Grokking Android

Getting Down to the Nitty Gritty of Android Development

Archive for the “Android” category:

Why Google Limits APIs With Every Android Release: We Devs are to Blame!

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Last week Android Q was released. And the first thing that came to my mind when reading the Android Q announcement was: “Finer grained location permissions! Thats’s great!” But then, it got me thinking: “Wait a moment! Why is this even necessary?” Don’t get me wrong, I really think this addition is necessary and it […]  Continue Reading  “Why Google Limits APIs With Every Android Release: We Devs are to Blame!”

Creating Kotlin DSLs

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Kotlin has many nice things going for it – be it null safety, data classes, extension functions, immutable collections or many other things. For me one additional thing is very interesting: The ability to create domain specific languages (DSLs) easily. Easily, because creating a DSL with Kotlin means that you simply choose to combine several […]  Continue Reading  “Creating Kotlin DSLs”

Those “mobile apps are doomed” headlines? They are wrong!

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So lately there are a lot of headlines appearing that say “Businesses Moving To Chatbots, AI; Away From Mobile Apps”, “The Rise of Chatbots – Why they’ll replace All Your Apps!” or “How Bots Will Completely Kill Websites and Mobile Apps”. First of all: Look at where those headlines appear. Some of these websites – […]  Continue Reading  “Those “mobile apps are doomed” headlines? They are wrong!”

Android Things: Remote Controlled Car – What’s Coming Up

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Being an Android Developer, Google’s announcement of Android Things immediately piqued my interest. As all the others I started out with buying one of the developer kits and then making some lights blink. Nice. But, well, if I have to be honest with myself, that was fun but actually of only limited use 🙂  Then […]  Continue Reading  “Android Things: Remote Controlled Car – What’s Coming Up”

Android’s ConstraintLayout: Align One View’s Edge to Another View’s Center

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As you can see from the following excerpt of ConstraintLayout's supported attributes, there is no layout_constraintStart_toCenterX attribute. Thus you cannot directly align the left edge of one view to the center of another view. But ConstraintLayout is flexible enough to get your view aligned to the center of another view without such an attribute. Even […]  Continue Reading  “Android’s ConstraintLayout: Align One View’s Edge to Another View’s Center”

Some Thoughts on Android’s new ConstraintLayout and Android Studio’s new Design Editor

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At this year’s IO Google introduced a new layout – the ConstraintLayout – and also presented it’s totally revamped layout editor. I am not going into how to use the layout. Google itself has done a good job in explaining it with its code lab “Using ConstraintLayout to design your views”. In this post I […]  Continue Reading  “Some Thoughts on Android’s new ConstraintLayout and Android Studio’s new Design Editor”

RxJava’s Side Effect Methods

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RxJava’s Observable class has plenty of methods that can be used to transform the stream of emitted items to the kind of data that you need. Those methods are at the very core of RxJava and form a big part of it’s attraction. But there are other methods, that do not change the stream of […]  Continue Reading  “RxJava’s Side Effect Methods”

Why use Observable.create() and not just inherit from Observable?

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When starting to use RxJava you have to create Observables. They are at the very core of RxJava. But how to do so? A look at the Observable class might make you dizzy. Looking at the source even more so. Not only does this beast consist of nearly 10.000 lines (though, 7600 lines of that […]  Continue Reading  “Why use Observable.create() and not just inherit from Observable?”

Selecting Items of a RecyclerView using StateListDrawables

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Last week, after I published my introduction to RecyclerView Paul Betts asked on Twitter whether ItemDecorators are useful for displaying the selection state of items. Well, I think using them for selection is not the right way to go. Instead, I think that you should stick with StateListDrawables and the activated state. The use case […]  Continue Reading  “Selecting Items of a RecyclerView using StateListDrawables”

A First Glance at Android’s RecyclerView

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At this year’s Google I/O, Google released a preview to the upcoming Android version. The so called L Developer Preview. This is a very big improvement over previous releases and I really love that Google is doing this. I think we all benefit by this decision. As developers and as consumers alike! Part of this […]  Continue Reading  “A First Glance at Android’s RecyclerView”