Fix getSwitchState.

InputReader::getSwitchState always returns AKEY_STATE_UNKNOWN
because SwitchInputMapper::getSources() returns 0 which cannot
match any source mask including AINPUT_SOURCE_ANY.  As a result
initial lid switch detection is broken.

This change adds a new source constant AINPUT_SOURCE_SWITCH
that indicates that the source has switches.

Change-Id: I5321ecf0ce84f1c2b4535f6c163d3f4dcf9b7a9b
diff --git a/include/ui/Input.h b/include/ui/Input.h
index 27f65bc..30b45f7 100644
--- a/include/ui/Input.h
+++ b/include/ui/Input.h
@@ -38,6 +38,15 @@
     AKEY_EVENT_FLAG_START_TRACKING = 0x40000000
 };
 
+enum {
+    /*
+     * Indicates that an input device has switches.
+     * This input source flag is hidden from the API because switches are only used by the system
+     * and applications have no way to interact with them.
+     */
+    AINPUT_SOURCE_SWITCH = 0x80000000,
+};
+
 /*
  * Maximum number of pointers supported per motion event.
  * Smallest number of pointers is 1.
diff --git a/services/input/InputReader.cpp b/services/input/InputReader.cpp
index 8e9a5a4..2e83256 100644
--- a/services/input/InputReader.cpp
+++ b/services/input/InputReader.cpp
@@ -744,7 +744,7 @@
 }
 
 uint32_t SwitchInputMapper::getSources() {
-    return 0;
+    return AINPUT_SOURCE_SWITCH;
 }
 
 void SwitchInputMapper::process(const RawEvent* rawEvent) {
diff --git a/services/input/tests/InputReader_test.cpp b/services/input/tests/InputReader_test.cpp
index 775747c..98d627d 100644
--- a/services/input/tests/InputReader_test.cpp
+++ b/services/input/tests/InputReader_test.cpp
@@ -1484,7 +1484,7 @@
     SwitchInputMapper* mapper = new SwitchInputMapper(mDevice);
     addMapperAndConfigure(mapper);
 
-    ASSERT_EQ(uint32_t(0), mapper->getSources());
+    ASSERT_EQ(uint32_t(AINPUT_SOURCE_SWITCH), mapper->getSources());
 }
 
 TEST_F(SwitchInputMapperTest, GetSwitchState) {