Merge pull request daimajia#100 from massimobio/master

Added a OnPageChangeListener to the SliderLayout

demo/src/main/java/com/daimajia/slider/demo/MainActivity.java

@@ -4,6 +4,7 @@
 import android.net.Uri;
 import android.os.Bundle;
 import android.support.v7.app.ActionBarActivity;
+import android.util.Log;
 import android.view.Menu;
 import android.view.MenuInflater;
 import android.view.MenuItem;
@@ -18,11 +19,12 @@
 import com.daimajia.slider.library.SliderLayout;
 import com.daimajia.slider.library.SliderTypes.BaseSliderView;
 import com.daimajia.slider.library.SliderTypes.TextSliderView;
+import com.daimajia.slider.library.Tricks.ViewPagerEx;
 
 import java.util.HashMap;
 
 
-public class MainActivity extends ActionBarActivity implements BaseSliderView.OnSliderClickListener{
+public class MainActivity extends ActionBarActivity implements BaseSliderView.OnSliderClickListener, ViewPagerEx.OnPageChangeListener{
 
     private SliderLayout mDemoSlider;
 
@@ -54,8 +56,8 @@ protected void onCreate(Bundle savedInstanceState) {
                     .setOnSliderClickListener(this);
 
             //add your extra information
-            if (textSliderView.getBundle() != null)
-                textSliderView.getBundle()
+            textSliderView.bundle(new Bundle());
+            textSliderView.getBundle()
                         .putString("extra",name);
 
            mDemoSlider.addSlider(textSliderView);
@@ -64,6 +66,7 @@ protected void onCreate(Bundle savedInstanceState) {
         mDemoSlider.setPresetIndicator(SliderLayout.PresetIndicators.Center_Bottom);
         mDemoSlider.setCustomAnimation(new DescriptionAnimation());
         mDemoSlider.setDuration(4000);
+        mDemoSlider.addOnPageChangeListener(this);
         ListView l = (ListView)findViewById(R.id.transformers);
         l.setAdapter(new TransformerAdapter(this));
         l.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@@ -109,4 +112,15 @@ public boolean onOptionsItemSelected(MenuItem item) {
         }
         return super.onOptionsItemSelected(item);
     }
+
+    @Override
+    public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {}
+
+    @Override
+    public void onPageSelected(int position) {
+        Log.d("Slider Demo", "Page Changed: " + position);
+    }
+
+    @Override
+    public void onPageScrollStateChanged(int state) {}
 }

library/src/main/java/com/daimajia/slider/library/Indicators/PagerIndicator.java

@@ -328,7 +328,7 @@ public void setViewPager(ViewPagerEx pager){
             throw new IllegalStateException("Viewpager does not have adapter instance");
         }
         mPager = pager;
-        mPager.setOnPageChangeListener(this);
+        mPager.addOnPageChangeListener(this);
         ((InfinitePagerAdapter)mPager.getAdapter()).getRealAdapter().registerDataSetObserver(dataChangeObserver);
     }
 
@@ -455,8 +455,7 @@ public void onPageSelected(int position) {
          if(mItemCount == 0){
             return;
         }
-        int n = position % mItemCount;
-        setItemAsSelected(n - 1);
+        setItemAsSelected(position-1);
     }
     @Override
     public void onPageScrollStateChanged(int state) {

library/src/main/java/com/daimajia/slider/library/SliderLayout.java

@@ -213,6 +213,16 @@ public boolean onTouch(View v, MotionEvent event) {
         }
     }
 
+    public void addOnPageChangeListener(ViewPagerEx.OnPageChangeListener onPageChangeListener){
+        if(onPageChangeListener != null){
+            mViewPager.addOnPageChangeListener(onPageChangeListener);
+        }
+    }
+
+    public void removeOnPageChangeListener(ViewPagerEx.OnPageChangeListener onPageChangeListener) {
+        mViewPager.removeOnPageChangeListener(onPageChangeListener);
+    }
+
     public void setCustomIndicator(PagerIndicator indicator){
         if(mIndicator != null){
             mIndicator.destroySelf();

library/src/main/java/com/daimajia/slider/library/Tricks/ViewPagerEx.java

@@ -208,7 +208,7 @@ public float getInterpolation(float t) {
     private boolean mCalledSuper;
     private int mDecorChildCount;
 
-    private OnPageChangeListener mOnPageChangeListener;
+    private ArrayList<OnPageChangeListener> mOnPageChangeListeners = new ArrayList<>();
     private OnPageChangeListener mInternalPageChangeListener;
     private OnAdapterChangeListener mAdapterChangeListener;
     private PageTransformer mPageTransformer;
@@ -305,6 +305,21 @@ public void onPageScrollStateChanged(int state) {
         }
     }
 
+    private void triggerOnPageChangeEvent(int position) {
+        for (OnPageChangeListener eachListener : mOnPageChangeListeners) {
+            if (eachListener != null) {
+                InfinitePagerAdapter infiniteAdapter = (InfinitePagerAdapter)mAdapter;
+                if (infiniteAdapter.getRealCount() == 0) {
+                    return;
+                }
+                int n = position % infiniteAdapter.getRealCount();
+                eachListener.onPageSelected(n);
+            }
+        }
+        if (mInternalPageChangeListener != null) {
+            mInternalPageChangeListener.onPageSelected(position);
+        }
+    }
     /**
      * A PageTransformer is invoked whenever a visible/attached page is scrolled.
      * This offers an opportunity for the application to apply a custom transformation
@@ -394,8 +409,10 @@ private void setScrollState(int newState) {
             // PageTransformers can do complex things that benefit from hardware layers.
             enableLayers(newState != SCROLL_STATE_IDLE);
         }
-        if (mOnPageChangeListener != null) {
-            mOnPageChangeListener.onPageScrollStateChanged(newState);
+        for (OnPageChangeListener eachListener : mOnPageChangeListeners) {
+            if (eachListener != null) {
+                eachListener.onPageScrollStateChanged(newState);
+            }
         }
     }
 
@@ -539,12 +556,7 @@ void setCurrentItemInternal(int item, boolean smoothScroll, boolean always, int
             // We don't have any idea how big we are yet and shouldn't have any pages either.
             // Just set things up and let the pending layout handle things.
             mCurItem = item;
-            if (dispatchSelected && mOnPageChangeListener != null) {
-                mOnPageChangeListener.onPageSelected(item);
-            }
-            if (dispatchSelected && mInternalPageChangeListener != null) {
-                mInternalPageChangeListener.onPageSelected(item);
-            }
+            triggerOnPageChangeEvent(item);
             requestLayout();
         } else {
             populate(item);
@@ -563,18 +575,12 @@ private void scrollToItem(int item, boolean smoothScroll, int velocity,
         }
         if (smoothScroll) {
             smoothScrollTo(destX, 0, velocity);
-            if (dispatchSelected && mOnPageChangeListener != null) {
-                mOnPageChangeListener.onPageSelected(item);
-            }
-            if (dispatchSelected && mInternalPageChangeListener != null) {
-                mInternalPageChangeListener.onPageSelected(item);
+            if (dispatchSelected) {
+                triggerOnPageChangeEvent(item);
             }
         } else {
-            if (dispatchSelected && mOnPageChangeListener != null) {
-                mOnPageChangeListener.onPageSelected(item);
-            }
-            if (dispatchSelected && mInternalPageChangeListener != null) {
-                mInternalPageChangeListener.onPageSelected(item);
+            if (dispatchSelected) {
+                triggerOnPageChangeEvent(item);
             }
             completeScroll(false);
             scrollTo(destX, 0);
@@ -583,13 +589,25 @@ private void scrollToItem(int item, boolean smoothScroll, int velocity,
     }
 
     /**
-     * Set a listener that will be invoked whenever the page changes or is incrementally
+     * Add a listener that will be invoked whenever the page changes or is incrementally
      * scrolled. See {@link OnPageChangeListener}.
      *
-     * @param listener Listener to set
+     * @param listener Listener to add
+     */
+    public void addOnPageChangeListener(OnPageChangeListener listener) {
+        if (!mOnPageChangeListeners.contains(listener)) {
+            mOnPageChangeListeners.add(listener);
+        }
+    }
+
+    /**
+     * Remove a listener that was added with addOnPageChangeListener
+     * See {@link OnPageChangeListener}.
+     *
+     * @param listener Listener to remove
      */
-    public void setOnPageChangeListener(OnPageChangeListener listener) {
-        mOnPageChangeListener = listener;
+    public void removeOnPageChangeListener(OnPageChangeListener listener) {
+        mOnPageChangeListeners.remove(listener);
     }
 
     /**
@@ -1706,9 +1724,10 @@ protected void onPageScrolled(int position, float offset, int offsetPixels) {
                 }
             }
         }
-
-        if (mOnPageChangeListener != null) {
-            mOnPageChangeListener.onPageScrolled(position, offset, offsetPixels);
+        for (OnPageChangeListener eachListener : mOnPageChangeListeners) {
+            if (eachListener != null) {
+                eachListener.onPageScrolled(position, offset, offsetPixels);
+            }
         }
         if (mInternalPageChangeListener != null) {
             mInternalPageChangeListener.onPageScrolled(position, offset, offsetPixels);