Cheat sheets

Six sheets, each one page, each generated from the same data as the site so it cannot drift.

TL;DR#

• adb — the commands.
• Lifecycle — activity, fragment and Compose.
• Versions — API level to version to codename.
• Permissions — the dangerous ones by group.
• Manifest — the elements that matter.
• Perfetto — trace commands and SQL.

Mental model#

A cheat sheet is a memory prosthetic for things you understand but cannot recall precisely. That is why these contain almost no explanation: if you need the explanation, the page it came from is one click away.

Where the analogy breaks#

Some of these sheets — the version table especially — are useful even before you understand the material, because they are pure lookup data.

The big picture#

Deep dive#

Each sheet is written to fit one printed page at a readable size. They are deliberately terse.

Sheet	What it is for
adb	connection, processes, services, packages, logs, input, tracing
lifecycle	activity and fragment callbacks, Compose effects, what survives
version	API level, version, codename, date, runtime
permissions	dangerous permissions by group with the API they changed in
manifest	components, permissions, features, SDK levels
perfetto	trace commands, config snippets, useful SQL

How it evolved#

The sheets are generated from the datasets at build time. When a new Android version lands, the version sheet updates without anyone editing it.

Curiosity corner#

• The version cheat sheet is the one people print most, because the API-level-to-version mapping is the single most frequently needed lookup in Android work.

Try it#

Print the adb sheet and keep it beside your keyboard for a week. You will stop needing it.

Check yourself#

Check yourself

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What does an API level identify?

The marketing version number of an Android releaseThe version of the platform interface that compatibility checks useThe kernel version shipped with the deviceThe version of the Play Store app

Sources#