Fix runtime crash on KitKat and prior.

This is a follow up CL to the previous CL [1], in which we started
calling Window#setNavigationBarColor(int) when the window visibility is
changed.

One thing we missed is that calling Window#setNavigationBarColor(int) on
KitKant or prior devices would result in a runtime crash.  Hence with
this CL we do not call that method unless the OS version is N or leter,
because specifying Color.TRANSPARENT would make sense on N+ devices.

  [1]: I14d9490e00caa852035a05830e76114cbe6af8f2
       6c04339c5aadb5118b0e0a8178b3d569956bbad7

Bug: 22564251
Bug: 27302540
Change-Id: Ib7299dd8c3dad4271f8fac453e690c83bda4a954

1 files changed, 8 insertions, 2 deletions

diff --git a/java/src/com/android/inputmethod/latin/LatinIME.java b/java/src/com/android/inputmethod/latin/LatinIME.java
index c2d9f965f..f938b6078 100644
--- a/java/src/com/android/inputmethod/latin/LatinIME.java
+++ b/java/src/com/android/inputmethod/latin/LatinIME.java
@@ -33,6 +33,7 @@ import android.content.res.Resources;
 import android.graphics.Color;
 import android.inputmethodservice.InputMethodService;
 import android.media.AudioManager;
+import android.os.Build;
 import android.os.Debug;
 import android.os.IBinder;
 import android.os.Message;
@@ -54,6 +55,7 @@ import android.view.inputmethod.InputMethodSubtype;
 
 import com.android.inputmethod.accessibility.AccessibilityUtils;
 import com.android.inputmethod.annotations.UsedForTesting;
+import com.android.inputmethod.compat.BuildCompatUtils;
 import com.android.inputmethod.compat.EditorInfoCompatUtils;
 import com.android.inputmethod.compat.InputMethodServiceCompatUtils;
 import com.android.inputmethod.compat.InputMethodSubtypeCompatUtils;
@@ -1908,7 +1910,11 @@ public class LatinIME extends InputMethodService implements KeyboardActionListen
     }
 
     private void setNavigationBarVisibility(final boolean visible) {
-        // Color.BLACK is ignored and default IME navigation bar color is used.
-        getWindow().getWindow().setNavigationBarColor(visible ? Color.BLACK : Color.TRANSPARENT);
+        if (BuildCompatUtils.EFFECTIVE_SDK_INT > Build.VERSION_CODES.M) {
+            // For N and later, IMEs can specify Color.TRANSPARENT to make the navigation bar
+            // transparent.  For other colors the system uses the default color.
+            getWindow().getWindow().setNavigationBarColor(
+                    visible ? Color.BLACK : Color.TRANSPARENT);
+        }
     }
 }