GUI: Add three new options for volume slider controls

GUIO_NOSPEECHVOLUME can be used for games that allow toggling of
speech but do not provide the ability for users to control speech
volume.

GUIO_LINKMUSICTOSFX and GUI_LINKSPEECHTOSFX can be used for games
that allow control of music, sfx, and speech in combinations, like
games that provide control of digital audio separately from MIDI,
or games that only control all three audio types through a single
volume control.

2 files changed, 63 insertions, 6 deletions

diff --git a/gui/options.cpp b/gui/options.cpp
index 371a949c35..aa5f7b46bb 100644
--- a/gui/options.cpp
+++ b/gui/options.cpp
@@ -627,18 +627,51 @@ void OptionsDialog::handleCommand(CommandSender *sender, uint32 cmd, uint32 data
 		_midiGainLabel->setLabel(Common::String::format("%.2f", (double)_midiGainSlider->getValue() / 100.0));
 		_midiGainLabel->draw();
 		break;
-	case kMusicVolumeChanged:
-		_musicVolumeLabel->setValue(_musicVolumeSlider->getValue());
+	case kMusicVolumeChanged: {
+		const int newValue = _musicVolumeSlider->getValue();
+		_musicVolumeLabel->setValue(newValue);
 		_musicVolumeLabel->draw();
+
+		if (_guioptions.contains(GUIO_LINKMUSICTOSFX)) {
+			updateSfxVolume(newValue);
+
+			if (_guioptions.contains(GUIO_LINKSPEECHTOSFX)) {
+				updateSpeechVolume(newValue);
+			}
+		}
+
 		break;
-	case kSfxVolumeChanged:
+	}
+	case kSfxVolumeChanged: {
+		const int newValue = _sfxVolumeSlider->getValue();
 		_sfxVolumeLabel->setValue(_sfxVolumeSlider->getValue());
 		_sfxVolumeLabel->draw();
+
+		if (_guioptions.contains(GUIO_LINKMUSICTOSFX)) {
+			updateMusicVolume(newValue);
+		}
+
+		if (_guioptions.contains(GUIO_LINKSPEECHTOSFX)) {
+			updateSpeechVolume(newValue);
+		}
+
 		break;
-	case kSpeechVolumeChanged:
-		_speechVolumeLabel->setValue(_speechVolumeSlider->getValue());
+	}
+	case kSpeechVolumeChanged: {
+		const int newValue = _speechVolumeSlider->getValue();
+		_speechVolumeLabel->setValue(newValue);
 		_speechVolumeLabel->draw();
+
+		if (_guioptions.contains(GUIO_LINKSPEECHTOSFX)) {
+			updateSfxVolume(newValue);
+
+			if (_guioptions.contains(GUIO_LINKMUSICTOSFX)) {
+				updateMusicVolume(newValue);
+			}
+		}
+
 		break;
+	}
 	case kMuteAllChanged:
 		// 'true' because if control is disabled then event do not pass
 		setVolumeSettingsState(true);
@@ -769,7 +802,7 @@ void OptionsDialog::setVolumeSettingsState(bool enabled) {
 	// Disable speech volume slider, when we are in subtitle only mode.
 	if (_subToggleGroup)
 		ena = ena && _subToggleGroup->getValue() != kSubtitlesSubs;
-	if (_guioptions.contains(GUIO_NOSPEECH))
+	if (_guioptions.contains(GUIO_NOSPEECH) || _guioptions.contains(GUIO_NOSPEECHVOLUME))
 		ena = false;
 
 	_speechVolumeDesc->setEnabled(ena);
@@ -1142,6 +1175,27 @@ int OptionsDialog::getSubtitleMode(bool subtitles, bool speech_mute) {
 	return kSubtitlesSubs;
 }
 
+void OptionsDialog::updateMusicVolume(const int newValue) const {
+	_musicVolumeLabel->setValue(newValue);
+	_musicVolumeSlider->setValue(newValue);
+	_musicVolumeLabel->draw();
+	_musicVolumeSlider->draw();
+}
+
+void OptionsDialog::updateSfxVolume(const int newValue) const {
+	_sfxVolumeLabel->setValue(newValue);
+	_sfxVolumeSlider->setValue(newValue);
+	_sfxVolumeLabel->draw();
+	_sfxVolumeSlider->draw();
+}
+
+void OptionsDialog::updateSpeechVolume(const int newValue) const {
+	_speechVolumeLabel->setValue(newValue);
+	_speechVolumeSlider->setValue(newValue);
+	_speechVolumeLabel->draw();
+	_speechVolumeSlider->draw();
+}
+
 void OptionsDialog::reflowLayout() {
 	if (_graphicsTabId != -1 && _tabWidget)
 		_tabWidget->setTabTitle(_graphicsTabId, g_system->getOverlayWidth() > 320 ? _("Graphics") : _("GFX"));
diff --git a/gui/options.h b/gui/options.h
index a6eebe5748..1b15258ab5 100644
--- a/gui/options.h
+++ b/gui/options.h
@@ -175,6 +175,9 @@ private:
 	//
 	// Volume controls
 	//
+	void updateMusicVolume(const int newValue) const;
+	void updateSfxVolume(const int newValue) const;
+	void updateSpeechVolume(const int newValue) const;
 	bool _enableVolumeSettings;
 
 	StaticTextWidget *_musicVolumeDesc;