Add master volume control slider

Adds support for a master volume control to the HomeScreen app.
The master volume slider appears when touching in the MediaArea
at the bottom of the screen. If there is no interaction with the
slider, it fades out after 5 seconds so that the AGL logo area
is not obscured. The volume slider is accessible across all
applications due to the MediaArea portion of HomeScreen always
being exposed to the screen.

The slider volume control is tied to the default PA sink and
applies proportional volume control across all channels of the
default sink when changed.  It also reacts to external volume
change events from other PA clients (e.g. Mixer app or pactl
CLI changes) and updates the master volume slider accordingly.

AGL-Bug: SPEC-550
Change-Id: I9bf55bc624f4bb95c162a79bd2eb314d8f945033
Signed-off-by: Matt Porter <mporter@konsulko.com>

1 files changed, 64 insertions, 0 deletions

diff --git a/homescreen/src/paclient.h b/homescreen/src/paclient.h
new file mode 100644
index 0000000..abf178b
--- /dev/null
+++ b/homescreen/src/paclient.h
@@ -0,0 +1,64 @@
+/*
+ * Copyright (C) 2016,2017 Konsulko Group
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <pulse/pulseaudio.h>
+
+#include <QtCore/QHash>
+#include <QtCore/QObject>
+
+class PaClient : public QObject
+{
+	Q_OBJECT
+	public:
+		PaClient();
+		~PaClient();
+
+		void init();
+		void close();
+
+		inline pa_context *context() const
+		{
+			return m_ctx;
+		}
+
+		inline void lock()
+		{
+			pa_threaded_mainloop_lock(m_ml);
+		}
+
+		inline void unlock()
+		{
+			pa_threaded_mainloop_unlock(m_ml);
+		}
+
+		pa_sink_info * getDefaultSinkInfo(void);
+		void setDefaultSinkInfo(const pa_sink_info *i);
+		void setMasterVolume(const pa_cvolume *);
+
+	public slots:
+		void incDecVolume(const int volume_delta);
+
+	signals:
+		void volumeExternallyChanged(int volume);
+
+	private:
+		bool m_init;
+		pa_threaded_mainloop *m_ml;
+		pa_mainloop_api *m_mlapi;
+		pa_context *m_ctx;
+		pa_cvolume m_master_cvolume;
+		pa_sink_info m_default_sink_info;
+};