added shareplus

TODO.md

@@ -32,5 +32,4 @@
 - [X] Add a Share button to the formula list. It will export the array string literal of the formula with the units from Corpus.withDependencies().
 - [X] Replace flutter-markdown with flutter-markdown-plus
 - [X] Heron's formula: investigate why a=3, b=40, c=5 yields NaN. Root cause: input values don't form a valid triangle (violate triangle inequality: 3+5=8 is not > 40). Added documentation note to the formula description.
-- [ ] 
+- [ ] Change Share package to share_plus, because share is deprecated.
-- [ ] Investigate startup time when there is no previous database and corpus is loaded from assets.

assets/formulas/optics.d4rt

@@ -1,4 +1,35 @@
 [
-  {"name":"Snell's Law","input":[{"name":"n1","unit":"scalar"},{"name":"n2","unit":"scalar"},{"name":"theta1","unit":"degree"}],"output":{"name":"theta2","unit":"degree"},"d4rtCode":"var theta1Rad = theta1 * (pi / 180); var sinTheta2 = (n1 * sin(theta1Rad)) / n2; theta2 = asin(sinTheta2) * (180 / pi);","tags":["physics","optics","light"]}
+  {
-]
+    "name": "Snell's Law",
+    "description": r'''
+Refraction of light when passing through different media
+
+$$n_1 \sin(\theta_1) = n_2 \sin(\theta_2)$$
+
+Where:
+- $n_1$: Refractive index of the first medium
+- $n_2$: Refractive index of the second medium
+- $\theta_1$: Angle of incidence (degrees)
+- $\theta_2$: Angle of refraction (degrees)
+
+![Figure](https://upload.wikimedia.org/wikipedia/commons/thumb/5/51/Snells_law_Diagram_B_vector.svg/330px-Snells_law_Diagram_B_vector.svg.png)
+
+Snell's Law describes how light bends when traveling between media with different refractive indices.
+The product of refractive index and sine of angle remains constant across the interface.
+
+''',
+    "input": [
+      {"name": "n1", "unit": "scalar"},
+      {"name": "n2", "unit": "scalar"},
+      {"name": "theta1", "unit": "degree"}
+    ],
+    "output": {"name": "theta2", "unit": "degree"},
+    "d4rtCode": r"""
+    var theta1Rad = theta1 * (pi / 180);
+    var sinTheta2 = (n1 * sin(theta1Rad)) / n2;
+    theta2 = asin(sinTheta2) * (180 / pi);
+    """,
+    "tags": ["physics", "optics", "light"]
+  }
+];
 

lib/ai/formula_list.dart

@@ -3,7 +3,7 @@ import 'package:flutter/services.dart'; // For Clipboard
 import 'package:d4rt_formulas/formula_models.dart';
 import '../corpus.dart';
 import 'formula_screen.dart';
-import 'package:share_plus/share_plus.dart';
+import 'package:share_plus/share_plus.dart' as share_plus;
 
 class FormulaList extends StatefulWidget {
   final Corpus corpus;
@@ -63,9 +63,11 @@ class _FormulaListState extends State<FormulaList> {
       final exportString = '[${literals.join(', ')}]';
       
       // Share the string
-      await Share.share(
+      await share_plus.SharePlus.instance.share(
-        exportString,
+        share_plus.ShareParams(
+          text: exportString,
           subject: 'Sharing formula: ${formula.name}',
+        ),
       );
     } catch (e) {
       _showErrorDialog('Error sharing formula: $e');

lib/ai/formula_screen.dart

@@ -45,6 +45,7 @@ class D4rtEditingController extends TextEditingController {
 
   FormulaResult? get d4rtValue => _lastValue;
 
+  @override
   set text(String newText) {
     super.text = newText;
     validate();

pubspec.lock

@@ -505,7 +505,7 @@ packages:
     source: hosted
     version: "1.3.0"
   markdown:
-    dependency: transitive
+    dependency: "direct main"
     description:
       name: markdown
       sha256: "935e23e1ff3bc02d390bad4d4be001208ee92cc217cb5b5a6c19bc14aaa318c1"

pubspec.yaml

@@ -37,6 +37,7 @@ dependencies:
   resource_portable:
   d4rt: ^0.2.0
   analyzer: ^8.4.1
+  markdown:
   flutter_markdown_plus:
   flutter_markdown_plus_latex:
   flutter_code_editor: