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.
Let’s say you have a
byte array of image data that you want to convert into an Image by showing up in an
ImageView in your layout. We can achieve that with a few lines of code.
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
User (exists by default).
Conversations has a field called
userId that should essentially store the
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.
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
ListAdapter) that fetches data from various sources like an array or a database. It’s mostly used to build image, video, audio galleries.
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
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.