diff --git a/app/src/main/java/com/benny/pxerstudio/shape/BaseShape.kt b/app/src/main/java/com/benny/pxerstudio/shape/BaseShape.kt
index 5b42261..e6453f7 100644
--- a/app/src/main/java/com/benny/pxerstudio/shape/BaseShape.kt
+++ b/app/src/main/java/com/benny/pxerstudio/shape/BaseShape.kt
@@ -34,13 +34,13 @@ abstract class BaseShape {
         return !hasEnded
     }
 
-    protected fun endDraw(previousPxer: ArrayList<Pxer>, pxerView: PxerView) {
+    protected fun PxerView.endDraw(previousPxer: ArrayList<Pxer>) {
         if (previousPxer.isEmpty()) {
             return
         }
-        pxerView.currentHistory.addAll(previousPxer)
+        this.currentHistory.addAll(previousPxer)
         previousPxer.clear()
-        pxerView.setUnrecordedChanges(true)
-        pxerView.finishAddHistory()
+        this.setUnrecordedChanges(true)
+        this.finishAddHistory()
     }
 }
diff --git a/app/src/main/java/com/benny/pxerstudio/shape/EraserShape.kt b/app/src/main/java/com/benny/pxerstudio/shape/EraserShape.kt
index 83c0c55..b1e58e4 100644
--- a/app/src/main/java/com/benny/pxerstudio/shape/EraserShape.kt
+++ b/app/src/main/java/com/benny/pxerstudio/shape/EraserShape.kt
@@ -58,7 +58,7 @@ class EraserShape : BaseShape() {
     override fun onDrawEnd(pxerView: PxerView) {
         super.onDrawEnd(pxerView)
         hasInit = false
-        endDraw(previousPxer, pxerView)
+        pxerView.endDraw(previousPxer)
     }
 
     init {
diff --git a/app/src/main/java/com/benny/pxerstudio/shape/draw/LineShape.kt b/app/src/main/java/com/benny/pxerstudio/shape/draw/LineShape.kt
index 9345560..675ccb6 100644
--- a/app/src/main/java/com/benny/pxerstudio/shape/draw/LineShape.kt
+++ b/app/src/main/java/com/benny/pxerstudio/shape/draw/LineShape.kt
@@ -68,7 +68,7 @@ class LineShape : DrawShape() {
     override fun onDrawEnd(pxerView: PxerView) {
         super.onDrawEnd(pxerView)
         hasInit = false
-        endDraw(previousPxer, pxerView)
+        pxerView.endDraw(previousPxer)
     }
 
     init {
diff --git a/app/src/main/java/com/benny/pxerstudio/shape/draw/RectShape.kt b/app/src/main/java/com/benny/pxerstudio/shape/draw/RectShape.kt
index 690033f..5044221 100644
--- a/app/src/main/java/com/benny/pxerstudio/shape/draw/RectShape.kt
+++ b/app/src/main/java/com/benny/pxerstudio/shape/draw/RectShape.kt
@@ -49,6 +49,6 @@ class RectShape : DrawShape() {
 
     override fun onDrawEnd(pxerView: PxerView) {
         super.onDrawEnd(pxerView)
-        endDraw(previousPxer, pxerView)
+        pxerView.endDraw(previousPxer)
     }
 }