Changing the scoring process for slider questions.

Previously sliders were scored as a value between 1 and 4 based on the
percentage across the screen that the slider was slid. This required you
to slide fully to the right to get a 4.

Now the slider is divided into n sections, where n is the number of answers
on the slider. With 4 answers the score will be exactly 1, 2, 3, or 4.
With more answers you may get a decimals, but the last section of the
slider will always result in a 4.

1 files changed, 8 insertions, 2 deletions

diff --git a/src/com/p4square/grow/model/SliderScoringEngine.java b/src/com/p4square/grow/model/SliderScoringEngine.java
index 76811b3..2961e95 100644
--- a/src/com/p4square/grow/model/SliderScoringEngine.java
+++ b/src/com/p4square/grow/model/SliderScoringEngine.java
@@ -15,12 +15,18 @@ public class SliderScoringEngine extends ScoringEngine {
 
     @Override
     public boolean scoreAnswer(Score score, Question question, RecordedAnswer userAnswer) {
-        float delta = Float.valueOf(userAnswer.getAnswerId()) * 3 + 1;
+        int numberOfAnswers = question.getAnswers().size();
+        if (numberOfAnswers == 0) {
+            throw new IllegalArgumentException("Question has no answers.");
+        }
 
-        if (delta < 0 || delta > 4) {
+        double answer = Double.valueOf(userAnswer.getAnswerId());
+        if (answer < 0 || answer > 1) {
             throw new IllegalArgumentException("Answer out of bounds.");
         }
 
+        double delta = Math.max(1, Math.ceil(answer * numberOfAnswers) / numberOfAnswers * 4);
+
         score.sum += delta;
         score.count++;