1 files changed, 62 insertions, 0 deletions
diff --git a/examples/multimedia/spectrum/spectrograph.h b/examples/multimedia/spectrum/spectrograph.h
new file mode 100644
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+++ b/examples/multimedia/spectrum/spectrograph.h
@@ -0,0 +1,62 @@
+// Copyright (C) 2017 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
+
+#ifndef SPECTROGRAPH_H
+#define SPECTROGRAPH_H
+
+#include "frequencyspectrum.h"
+
+#include <QWidget>
+
+/**
+ * Widget which displays a spectrograph showing the frequency spectrum
+ * of the window of audio samples most recently analyzed by the Engine.
+ */
+class Spectrograph : public QWidget
+{
+    Q_OBJECT
+
+public:
+    explicit Spectrograph(QWidget *parent = nullptr);
+    ~Spectrograph();
+
+    void setParams(int numBars, qreal lowFreq, qreal highFreq);
+
+    // QObject
+    void timerEvent(QTimerEvent *event) override;
+
+    // QWidget
+    void paintEvent(QPaintEvent *event) override;
+    void mousePressEvent(QMouseEvent *event) override;
+
+signals:
+    void infoMessage(const QString &message, int intervalMs);
+
+public slots:
+    void reset();
+    void spectrumChanged(const FrequencySpectrum &spectrum);
+
+private:
+    int barIndex(qreal frequency) const;
+    QPair<qreal, qreal> barRange(int barIndex) const;
+    void updateBars();
+
+    void selectBar(int index);
+
+private:
+    struct Bar
+    {
+        Bar() : value(0.0), clipped(false) { }
+        qreal value;
+        bool clipped;
+    };
+
+    QList<Bar> m_bars;
+    int m_barSelected;
+    int m_timerId;
+    qreal m_lowFreq;
+    qreal m_highFreq;
+    FrequencySpectrum m_spectrum;
+};
+
+#endif // SPECTROGRAPH_H