Warn about custom namespaces on builtin tags

This CL adds a lint check which flags using unknown namespaces
on non custom views.

Change-Id: I5d53635e5e0ea7be774f90c07103f1defae97980

4 files changed, 44 insertions, 6 deletions

diff --git a/lint/libs/lint_checks/src/com/android/tools/lint/checks/DetectMissingPrefix.java b/lint/libs/lint_checks/src/com/android/tools/lint/checks/DetectMissingPrefix.java
index 6ce22f7..71ea704 100644
--- a/lint/libs/lint_checks/src/com/android/tools/lint/checks/DetectMissingPrefix.java
+++ b/lint/libs/lint_checks/src/com/android/tools/lint/checks/DetectMissingPrefix.java
@@ -17,11 +17,13 @@
 package com.android.tools.lint.checks;
 
 import static com.android.SdkConstants.ANDROID_PKG_PREFIX;
+import static com.android.SdkConstants.ANDROID_URI;
 import static com.android.SdkConstants.ATTR_CLASS;
 import static com.android.SdkConstants.ATTR_CORE_APP;
 import static com.android.SdkConstants.ATTR_LAYOUT;
 import static com.android.SdkConstants.ATTR_PACKAGE;
 import static com.android.SdkConstants.ATTR_STYLE;
+import static com.android.SdkConstants.TOOLS_URI;
 import static com.android.SdkConstants.VIEW_TAG;
 import static com.android.SdkConstants.XMLNS_PREFIX;
 import static com.android.resources.ResourceFolderType.ANIM;
@@ -44,6 +46,7 @@ import com.android.tools.lint.detector.api.XmlContext;
 
 import org.w3c.dom.Attr;
 import org.w3c.dom.Element;
+import org.w3c.dom.Node;
 
 import java.util.Collection;
 import java.util.EnumSet;
@@ -134,6 +137,21 @@ public class DetectMissingPrefix extends LayoutDetector {
                     context.getLocation(attribute),
                     "Attribute is missing the Android namespace prefix",
                     null);
+        } else if (!ANDROID_URI.equals(uri)
+                && !TOOLS_URI.equals(uri)
+                && context.getResourceFolderType() == ResourceFolderType.LAYOUT
+                && !isCustomView(attribute.getOwnerElement())
+                // TODO: Consider not enforcing that the parent is a custom view
+                // too, though in that case we should filter out views that are
+                // layout params for the custom view parent:
+                // ....&& !attribute.getLocalName().startsWith(ATTR_LAYOUT_RESOURCE_PREFIX)
+                && attribute.getOwnerElement().getParentNode().getNodeType() == Node.ELEMENT_NODE
+                && !isCustomView((Element) attribute.getOwnerElement().getParentNode())) {
+            context.report(MISSING_NAMESPACE, attribute,
+                    context.getLocation(attribute),
+                    String.format("Unexpected namespace prefix \"%1$s\" found for tag %2$s",
+                            attribute.getPrefix(), attribute.getOwnerElement().getTagName()),
+                            null);
         }
     }
 
diff --git a/lint/libs/lint_checks/tests/src/com/android/tools/lint/checks/DetectMissingPrefixTest.java b/lint/libs/lint_checks/tests/src/com/android/tools/lint/checks/DetectMissingPrefixTest.java
index 944fe4f..3c03ea2 100644
--- a/lint/libs/lint_checks/tests/src/com/android/tools/lint/checks/DetectMissingPrefixTest.java
+++ b/lint/libs/lint_checks/tests/src/com/android/tools/lint/checks/DetectMissingPrefixTest.java
@@ -28,13 +28,15 @@ public class DetectMissingPrefixTest extends AbstractCheckTest {
     public void test() throws Exception {
         assertEquals(
             "res/layout/namespace.xml:2: Error: Attribute is missing the Android namespace prefix [MissingPrefix]\n" +
-            "<LinearLayout xmlns:android=\"http://schemas.android.com/apk/res/android\" android:id=\"@+id/newlinear\" android:orientation=\"vertical\" android:layout_width=\"match_parent\" android:layout_height=\"match_parent\" orientation=\"true\">\n" +
-            "                                                                                                             ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\n" +
+            "<LinearLayout xmlns:android=\"http://schemas.android.com/apk/res/android\" xmlns:other=\"http://foo.bar\" android:id=\"@+id/newlinear\" android:orientation=\"vertical\" android:layout_width=\"match_parent\" android:layout_height=\"match_parent\" orientation=\"true\">\n" +
+            "                                                                                                                                          ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\n" +
             "res/layout/namespace.xml:3: Error: Attribute is missing the Android namespace prefix [MissingPrefix]\n" +
             "    <Button style=\"@style/setupWizardOuterFrame\" android.text=\"Button\" android:id=\"@+id/button1\" android:layout_width=\"wrap_content\" android:layout_height=\"wrap_content\"></Button>\n" +
             "                                                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\n" +
-            "2 errors, 0 warnings\n" +
-            "",
+            "res/layout/namespace.xml:5: Error: Unexpected namespace prefix \"other\" found for tag LinearLayout [MissingPrefix]\n" +
+            "    <LinearLayout other:orientation=\"horizontal\"/>\n" +
+            "                  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\n" +
+            "3 errors, 0 warnings\n",
 
             lintFiles("res/layout/namespace.xml"));
     }
diff --git a/lint/libs/lint_checks/tests/src/com/android/tools/lint/checks/data/res/layout/namespace.xml b/lint/libs/lint_checks/tests/src/com/android/tools/lint/checks/data/res/layout/namespace.xml
index e8f60bb..a984333 100644
--- a/lint/libs/lint_checks/tests/src/com/android/tools/lint/checks/data/res/layout/namespace.xml
+++ b/lint/libs/lint_checks/tests/src/com/android/tools/lint/checks/data/res/layout/namespace.xml
@@ -1,6 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
-<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:id="@+id/newlinear" android:orientation="vertical" android:layout_width="match_parent" android:layout_height="match_parent" orientation="true">
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:other="http://foo.bar" android:id="@+id/newlinear" android:orientation="vertical" android:layout_width="match_parent" android:layout_height="match_parent" orientation="true">
     <Button style="@style/setupWizardOuterFrame" android.text="Button" android:id="@+id/button1" android:layout_width="wrap_content" android:layout_height="wrap_content"></Button>
     <ImageView android:style="@style/bogus" android:id="@+id/android_logo" android:layout_width="wrap_content" android:layout_height="wrap_content" android:src="@drawable/android_button" android:focusable="false" android:clickable="false" android:layout_weight="1.0" />
+    <LinearLayout other:orientation="horizontal"/>
 </LinearLayout>
 
diff --git a/lint/libs/lint_checks/tests/src/com/android/tools/lint/checks/data/res/layout/namespace2.xml b/lint/libs/lint_checks/tests/src/com/android/tools/lint/checks/data/res/layout/namespace2.xml
index a45af90..59001c2 100644
--- a/lint/libs/lint_checks/tests/src/com/android/tools/lint/checks/data/res/layout/namespace2.xml
+++ b/lint/libs/lint_checks/tests/src/com/android/tools/lint/checks/data/res/layout/namespace2.xml
@@ -6,7 +6,24 @@
     customprefix:layout_width="match_parent"
     customprefix:layout_height="match_parent"
     customprefix:orientation="vertical"
-    bogus:orientation="bogus"
     orientation="true">
 
+    <view class="foo.bar.LinearLayout">
+        bogus:orientation="bogus"
+    </view>
+
+    <foo.bar.LinearLayout
+        customprefix:id="@+id/newlinear2"
+        customprefix:layout_width="match_parent"
+        customprefix:layout_height="match_parent"
+        customprefix:orientation="vertical"
+        bogus:orientation="bogus"
+        orientation="true">
+
+        <view class="foo.bar.LinearLayout">
+            bogus:orientation="bogus"
+        </view>
+
+    </foo.bar.LinearLayout>
+
 </LinearLayout>