Learn Jetpack Compose By Example

Over the course of the last few years Android development has gone through significant changes in how we structure our apps, the language we use for development, the tooling & libraries that help us speed up our development and the improvements in testing our apps. What had not changed in all these years is the Android UI toolkit. This changes with Jetpack Compose that aims to re-imagine what Android UI development would look like using declarative programming principles. It is heavily influenced by existing web and mobile frameworks such as React, Litho, Vue & Flutter and would be a paradigm shift in Android UI development as we know it.

This repository aims to show the Jetpack Compose way of building common Android UI that we are accustomed to building.

Talks

I've also used the examples listed in this repo and given talks at conferences. If video is your preferred medium of learning, you can head to the links below

360|AnDev 2020: Learning Jetpack Compose By Example Video| Slides

Android Summit 2020: Learn Jetpack Compose By Example v2 Slides

Setup

To try out this sample app, you need to at least use the Canary version of Android Studio 4.2, specifically Android Studio 4.2 Canary 15. You can download it here. In general, Jetpack Compose requires you to use the Canary version of Android Studio.

Examples

Each example is meant to be self contained and tries to explain all the concepts that its using with comments. Compose also comes with this nifty feature that lets you preview each component in the IntelliJ IDE itself. To do so, go to any of the examples and then click on the preview button in the top right corner. This is possible if your @Composable component has a corresponding @Preview method associated with it. Look at the examples below for all this to make a bit more sense.

General

Example	Preview
How do I display text on the screen using Jetpack Compose?
How do I make a view clickable and do actions when clicked?
How do I add padding around a view? How do I add an offset to a layout? How do I enforce a layout to have a fixed aspect ratio?
How do I add a background color to any section of the screen? Example 1 Example 2
How do I get FrameLayout like functionality to stack views on top of one another?
How do I do animation in Jetpack Compose? Example: Rotation Animation Example: Color Change Animation
How do styles & themes work in Jetpack Compose? How do I add dark mode capability to my app?

State Management

Example	Preview
How do I store state information in Jetpack Compose?
How do I retain state across process death & activity recreation(like orientation changes)?
How do I use LiveData/ViewModels with Jetpack Compose?
How do I use Coroutine Flow to update my components/views with Jetpack Compose?
How do you launch a Coroutine inside a Composable? How do you do side-effects in Jetpack Compose?
How do you handle back press in Jetpack Compose?

Material Design

Example	Preview
How do I add a Material Design Card? How do I display a linear progress bar? What about a circular progress bar? How do I add a Snackbar? How to add a Material Design Slider? How to configure a two/three state checkbox? How do I add a radio button group?
How do I add a Floating Action Button to my screen?
How do I create a Bottom App Bar?
How do I add a drawer to my screen?
How do I add Ripple effect to a view?
How do I add a Button to my screen?
How do I display an alert dialog/popup modal?
How do I make Material Filter Chips that overflow to multiple rows?
How do I add a shadow around my view?

Text

Example	Preview
How do I style & customize my text?
How do you take text input from a user in Jetpack Compose? How can I use a custom text style for a text input? How can I change the keyboard type to accept numbers? How can I create a Search bar? How can I apply a visual transformation to an input text? How can I provide a hint for the text input field? Is there filled text field as per Material Design specification?
How do I animate parts of my text? How do I describe parts of my text to be replaced by alternate views?

Images

Example	Preview
How do I display an image in Jetpack Compose? How to load an image from the resource folder? How to make an image view with rounded corners? How to load an image over the network using Picasso? How to load an image over the network using Glide?

Lists

Example	Preview
How do I display a list in my app? Is there a RecyclerView equivalent?
How can I have a grid layout?
How can I build a horizontally scrollable carousel?
How can I add animations for insertion/deletion of a list item?

Flexible Layouts

Example	Preview
How do I align the baseline of two views? What's the layout weight equivalent in Jetpack Compose? Example with equal weights Example with unequal weights How do I auto arrange my views similar to FlexBox? Add space between views Evenly distribute space Add space around the views Tightly packed centering of views
How do I use constraint layouts? How do I use guidelines with constraint layouts? How do I add barriers when using constraint layouts? How do I add bias when using constraint layouts?

Custom Views

Example	Preview
How do I draw using a canvas?
Example of a measuring scale component
How do I make a view zoomable?
How do I detect touch events in a custom view?

Interoperability

Example	Preview
How can I use Jetpack Compose components inside existing screens?

Testing

Credits

Author: Vinay Gaba ([email protected])

License

Copyright 2020 Vinay Gaba

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

   http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.