Jetpack Compose is a set of contemporary tools that allows developers to build native Android user interfaces.
Jetpack is driven by a declarative programming model; the Jetpack Composes automatically manipulates the user interface according to the description given by the developers.
As soon as Compose detects any change in the state of the app, the UI is updated automatically. As Compose is built using Kotlin, it has direct to all the Jetpack and Android APIs it is completely interoperable with the Java programming language. You can create random blends of the classical and contemporary views along with the material designs and animation components, as the Jetpack Compose is compatible with the existing User-Interface toolkit.
On getting influenced by the widespread front-end toolkits and frameworks such as React.js and Flutter, Google announced the Jetpack Compose at Google I/O 2019. Google responded to the declarative UI framework trend by launching the Jetpack Compose to allow developers to alter the way of creating user-interfaces in Android swiftly and efficiently.
Jetpack Compose has been integrated into the Jetpack suite of libraries and is backwards compatible, that is, compatible with all the pre-existing platform versions. Even though Jetpack Compose is in its early preview state, it is much talked about in the Android community.
Download the latest canary version of Android Studio Preview for availing the best features of the Compose. You can exploit the smart editor features of Android Studio that comes with various new project templates and the ability to instantly preview your Compose User-Interface, so it is recommended that you use Android Studio to develop your app along with Jetpack Compose.
Important: As the Jetpack Compose is still in its pre-alpha state, you must not use in production apps, as it is subjected to upgrades and modifications and can possibly asynchronise your code later.
MVVM with Jetpack
Over the years it has been witnessed that Innovations often come in waves in the Mobile application development industry. It is important to move along the waves and stay upgraded up to the mark, to be in the market as if there are other stable and promising platforms, you can be eradicated from the industry. The tech-savvy people have been talking about creating declarative and reactive programming models to enhance the apps’ business logic from the last few years.
Due to the exponential advent in the mobile development industry, people have drifted away from the obsolete imperative MVC/P (Model-View-Controller/Presenter) paradigm to a more reactive approach known as the MVVM (Model-View-ViewModel).
The MVVM enables the user interface to reconstruct itself or merely update specific sections of the User-Interface when the data stream inside the ViewModel is updated. Instead of interactions, you work with data values in declarative programming. This makes it more composable, less error-prone and efficient to test.
What’s new in Android Jetpack Compose?
The top libraries that is included in the open-source project, Jetpack Compose for efficient UI development.
Additions in Alpha Version
CameraX: This library allows to efficiently integrate camera functionalities without the hassle of interruption from underlying components. CameraX API is backwards compatible with all the versions higher than Android 5.0 (API 21).
LiveData and Lifecycles along with coroutines: Using Lifecycle and LiveData KTX you can support your common one-shot asynchronous operations as Kotlin coroutines are lifecycle-aware.
Benchmark: This library is continuously used for benchmarking Jetpack libraries so that no latency is introduced in the system. It allows us to measure database queries, RecyclerView scroll or view inflation.
Security: The new security library is used for maximizing the security of static data of the application. It provides highly encrypted services for service-based apps such as banking and chat.
Additions in Beta Version
ConstraintLayout 2.0: This library targets on the optimisation of layouts and allows us to customise them with the help of helper classes. It comes with a specific MotionLayout that allows us to manipulate motion and widget animations in our applications.
Biometrics Prompt: The biometric prompt comes with a set of default classes that allows user to use biometric credentials for authentication of their credentials. It provides high security as it minimises the chances of data breach and session hijacking explicitly and helps in the identification of intruders also.
Enterprise: By implementing the Jetpack Enterprise library you can design the apps to reverse feedback to Enterprise Mobility Management providers as keyed app states.
Android for Cars: It allows you to create a driver-optimised version of your app that can be installed into the vehicle’s infotainment system automatically using the Android Automotive OS.
Why you should prefer Jetpack Compose over the current UI Building process in Android?
The top three features that make Jetpack Compose highly referable over the classic Android user-interface are:
Being a declarative User Interface framework, Jetpack Compose allows us to describe our view taking the assistance of mutation and further classical imperative programming concepts.
Let’s consider the example of “hiding a view”.With the conventional Android user interface toolkit, we will have to assign the pointer to the user interface component by using the findViewById() method for obtaining the memory reference address for hiding the View and then invoke the setVisibility() by creating its object.
While in the case of declarative UI, we simply need to describe the user interface component as visible or invisible. And if you need to alter the visibility further you can merely re-run the code after describing the user interface again. This eliminates the tedious part of creating a reference variable for the View that you have created, rather you can simply create new parameters and re-run your code.
Jet Compose doesn’t create the entire View again from the scratch, it just overwrites the changes that you make on the pre-existing View created earlier.
The key advantage of using the Compose library for developers is that it is not coupled to the operating system. In the current system, an entirely new version of the operating system is required by Google for updating the Linear Layout component in Android. A lot of fragmentation issues are reported by the developers, even if they are using any of the contemporary Android versions.
This implies that we can’t even rely on user’s having access to the contemporary user interface toolkit due to risk of fragment issues. This is due to the negligence and lack of updates made in this sector of Android.
The ingress of Jetpack Compose library allows developers to include new features without altering the operating system version. They do not rely on the version of operating system you are using and reduce fragmentation risks.
Apart from this, contrasting to the Linear Layout component, the pre-existing applications will not get interrupted with the release of new versions Jetpack Compose. This is because Jet Compose doesn’t add any restrictions to compel you to update it.
This resolves the sustained issues the View hierarchy had, as it eliminates the existing UI toolkit from Android Studio. Hence, it triggers a completely new code.
While previously as soon as you switched to a new version of the Android Studio, along with the operating system, the Linear Layout component is also upgraded which is accompanied by changes initiated into the application that rely on it completely.
Finally, Jetpack Compose cleared the stack of long-standing issues faced by developers working on the classic Android User-Interface toolkit. It was just because of the idea of making it independent with the ingress of Jetpack Compose.
Android Studio has been ruling the market for over a decade now, but its User-Interface code has started depreciating. This is because of the obsolete and redundant View class code. Jetpack Compose allows us to write composed, well-structured and distinct codes, as its name indicates.
Jetpack Compose toolkit dependencies
In order to worth with Jetpack Compose, we need to append the following Jetpack Compose toolkit dependencies in your project’s build.gradle file.
- The dependency to synchronise the project with Jetpack Compose
- Implementation ‘androidx.compose.ui:ui:1.0.0-alpha01’
- The dependency required for adding tool support and views: implementation ‘androidx.ui:ui-tooling:1.0.0-alpha01’
- This dependency allows us to exploit the fundamental properties such as boxes, images, scroll, shapes, border, background, animations and so on: implementation ‘androidx.compose.foundation:foundation:1.0.0-alpha01’
- This dependency is used for including the material design toolkit: implementation ‘androidx.compose.material:material:1.0.0-alpha01’
- These dependencies used for including the Material design icons: implementation ‘androidx.compose.material:material-icons-core:1.0.0-alpha01’ implementation ‘androidx.compose.material:material-icons-extended:1.0.0-alpha01’
- These dependencies used for Integration with observables implementation ‘androidx.compose.runtime:runtime-livedata:1.0.0-alpha01’ implementation ‘androidx.compose.runtime:runtime-rxjava2:1.0.0-alpha01’
- This dependency is used for launching user interface tests: androidTestImplementation ‘androidx.ui:ui-test:1.0.0-alpha01’
After adding these dependencies you can efficiently work with all the contemporary design components available in the Android toolkit including material designs and animation libraries. Jetpack Compose is highly recommendable for budding Android Developers who are not familiar with the operating system concepts.
Generally, for beginners, it becomes very difficult to track app crashes due to fragmentation and other operating system issues, so they end up making some developmental anomalies. Jetpack Compose makes the app updates independent of the operating system versions this reduces overhead costs and tediousness of frequent updates in the operating system and using reference variables.
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By Vanshika Singolia