Fix crash when a formatter XML references a color resource

[halfhp]

Fixes #88

Cause

Formatter XML such as linePaint.color="@color/accent_blue" crashed with IllegalArgumentException: Unknown color. AAPT2 compiles that reference to the form @2131034163, and Fig's parseIntAttr passed any value starting with @ straight to Color.parseColor, which only understands hex and named colors. The 2019 comment on the issue said this would be fixed in Fig for 1.5.8, but the fix never landed: figlib 1.0.11 on Maven Central still has the bug.

Fix

• parseIntAttr now resolves @ values as resource references and reads them by resource type: color yields the color value, dimen the pixel size, anything else the integer. Both the compiled @<id> form and the @color/name string form are handled.
• Negative integers are now accepted too; they previously fell through to Color.parseColor as well.
• An unresolvable reference throws an IllegalArgumentException naming the value, instead of the opaque "Unknown color".

Fig folded into androidplot-core

Fig (com.halfhp.fig:figlib) is a three-file library by the same author whose only known consumer is Androidplot, and whose publishing pipeline is defunct. Its sources and test now live in com.androidplot.util.fig, under the SPDX header. Callers in Plot, Formatter and XYRegionFormatter are rewired, and the external dependency is gone from the published POM, which now lists only androidx.annotation. Nothing in Androidplot's public API exposed Fig types.

Documentation

• New docs/xml_configuration.md describes the property-path syntax, accepted value types (including resource references), the androidPlot. layout prefix, and the ProGuard requirement. Adapted from Fig's README in Androidplot terms.
• The quickstart's two links to the external Fig repo now point at that page; the index links it from the XML Attributes section.
• docs/release_notes.md gains a 1.5.12 entry covering this fix, the Fig merge, the SDK 37 toolchain and snapshot publishing.

Verification

• New FigTest cases cover a color reference, an integer reference, hex color, negative int and an unresolvable reference. The reference cases fail on the old logic and pass on the fix (checked both ways).
• Fig's original FigTest cases pass after the move.
• Full suite: 211 tests, 0 failures. Lint, coverage report, core release AAR and demoapp debug build all pass.
• The demoapp's line_point_formatter.xml now references a color resource, and aapt2 dump xmltree confirms it compiles to a reference. It's used by the Animated XY Plot and FX Plot examples, so those screens act as a live regression check.

[codecov-commenter]

⚠️ Please install the to ensure uploads and comments are reliably processed by Codecov.

Codecov Report

❌ Patch coverage is 66.25767% with 55 lines in your changes missing coverage. Please review.
✅ Project coverage is 69.16%. Comparing base (47c23df) to head (3be3ce4).

Files with missing lines	Patch %	Lines
...re/src/main/java/com/androidplot/util/fig/Fig.java	63.90%	33 Missing and 15 partials ⚠️
...c/main/java/com/androidplot/util/fig/FigUtils.java	82.14%	3 Missing and 2 partials ⚠️
...in/java/com/androidplot/util/fig/FigException.java	0.00%	2 Missing ⚠️
❗ Your organization needs to install the Codecov GitHub app to enable full functionality.

Additional details and impacted files

@@             Coverage Diff              @@
##             master     #134      +/-   ##
============================================
- Coverage     69.26%   69.16%   -0.10%     
- Complexity     1199     1233      +34     
============================================
  Files           106      109       +3     
  Lines          4997     5160     +163     
  Branches        512      537      +25     
============================================
+ Hits           3461     3569     +108     
- Misses         1210     1248      +38     
- Partials        326      343      +17     

☔ View full report in Codecov by Harness.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.