Example: Port qtcharts audio example to qtgraphs

Task-number: PYSIDE-841
Pick-to: 6.8 6.9
Change-Id: Id8a81c06078c147eb50f1f1d688841e8a6bab18b
Reviewed-by: Friedemann Kleint <[email protected]>
Reviewed-by: Cristian Maureira-Fredes <[email protected]>

Author: Ece Cinucen

examples/graphs/2d/graphsaudio/GraphsAudio/Main.qml

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+// Copyright (C) 2025 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
+
+import QtQuick
+import QtQuick.Controls
+import QtGraphs
+
+ApplicationWindow {
+    visible: true
+    width: 1000
+    height: 800
+    title: "Data from the microphone (" + device_name + ")"
+
+    GraphsView {
+        id: graph
+        anchors.fill: parent
+
+        LineSeries {
+            id: audio_series
+            width: 2
+            color: "#007acc"
+        }
+
+        axisX: ValueAxis  {
+            min: 0
+            max: 2000
+            tickInterval : 500
+            labelFormat: "%g"
+            titleText: "Samples"
+        }
+
+        axisY: ValueAxis  {
+            min: -1
+            max: 1
+            tickInterval : 0.5
+            labelFormat: "%0.1f"
+            titleText: "Audio level"
+        }
+    }
+
+    Connections {
+        target: audio_bridge
+        function onDataUpdated(buffer) {
+            audio_series.clear()
+            for (let i = 0; i < buffer.length; ++i) {
+                audio_series.append(buffer[i])
+            }
+        }
+    }
+}

examples/graphs/2d/graphsaudio/GraphsAudio/qmldir

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+module GraphsAudio
+Main 1.0 Main.qml

examples/graphs/2d/graphsaudio/doc/graphsaudio.rst

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+GraphsAudio Example
+===================
+
+This example shows the drawing of dynamic data (microphone input) using QtGraphs and Qml.
+
+.. image:: graphsaudio.webp
+   :width: 400
+   :alt: GraphsAudio Screenshot

examples/graphs/2d/graphsaudio/doc/graphsaudio.webp

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+{
+    "files": ["main.py", "GraphsAudio/Main.qml", "GraphsAudio/qmldir"]
+}

examples/graphs/2d/graphsaudio/graphsaudio.pyproject

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+# Copyright (C) 2025 The Qt Company Ltd.
+# SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
+from __future__ import annotations
+
+import sys
+from pathlib import Path
+from PySide6.QtCore import QObject, QPointF, Slot, Signal
+from PySide6.QtMultimedia import QAudioFormat, QAudioSource, QMediaDevices
+from PySide6.QtWidgets import QMessageBox
+from PySide6.QtQml import QQmlApplicationEngine
+from PySide6.QtGui import QGuiApplication
+
+
+SAMPLE_COUNT = 2000
+RESOLUTION = 4
+
+
+class Audio(QObject):
+    dataUpdated = Signal(list)
+
+    def __init__(self, device):
+        super().__init__()
+
+        format_audio = QAudioFormat()
+        format_audio.setSampleRate(8000)
+        format_audio.setChannelCount(1)
+        format_audio.setSampleFormat(QAudioFormat.UInt8)
+
+        self.device_name = device.description()
+
+        self._audio_input = QAudioSource(device, format_audio, self)
+        self._io_device = self._audio_input.start()
+        self._io_device.readyRead.connect(self._readyRead)
+
+        self._buffer = [QPointF(x, 0) for x in range(SAMPLE_COUNT)]
+
+    def closeEvent(self, event):
+        if self._audio_input is not None:
+            self._audio_input.stop()
+        event.accept()
+
+    @Slot()
+    def _readyRead(self):
+        data = self._io_device.readAll()
+        available_samples = data.size() // RESOLUTION
+        start = 0
+        if (available_samples < SAMPLE_COUNT):
+            start = SAMPLE_COUNT - available_samples
+            for s in range(start):
+                self._buffer[s].setY(self._buffer[s + available_samples].y())
+
+        data_index = 0
+        for s in range(start, SAMPLE_COUNT):
+            value = (ord(data[data_index]) - 128) / 128
+            self._buffer[s].setY(value)
+            data_index = data_index + RESOLUTION
+
+        self.dataUpdated.emit(self._buffer)
+
+
+if __name__ == '__main__':
+    app = QGuiApplication(sys.argv)
+    engine = QQmlApplicationEngine()
+
+    input_devices = QMediaDevices.audioInputs()
+    if not input_devices:
+        QMessageBox.warning(None, "audio", "There is no audio input device available.")
+        sys.exit(-1)
+
+    audio_bridge = Audio(input_devices[0])
+    engine.rootContext().setContextProperty("audio_bridge", audio_bridge)
+
+    device = input_devices[0]
+    device_name = device.description()
+    engine.rootContext().setContextProperty("device_name", device_name)
+
+    engine.addImportPath(Path(__file__).parent)
+    engine.loadFromModule("GraphsAudio", "Main")
+
+    sys.exit(app.exec())