androidx.viewpager2.widget.ViewPager2 Java Examples

/**
 * Set the page count for the view pager.
 *
 * @param pageCount The page count to be set.
 * @param onPageChangeListener The page change listener to receive page change events.
 */
public void setPageCount(int pageCount,
        @Nullable ViewPager.OnPageChangeListener onPageChangeListener) {
    this.mPageCount = pageCount;

    if (mViewPager == null) {
        addView(LayoutInflater.from(getContext()).inflate(
                R.layout.adm_view_pager, this, false));
        mViewPager = findViewById(R.id.adm_view_pager);
    }

    mViewPager.setAdapter(new ViewPagerAdapter(pageCount));
    mViewPager.registerOnPageChangeCallback(new ViewPager2.OnPageChangeCallback() {
        @Override
        public void onPageScrolled(int position,
                float positionOffset, int positionOffsetPixels) {
            super.onPageScrolled(position, positionOffset, positionOffsetPixels);

            setProgress((position + positionOffset) / (mPageCount - 1));
        }
    });

    if (mViewPager.getAdapter() != null) {
        mViewPager.getAdapter().notifyDataSetChanged();
    }
}
 

@Override public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {
    mAdapter = new SampleRecyclerAdapter(5);

    ViewPager2 viewpager = view.findViewById(R.id.viewpager);
    viewpager.setAdapter(mAdapter);

    // CircleIndicator3 for RecyclerView
    CircleIndicator3 indicator = view.findViewById(R.id.indicator);
    indicator.setViewPager(viewpager);

    // CurrentItem
    viewpager.setCurrentItem(2,false);

    // Observe Data Change
    mAdapter.registerAdapterDataObserver(indicator.getAdapterDataObserver());
    view.findViewById(R.id.add).setOnClickListener(new View.OnClickListener() {
        @Override public void onClick(View v) {
            mAdapter.add();
        }
    });
    view.findViewById(R.id.remove).setOnClickListener(v -> {
        mAdapter.remove();
    });
}
 

/**
 * Checks whether a child can be scrolled.
 *
 * @param orientation The current orientation of the view.
 * @param delta The delta to check the scrolling.
 *
 * @return Returns {@code true} if a child can be scrolled.
 */
private boolean canChildScroll(int orientation, float delta) {
    if (getChildCount() <= 0) {
        return false;
    }

    int direction = -((int) Math.signum(delta));
    switch (orientation) {
        default:
            throw new IllegalArgumentException();
        case ViewPager2.ORIENTATION_HORIZONTAL:
            return getChildAt(0).canScrollHorizontally(direction);
        case ViewPager2.ORIENTATION_VERTICAL:
            return getChildAt(0).canScrollVertically(direction);
    }
}
 

private void setUpOnPageChangedListener() {
    pageChangeCallback = new ViewPager2.OnPageChangeCallback() {
        @Override
        public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
            float globalPositionOffsetPixels = position * (dotsStrokeSize + dotsSpacing * 2) + (dotsStrokeSize + dotsSpacing * 2) * positionOffset;
            float indicatorTranslationX = globalPositionOffsetPixels + horizontalMargin + dotsStrokeWidth - dotIndicatorAdditionalSize / 2f;
            dotIndicatorSpring.getSpring().setFinalPosition(indicatorTranslationX);

            if (!dotIndicatorSpring.isRunning()) {
                dotIndicatorSpring.start();
            }
        }

        @Override
        public void onPageSelected(int position) {
            super.onPageSelected(position);
        }

        @Override
        public void onPageScrollStateChanged(int state) {
            super.onPageScrollStateChanged(state);
        }
    };
}
 

ViewHolder(View itemView) {
    super(itemView);
    myTextView = itemView.findViewById(R.id.tvTitle);
    relativeLayout = itemView.findViewById(R.id.container);
    button = itemView.findViewById(R.id.btnToggle);

    button.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {


            if(viewPager2.getOrientation() == ViewPager2.ORIENTATION_VERTICAL)
            viewPager2.setOrientation(ViewPager2.ORIENTATION_HORIZONTAL);
            else{
                viewPager2.setOrientation(ViewPager2.ORIENTATION_VERTICAL);
            }
        }
    });
}
 

public void setViewPager(@Nullable ViewPager2 viewPager) {
    mViewpager = viewPager;
    if (mViewpager != null && mViewpager.getAdapter() != null) {
        mLastPosition = -1;
        createIndicators();
        mViewpager.unregisterOnPageChangeCallback(mInternalPageChangeCallback);
        mViewpager.registerOnPageChangeCallback(mInternalPageChangeCallback);
        mInternalPageChangeCallback.onPageSelected(mViewpager.getCurrentItem());
    }
}
 

public void checkFlow() {
    ViewPager2 viewPager = findViewById(R.id.verification_pager);
    if (Lbryio.isSignedIn()) {
        boolean flowHandled = false;
        if (flow == VERIFICATION_FLOW_WALLET) {
            viewPager.setCurrentItem(VerificationPagerAdapter.PAGE_VERIFICATION_WALLET, false);
            flowHandled = true;
        } else if (flow == VERIFICATION_FLOW_REWARDS) {
            User user = Lbryio.currentUser;
            if (!user.isIdentityVerified()) {
                // phone number verification required
                viewPager.setCurrentItem(VerificationPagerAdapter.PAGE_VERIFICATION_PHONE, false);
                flowHandled = true;
            } else if (!user.isRewardApproved()) {
                // manual verification required
                viewPager.setCurrentItem(VerificationPagerAdapter.PAGE_VERIFICATION_MANUAL, false);
                flowHandled = true;
            }
        }

        if (!flowHandled) {
            // user has already been verified and or reward approved
            setResult(RESULT_CANCELED);
            finish();
            return;
        }
    }
}
 

@Override
public void onPhoneVerified() {
    showLoading();
    FetchCurrentUserTask task = new FetchCurrentUserTask(new FetchCurrentUserTask.FetchUserTaskHandler() {
        @Override
        public void onSuccess(User user) {
            Lbryio.currentUser = user;
            if (user.isIdentityVerified() && user.isRewardApproved()) {
                // verified for rewards
                LbryAnalytics.logEvent(LbryAnalytics.EVENT_REWARD_ELIGIBILITY_COMPLETED);

                setResult(RESULT_OK);
                finish();
                return;
            }

            // show manual verification page if the user is still not reward approved
            ViewPager2 viewPager = findViewById(R.id.verification_pager);
            viewPager.setCurrentItem(VerificationPagerAdapter.PAGE_VERIFICATION_MANUAL, false);
            hideLoading();
        }

        @Override
        public void onError(Exception error) {
            showFetchUserError(error != null ? error.getMessage() : getString(R.string.fetch_current_user_error));
            hideLoading();
        }
    });
    task.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);
}
 

/**
 * This method will link the given ViewPager and this BottomNavigationViewInner together so that
 * changes in one are automatically reflected in the other. This includes scroll state changes
 * and clicks.
 *
 * @param viewPager
 * @param smoothScroll whether ViewPager changed with smooth scroll animation
 */
public BottomNavigationViewInner setupWithViewPager(final ViewPager2 viewPager, boolean smoothScroll) {
    if (mViewPager != null) {
        // If we've already been setup with a ViewPager, remove us from it
        if (mPageChangeListener != null) {
            mViewPager.unregisterOnPageChangeCallback(mPageChangeListener);
        }
    }

    if (null == viewPager) {
        mViewPager = null;
        super.setOnNavigationItemSelectedListener(null);
        return this;
    }

    mViewPager = viewPager;

    // Add our custom OnPageChangeListener to the ViewPager
    if (mPageChangeListener == null) {
        mPageChangeListener = new BottomNavigationViewExOnPageChangeListener(this);
    }
    viewPager.registerOnPageChangeCallback(mPageChangeListener);

    // Now we'll add a navigation item selected listener to set ViewPager's current item
    OnNavigationItemSelectedListener listener = getOnNavigationItemSelectedListener();
    mMyOnNavigationItemSelectedListener = new MyOnNavigationItemSelectedListener(viewPager, this, smoothScroll, listener);
    super.setOnNavigationItemSelectedListener(mMyOnNavigationItemSelectedListener);
    return this;
}
 

MyOnNavigationItemSelectedListener(ViewPager2 viewPager, BottomNavigationViewInner bnve, boolean smoothScroll, OnNavigationItemSelectedListener listener) {
    this.viewPagerRef = new WeakReference<>(viewPager);
    this.listener = listener;
    this.smoothScroll = smoothScroll;

    // create items
    Menu menu = bnve.getMenu();
    int size = menu.size();
    items = new SparseIntArray(size);
    for (int i = 0; i < size; i++) {
        int itemId = menu.getItem(i).getItemId();
        items.put(itemId, i);
    }
}
 

@Override
        public boolean onNavigationItemSelected(MenuItem item) {
            int position = items.get(item.getItemId());
            // only set item when item changed
            if (previousPosition == position) {
                return true;
            }
//            Log.d("onNavigationItemSelecte", "position:"  + position);
            // user listener
            if (null != listener) {
                boolean bool = listener.onNavigationItemSelected(item);
                // if the selected is invalid, no need change the view pager
                if (!bool) {
                    return false;
                }
            }

            // change view pager
            ViewPager2 viewPager = viewPagerRef.get();
            if (null == viewPager) {
                return false;
            }

            // use isNavigationItemClicking flag to avoid `ViewPager.OnPageChangeListener` trigger
            isNavigationItemClicking = true;
            viewPager.setCurrentItem(items.get(item.getItemId()), smoothScroll);
            isNavigationItemClicking = false;

            // update previous position
            previousPosition = position;

            return true;
        }
 

@Override
public BottomNavigationViewInner setupWithViewPager(ViewPager2 viewPager) {
    try {
        return super.setupWithViewPager(viewPager);
    } catch (Exception e) {
        return this;
    }
}
 

@Override
public BottomNavigationViewInner setupWithViewPager(ViewPager2 viewPager, boolean smoothScroll) {
    try {
        return super.setupWithViewPager(viewPager, smoothScroll);
    } catch (Exception e) {
        return this;
    }
}
 

private void initView(View view) {

        toolbar = view.findViewById(R.id.toolbar);

        AppBarLayout appBarLayout = view.findViewById(R.id.appbar_layout);

        // important
        if (isStatusBarTranslucent()) {
            appendStatusBarPadding(appBarLayout);
        }

        TabLayout tabLayout = view.findViewById(R.id.tab_layout);
        ViewPager2 viewPager = view.findViewById(R.id.view_pager);

        tabLayout.addTab(tabLayout.newTab().setText("Android"));
        tabLayout.addTab(tabLayout.newTab().setText("Awesome"));
        tabLayout.addTab(tabLayout.newTab().setText("Navigation"));

        viewPager.setAdapter(new ViewPagerAdapter(this));

        new TabLayoutMediator(tabLayout, viewPager, (tab, position) -> {
            String[] titles = new String[]{"Android", "Awesome", "Navigation"};
            tab.setText(titles[position]);
            viewPager.setCurrentItem(position);
        }).attach();

        viewPager.setCurrentItem(0);

    }
 

public TabLayoutMediator(
    @NonNull TabLayout tabLayout,
    @NonNull ViewPager2 viewPager,
    boolean autoRefresh,
    @NonNull TabConfigurationStrategy tabConfigurationStrategy) {
  this(tabLayout, viewPager, autoRefresh, /* smoothScroll= */ true, tabConfigurationStrategy);
}
 

public TabLayoutMediator(
    @NonNull TabLayout tabLayout,
    @NonNull ViewPager2 viewPager,
    boolean autoRefresh,
    boolean smoothScroll,
    @NonNull TabConfigurationStrategy tabConfigurationStrategy) {
  this.tabLayout = tabLayout;
  this.viewPager = viewPager;
  this.autoRefresh = autoRefresh;
  this.smoothScroll = smoothScroll;
  this.tabConfigurationStrategy = tabConfigurationStrategy;
}
 

private void tabLayoutMediator(ViewPager2 viewPager) {
    new TabLayoutMediator(binding.tabLayout, viewPager,
            (tab, position) -> {
                if (OrientationUtilsKt.isLandscape()) {
                    setupTabletTabTitles(tab, position);
                } else {
                    setupTabTitles(tab, position);
                }
            }).attach();
}
 

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    tutorialView = inflater.inflate(R.layout.fragment_tutorial, container, false);
    ViewPager2 viewPager = tutorialView.findViewById(R.id.view_pager);
    List<String> pages = new ArrayList<>();
    pages.add("first");
    pages.add("Second");
    pages.add("third");
    TutorialAdapter tutorialAdapter = new TutorialAdapter(getContext(), pages);
    viewPager.setAdapter(tutorialAdapter);
    return tutorialView;
}
 

private void initWeekPagerChangeCallback() {
	weekPager.registerOnPageChangeCallback(new ViewPager2.OnPageChangeCallback() {
		@Override
		public void onPageSelected(int selectedWeekIndex) {
			super.onPageSelected(selectedWeekIndex);
			refreshRecenterMenuItem();
		}
	});
}
 

public TabLayoutMediator(
    @NonNull TabLayout tabLayout,
    @NonNull ViewPager2 viewPager,
    @NonNull TabConfigurationStrategy tabConfigurationStrategy) {
  this(tabLayout, viewPager, /* autoRefresh= */ true, tabConfigurationStrategy);
}
 

ViewPagerAdapter(Context context, List<String> data, ViewPager2 viewPager2) {
    this.mInflater = LayoutInflater.from(context);
    this.mData = data;
    this.viewPager2 = viewPager2;
}
 

ViewPagerOnTabSelectedListener(ViewPager2 viewPager, boolean smoothScroll) {
  this.viewPager = viewPager;
  this.smoothScroll = smoothScroll;
}
 

public void setHorizontalConsumer(@Nullable ViewPager2 consumer) {
    this.horizontalConsumer = consumer;
}
 

ViewPagerOnTabSelectedListener(ViewPager2 viewPager) {
    this.mViewPager = viewPager;
}
 

public WelcomeFragment3(Activity activity, ViewPager2 viewPager2) {
    this.activity = activity;
    this.viewPager2 = viewPager2;
}
 

public void setViewPager(ViewPager2 viewPager) {
    this.viewPager = viewPager;
    setUpViewPager();
    refreshDots();
}
 

public WelcomeFragment1(Activity activity, ViewPager2 viewPager2) {
    this.activity = activity;
    this.viewPager2 = viewPager2;
}
 

public WelcomeFragment0(ViewPager2 viewPager2){
    this.viewPager2 = viewPager2;
}
 

public WelcomeFragment2(Activity activity, ViewPager2 viewPager2) {
    this.activity = activity;
    this.viewPager2 = viewPager2;
}
 

public WelcomeFragment5(Activity activity, ViewPager2 viewPager2) {
    this.activity = activity;
    this.viewPager2 = viewPager2;
}