The Quick Speech example reads out user-provided text.
The Quick Speech example demonstrates how the TextToSpeech type can be used in a Qt Quick application to read out text and to control the speech.
The example uses Qt Quick Controls to provide controls for the speech's pitch, volume, and rate. It also lets the user select an engine, a language, and a voice.
First, we initialize the text to speech object tts:
TextToSpeech { id: tts volume: volumeSlider.value pitch: pitchSlider.value rate: rateSlider.value
Switch cases are used to update the Label statusLabel in the footer.
onStateChanged: updateStateLabel(state) function updateStateLabel(state) { switch (state) { case TextToSpeech.Ready: statusLabel.text = qsTr("Ready") break case TextToSpeech.Speaking: statusLabel.text = qsTr("Speaking") break case TextToSpeech.Paused: statusLabel.text = qsTr("Paused...") break case TextToSpeech.Error: statusLabel.text = qsTr("Error!") break }
The TextArea input is used to get the text to input and the onSayingWord signal as the trigger and also to know the position to highlight words as they are spoken.
onSayingWord: (word, id, start, length)=> { input.select(start, start + length)
The TextArea input is declared here:
ColumnLayout { anchors.fill: parent anchors.margins: 8 id: inputForm TextArea { id: input wrapMode: TextEdit.WordWrap text: qsTr("Hello, world!") Layout.fillWidth: true Layout.minimumHeight: implicitHeight font.pointSize: 24 }
Button types are arranged with a RowLayout and configured to control the TextToSpeech tts.
A Button is created labeled "Speak". It is enabled if tts's state property is either Paused or
Ready.
RowLayout { Button { text: qsTr("Speak") enabled: [TextToSpeech.Paused, TextToSpeech.Ready].includes(tts.state)
When the button is clicked, the available voices on the target devices are retrieved, and tts.voice is set to the currently selected voice of voicesComboBox. Then
TextToSpeech::say() is called and is passed the text in the inputbox.
onClicked: { //! [say0] let voices = tts.availableVoices() tts.voice = voices[voicesComboBox.currentIndex] //! [say1] tts.say(input.text) }
These buttons are similar in implementation to the Speak button:
Button { text: qsTr("Pause") enabled: tts.state == TextToSpeech.Speaking onClicked: tts.pause() visible: tts.engineCapabilities & TextToSpeech.Capabilities.PauseResume } //! [pause] //! [resume] Button { text: qsTr("Resume") enabled: tts.state == TextToSpeech.Paused onClicked: tts.resume() visible: tts.engineCapabilities & TextToSpeech.Capabilities.PauseResume } //! [resume] Button { text: qsTr("Stop") enabled: [TextToSpeech.Speaking, TextToSpeech.Paused].includes(tts.state) onClicked: tts.stop() } }
A GridLayout is used to arrange the controls and labels for the selection of engine, locale, voice, volume, pitch, and rate options for text to speech synthesis.
A group of ComboBox components are used for selecting these parameters.
For the engine selection ComboBox, tts.availableEngines() is used as the model.
The onActivated triggers assigning tts.engine the current text at the ComboBoxes current index.
Text { text: qsTr("Engine:") } ComboBox { id: enginesComboBox Layout.fillWidth: true model: tts.availableEngines() onActivated: { tts.engine = textAt(currentIndex) updateLocales() updateVoices()
The last two lines in the above code snippet show that the available locales and voices are updated at this point as well, as they are dependent on the selected engine. Those functions are covered in a following section.
The localesComboBox is implemented the same way as engineComboBox, but without updating the available engines.
}
}
Text {
text: qsTr("Locale:")
}
ComboBox {
id: localesComboBox
Layout.fillWidth: true
onActivated: {
let locales = tts.availableLocales()
tts.locale = locales[currentIndex]
updateVoices()
}
}
Text {
text: qsTr("Voice:")
}
ComboBox {
id: voicesComboBox
Layout.fillWidth: true
}
These controls are implemented with Sliders as follows:
Text { text: qsTr("Volume:") } Slider { id: volumeSlider from: 0 to: 1.0 stepSize: 0.2 value: 0.8 Layout.fillWidth: true } Text { text: qsTr("Pitch:") } Slider { id: pitchSlider from: -1.0 to: 1.0 stepSize: 0.5 value: 0 Layout.fillWidth: true } Text { text: qsTr("Rate:") } Slider { id: rateSlider from: -1.0 to: 1.0 stepSize: 0.5 value: 0 Layout.fillWidth: true } } }
By using the Component.onCompleted signal, the following is done once the root ApplicationWindow has been instantiated.
enginesComboBox index is set to the currently set engine of tts.tts is signaled.Component.onCompleted: { enginesComboBox.currentIndex = tts.availableEngines().indexOf(tts.engine) // some engines initialize asynchronously if (tts.state == TextToSpeech.Ready) { engineReady()
Used throughout the application, the updateLocales() and updateVoice() functions are implemented as follows:
} else { tts.stateChanged.connect(root.engineReady) } tts.updateStateLabel(tts.state) } function engineReady() { tts.stateChanged.disconnect(root.engineReady) if (tts.state != TextToSpeech.Ready) { tts.updateStateLabel(tts.state) return; } updateLocales() updateVoices() } function updateLocales() { let allLocales = tts.availableLocales().map((locale) => locale.nativeLanguageName) let currentLocaleIndex = allLocales.indexOf(tts.locale.nativeLanguageName) localesComboBox.model = allLocales localesComboBox.currentIndex = currentLocaleIndex } function updateVoices() { voicesComboBox.model = tts.availableVoices().map((voice) => voice.name) let indexOfVoice = tts.availableVoices().indexOf(tts.voice) voicesComboBox.currentIndex = indexOfVoice
To run the example from Qt Creator, open the Welcome mode and select the example from Examples. For more information, see Qt Creator: Tutorial: Build and run.
