add a time conversion class

convert time depending on current playback speed and preferences

core/src/main/java/de/danoeh/antennapod/core/util/TimeSpeedConverter.java

@@ -0,0 +1,22 @@
+package de.danoeh.antennapod.core.util;
+
+import de.danoeh.antennapod.core.preferences.UserPreferences;
+
+public class TimeSpeedConverter {
+    private TimeSpeedConverter() {
+
+    }
+
+    /** Convert millisecond according to the current playback speed
+     * @param time: time to convert
+     * @return converted time (can be < 0 if time is < 0)
+     */
+    public static int convert(int time) {
+        boolean timeRespectsSpeed = UserPreferences.timeRespectsSpeed();
+        if (time > 0 && timeRespectsSpeed) {
+            float speed = Float.parseFloat(UserPreferences.getPlaybackSpeed());
+            return (int)(time / speed);
+        }
+        return time;
+    }
+}