diff --git a/.idea/misc.xml b/.idea/misc.xml
index 5d19981..ba7052b 100644
--- a/.idea/misc.xml
+++ b/.idea/misc.xml
@@ -1,8 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
-  <component name="EntryPointsManager">
-    <entry_points version="2.0" />
-  </component>
   <component name="NullableNotNullManager">
     <option name="myDefaultNullable" value="android.support.annotation.Nullable" />
     <option name="myDefaultNotNull" value="android.support.annotation.NonNull" />
@@ -27,17 +24,7 @@
       </value>
     </option>
   </component>
-  <component name="ProjectLevelVcsManager" settingsEditedManually="false">
-    <OptionsSetting value="true" id="Add" />
-    <OptionsSetting value="true" id="Remove" />
-    <OptionsSetting value="true" id="Checkout" />
-    <OptionsSetting value="true" id="Update" />
-    <OptionsSetting value="true" id="Status" />
-    <OptionsSetting value="true" id="Edit" />
-    <ConfirmationsSetting value="0" id="Add" />
-    <ConfirmationsSetting value="0" id="Remove" />
-  </component>
-  <component name="ProjectRootManager" version="2" languageLevel="JDK_1_7" default="true" assert-keyword="true" jdk-15="true" project-jdk-name="1.8" project-jdk-type="JavaSDK">
+  <component name="ProjectRootManager" version="2" languageLevel="JDK_1_7" default="true" project-jdk-name="1.8" project-jdk-type="JavaSDK">
     <output url="file://$PROJECT_DIR$/build/classes" />
   </component>
   <component name="ProjectType">
diff --git a/.idea/vcs.xml b/.idea/vcs.xml
new file mode 100644
index 0000000..94a25f7
--- /dev/null
+++ b/.idea/vcs.xml
@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="VcsDirectoryMappings">
+    <mapping directory="$PROJECT_DIR$" vcs="Git" />
+  </component>
+</project>
\ No newline at end of file
diff --git a/Demo/Demo.iml b/Demo/Demo.iml
index c079272..f1f115f 100644
--- a/Demo/Demo.iml
+++ b/Demo/Demo.iml
@@ -9,7 +9,6 @@
     <facet type="android" name="Android">
       <configuration>
         <option name="SELECTED_BUILD_VARIANT" value="debug" />
-        <option name="SELECTED_TEST_ARTIFACT" value="_android_test_" />
         <option name="ASSEMBLE_TASK_NAME" value="assembleDebug" />
         <option name="COMPILE_JAVA_TASK_NAME" value="compileDebugSources" />
         <afterSyncTasks>
@@ -23,7 +22,7 @@
       </configuration>
     </facet>
   </component>
-  <component name="NewModuleRootManager" LANGUAGE_LEVEL="JDK_1_7" inherit-compiler-output="false">
+  <component name="NewModuleRootManager" LANGUAGE_LEVEL="JDK_1_7">
     <output url="file://$MODULE_DIR$/build/intermediates/classes/debug" />
     <output-test url="file://$MODULE_DIR$/build/intermediates/classes/test/debug" />
     <exclude-output />
@@ -47,7 +46,6 @@
       <sourceFolder url="file://$MODULE_DIR$/src/debug/assets" type="java-resource" />
       <sourceFolder url="file://$MODULE_DIR$/src/debug/aidl" isTestSource="false" />
       <sourceFolder url="file://$MODULE_DIR$/src/debug/java" isTestSource="false" />
-      <sourceFolder url="file://$MODULE_DIR$/src/debug/jni" isTestSource="false" />
       <sourceFolder url="file://$MODULE_DIR$/src/debug/rs" isTestSource="false" />
       <sourceFolder url="file://$MODULE_DIR$/src/debug/shaders" isTestSource="false" />
       <sourceFolder url="file://$MODULE_DIR$/src/testDebug/res" type="java-test-resource" />
@@ -55,7 +53,6 @@
       <sourceFolder url="file://$MODULE_DIR$/src/testDebug/assets" type="java-test-resource" />
       <sourceFolder url="file://$MODULE_DIR$/src/testDebug/aidl" isTestSource="true" />
       <sourceFolder url="file://$MODULE_DIR$/src/testDebug/java" isTestSource="true" />
-      <sourceFolder url="file://$MODULE_DIR$/src/testDebug/jni" isTestSource="true" />
       <sourceFolder url="file://$MODULE_DIR$/src/testDebug/rs" isTestSource="true" />
       <sourceFolder url="file://$MODULE_DIR$/src/testDebug/shaders" isTestSource="true" />
       <sourceFolder url="file://$MODULE_DIR$/src/main/res" type="java-resource" />
@@ -63,25 +60,22 @@
       <sourceFolder url="file://$MODULE_DIR$/src/main/assets" type="java-resource" />
       <sourceFolder url="file://$MODULE_DIR$/src/main/aidl" isTestSource="false" />
       <sourceFolder url="file://$MODULE_DIR$/src/main/java" isTestSource="false" />
-      <sourceFolder url="file://$MODULE_DIR$/src/main/jni" isTestSource="false" />
       <sourceFolder url="file://$MODULE_DIR$/src/main/rs" isTestSource="false" />
       <sourceFolder url="file://$MODULE_DIR$/src/main/shaders" isTestSource="false" />
-      <sourceFolder url="file://$MODULE_DIR$/src/test/res" type="java-test-resource" />
-      <sourceFolder url="file://$MODULE_DIR$/src/test/resources" type="java-test-resource" />
-      <sourceFolder url="file://$MODULE_DIR$/src/test/assets" type="java-test-resource" />
-      <sourceFolder url="file://$MODULE_DIR$/src/test/aidl" isTestSource="true" />
-      <sourceFolder url="file://$MODULE_DIR$/src/test/java" isTestSource="true" />
-      <sourceFolder url="file://$MODULE_DIR$/src/test/jni" isTestSource="true" />
-      <sourceFolder url="file://$MODULE_DIR$/src/test/rs" isTestSource="true" />
-      <sourceFolder url="file://$MODULE_DIR$/src/test/shaders" isTestSource="true" />
       <sourceFolder url="file://$MODULE_DIR$/src/androidTest/res" type="java-test-resource" />
       <sourceFolder url="file://$MODULE_DIR$/src/androidTest/resources" type="java-test-resource" />
       <sourceFolder url="file://$MODULE_DIR$/src/androidTest/assets" type="java-test-resource" />
       <sourceFolder url="file://$MODULE_DIR$/src/androidTest/aidl" isTestSource="true" />
       <sourceFolder url="file://$MODULE_DIR$/src/androidTest/java" isTestSource="true" />
-      <sourceFolder url="file://$MODULE_DIR$/src/androidTest/jni" isTestSource="true" />
       <sourceFolder url="file://$MODULE_DIR$/src/androidTest/rs" isTestSource="true" />
       <sourceFolder url="file://$MODULE_DIR$/src/androidTest/shaders" isTestSource="true" />
+      <sourceFolder url="file://$MODULE_DIR$/src/test/res" type="java-test-resource" />
+      <sourceFolder url="file://$MODULE_DIR$/src/test/resources" type="java-test-resource" />
+      <sourceFolder url="file://$MODULE_DIR$/src/test/assets" type="java-test-resource" />
+      <sourceFolder url="file://$MODULE_DIR$/src/test/aidl" isTestSource="true" />
+      <sourceFolder url="file://$MODULE_DIR$/src/test/java" isTestSource="true" />
+      <sourceFolder url="file://$MODULE_DIR$/src/test/rs" isTestSource="true" />
+      <sourceFolder url="file://$MODULE_DIR$/src/test/shaders" isTestSource="true" />
       <excludeFolder url="file://$MODULE_DIR$/build/intermediates/assets" />
       <excludeFolder url="file://$MODULE_DIR$/build/intermediates/blame" />
       <excludeFolder url="file://$MODULE_DIR$/build/intermediates/classes" />
@@ -102,6 +96,5 @@
     <orderEntry type="jdk" jdkName="Android API 24 Platform" jdkType="Android SDK" />
     <orderEntry type="sourceFolder" forTests="false" />
     <orderEntry type="module" module-name="WheelPicker-WheelPicker" exported="" />
-    <orderEntry type="library" exported="" name="gson-2.2.4" level="project" />
   </component>
 </module>
\ No newline at end of file
diff --git a/WheelPicker.iml b/WheelPicker.iml
index b99df59..4b8a905 100644
--- a/WheelPicker.iml
+++ b/WheelPicker.iml
@@ -13,7 +13,7 @@
     <content url="file://$MODULE_DIR$">
       <excludeFolder url="file://$MODULE_DIR$/.gradle" />
     </content>
-    <orderEntry type="inheritedJdk" />
+    <orderEntry type="jdk" jdkName="1.8" jdkType="JavaSDK" />
     <orderEntry type="sourceFolder" forTests="false" />
   </component>
 </module>
\ No newline at end of file
diff --git a/WheelPicker/WheelPicker-WheelPicker.iml b/WheelPicker/WheelPicker-WheelPicker.iml
index b6991d8..a05c2e1 100644
--- a/WheelPicker/WheelPicker-WheelPicker.iml
+++ b/WheelPicker/WheelPicker-WheelPicker.iml
@@ -9,7 +9,6 @@
     <facet type="android" name="Android">
       <configuration>
         <option name="SELECTED_BUILD_VARIANT" value="debug" />
-        <option name="SELECTED_TEST_ARTIFACT" value="_android_test_" />
         <option name="ASSEMBLE_TASK_NAME" value="assembleDebug" />
         <option name="COMPILE_JAVA_TASK_NAME" value="compileDebugSources" />
         <afterSyncTasks>
@@ -20,11 +19,11 @@
         <option name="RES_FOLDER_RELATIVE_PATH" value="/src/main/res" />
         <option name="RES_FOLDERS_RELATIVE_PATH" value="file://$MODULE_DIR$/src/main/res" />
         <option name="ASSETS_FOLDER_RELATIVE_PATH" value="/src/main/assets" />
-        <option name="LIBRARY_PROJECT" value="true" />
+        <option name="PROJECT_TYPE" value="1" />
       </configuration>
     </facet>
   </component>
-  <component name="NewModuleRootManager" LANGUAGE_LEVEL="JDK_1_7" inherit-compiler-output="false">
+  <component name="NewModuleRootManager" LANGUAGE_LEVEL="JDK_1_7">
     <output url="file://$MODULE_DIR$/build/intermediates/classes/debug" />
     <output-test url="file://$MODULE_DIR$/build/intermediates/classes/test/debug" />
     <exclude-output />
@@ -48,7 +47,6 @@
       <sourceFolder url="file://$MODULE_DIR$/src/debug/assets" type="java-resource" />
       <sourceFolder url="file://$MODULE_DIR$/src/debug/aidl" isTestSource="false" />
       <sourceFolder url="file://$MODULE_DIR$/src/debug/java" isTestSource="false" />
-      <sourceFolder url="file://$MODULE_DIR$/src/debug/jni" isTestSource="false" />
       <sourceFolder url="file://$MODULE_DIR$/src/debug/rs" isTestSource="false" />
       <sourceFolder url="file://$MODULE_DIR$/src/debug/shaders" isTestSource="false" />
       <sourceFolder url="file://$MODULE_DIR$/src/testDebug/res" type="java-test-resource" />
@@ -56,7 +54,6 @@
       <sourceFolder url="file://$MODULE_DIR$/src/testDebug/assets" type="java-test-resource" />
       <sourceFolder url="file://$MODULE_DIR$/src/testDebug/aidl" isTestSource="true" />
       <sourceFolder url="file://$MODULE_DIR$/src/testDebug/java" isTestSource="true" />
-      <sourceFolder url="file://$MODULE_DIR$/src/testDebug/jni" isTestSource="true" />
       <sourceFolder url="file://$MODULE_DIR$/src/testDebug/rs" isTestSource="true" />
       <sourceFolder url="file://$MODULE_DIR$/src/testDebug/shaders" isTestSource="true" />
       <sourceFolder url="file://$MODULE_DIR$/src/main/res" type="java-resource" />
@@ -64,25 +61,22 @@
       <sourceFolder url="file://$MODULE_DIR$/src/main/assets" type="java-resource" />
       <sourceFolder url="file://$MODULE_DIR$/src/main/aidl" isTestSource="false" />
       <sourceFolder url="file://$MODULE_DIR$/src/main/java" isTestSource="false" />
-      <sourceFolder url="file://$MODULE_DIR$/src/main/jni" isTestSource="false" />
       <sourceFolder url="file://$MODULE_DIR$/src/main/rs" isTestSource="false" />
       <sourceFolder url="file://$MODULE_DIR$/src/main/shaders" isTestSource="false" />
-      <sourceFolder url="file://$MODULE_DIR$/src/androidTest/res" type="java-test-resource" />
-      <sourceFolder url="file://$MODULE_DIR$/src/androidTest/resources" type="java-test-resource" />
-      <sourceFolder url="file://$MODULE_DIR$/src/androidTest/assets" type="java-test-resource" />
-      <sourceFolder url="file://$MODULE_DIR$/src/androidTest/aidl" isTestSource="true" />
-      <sourceFolder url="file://$MODULE_DIR$/src/androidTest/java" isTestSource="true" />
-      <sourceFolder url="file://$MODULE_DIR$/src/androidTest/jni" isTestSource="true" />
-      <sourceFolder url="file://$MODULE_DIR$/src/androidTest/rs" isTestSource="true" />
-      <sourceFolder url="file://$MODULE_DIR$/src/androidTest/shaders" isTestSource="true" />
       <sourceFolder url="file://$MODULE_DIR$/src/test/res" type="java-test-resource" />
       <sourceFolder url="file://$MODULE_DIR$/src/test/resources" type="java-test-resource" />
       <sourceFolder url="file://$MODULE_DIR$/src/test/assets" type="java-test-resource" />
       <sourceFolder url="file://$MODULE_DIR$/src/test/aidl" isTestSource="true" />
       <sourceFolder url="file://$MODULE_DIR$/src/test/java" isTestSource="true" />
-      <sourceFolder url="file://$MODULE_DIR$/src/test/jni" isTestSource="true" />
       <sourceFolder url="file://$MODULE_DIR$/src/test/rs" isTestSource="true" />
       <sourceFolder url="file://$MODULE_DIR$/src/test/shaders" isTestSource="true" />
+      <sourceFolder url="file://$MODULE_DIR$/src/androidTest/res" type="java-test-resource" />
+      <sourceFolder url="file://$MODULE_DIR$/src/androidTest/resources" type="java-test-resource" />
+      <sourceFolder url="file://$MODULE_DIR$/src/androidTest/assets" type="java-test-resource" />
+      <sourceFolder url="file://$MODULE_DIR$/src/androidTest/aidl" isTestSource="true" />
+      <sourceFolder url="file://$MODULE_DIR$/src/androidTest/java" isTestSource="true" />
+      <sourceFolder url="file://$MODULE_DIR$/src/androidTest/rs" isTestSource="true" />
+      <sourceFolder url="file://$MODULE_DIR$/src/androidTest/shaders" isTestSource="true" />
       <excludeFolder url="file://$MODULE_DIR$/build/intermediates/blame" />
       <excludeFolder url="file://$MODULE_DIR$/build/intermediates/bundles" />
       <excludeFolder url="file://$MODULE_DIR$/build/intermediates/classes" />
@@ -102,6 +96,6 @@
     </content>
     <orderEntry type="jdk" jdkName="Android API 24 Platform" jdkType="Android SDK" />
     <orderEntry type="sourceFolder" forTests="false" />
-    <orderEntry type="library" exported="" name="gson-2.2.4" level="project" />
+    <orderEntry type="library" exported="" name="com.google.code.gson:gson:2.2.4@jar" level="project" />
   </component>
 </module>
\ No newline at end of file
diff --git a/WheelPicker/src/main/java/com/aigestudio/wheelpicker/WheelPicker.java b/WheelPicker/src/main/java/com/aigestudio/wheelpicker/WheelPicker.java
index 6ec732a..53673e8 100644
--- a/WheelPicker/src/main/java/com/aigestudio/wheelpicker/WheelPicker.java
+++ b/WheelPicker/src/main/java/com/aigestudio/wheelpicker/WheelPicker.java
@@ -20,6 +20,7 @@
 import android.view.ViewConfiguration;
 import android.widget.Scroller;
 
+import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
 
@@ -539,6 +540,8 @@ private void computeCurrentItemRect() {
     protected void onDraw(Canvas canvas) {
         if (null != mOnWheelChangeListener)
             mOnWheelChangeListener.onWheelScrolled(mScrollOffsetY);
+        if(mData.size() == 0)
+            return;
         int drawnDataStartPos = -mScrollOffsetY / mItemHeight - mHalfDrawnItemCount;
         for (int drawnDataPos = drawnDataStartPos + mSelectedItemPosition,
              drawnOffsetPos = -mHalfDrawnItemCount;