Support setting auto scroll speed

sample/src/main/java/com/tmall/ultraviewpager/sample/PagerActivity.java

@@ -234,6 +234,7 @@ public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
         }
         if (buttonView == autoScrollCheckBox) {
             if (isChecked) {
+                ultraViewPager.setAutoScrollSpeed(1000);
                 SparseIntArray special = new SparseIntArray();
                 special.put(0, 5000);
                 special.put(1, 1500);

ultraviewpager/src/main/java/com/tmall/ultraviewpager/IUltraViewPagerFeature.java

@@ -28,6 +28,7 @@
 
 import android.graphics.Bitmap;
 import android.util.SparseIntArray;
+import android.view.animation.Interpolator;
 
 /**
  * Created by mikeafc on 15/11/30.
@@ -97,6 +98,21 @@ interface IUltraViewPagerFeature {
      */
     void setAutoScroll(int intervalInMillis, SparseIntArray intervalArray);
 
+    /**
+     * Set the scroll speed for this ViewPager.
+     *
+     * @param duration The default duration to scroll
+     */
+    void setAutoScrollSpeed(int duration);
+
+    /**
+     * Set the scroll speed and interpolator for this ViewPager.
+     *
+     * @param duration     The default duration to scroll
+     * @param interpolator The default interpolator to scroll
+     */
+    void setAutoScrollSpeed(int duration, Interpolator interpolator);
+
     /**
      * Disable auto-scroll mode
      */

ultraviewpager/src/main/java/com/tmall/ultraviewpager/UltraViewPager.java

@@ -34,11 +34,11 @@
 import android.support.v4.view.PagerAdapter;
 import android.support.v4.view.ViewPager;
 import android.util.AttributeSet;
-import android.util.Log;
 import android.util.SparseIntArray;
 import android.view.MotionEvent;
 import android.view.View;
 import android.view.ViewGroup;
+import android.view.animation.Interpolator;
 import android.widget.RelativeLayout;
 
 /**
@@ -328,6 +328,16 @@ public void setAutoScroll(int intervalInMillis, SparseIntArray intervalArray) {
         startTimer();
     }
 
+    @Override
+    public void setAutoScrollSpeed(int duration) {
+        viewPager.setAutoScrollSpeed(duration);
+    }
+
+    @Override
+    public void setAutoScrollSpeed(int duration, Interpolator interpolator) {
+        viewPager.setAutoScrollSpeed(duration, interpolator);
+    }
+
     @Override
     public void disableAutoScroll() {
         stopTimer();

ultraviewpager/src/main/java/com/tmall/ultraviewpager/UltraViewPagerScroller.java

@@ -0,0 +1,37 @@
+package com.tmall.ultraviewpager;
+
+import android.content.Context;
+import android.view.animation.Interpolator;
+import android.widget.Scroller;
+
+/**
+ * Created by Jimmy Sun on 19/04/16.
+ */
+class UltraViewPagerScroller extends Scroller {
+    private int mDuration = 1000;
+
+    UltraViewPagerScroller(Context context, Interpolator interpolator) {
+        super(context, interpolator);
+    }
+
+    @Override
+    public void startScroll(int startX, int startY, int dx, int dy, int duration) {
+        // Ignore received duration, use fixed one instead
+        super.startScroll(startX, startY, dx, dy, mDuration);
+    }
+
+    @Override
+    public void startScroll(int startX, int startY, int dx, int dy) {
+        // Ignore received duration, use fixed one instead
+        super.startScroll(startX, startY, dx, dy, mDuration);
+    }
+
+    /**
+     * Set the scroll speed.
+     *
+     * @param duration The default duration to scroll
+     */
+    void setScrollDuration(int duration) {
+        mDuration = duration;
+    }
+}

ultraviewpager/src/main/java/com/tmall/ultraviewpager/UltraViewPagerView.java

@@ -30,13 +30,15 @@
 import android.support.v4.view.PagerAdapter;
 import android.support.v4.view.ViewPager;
 import android.util.AttributeSet;
-import android.util.TypedValue;
 import android.view.MotionEvent;
 import android.view.View;
 import android.view.ViewGroup;
+import android.view.animation.Interpolator;
 
 import com.tmall.ultraviewpager.transformer.UltraVerticalTransformer;
 
+import java.lang.reflect.Field;
+
 /**
  * Created by mikeafc on 15/11/25.
  */
@@ -266,6 +268,25 @@ public void setMultiScreen(float ratio) {
         }
     }
 
+    public void setAutoScrollSpeed(int duration) {
+        setAutoScrollSpeed(duration, null);
+    }
+
+    public void setAutoScrollSpeed(int duration, Interpolator interpolator) {
+        if (duration >= 0) {
+            try {
+                Field mScroller = ViewPager.class.getDeclaredField("mScroller");
+                mScroller.setAccessible(true);
+                UltraViewPagerScroller scroller = new UltraViewPagerScroller(getContext(),
+                        interpolator);
+                scroller.setScrollDuration(duration);
+                mScroller.set(this, scroller);
+            } catch (Exception e) {
+                e.printStackTrace();
+            }
+        }
+    }
+
     public void setEnableLoop(boolean status) {
         enableLoop = status;
         if (pagerAdapter != null) {