libgui: Normalize IDisplayEventConnection methods

This change modifies the IDisplayEventConnection API such that every
synchronous method returns a status_t (to be able to return transport
errors). This required changing getDataChannel to return its channel by
output parameter rather than return type.

Currently no more error messages are checked than before, but this will
both enable calling code to check error messages if it desires and,
more importantly, allow the Bp/Bn code to be semi-automatically
generated using SafeInterface.

Test: libgui_tests + manual testing
Change-Id: I8d5bc5ef0475cee07b638a97079b234f0384c022

1 files changed, 1 insertions, 1 deletions

diff --git a/libs/gui/DisplayEventReceiver.cpp b/libs/gui/DisplayEventReceiver.cpp
index 07e07e058b..16b06e9a6e 100644
--- a/libs/gui/DisplayEventReceiver.cpp
+++ b/libs/gui/DisplayEventReceiver.cpp
@@ -37,7 +37,7 @@ DisplayEventReceiver::DisplayEventReceiver() {
     if (sf != NULL) {
         mEventConnection = sf->createDisplayEventConnection();
         if (mEventConnection != NULL) {
-            mDataChannel = mEventConnection->getDataChannel();
+            mEventConnection->getDataChannel(&mDataChannel);
         }
     }
 }