SKILL.md
This skill guides through the process of migrating an existing Android XML View
to Jetpack Compose. It performs a stable, safe and visually consistent
transition by following a structured, 10-step methodology. This skill migrates
UI (XML to Jetpack Compose) only.
Objective
To systematically convert a single legacy XML layout into modern, declarative
Jetpack Compose UI while maintaining pixel-perfect visual parity and functional
integrity.
Summary of the 10-step migration process
- Identify the optimal XML candidate for migration
- Analyze the project and layout
- Create a plan
- Capture the XML View UI
- Set up Compose dependencies and compiler
- Set up Compose theming
- Migrate the XML layout to Compose
- Validate the migration
- Replace usages
- XML code removal
Detailed steps
Step 1: Identify the optimal XML candidate for migration
If the user has explicitly specified a target XML layout, proceed to Step 2.
Otherwise, analyze the codebase to identify the best candidate for migration by
following the logic in references/identify-optimal-xml-candidate.md.
Step 2: Analyze the project and layout
Analyze the identified XML View's structure, hierarchy, and implementation
details.
Use references/analysis-of-the-project-and-layout.md to
guide your technical audit of the layout and surrounding project context.
Step 3: Create a plan
Using the outputs and analysis done in the Step 1 and 2, generate a
step-by-step plan for the migration. If you support user interaction, present
to the user and ask for approval before proceeding. If user interaction is not
supported, proceed to Step 4 following the generated plan.
Step 4: Capture the XML View UI
IF you support user interaction, ask the user to upload a screenshot of the
XML View UI or provide an absolute path to a file. Use this image as a visual
reference for the layout migration in Step 7.
ELSE IF you are able to run an Android emulator, locate an existing
screenshot test for the XML candidate. If none exists, create one using the
existing project testing framework. If no framework exists,
use UI Automator or Espresso to create a screenshot test with minimum
required setup. Run the test and take a baseline screenshot of the XML UI.
ELSE proceed to Step 5.
Step 5: Set up Compose dependencies and compiler
Check build.gradle or libs.versions.toml for Compose dependencies and
compiler setup. If missing, use
Setup Compose Dependencies and Compiler.
Run a sync to ensure dependencies resolve without errors.
Step 6: Set up Compose theming
If the project already has Compose theming set up, proceed to Step 7. If Compose
theming is missing, initialize it. For Material-based projects, follow
Material 3 migration guidelines.
For custom design systems, apply expert judgment to migrate XML theming and
match existing styles.
Constraints: Do not migrate the entire theme. Implement only the minimum
theming required for the specific XML candidate. Maintain original XML themes
for interoperability. Maintain existing project code conventions, patterns,
names and values.
Step 7: Migrate the XML View to Compose
Convert the XML candidate to Jetpack Compose code, referencing
references/xml-layout-migration.md and the image from Step 4.
You must include a Compose Preview for the newly created composable to
facilitate visual verification.
Step 8: Replace usages
Replace the usages of the migrated XML layout to use the new Compose component.
- To add Compose in Views, use Compose in Views.
- To add Views in Compose, use Views in Compose.
Step 9: Validate the migration
Compare the baseline screenshot image from Step 4 with the rendered Compose
Preview of the new composable. Ignore string content; focus on layout and
styling. Iterate on the Compose code until visual parity is achieved. Once
verified, write a Compose UI test for the new composable.
Step 10: XML code removal
Delete the migrated XML file and its associated legacy tests. Caution: Only
remove code and resources that are not referenced by other parts of the project.