| /* |
| * Copyright (C) 2015 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package com.android.deskclock.widget; |
| |
| import android.content.Context; |
| import android.support.v4.view.ViewPager; |
| import android.text.TextUtils; |
| import android.util.AttributeSet; |
| import android.view.View; |
| |
| import java.util.Locale; |
| |
| /** |
| * A {@link ViewPager} that's aware of RTL changes when used with FragmentPagerAdapter. |
| */ |
| public final class RtlViewPager extends ViewPager { |
| |
| /** |
| * Callback interface for responding to changing state of the selected page. |
| * Positions supplied will always be the logical position in the adapter - |
| * that is, the 0 index corresponds to the left-most page in LTR and the |
| * right-most page in RTL. |
| */ |
| private OnPageChangeListener mListener; |
| |
| public RtlViewPager(Context context) { |
| this(context, null /* attrs */); |
| } |
| |
| public RtlViewPager(Context context, AttributeSet attrs) { |
| super(context, attrs); |
| addOnPageChangeListener(new ViewPager.OnPageChangeListener() { |
| @Override |
| public void onPageScrolled(int position, float offset, int offsetPixels) { |
| // Do nothing |
| } |
| |
| @Override |
| public void onPageSelected(int position) { |
| if (mListener != null) { |
| mListener.onPageSelected(getRtlAwareIndex(position)); |
| } |
| } |
| |
| @Override |
| public void onPageScrollStateChanged(int state) { |
| // Do nothing |
| } |
| }); |
| } |
| |
| @Override |
| public int getCurrentItem() { |
| return getRtlAwareIndex(super.getCurrentItem()); |
| } |
| |
| @Override |
| public void setCurrentItem(int item) { |
| super.setCurrentItem(getRtlAwareIndex(item)); |
| } |
| |
| @Override |
| public void setOnPageChangeListener(OnPageChangeListener unused) { |
| throw new UnsupportedOperationException("Use setOnRTLPageChangeListener instead"); |
| } |
| |
| /** |
| * Get a "RTL friendly" index. If the locale is LTR, the index is returned as is. |
| * Otherwise it's transformed so view pager can render views using the new index for RTL. For |
| * example, the second view will be rendered to the left of first view. |
| * |
| * @param index The logical index. |
| */ |
| public int getRtlAwareIndex(int index) { |
| if (TextUtils.getLayoutDirectionFromLocale(Locale.getDefault()) == |
| View.LAYOUT_DIRECTION_RTL) { |
| return getAdapter().getCount() - index - 1; |
| } |
| return index; |
| } |
| |
| /** |
| * Sets a {@link OnPageChangeListener}. The listener will be called when a page is selected. |
| */ |
| public void setOnRTLPageChangeListener(OnPageChangeListener listener) { |
| mListener = listener; |
| } |
| } |