https://github.com/frostyshadows/android-cheatsheet
Helpful visual guides for Android development
https://github.com/frostyshadows/android-cheatsheet
Last synced: 3 months ago
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Helpful visual guides for Android development
- Host: GitHub
- URL: https://github.com/frostyshadows/android-cheatsheet
- Owner: frostyshadows
- Created: 2020-05-22T14:39:46.000Z (about 5 years ago)
- Default Branch: master
- Last Pushed: 2025-01-05T02:13:25.000Z (5 months ago)
- Last Synced: 2025-01-20T10:44:02.353Z (4 months ago)
- Homepage:
- Size: 6.31 MB
- Stars: 72
- Watchers: 3
- Forks: 16
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
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README
# Android Cheatsheet
This is a collection of visual guides that I find myself coming back to repeatedly while doing Android development. Open to contributions!
## Table of contents
[Activities and Fragments](#activities-and-fragments)
[User interface](#user-interface)
[Kotlin](#kotlin)
[Jetpack Compose](#jetpack-compose)
[Architecture](#architecture)
[Build process](#build-process)
[General software engineering](#general-software-engineering)
## Activities and Fragments
### Lifecycle flowchart
### Callback methods
| Callback | When | What |Is Activity visible|
| --------------|---------------------------------|-----------------------------------------------------|:-----------------:|
|onCreate() | Activity is first created | All the necessary UI elements should be initialized | no |
| onStart() | Activity becomes visible to user| Code that maintains the UI, start async tasks (get data from API or database), register listeners | yes |
| onResume() | Activity becomes interactable to user| Starts animations | yes |
| onPause() | User is leaving the activity | Stops animations |partially visible |
| onStop() | Activity is no longer visible to user| Unregisters listeners and resources allocated in onStart()|no |
| onRestart() | Activity in the stopped state is about to start again (on back click) | Cursor objects should be re-queried | no |
| onDestroy() | Activity is destroyed from memory| | no |
### Launch modes
| Mode | Default | Instantiation | New Task on Launch | Allow other activities within Task |
| ---------------| --------------|--------------------| -------------------| -----------------------------------|
| standard | Yes | Everytime an intent is created, a new instance is created. Also instances can be member of multiple tasks and more than one instance in a Task. | No. Open in the same Task that originated the intent | Yes |
| singleTop | No | Exactly like standard but if the activity is at the top of the Task stack then it uses the existing instance. | No. Open in the same Task that originated the intent | Yes |
| singleTask | No | Single instance | Yes. Always a Root Task. | Yes |
| singleInstance | No | Single instance | Yes. Always a Root Task. | Never. Always the only activity in the task |
[Source](https://guides.codepath.com/android/Navigation-and-Task-Stacks)
## User interface
### RecyclerView pieces
| Piece | What it does |
|-----------------|------------------------------------------------------------------------------------------------------------------------------|
| `RecyclerView` | The `ViewGroup` that contains the views corresponding to your data. |
| item | One data item of the list to display. Can be of any type; often a data class you define. |
| `Adapter` | Takes data and prepares it for `RecyclerView` to display. |
| `ViewHolder`s | A pool of views for `RecyclerView` to use and reuse to display items. Each individual `ViewHolder` is a wrapper around a `View`. |
| `View` | A layout that can display one data item. |
| `LayoutManager` | Measures and positions individual item views within a `RecyclerView` and determines the policy for when to recycle item views that are no longer visible. The ones provided in the `RecyclerView` library are `LinearLayoutManager`, `GridLayoutManager`, and `StaggeredGridLayoutManager` |
[Source](https://developer.android.com/codelabs/basic-android-kotlin-training-recyclerview-scrollable-list)
### ImageView ScaleTypes
[Source](https://thoughtbot.com/blog/android-imageview-scaletype-a-visual-guide)
### [PorterDuff modes](https://developer.android.com/reference/android/graphics/PorterDuff.Mode) for tinting
[Source](https://chiuki.github.io/android-shaders-filters/#/)
## Kotlin
### Kotlin Standard Library functions
### Type system
[Source](http://natpryce.com/articles/000818.html)
### Kotlin Flow Cheatsheet
[Source](https://medium.com/@galou.minisini/advanced-kotlin-flow-cheat-sheet-for-android-engineer-cb8157d4f848)
## Jetpack Compose
### Three phases of a frame
[Source](https://developer.android.com/jetpack/compose/phases)
### Centering items in Composables
### Choosing an API to implement an animation
[Source](https://developer.android.com/develop/ui/compose/animation/choose-api)
## Architecture
### Uncle Bob's clean architecture
[Source](https://android.jlelse.eu/thoughts-on-clean-architecture-b8449d9d02df)
## Build process
[Source](https://stuff.mit.edu/afs/sipb/project/android/docs/tools/building/index.html)
## General software engineering
### Code review checklist
[Source](https://www.michaelagreiler.com/code-review-checklist-2/)
### Gang of Four design patterns
[Source](http://www.blackwasp.co.uk/GangOfFour.aspx)