UI: Add volume controls to properties window

This makes it easier for users to edit volume controls of a source,
without first closing the properties window.

UI/forms/OBSBasicProperties.ui

@@ -44,7 +44,7 @@
       <property name="frameShadow">
        <enum>QFrame::Plain</enum>
       </property>
-      <layout class="QVBoxLayout" name="verticalLayout_7">
+      <layout class="QHBoxLayout" name="previewLayout">
        <property name="spacing">
         <number>0</number>
        </property>

UI/volume-control.hpp

@@ -280,6 +280,8 @@ class MuteCheckBox;
 class VolControl : public QWidget {
 	Q_OBJECT
 
+	friend class OBSBasicProperties;
+
 private:
 	OBSSource source;
 	QLabel *nameLabel;

UI/window-basic-properties.cpp

@@ -21,6 +21,7 @@
 #include "qt-wrappers.hpp"
 #include "display-helpers.hpp"
 #include "properties-view.hpp"
+#include "volume-control.hpp"
 
 #include <QCloseEvent>
 #include <QScreen>
@@ -51,6 +52,12 @@ OBSBasicProperties::OBSBasicProperties(QWidget *parent, OBSSource source_)
 			OBSBasicProperties::SourceRemoved, this),
 	  renamedSignal(obs_source_get_signal_handler(source), "rename",
 			OBSBasicProperties::SourceRenamed, this),
+	  audioActivated(obs_source_get_signal_handler(source),
+			 "audio_activate", OBSBasicProperties::AudioActivated,
+			 this),
+	  audioDeactivated(obs_source_get_signal_handler(source),
+			   "audio_deactivate",
+			   OBSBasicProperties::AudioDeactivated, this),
 	  oldSettings(obs_data_create())
 {
 	int cx = (int)config_get_int(App()->GlobalConfig(), "PropertiesWindow",
@@ -114,6 +121,7 @@ OBSBasicProperties::OBSBasicProperties(QWidget *parent, OBSSource source_)
 	bool drawable_type = type == OBS_SOURCE_TYPE_INPUT ||
 			     type == OBS_SOURCE_TYPE_SCENE;
 	bool drawable_preview = (caps & OBS_SOURCE_VIDEO) != 0;
+	bool verticalMixer = true;
 
 	if (drawable_preview && drawable_type) {
 		ui->preview->show();
@@ -166,7 +174,30 @@ OBSBasicProperties::OBSBasicProperties(QWidget *parent, OBSSource source_)
 
 	} else {
 		ui->preview->hide();
+		verticalMixer = false;
 	}
+
+	if ((caps & OBS_SOURCE_AUDIO) == OBS_SOURCE_AUDIO) {
+		vol = new VolControl(source, false, verticalMixer);
+		vol->nameLabel->hide();
+
+		if (!verticalMixer) {
+			QVBoxLayout *mainLayout =
+				qobject_cast<QVBoxLayout *>(vol->layout());
+
+			if (mainLayout)
+				mainLayout->addStretch();
+		} else {
+			ui->previewLayout->addSpacing(9);
+		}
+
+		ui->previewLayout->addWidget(vol);
+	}
+
+	if (obs_source_audio_active(source))
+		ShowVolumeControls();
+	else
+		HideVolumeControls();
 }
 
 OBSBasicProperties::~OBSBasicProperties()
@@ -301,6 +332,30 @@ void OBSBasicProperties::UpdateProperties(void *data, calldata_t *)
 				  "ReloadProperties");
 }
 
+void OBSBasicProperties::AudioActivated(void *data, calldata_t *)
+{
+	QMetaObject::invokeMethod(static_cast<OBSBasicProperties *>(data),
+				  "ShowVolumeControls");
+}
+
+void OBSBasicProperties::AudioDeactivated(void *data, calldata_t *)
+{
+	QMetaObject::invokeMethod(static_cast<OBSBasicProperties *>(data),
+				  "HideVolumeControls");
+}
+
+void OBSBasicProperties::ShowVolumeControls()
+{
+	if (vol)
+		vol->show();
+}
+
+void OBSBasicProperties::HideVolumeControls()
+{
+	if (vol)
+		vol->hide();
+}
+
 static bool ConfirmReset(QWidget *parent)
 {
 	QMessageBox::StandardButton button;

UI/window-basic-properties.hpp

@@ -26,6 +26,7 @@
 
 class OBSPropertiesView;
 class OBSBasic;
+class VolControl;
 
 #include "ui_OBSBasicProperties.h"
 
@@ -42,10 +43,13 @@ class OBSBasicProperties : public QDialog {
 	OBSSignal removedSignal;
 	OBSSignal renamedSignal;
 	OBSSignal updatePropertiesSignal;
+	OBSSignal audioActivated;
+	OBSSignal audioDeactivated;
 	OBSData oldSettings;
 	OBSPropertiesView *view;
 	QDialogButtonBox *buttonBox;
 	QSplitter *windowSplitter;
+	VolControl *vol = nullptr;
 
 	OBSSourceAutoRelease sourceA;
 	OBSSourceAutoRelease sourceB;
@@ -57,6 +61,8 @@ class OBSBasicProperties : public QDialog {
 	static void UpdateProperties(void *data, calldata_t *params);
 	static void DrawPreview(void *data, uint32_t cx, uint32_t cy);
 	static void DrawTransitionPreview(void *data, uint32_t cx, uint32_t cy);
+	static void AudioActivated(void *data, calldata_t *params);
+	static void AudioDeactivated(void *data, calldata_t *params);
 	void UpdateCallback(void *obj, obs_data_t *settings);
 	bool ConfirmQuit();
 	int CheckSettings();
@@ -65,6 +71,8 @@ class OBSBasicProperties : public QDialog {
 private slots:
 	void on_buttonBox_clicked(QAbstractButton *button);
 	void AddPreviewButton();
+	void ShowVolumeControls();
+	void HideVolumeControls();
 
 public:
 	OBSBasicProperties(QWidget *parent, OBSSource source_);