Detecting Common Gestures on Android Using GestureDetector

Gestures are those subtle motions to trigger interactions between the touch screen and the user. It lasts for the time between the first touch on the screen to the point when the last finger leaves the surface. We’re all familiar with it as it’s the most common way to communicate with apps on our mobiles, tablets, etc. these days. Some examples are scrolling in an app by swiping vertically/horizontally, pinch to zoom, long press to select and so on.

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QuickTip: Store Undefined and Null in Class/Table Rows on Parse.com

Parse store undefined and null

I’ve been working on an Android app backed by Parse.com to make my development process faster and easier. So while coding the app I made a decision to have 2 classes (tables) called Conversations and User (exists by default). Conversations has a field called userId that should essentially store the objectId from User class. But some conversations are created by guest so for those records I decided to store NULL or “nothing” (undefined) under the userId column rather than Pointers which is what the column type is.

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Understanding GridView in Android with Custom Adapters by Building an Image Gallery

GridView is a ViewGroup just like ListView that allows us to display items in a two-dimensional scrolling grid. Just like a ListView the data into a GridView is populated by an Adapter (ListAdapter) that fetches data from various sources like an array or a database. It’s mostly used to build image, video, audio galleries.

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Android Realtime (Instant) Search with Filter Class and Filterable Interface Using Custom and Inbuilt Adapter

Android has an excellent Fitler class that helps us filter data from an entire data set based on some pattern (for example a string) provided. Filters are usually created by classes implementing the Filterable interface. It makes sense to use filters (implement the Filterable interface) mostly with adapters, which means Filterable classes are usually Adapter implementations.

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Adding Search Functionality to Your Android Application Activity with SearchView and Search Dialog

If you’re building an android application, then most likely you’ll need to implement a search in it to let the user search through a set of data that could be emails, messages, chats, photos, files, etc. Android provides us with a search widget called SearchView that provides a user interface for the user to enter a search query and submit the request. The preferred way to use this widget to provide search in our application is to use it in the action bar.

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