Update the license mechanism to show package names (#5051)

packages/flutter/lib/src/foundation/licenses.dart

@@ -44,10 +44,12 @@ abstract class LicenseEntry {
   /// const constructors so that they can be used in const expressions.
   const LicenseEntry();
 
-  /// Returns each paragraph of the license as a [LicenseParagraph], which
-  /// consists of a string and some formatting information. Paragraphs can
-  /// include newline characters, but this is discouraged as it results in
-  /// ugliness.
+  /// The names of the packages that this license entry applies to.
+  Iterable<String> get packages;
+
+  /// The paragraphs of the license, each as a [LicenseParagraph] consisting of
+  /// a string and some formatting information. Paragraphs can include newline
+  /// characters, but this is discouraged as it results in ugliness.
   Iterable<LicenseParagraph> get paragraphs;
 }
 
@@ -65,7 +67,7 @@ enum _LicenseEntryWithLineBreaksParserState {
 ///
 /// ```dart
 ///   LicenseRegistry.addLicense(() {
-///     yield new LicenseEntryWithLineBreaks('''
+///     yield new LicenseEntryWithLineBreaks(<String>['my_library'], '''
 /// Copyright 2016 The Sample Authors. All rights reserved.
 ///
 /// Redistribution and use in source and binary forms, with or without
@@ -102,7 +104,10 @@ class LicenseEntryWithLineBreaks extends LicenseEntry {
   /// Create a license entry for a license whose text is hard-wrapped within
   /// paragraphs and has paragraph breaks denoted by blank lines or with
   /// indented text.
-  const LicenseEntryWithLineBreaks(this.text);
+  const LicenseEntryWithLineBreaks(this.packages, this.text);
+
+  @override
+  final List<String> packages;
 
   /// The text of the license.
   ///

packages/flutter/lib/src/material/about.dart

@@ -355,7 +355,6 @@ class _LicensePageState extends State<LicensePage> {
 
   Future<Null> _initLicenses() async {
     await for (LicenseEntry license in LicenseRegistry.licenses) {
-      bool haveMargin = true;
       setState(() {
         _licenses.add(new Padding(
           padding: new EdgeInsets.symmetric(vertical: 18.0),
@@ -364,10 +363,20 @@ class _LicensePageState extends State<LicensePage> {
             textAlign: TextAlign.center
           )
         ));
+        _licenses.add(new Container(
+          decoration: new BoxDecoration(
+            border: new Border(bottom: new BorderSide(width: 0.0))
+          ),
+          child: new Text(
+            license.packages.join(', '),
+            style: new TextStyle(fontWeight: FontWeight.bold),
+            textAlign: TextAlign.center
+          )
+        ));
         for (LicenseParagraph paragraph in license.paragraphs) {
           if (paragraph.indent == LicenseParagraph.centeredIndent) {
             _licenses.add(new Padding(
-              padding: new EdgeInsets.only(top: haveMargin ? 0.0 : 16.0),
+              padding: new EdgeInsets.only(top: 16.0),
               child: new Text(
                 paragraph.text,
                 style: new TextStyle(fontWeight: FontWeight.bold),
@@ -377,11 +386,10 @@ class _LicensePageState extends State<LicensePage> {
           } else {
             assert(paragraph.indent >= 0);
             _licenses.add(new Padding(
-              padding: new EdgeInsets.only(top: haveMargin ? 0.0 : 8.0, left: 16.0 * paragraph.indent),
+              padding: new EdgeInsets.only(top: 8.0, left: 16.0 * paragraph.indent),
               child: new Text(paragraph.text)
             ));
           }
-          haveMargin = false;
         }
       });
     }

packages/flutter/lib/src/services/binding.dart

@@ -35,7 +35,16 @@ abstract class ServicesBinding extends BindingBase {
   Stream<LicenseEntry> _addLicenses() async* {
     final String rawLicenses = await rootBundle.loadString('LICENSE', cache: false);
     final List<String> licenses = rawLicenses.split(_licenseSeparator);
-    for (String license in licenses)
-      yield new LicenseEntryWithLineBreaks(license);
+    for (String license in licenses) {
+      final int split = license.indexOf('\n\n');
+      if (split >= 0) {
+        yield new LicenseEntryWithLineBreaks(
+          license.substring(0, split).split('\n'),
+          license.substring(split + 2)
+        );
+      } else {
+        yield new LicenseEntryWithLineBreaks(const <String>[], license);
+      }
+    }
   }
 }

packages/flutter/test/foundation/licenses_test.dart

@@ -9,7 +9,7 @@ void main() {
   test('LicenseEntryWithLineBreaks - most cases', () {
     // There's some trailing spaces in this string.
     // To avoid IDEs stripping them, I've escaped them as \u0020.
-    List<LicenseParagraph> paragraphs = new LicenseEntryWithLineBreaks('''
+    List<LicenseParagraph> paragraphs = new LicenseEntryWithLineBreaks(null, '''
 A
 A
 A
@@ -157,16 +157,16 @@ S
   });
 
   test('LicenseEntryWithLineBreaks - leading and trailing whitespace', () {
-    expect(new LicenseEntryWithLineBreaks('    \n\n    ').paragraphs.toList(), isEmpty);
+    expect(new LicenseEntryWithLineBreaks(null, '    \n\n    ').paragraphs.toList(), isEmpty);
 
     List<LicenseParagraph> paragraphs;
 
-    paragraphs = new LicenseEntryWithLineBreaks('    \nA\n    ').paragraphs.toList();
+    paragraphs = new LicenseEntryWithLineBreaks(null, '    \nA\n    ').paragraphs.toList();
     expect(paragraphs[0].text, 'A');
     expect(paragraphs[0].indent, 0);
     expect(paragraphs, hasLength(1));
 
-    paragraphs = new LicenseEntryWithLineBreaks('\n\n\nA\n\n\n').paragraphs.toList();
+    paragraphs = new LicenseEntryWithLineBreaks(null, '\n\n\nA\n\n\n').paragraphs.toList();
     expect(paragraphs[0].text, 'A');
     expect(paragraphs[0].indent, 0);
     expect(paragraphs, hasLength(1));
@@ -175,12 +175,12 @@ S
   test('LicenseRegistry', () async {
     expect(await LicenseRegistry.licenses.toList(), isEmpty);
     LicenseRegistry.addLicense(() async* {
-      yield new LicenseEntryWithLineBreaks('A');
-      yield new LicenseEntryWithLineBreaks('B');
+      yield new LicenseEntryWithLineBreaks(null, 'A');
+      yield new LicenseEntryWithLineBreaks(null, 'B');
     });
     LicenseRegistry.addLicense(() async* {
-      yield new LicenseEntryWithLineBreaks('C');
-      yield new LicenseEntryWithLineBreaks('D');
+      yield new LicenseEntryWithLineBreaks(null, 'C');
+      yield new LicenseEntryWithLineBreaks(null, 'D');
     });
     expect(await LicenseRegistry.licenses.toList(), hasLength(4));
     List<LicenseEntry> licenses = await LicenseRegistry.licenses.toList();

packages/flutter_tools/lib/src/flx.dart

@@ -203,24 +203,51 @@ Map<_Asset, List<_Asset>> _parseAssets(
 final String _licenseSeparator = '\n' + ('-' * 80) + '\n';
 
 /// Returns a ZipEntry representing the license file.
-ZipEntry _obtainLicenses(
+Future<ZipEntry> _obtainLicenses(
   PackageMap packageMap,
   String assetBase
-) {
+) async {
   // Read the LICENSE file from each package in the .packages file,
   // splitting each one into each component license (so that we can
   // de-dupe if possible).
-  final Set<String> packageLicenses = new Set<String>();
-  final Iterable<Uri> packages = packageMap.map.values;
-  for (Uri package in packages) {
+  // For the sky_engine package we assume each license starts with
+  // package names. For the other packages we assume that each
+  // license is raw.
+  final Map<String, Set<String>> packageLicenses = <String, Set<String>>{};
+  for (String packageName in packageMap.map.keys) {
+    final Uri package = packageMap.map[packageName];
     if (package != null && package.scheme == 'file') {
       final File file = new File.fromUri(package.resolve('../LICENSE'));
-      if (file.existsSync())
-        packageLicenses.addAll(file.readAsStringSync().split(_licenseSeparator));
+      if (file.existsSync()) {
+        final List<String> rawLicenses = (await file.readAsString()).split(_licenseSeparator);
+        for (String rawLicense in rawLicenses) {
+          String licenseText;
+          List<String> packageNames;
+          if (packageName == 'sky_engine') {
+            final int split = rawLicense.indexOf('\n\n');
+            if (split >= 0) {
+              packageNames = rawLicense.substring(0, split).split('\n');
+              licenseText = rawLicense.substring(split + 2);
+            }
+          }
+          if (licenseText == null) {
+            licenseText = rawLicense;
+            packageNames = <String>[packageName];
+          }
+          packageLicenses.putIfAbsent(rawLicense, () => new Set<String>())
+            ..addAll(packageNames);
+        }
+      }
     }
   }
 
-  final List<String> combinedLicensesList = packageLicenses.toList();
+  final List<String> combinedLicensesList = packageLicenses.keys.map(
+    (String license) {
+      List<String> packageNames = packageLicenses[license].toList()
+       ..sort();
+      return packageNames.join('\n') + '\n\n' + license;
+    }
+  ).toList();
   combinedLicensesList.sort();
 
   final String combinedLicenses = combinedLicensesList.join(_licenseSeparator);
@@ -464,7 +491,8 @@ Future<int> assemble({
   if (fontManifest != null)
     zipBuilder.addEntry(fontManifest);
 
-  zipBuilder.addEntry(_obtainLicenses(packageMap, assetBasePath));
+  // TODO(ianh): Only do the following line if we've changed packages
+  zipBuilder.addEntry(await _obtainLicenses(packageMap, assetBasePath));
 
   ensureDirectoryExists(outputPath);