Fix empty span utils casting crash

Author: mgod

example/src/androidTest/java/com/tokenautocompleteexample/SpanUtilsTest.java

@@ -0,0 +1,22 @@
+package com.tokenautocompleteexample;
+
+import android.text.Spanned;
+import android.text.TextPaint;
+
+import com.tokenautocomplete.SpanUtils;
+
+import org.junit.Test;
+
+import static org.junit.Assert.assertNull;
+
+public class SpanUtilsTest {
+
+    @Test
+    public void testSpanUtilsHandlesNonSpannableTextUtilsResponse() {
+        TextPaint dummy = new TextPaint();
+        //this used to crash, so we're making sure it runs and returns null
+        Spanned ellipsized = SpanUtils.ellipsizeWithSpans(null,
+                null, 0, dummy, "", 150);
+        assertNull(ellipsized);
+    }
+}

library/src/main/java/com/tokenautocomplete/SpanUtils.java

@@ -7,7 +7,7 @@
 import android.text.TextPaint;
 import android.text.TextUtils;
 
-class SpanUtils {
+public class SpanUtils {
 
     private static class EllipsizeCallback implements TextUtils.EllipsizeCallback {
         int start = 0;
@@ -21,7 +21,7 @@ public void ellipsized(int ellipsedStart, int ellipsedEnd) {
     }
 
     @Nullable
-    static Spanned ellipsizeWithSpans(@Nullable CharSequence prefix, @Nullable CountSpan countSpan,
+    public static Spanned ellipsizeWithSpans(@Nullable CharSequence prefix, @Nullable CountSpan countSpan,
                                            int tokenCount, @NonNull TextPaint paint,
                                            @NonNull CharSequence originalText, float maxWidth) {
 
@@ -33,10 +33,12 @@ static Spanned ellipsizeWithSpans(@Nullable CharSequence prefix, @Nullable Count
         }
 
         EllipsizeCallback ellipsizeCallback = new EllipsizeCallback();
-        Spanned tempEllipsized = (Spanned) TextUtils.ellipsize(originalText, paint, maxWidth - countWidth,
+        CharSequence tempEllipsized = TextUtils.ellipsize(originalText, paint, maxWidth - countWidth,
                 TextUtils.TruncateAt.END, false, ellipsizeCallback);
         SpannableStringBuilder ellipsized = new SpannableStringBuilder(tempEllipsized);
-        TextUtils.copySpansFrom(tempEllipsized, 0, tempEllipsized.length(), Object.class, ellipsized, 0);
+        if (tempEllipsized instanceof Spanned) {
+            TextUtils.copySpansFrom((Spanned)tempEllipsized, 0, tempEllipsized.length(), Object.class, ellipsized, 0);
+        }
 
         if (prefix != null && prefix.length() > ellipsizeCallback.start) {
             //We ellipsized part of the prefix, so put it back