qreal minOpacity,
+								 QColor color);
+
+  void initialise();
+  void updateSize();
+  void updateTimer();
+  void updatePosition();
+
+private:
+  // Configurable settings.
+  QColor m_color;
+  qreal m_roundness; // 0..100
+  qreal m_minTrailOpacity;
+  qreal m_trailFadePercentage;
+  int m_revPerSec; // revolutions per second
+  int m_numberOfLines;
+  int m_lineLength;
+  int m_lineWidth;
+  int m_innerRadius;
+
+private:
+  QtWaitingSpinner(const QtWaitingSpinner&);
+  QtWaitingSpinner& operator=(const QtWaitingSpinner&);
+
+  QTimer *m_timer;
+  QWidget *m_parent;
+  bool m_centreOnParent;
+  int m_currentCounter;
+  bool m_isSpinning;
+};
+
+#endif // QTWAITINGSPINNER_H