Add namespace handling in attribute values

Previously, you could only reference namespace prefixes in attribute names:

<View xmlns:appcompat="http://schemas.android.com/apk/res/android.support.v7.appcompat"
      appcompat:name="hey"
      ...

Now you can also reference them in resource names within an attribute value:

      ...
      android:text="@appcompat:string/confirm"
      ...

Which will be treated as "@android.support.v7.appcompat:string/confirm".

Change-Id: Ib076e867a990c80cf877a704eb77cd1ef0b23b52

1 files changed, 15 insertions, 0 deletions

diff --git a/tools/aapt2/Util.cpp b/tools/aapt2/Util.cpp
index c2418ebebf4c..7adaf1ef6a92 100644
--- a/tools/aapt2/Util.cpp
+++ b/tools/aapt2/Util.cpp
@@ -28,6 +28,9 @@
 namespace aapt {
 namespace util {
 
+constexpr const char16_t* kSchemaAuto = u"http://schemas.android.com/apk/res-auto";
+constexpr const char16_t* kSchemaPrefix = u"http://schemas.android.com/apk/res/";
+
 static std::vector<std::string> splitAndTransform(const StringPiece& str, char sep,
         const std::function<char(char)>& f) {
     std::vector<std::string> parts;
@@ -279,5 +282,17 @@ std::unique_ptr<uint8_t[]> copy(const BigBuffer& buffer) {
     return data;
 }
 
+Maybe<std::u16string> extractPackageFromNamespace(const std::u16string& namespaceUri) {
+    if (stringStartsWith<char16_t>(namespaceUri, kSchemaPrefix)) {
+        StringPiece16 schemaPrefix = kSchemaPrefix;
+        StringPiece16 package = namespaceUri;
+        return package.substr(schemaPrefix.size(), package.size() - schemaPrefix.size())
+                .toString();
+    } else if (namespaceUri == kSchemaAuto) {
+        return std::u16string();
+    }
+    return {};
+}
+
 } // namespace util
 } // namespace aapt