Android scroll page by page

ScrollView и HorizontalScrollView

При большом количестве информации, которую нужно поместить на экране приходится использовать полосы прокрутки. В Android существуют специальные компоненты ScrollView и HorizontalScrollView, которые являются контейнерными элементами и наследуются от ViewGroup. Обратите внимание, что класс TextView использует свою собственную прокрутку и не нуждается в добавлении отдельных полос прокрутки. Но использование отдельных полос даже с TextView может улучшить вид вашего приложения и повышает удобство работы для пользователя.

На панели инструментов компоненты можно найти в разделе Containers.

В контейнеры ScrollView и HorizontalScrollView можно размещать только один дочерний элемент (обычно LinearLayout), который в свою очередь может быть контейнером для других элементов. Виджет ScrollView, несмотря на свое название, поддерживает только вертикальную прокрутку, поэтому для создания вертикальной и горизонтальной прокрутки необходимо использовать ScrollView в сочетании с HorizontalScrollView. Обычно ScrollView используют в качестве корневого элемента, а HorizontalScrollView в качестве дочернего. Можно и наоборот, пробуйте.

В в теле метода onCreate() создайте ссылку на элемент TextView, объявленный в XML-разметке, и запишите в него через метод setText() какой-нибуль длинный текст, который не поместится в видимые размеры экрана устройства:

Запустив проект, вы должны увидеть вертикальную и горизонтальную полосы прокрутки при попытке скролирования.

Если полосы прокрутки вас раздражают, то используйте атрибут android:scrollbars=»none», который скроет их.

По такому же принципу можете вложить ImageView, чтобы просматривать большие картинки:

Методы scrollBy() и scrollTo()

Вы можете программно прокручивать контент с помощью методов scrollBy() и scrollTo(). Например, можно организовать автоматическую прокрутку во время чтения. В нашем примере мы будем прокручивать контент с помощью трёх кнопок.

Сам код для методов:

Дополнительное чтение

Библиотека ParallaxScrollView с использованием эффекта параллакса. Вы прокручиваете длинный текст, а задний фон прокручивается чуть медленнее. Возможно, кому-то пригодится. Там же можно скачать готовое демо и просмотреть в действии.

Источник

10 Best Mobile-friendly One Page Scroll Plugins (2021 Update)

What Is One Page Scroll?

One Page Scroll is a web technology that brings the native mobile app scroll experience to the web.

With One Page Scroll, your visitors are able to smoothly scroll through page sections (with full width & height) just like on the mobile devices.

The Best One Page Scroll Plugin

In this post, we list here the 10 best touch-enabled one page scroll jQuery & Vanilla JavaScript plugins that work perfectly on both desktop and mobile. Enjoy.

Originally Published Feb 14 2019, updated Feb 12 2021

Table of contents:

Best jQuery One Page Scroll Plugins

Create Fullscreen One Page Scrolling Websites With fullPage.js

fullPage.js is yet another jQuery plugin for one page website that allows you to create vertical or horizontal scrolling web page with smooth animations and easing options.

Auto Snap To Next Section On Scroll — SnapScroll

A jQuery plugin for one page scrolling website that has the ability to automatically scroll to next page section when you scroll up/down the webpage using mousewheel.

jQuery Plugin For One Page Navigation Plugin — Page Scroll To ID

A jQuery plugin to create anchor links which allow you to vertically and horizontally scroll to corresponding sections of your page with custom animations and easing effects.

Easy jQuery Plugin For Vertical Scroll Snapping — Scrollify

A jQuery plugin that enhances your one page scrolling website experience by providing snapping behavior as you scroll down the page.

Horizontal & Vertical One Page Scroll Plugin — jQuery fsscroll

Best Vanilla JavaScript One Page Scroll Plugins

Side Navigation For One Page Scroll Website – dot-nav

The dot-nav JavaScript library automatically generates a vertical side navigation for one page scrolling website.

fullPageScrollPureJS

A pure JavaScript / CSS implementation of cross-platform smooth one page scrolling effect with no 3rd dependencies.

Easy One Page Scroll Navigation Library – slide-nav

A lightweight, easy-to-use JavaScript plugin used to create a sticky navigation for your one page scrolling webpages. Scrollspy and smooth scrolling are supported as well.

fullPage.js

Just another JavaScript plugin that implements the touch-enabled fullscreen one page scroll effect for your single page web application using pure JavaScript.

onepagescroll.js

A lightweight JavaScript library that makes it easier to create a smooth scrolling effect with a side page navigation for your one-page website / single page application. Keyboard navigation and touch events supported.

More Resources:

Want more jQuery plugins or JavaScript libraries to create awesome one page scrolling effects on the web & mobile? Check out the jQuery One Page Scroll and JavaScript One Page Scroll sections.

Источник

Android scroll page by page

Скролл-шутер на андроид, где вы будете управлять военный самолетом и уничтожать противников.

Спейс шутер на андроид, где вы будете сражаться с Альянсом.

Авиационная экшен аркада в необычном рисованном стиле.

Классический скролл — шутер с красочной графикой.

Отличный скролл-шутер с красочной графикой.

Скролл шутер на драконе.

Яркие космические бои с невероятно большим количеством врагов.

Вертикальный скролл-шутер с оригинальным подходом.

Спасите космос и расстреляйте всех захватчиков.

Скролл-шутер на андроид, сделанный в стиле аниме.

Управляйте космическим кораблем и уничтожайте агрессивных инопланетян.

Управляйте космическим кораблем и дайте отпор всем инопланетянам.

Динамичный скролл шутер с стикменом.

Динамичсный скролл-шутер с аниме уклоном.

Управляйте космическим кораблем и уничтожайте корабли инопланетян.

Смесь арканоида и скрол-шутера.

Увлекательная аркада по уничтожению космических пришельцев для игры двум игрокам на одном устройстве.

Источник

Endless Scrolling with AdapterViews and RecyclerView

A common application feature is to load automatically more items as the user scrolls through the items (aka infinite scroll). This is done by triggering a request for more data once the user crosses a threshold of remaining items before they’ve hit the end.

The approaches for ListView, GridView and RecyclerView (the successor to ListView) are documented here. Both are similar in code except that the LayoutManager in the RecyclerView needs to be passed in to provide the necessary information to implement infinite scrolling.

In both cases, the information needed to implement the scrolling include determining the last visible item within the list and some type of threshold value to start fetching more data before the last item has been reached. This data can be used to decide when to load more data from an external source:

To provide the appearance of endless scrolling, it’s important to fetch data before the user gets to the end of the list. Adding a threshold value therefore helps anticipate the need to append more data.

NOTE: This page is describing a straightforward yet a bit dated solution. For Android University courses it’s recommended to use this approach for simplicity. For more advanced cases, Google released its own Paging Library. You can see this guide for more information.

We can use a similar approach with the RecyclerView by defining an interface EndlessRecyclerViewScrollListener that requires an onLoadMore() method to be implemented. The LayoutManager, which is responsible in the RecyclerView for rendering where items should be positioned and manages scrolling, provides information about the current scroll position relative to the adapter. For this reason, we need to pass an instance of what LayoutManager is being used to collect the necessary information to ascertain when to load more data.

Implementing endless pagination for RecyclerView requires the following steps:

1. Copy over the EndlessRecyclerViewScrollListener.java into your application.
2. Call addOnScrollListener(. ) on a RecyclerView to enable endless pagination. Pass in an instance of EndlessRecyclerViewScrollListener and implement the onLoadMore which fires whenever a new page needs to be loaded to fill up the list.
3. Inside the aforementioned onLoadMore method, load additional items into the adapter either by sending out a network request or by loading from another source.

To start handling the scroll events for steps 2 and 3, we need to use the addOnScrollListener() method in our Activity or Fragment and pass in the instance of the EndlessRecyclerViewScrollListener with the layout manager as shown below:

When you intend to perform a new search, make sure to clear the existing contents from the list and notify the adapter the contents have changed as soon as possible. Make sure also to reset the state of the EndlessRecyclerViewScrollListener with the resetState method:

You can refer to this code sample for usage and this code sample for the full endless scroll source code.

All of the code needed is already incorporated in the EndlessRecyclerViewScrollListener.java code snippet above. However, if you wish to understand how the endless scrolling is calculated, the detailed explanation is available here.

If you are running into problems, please carefully consider the following suggestions:

For the ListView, make sure to setup the setOnScrollListener listener in the onCreate method of the Activity or onCreateView in a Fragment and not much later otherwise you may encounter unexpected issues.

In order for the pagination system to continue working reliably, you should make sure to clear the adapter of items (or notify adapter after clearing the array) before appending new items to the list. For RecyclerView, it is highly recommended to make more granular updates when notifying the adapter. See this video talk for more context.

In order for this pagination system to trigger, keep in mind that as loadNextDataFromApi is called, new data needs to be appended to the existing data source. In other words, only clear items from the list when on the initial «page». Subsequent «pages» of data should be appended to the existing data.

If you see Cannot call this method in a scroll callback. Scroll callbacks might be run during a measure & layout pass where you cannot change the RecyclerView data. , you need to do the following inside your onLoadMore() method as outlined in this Stack Overflow article to delay the adapter update:

To display the last row as a ProgressBar indicating that the ListView is loading data, we do the trick in the Adapter. Having defined two types of views in getItemViewType(int position) , we can display the last row differently from a normal data row. It can be a ProgressBar or some text to indicate that the ListView has reached the last row by comparing the size of data List to the number of items on the server side. See this gist for sample code.

If you use RecyclerView to implement ‘infinite scrolling’ over output of the web service, or some other resource that requires slow background calls with multiple items at once, it may be reasonable to try the Uncover library from Maven central:

This library requires you to implement the primary data fetcher, mediating between fast single item UI-thread calls on model and slow chunked calls on the background on your fetcher:

The model.install glues model, view and adapter into working implementation. When the user swipes forward quickly, the library skips unneeded fetches of data between the new and old position, last requested data are fetched first, and any pending requests are dropped from the queue if they data are no longer visible.

See Implementing with RecyclerView section for the most recent and relevant instructions. ListView is no longer used in modern Android applications.

Every AdapterView (such as ListView and GridView ) has support for binding to the OnScrollListener events which are triggered whenever a user scrolls through the collection. Using this system, we can define a basic EndlessScrollListener which supports most use cases by creating our own class that extends OnScrollListener :

Notice that this is an abstract class, and that in order to use this, you must extend this base class and define the onLoadMore method to actually retrieve the new data. We can define now an anonymous class within any activity that extends EndlessScrollListener and bind that to the AdapterView. For example:

Now as you scroll, items will be automatically filling in because the onLoadMore method will be triggered once the user crosses the visibleThreshold . This approach works equally well for a GridView and the listener gives access to both the page as well as the totalItemsCount to support both pagination and offset based fetching.

Источник