Android ViewFlipper and ViewSwitcher with GestureDetector Swipes/Flings

While developing an Android application, most of us will encounter the need to integrate a section in our app where the user can switch between Views. So it should show one view which can be an ImageView or a collection inside LinearLayout, RelativeLayout, etc. at a time that can be swiped/flinged to move to the next or previous item. Think of a slideshow of images or a step-based process like e-commerce checkouts. Basically whenever you want to swipe through a set of related sections but show only one at a time then you can leverage ViewFlipper or ViewSwitcher class widgets that Android provides us. The detection of gestures can be achieved with major use of the MotionEvent class but we’ll make use of GestureDetector for this article.

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Quick Tip: Android ViewFlipper Jump/Move/Switch To a Certain Child View

At times you might want to jump the user to a specific View inside a ViewFlipper on the click of some other View or some such scenario. So let’s say we have a ViewFlipper in our layout resource like this:

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Using onTouchEvent() and View.OnTouchListener Interface with MotionEvent to Detect Common Gestures Like Tap and Swipes on Android

Touch gestures like tapping, swiping vertically/horizontally, panning, etc. occurs when a user places one or more fingers on the screen and by the time the last finger looses contact, the entire pattern of finger movements is interpreted as a particular gesture by your android application. First all the relevant data of touch events are gathered and then they’re interpreted to see which gestures they match and the pertaining actions are executed as specified in the code.

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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

Update: Parse is shutting down. So you should start migrating.

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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