Dependency diagrams for the Android Studio codebase

Use visualize-iml-deps.py to visualize .iml module dependencies. To run it you may need to install a few Python libraries like networkx and pydot.

Usage example

This is the command used to produce example.png:

./visualize-iml-deps.py \
    $SRC/tools/adt/idea/.idea/modules.xml \
    --transitive-reduction \
    --count-lines \
    --draw-to-scale \
    --num-modules 40 \
    --exclude '*aswb*' \
    --out example.png

Use --help to see all available options.

Important notes:

• If you use --transitive-reduction, then some dependency edges will be hidden in order to improve readability. Specifically, we hide all edges which are already implied by transitivity.

• If you use --num-modules N, then only the largest N modules will be shown. All other modules will be removed. Transitive dependency paths are preserved and are represented by dotted edges.

Tip: to share diagrams internally, use --format dot and upload the result to Google's internal GraphViz server: http://graphviz.

Details

If you try to build a dependency diagram using Bazel:

$ bazel cquery 'kind(_iml_module_, deps(//tools/adt/idea/studio:android-studio))' --output=graph

then the result is too large and completely unreadable.

So instead we do the following:

• Quantify module size by counting lines of code (--count-lines).
• Draw modules as circles with area proportional to module size (--draw-to-scale).
• Hide small modules, test modules, and ASwB modules (--num-modules 40 --exclude '*aswb*').
  • And add dotted edges where needed to preserve transitive dependency paths.
• Use transitive reduction to hide edges that are already implied by transitivity (--transitive-reduction).
• Shorten module names by removing common prefixes.

Example diagram