Make sure the recording thread in sf::SoundRecorder is stopped before sf::SoundBufferRecorder is destroyed.

Fixes a "pure virtual method called" crash.
Also updated the documentation and the VoIP example.

examples/voip/Client.cpp

@@ -32,10 +32,22 @@ public:
     {
     }
 
+    ////////////////////////////////////////////////////////////
+    /// Destructor
+    ///
+    /// \see SoundRecorder::~SoundRecorder()
+    ///
+    ////////////////////////////////////////////////////////////
+    ~NetworkRecorder()
+    {
+        // Make sure to stop the recording thread
+        stop();
+    }
+
 private:
 
     ////////////////////////////////////////////////////////////
-    /// /see SoundRecorder::OnStart
+    /// \see SoundRecorder::onStart
     ///
     ////////////////////////////////////////////////////////////
     virtual bool onStart()
@@ -52,7 +64,7 @@ private:
     }
 
     ////////////////////////////////////////////////////////////
-    /// /see SoundRecorder::ProcessSamples
+    /// \see SoundRecorder::onProcessSamples
     ///
     ////////////////////////////////////////////////////////////
     virtual bool onProcessSamples(const sf::Int16* samples, std::size_t sampleCount)
@@ -67,7 +79,7 @@ private:
     }
 
     ////////////////////////////////////////////////////////////
-    /// /see SoundRecorder::OnStop
+    /// \see SoundRecorder::onStop
     ///
     ////////////////////////////////////////////////////////////
     virtual void onStop()
@@ -98,7 +110,7 @@ private:
 void doClient(unsigned short port)
 {
     // Check that the device can capture audio
-    if (sf::SoundRecorder::isAvailable() == false)
+    if (!sf::SoundRecorder::isAvailable())
     {
         std::cout << "Sorry, audio capture is not supported by your system" << std::endl;
         return;

include/SFML/Audio/SoundBufferRecorder.hpp

@@ -45,6 +45,12 @@ class SFML_AUDIO_API SoundBufferRecorder : public SoundRecorder
 {
 public:
 
+    ////////////////////////////////////////////////////////////
+    /// \brief destructor
+    ///
+    ////////////////////////////////////////////////////////////
+    ~SoundBufferRecorder();
+
     ////////////////////////////////////////////////////////////
     /// \brief Get the sound buffer containing the captured audio data
     ///

include/SFML/Audio/SoundRecorder.hpp

@@ -316,11 +316,20 @@ private:
 /// from this separate thread. It is important to keep this in
 /// mind, because you may have to take care of synchronization
 /// issues if you share data between threads.
+/// Another thing to bear in mind is that you must call stop()
+/// in the destructor of your derived class, so that the recording
+/// thread finishes before your object is destroyed.
 ///
 /// Usage example:
 /// \code
 /// class CustomRecorder : public sf::SoundRecorder
 /// {
+///     ~CustomRecorder()
+///     {
+///         // Make sure to stop the recording thread
+///         stop();
+///     }
+///
 ///     virtual bool onStart() // optional
 ///     {
 ///         // Initialize whatever has to be done before the capture starts

src/SFML/Audio/SoundBufferRecorder.cpp

@@ -32,6 +32,14 @@
 
 namespace sf
 {
+////////////////////////////////////////////////////////////
+SoundBufferRecorder::~SoundBufferRecorder()
+{
+    // Make sure to stop the recording thread
+    stop();
+}
+
+
 ////////////////////////////////////////////////////////////
 bool SoundBufferRecorder::onStart()
 {

src/SFML/Audio/SoundRecorder.cpp

@@ -31,6 +31,7 @@
 #include <SFML/System/Sleep.hpp>
 #include <SFML/System/Err.hpp>
 #include <cstring>
+#include <cassert>
 
 #ifdef _MSC_VER
     #pragma warning(disable: 4355) // 'this' used in base member initializer list
@@ -59,7 +60,12 @@ m_deviceName        (getDefaultDevice())
 ////////////////////////////////////////////////////////////
 SoundRecorder::~SoundRecorder()
 {
-    // Nothing to do
+    // This assertion is triggered if the recording is still running while
+    // the object is destroyed. It ensures that stop() is called in the
+    // destructor of the derived class, which makes sure that the recording
+    // thread finishes before the derived object is destroyed. Otherwise a
+    // "pure virtual method called" exception is triggered.
+    assert(!m_isCapturing && "You must call stop() in the destructor of your derived class, so that the recording thread finishes before your object is destroyed.");
 }
 
 
@@ -114,13 +120,16 @@ bool SoundRecorder::start(unsigned int sampleRate)
 ////////////////////////////////////////////////////////////
 void SoundRecorder::stop()
 {
-    // Stop the capturing thread
+    // Stop the capturing thread if there is one
+    if (m_isCapturing)
+    {
         m_isCapturing = false;
         m_thread.wait();
 
         // Notify derived class
         onStop();
     }
+}
 
 
 ////////////////////////////////////////////////////////////