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Create Diagonal Cut View in Android

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Rotate. View. background. Recently, my friend create a detailed post on how to make diagonal shape view in Android . In that post, he detailed every step to create a custom view to achieve that shape. But, I wonder, if I create that without creating custom view and by using background only. Turn out, I can do that, by rotating the layer-list item. diagonal cut view concept Let’s jump into code and create the view : Create a simple layout <RelativeLayout android:id="@+id/background" android:layout_width="match_parent" android:layout_height="300dp" android:background="@drawable/background" /> Now we need to create the @drawable/background. Create  new  drawable resource file. Delete generated code, and replace it with layer-list. <layer-list xmlns:android="http://schemas.android.com/apk/res/android"> </layer-list> Layer list basically like a layer in image editor ...
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HashMaps, ArrayMaps and SparseArrays in Android

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This article will show why and when to use  ArrayMap  and  SparseArray  to optimize your Android Applications. Android developers must be observing Lint warnings recently to replace some of their HashMaps with SparseArrays with a promise of memory optimization. Good for us! There are few classes we should learn to use, like ArrayMap and SimpleArrayMap. There are also multiple variants of SparseArrays. This post will describe these classes along with their internals. Let’s start with some code showing how to use these classes java. util . HashMap < String , String > hashMap = new java. util . HashMap < String , String > ( 16 ) ; hashMap. put ( "key" , "value" ) ; hashMap. get ( "key" ) ; hashMap. entrySet ( ) . iterator ( ) ; android. util . ArrayMap < String , String > arrayMap = new android. util . ArrayMap < String , String > ( 16 ) ; arrayMap. put ( "key" , "value" ) ; arrayMap. get ( ...
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Handling data change in RecyclerView gracefully using DiffUtil

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DiffUtil  is an Android support library utility class which helps to ease out the process of finding which item changed in a list of data. It helps to calculate the difference between an old list and a new list and trigger updates to list items. If you are new to RecyclerView checkout my previous  posts . DiffUtil can be very useful when showing a list of data using RecyclerView where the data can be changed in future based on new values. Unlike ListView,  RecyclerView’s adapter  provides the following notify methods to only update those items that changed. notifyItemChanged(int) notifyItemInserted(int) notifyItemRemoved(int) notifyItemRangeChanged(int, int) notifyItemRangeInserted(int, int) notifyItemRangeRemoved(int, int) But since it only provides the methods, it is your responsibility to identify what are the changes in the new list compared to the old one and which method to call. This is where DiffUtil is very useful. It can identify data ch...
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