am 559a2420: Merge "MidiDevice: document that opens can return nulls" into mnc-dev
* commit '559a2420d396ef7a7c7bcab012bef379ad864bff':
MidiDevice: document that opens can return nulls
diff --git a/media/java/android/media/midi/MidiDevice.java b/media/java/android/media/midi/MidiDevice.java
index 93fb6d2..e1990cd 100644
--- a/media/java/android/media/midi/MidiDevice.java
+++ b/media/java/android/media/midi/MidiDevice.java
@@ -113,8 +113,13 @@
/**
* Called to open a {@link MidiInputPort} for the specified port number.
*
+ * An input port can only be used by one sender at a time.
+ * Opening an input port will fail if another application has already opened it for use.
+ * A {@link MidiDeviceStatus} can be used to determine if an input port is already open.
+ *
* @param portNumber the number of the input port to open
- * @return the {@link MidiInputPort}
+ * @return the {@link MidiInputPort} if the open is successful,
+ * or null in case of failure.
*/
public MidiInputPort openInputPort(int portNumber) {
try {
@@ -133,8 +138,11 @@
/**
* Called to open a {@link MidiOutputPort} for the specified port number.
*
+ * An output port may be opened by multiple applications.
+ *
* @param portNumber the number of the output port to open
- * @return the {@link MidiOutputPort}
+ * @return the {@link MidiOutputPort} if the open is successful,
+ * or null in case of failure.
*/
public MidiOutputPort openOutputPort(int portNumber) {
try {