add can_change_{sample_rate,buffer_size}_while_running() methods to an AudioBackend

Allows the GUI and other stuff to know whether or not changing the SR/bufsize is possible while running, which is about to become useful

1 files changed, 11 insertions, 0 deletions

diff --git a/libs/ardour/ardour/audio_backend.h b/libs/ardour/ardour/audio_backend.h
index 77b7eadb48..4192f0ea8b 100644
--- a/libs/ardour/ardour/audio_backend.h
+++ b/libs/ardour/ardour/audio_backend.h
@@ -147,6 +147,17 @@ class AudioBackend {
      */
     virtual uint32_t available_output_channel_count (const std::string& device) const = 0;
 
+    /* Return true if the derived class can change the sample rate of the
+     * device in use while the device is already being used. Return false
+     * otherwise. (example: JACK cannot do this as of September 2013)
+     */
+    virtual bool can_change_sample_rate_when_running () const = 0;
+    /* Return true if the derived class can change the buffer size of the
+     * device in use while the device is already being used. Return false
+     * otherwise. 
+     */
+    virtual bool can_change_buffer_size_when_running () const = 0;
+
     /* Set the hardware parameters.
      * 
      * If called when the current state is stopped or paused,