Java Code Examples for androidx.viewpager.widget.ViewPager#OnPageChangeListener

/**
 * Set a listener that will be invoked whenever the page changes or is incrementally
 * scrolled. See {@link ViewPager.OnPageChangeListener}.
 *
 * @param listener Listener to set
 * @deprecated Use {@link #addOnPageChangeListener(ViewPager.OnPageChangeListener)}
 * and {@link #removeOnPageChangeListener(ViewPager.OnPageChangeListener)} instead.
 */
@Deprecated
public void setOnPageChangeListener(@Nullable ViewPager.OnPageChangeListener listener) {
    if (listener != null) {
        addOnPageChangeListener(listener);
    } else {
        mViewPagerOnPageChangeListeners.clear();
    }
}
 

@Override
public void onScroll(float currentViewPosition) {
    ViewPagerLayoutManager layoutManager = getLayoutManager();
    if (layoutManager == null) return;

    int currentIndex = getCurrentItem();
    int newIndex = layoutManager.getNextPosition();
    if (currentIndex != newIndex) {
        notifyScroll(currentViewPosition, currentIndex, newIndex,
                getViewHolder(currentIndex), getViewHolder(newIndex));

        if (!mViewPagerOnPageChangeListeners.isEmpty()) {
            float positionOffset;

            if (newIndex > currentIndex) {
                positionOffset = -currentViewPosition;
                if (positionOffset == 1) {
                    positionOffset = 0;
                    currentIndex += 1;
                }
            } else {
                positionOffset = 1 - currentViewPosition;
                currentIndex -= 1;
            }

            for (ViewPager.OnPageChangeListener listener : mViewPagerOnPageChangeListeners) {
                listener.onPageScrolled(currentIndex, positionOffset, 0);
            }
        }
    }
}
 

@Override
public void setOnPageChangeListener(ViewPager.OnPageChangeListener listener) {
    mListener = listener;
}
 

public void setOnPageChangeListener(ViewPager.OnPageChangeListener listener) {
    this.delegatePageListener = listener;
}
 

@Override
public void setOnPageChangeListener(ViewPager.OnPageChangeListener listener) {
    mListener = listener;
}
 

@SuppressWarnings("unused")
public void removeOnPageChangeListener(ViewPager.OnPageChangeListener listener) {
    if (listener != this.listener)
        miPager.removeOnPageChangeListener(listener);
}
 

@Override
public void setOnPageChangeListener(ViewPager.OnPageChangeListener listener) {
    mListener = listener;
}
 

@SuppressWarnings("unused")
public void addOnPageChangeListener(ViewPager.OnPageChangeListener listener) {
    miPager.addOnPageChangeListener(listener);
}
 

@Override
public void attachToPager(@NonNull final ScrollingPagerIndicator indicator, @NonNull final ViewPager pager) {
    attachedAdapter = pager.getAdapter();
    if (attachedAdapter == null) {
        throw new IllegalStateException("Set adapter before call attachToPager() method");
    }

    this.pager = pager;

    updateIndicatorDotsAndPosition(indicator);

    dataSetObserver = new DataSetObserver() {
        @Override
        public void onChanged() {
            indicator.reattach();
        }

        @Override
        public void onInvalidated() {
            onChanged();
        }
    };
    attachedAdapter.registerDataSetObserver(dataSetObserver);

    onPageChangeListener = new ViewPager.OnPageChangeListener() {

        boolean idleState = true;

        @Override
        public void onPageScrolled(int position, float positionOffset, int positionOffsetPixel) {
            updateIndicatorOnPagerScrolled(indicator, position, positionOffset);
        }

        @Override
        public void onPageSelected(int position) {
            if (idleState) {
                updateIndicatorDotsAndPosition(indicator);
            }
        }

        @Override
        public void onPageScrollStateChanged(int state) {
            idleState = state == ViewPager.SCROLL_STATE_IDLE;
        }
    };
    pager.addOnPageChangeListener(onPageChangeListener);
}
 

public void addViewPagerChangeListener(ViewPager.OnPageChangeListener listener) {
    checkPreconditions();
    viewPager.addOnPageChangeListener(listener);
}
 

@Override
public void setOnPageChangeListener(ViewPager.OnPageChangeListener listener) {
    mListener = listener;
}
 

@Override
public void setOnPageChangeListener(ViewPager.OnPageChangeListener listener) {
    mListener = listener;
}
 

/**
 * Set the {@link ViewPager.OnPageChangeListener}. When using {@link SlidingTabLayout} you are
 * required to set any {@link ViewPager.OnPageChangeListener} through this method. This is so that
 * the layout can update it's scroll position correctly.
 *
 * @see ViewPager#setOnPageChangeListener(ViewPager.OnPageChangeListener)
 */
public void setOnPageChangeListener(ViewPager.OnPageChangeListener listener) {
  mViewPagerPageChangeListener = listener;
}
 

/**
 * Set the {@link ViewPager.OnPageChangeListener}. When using {@link arcus.app.common.view.SlidingTabLayout} you are
 * required to set any {@link ViewPager.OnPageChangeListener} through this method. This is so
 * that the layout can update it's scroll position correctly.
 *
 * @see ViewPager#setOnPageChangeListener(ViewPager.OnPageChangeListener)
 */
public void setOnPageChangeListener(ViewPager.OnPageChangeListener listener) {
    mViewPagerPageChangeListener = listener;
}
 

/**
    * Set a listener will be called when the current page is changed.
    * @param listener The {@link ViewPager.OnPageChangeListener} will be called.
    */
public void setOnPageChangeListener(ViewPager.OnPageChangeListener listener) {
       mListener = listener;
   }
 

/**
 * Set a separate OnPageChangeListener for internal use by the support library.
 *
 * @param listener Listener to set
 * @return The old listener that was set, if any.
 */
ViewPager.OnPageChangeListener setInternalPageChangeListener(ViewPager.OnPageChangeListener listener) {
    ViewPager.OnPageChangeListener oldListener = mInternalPageChangeListener;
    mInternalPageChangeListener = listener;
    return oldListener;
}
 

/**
 * Remove a listener that was previously added via
 * {@link #addOnPageChangeListener(ViewPager.OnPageChangeListener)}.
 *
 * @param listener listener to remove
 */
public void removeOnPageChangeListener(@Nullable ViewPager.OnPageChangeListener listener) {
    mViewPagerOnPageChangeListeners.remove(listener);
}
 

/**
 * Set the {@link ViewPager.OnPageChangeListener}. When using {@link SmartTabLayout} you are
 * required to set any {@link ViewPager.OnPageChangeListener} through this method. This is so
 * that the layout can update it's scroll position correctly.
 *
 * @see ViewPager#setOnPageChangeListener(ViewPager.OnPageChangeListener)
 */
public void setOnPageChangeListener(ViewPager.OnPageChangeListener listener) {
  viewPagerPageChangeListener = listener;
}
 

/**
 * Set a page change listener which will receive forwarded events.
 *
 * @param listener
 */
void setOnPageChangeListener(ViewPager.OnPageChangeListener listener);
 

/**
 * Add a listener that will be invoked whenever the page changes or is incrementally
 * scrolled. See {@link ViewPager.OnPageChangeListener}.
 * <p>
 * <p>Components that add a listener should take care to remove it when finished.
 * Other components that take ownership of a view may call {@link #clearOnPageChangeListeners()}
 * to remove all attached listeners.</p>
 *
 * @param listener listener to add
 */
public void addOnPageChangeListener(@Nullable ViewPager.OnPageChangeListener listener) {
    mViewPagerOnPageChangeListeners.add(listener);
}