Add "Extra Text" lint detector.

This new lint check looks for XML text content in resource files where
text is not expected, such as layout files. This is typically the
result of a typo.

This CL also improves the command line XML parser's position handling
such that it can handle positions on text nodes (until now it just
supported element and attribute positions), and similarly for Eclipse.

Change-Id: I6f69a8dc725a5b5b19f8ad5bb889ae25ee82600a

6 files changed, 247 insertions, 3 deletions

diff --git a/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/lint/EclipseLintClient.java b/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/lint/EclipseLintClient.java
index 310d689..d105867 100644
--- a/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/lint/EclipseLintClient.java
+++ b/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/lint/EclipseLintClient.java
@@ -587,6 +587,22 @@ public class EclipseLintClient extends LintClient implements IDomParser {
                 int column = -1;
                 int offset = mRegion.getStartOffset();
 
+                if (mRegion instanceof org.w3c.dom.Text && mDocument != null) {
+                    // For text nodes, skip whitespace prefix, if any
+                    for (int i = offset;
+                            i < mRegion.getEndOffset() && i < mDocument.getLength(); i++) {
+                        try {
+                            char c = mDocument.getChar(i);
+                            if (!Character.isWhitespace(c)) {
+                                offset = i;
+                                break;
+                            }
+                        } catch (BadLocationException e) {
+                            break;
+                        }
+                    }
+                }
+
                 if (mDocument != null && offset < mDocument.getLength()) {
                     line = mDocument.getLineOfOffset(offset);
                     column = -1;
diff --git a/lint/cli/src/com/android/tools/lint/PositionXmlParser.java b/lint/cli/src/com/android/tools/lint/PositionXmlParser.java
index 7efdd57..b4af282 100644
--- a/lint/cli/src/com/android/tools/lint/PositionXmlParser.java
+++ b/lint/cli/src/com/android/tools/lint/PositionXmlParser.java
@@ -28,6 +28,7 @@ import org.w3c.dom.Attr;
 import org.w3c.dom.Document;
 import org.w3c.dom.Element;
 import org.w3c.dom.Node;
+import org.w3c.dom.Text;
 import org.xml.sax.Attributes;
 import org.xml.sax.InputSource;
 import org.xml.sax.Locator;
@@ -139,12 +140,13 @@ public class PositionXmlParser implements IDomParser {
                         if (t == '\n') {
                             line++;
                             column = 0;
+                        } else {
+                            column++;
                         }
-                        column++;
                     }
 
                     OffsetPosition attributePosition = new OffsetPosition(line, column, index);
-                    // Also set end range for retrieval in getEndPosition
+                    // Also set end range for retrieval in getLocation
                     attributePosition.next = new OffsetPosition(line, column, matcher.end());
                     return attributePosition;
                 } else {
@@ -152,6 +154,81 @@ public class PositionXmlParser implements IDomParser {
                     return pos;
                 }
             }
+        } else if (node instanceof Text) {
+            // Position of parent element, if any
+            OffsetPosition pos = null;
+            if (node.getPreviousSibling() != null) {
+                pos = (OffsetPosition) node.getPreviousSibling().getUserData(POS_KEY);
+            }
+            if (pos == null) {
+                pos = (OffsetPosition) node.getParentNode().getUserData(POS_KEY);
+            }
+            if (pos != null) {
+                // Attempt to point forward to the actual text node
+                int startOffset = pos.getOffset();
+                int endOffset = pos.next.getOffset();
+                int line = pos.getLine();
+                int column = pos.getColumn();
+
+                // Find attribute in the text
+                String contents = (String) node.getOwnerDocument().getUserData(CONTENT_KEY);
+                if (contents == null || contents.length() < endOffset) {
+                    return null;
+                }
+
+                boolean inAttribute = false;
+                for (int offset = startOffset; offset <= endOffset; offset++) {
+                    char c = contents.charAt(offset);
+                    if (c == '>' && !inAttribute) {
+                        // Found the end of the element open tag: this is where the
+                        // text begins.
+
+                        // Skip >
+                        offset++;
+
+                        // Skip text whitespace prefix, if the text node contains non-whitespace
+                        // characters
+                        String text = node.getNodeValue();
+                        int textIndex = 0;
+                        int textLength = text.length();
+                        int newLine = line;
+                        int newColumn = column;
+                        for (; textIndex < text.length(); textIndex++) {
+                            char t = text.charAt(textIndex);
+                            if (t == '\n') {
+                                newLine++;
+                                newColumn = 0;
+                            } else {
+                                newColumn++;
+                            }
+                            if (!Character.isWhitespace(t)) {
+                                break;
+                            }
+                        }
+                        if (textIndex == textLength) {
+                            textIndex = 0; // Whitespace node
+                        } else {
+                            line = newLine;
+                            column = newColumn;
+                        }
+
+                        OffsetPosition attributePosition = new OffsetPosition(line, column,
+                                offset);
+                        // Also set end range for retrieval in getLocation
+                        attributePosition.next = new OffsetPosition(line, column,
+                                offset + textLength);
+                        return attributePosition;
+                    } else if (c == '"') {
+                        inAttribute = !inAttribute;
+                    } else if (c == '\n') {
+                        line++;
+                        column = -1; // pre-subtract column added below
+                    }
+                    column++;
+                }
+
+                return pos;
+            }
         }
 
         return (OffsetPosition) node.getUserData(POS_KEY);
diff --git a/lint/libs/lint_checks/src/com/android/tools/lint/checks/BuiltinIssueRegistry.java b/lint/libs/lint_checks/src/com/android/tools/lint/checks/BuiltinIssueRegistry.java
index 689ad89..5d31523 100644
--- a/lint/libs/lint_checks/src/com/android/tools/lint/checks/BuiltinIssueRegistry.java
+++ b/lint/libs/lint_checks/src/com/android/tools/lint/checks/BuiltinIssueRegistry.java
@@ -51,7 +51,7 @@ public class BuiltinIssueRegistry extends IssueRegistry {
     private static final List<Issue> sIssues;
 
     static {
-        List<Issue> issues = new ArrayList<Issue>();
+        List<Issue> issues = new ArrayList<Issue>(60);
 
         issues.add(AccessibilityDetector.ISSUE);
         issues.add(MathDetector.ISSUE);
@@ -86,6 +86,7 @@ public class BuiltinIssueRegistry extends IssueRegistry {
         issues.add(TextFieldDetector.ISSUE);
         issues.add(UnusedResourceDetector.ISSUE);
         issues.add(UnusedResourceDetector.ISSUE_IDS);
+        issues.add(ExtraTextDetector.ISSUE);
         issues.add(ArraySizeDetector.INCONSISTENT);
         issues.add(ManifestOrderDetector.ISSUE);
         issues.add(SecurityDetector.EXPORTED_SERVICE);
diff --git a/lint/libs/lint_checks/src/com/android/tools/lint/checks/ExtraTextDetector.java b/lint/libs/lint_checks/src/com/android/tools/lint/checks/ExtraTextDetector.java
new file mode 100644
index 0000000..cf5d2e6
--- /dev/null
+++ b/lint/libs/lint_checks/src/com/android/tools/lint/checks/ExtraTextDetector.java
@@ -0,0 +1,107 @@
+/*
+ * Copyright (C) 2011 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.tools.lint.checks;
+
+import com.android.resources.ResourceFolderType;
+import com.android.tools.lint.detector.api.Category;
+import com.android.tools.lint.detector.api.Issue;
+import com.android.tools.lint.detector.api.ResourceXmlDetector;
+import com.android.tools.lint.detector.api.Scope;
+import com.android.tools.lint.detector.api.Severity;
+import com.android.tools.lint.detector.api.Speed;
+import com.android.tools.lint.detector.api.XmlContext;
+
+import org.w3c.dom.Document;
+import org.w3c.dom.Node;
+import org.w3c.dom.NodeList;
+
+/**
+ * Check which looks for invalid resources. Aapt already performs some validation,
+ * such as making sure that resource references point to resources that exist, but this
+ * detector looks for additional issues.
+ */
+public class ExtraTextDetector extends ResourceXmlDetector {
+    private boolean mFoundText;
+
+    /** The main issue discovered by this detector */
+    public static final Issue ISSUE = Issue.create(
+            "ExtraText", //$NON-NLS-1$
+            "Looks for extraneous text in layout files",
+            "Layout resource files should only contain elements and attributes. Any XML " +
+            "text content found in the file is likely accidental (and potentially " +
+            "dangerous if the text resembles XML and the developer believes the text " +
+            "to be functional)",
+            Category.CORRECTNESS,
+            3,
+            Severity.WARNING,
+            ExtraTextDetector.class,
+            Scope.RESOURCE_FILE_SCOPE);
+
+    /** Constructs a new detector */
+    public ExtraTextDetector() {
+    }
+
+    @Override
+    public boolean appliesTo(ResourceFolderType folderType) {
+        return folderType == ResourceFolderType.LAYOUT
+                || folderType == ResourceFolderType.MENU
+                || folderType == ResourceFolderType.ANIMATOR
+                || folderType == ResourceFolderType.ANIMATOR
+                || folderType == ResourceFolderType.DRAWABLE
+                || folderType == ResourceFolderType.COLOR;
+    }
+
+    @Override
+    public Speed getSpeed() {
+        return Speed.FAST;
+    }
+
+    @Override
+    public void visitDocument(XmlContext context, Document document) {
+        mFoundText = false;
+        visitNode(context, document);
+    }
+
+    private void visitNode(XmlContext context, Node node) {
+        short nodeType = node.getNodeType();
+        if (nodeType == Node.TEXT_NODE && !mFoundText) {
+            String text = node.getNodeValue();
+            for (int i = 0, n = text.length(); i < n; i++) {
+                char c = text.charAt(i);
+                if (!Character.isWhitespace(c)) {
+                    String snippet = text.trim();
+                    int maxLength = 100;
+                    if (snippet.length() > maxLength) {
+                        snippet = snippet.substring(0, maxLength) + "...";
+                    }
+                    context.report(ISSUE, context.getLocation(node),
+                            String.format("Unexpected text found in layout file: \"%1$s\"",
+                                    snippet), null);
+                    mFoundText = true;
+                    break;
+                }
+            }
+        }
+
+        // Visit children
+        NodeList childNodes = node.getChildNodes();
+        for (int i = 0, n = childNodes.getLength(); i < n; i++) {
+            Node child = childNodes.item(i);
+            visitNode(context, child);
+        }
+    }
+}
diff --git a/lint/libs/lint_checks/tests/src/com/android/tools/lint/checks/ExtraTextDetectorTest.java b/lint/libs/lint_checks/tests/src/com/android/tools/lint/checks/ExtraTextDetectorTest.java
new file mode 100644
index 0000000..35c38ac
--- /dev/null
+++ b/lint/libs/lint_checks/tests/src/com/android/tools/lint/checks/ExtraTextDetectorTest.java
@@ -0,0 +1,35 @@
+/*
+ * Copyright (C) 2011 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.tools.lint.checks;
+
+import com.android.tools.lint.detector.api.Detector;
+
+@SuppressWarnings("javadoc")
+public class ExtraTextDetectorTest extends AbstractCheckTest {
+    @Override
+    protected Detector getDetector() {
+        return new ExtraTextDetector();
+    }
+
+    public void testBroken() throws Exception {
+        assertEquals(
+                "broken.xml:5: Warning: Unexpected text found in layout file: \"ImageButton " +
+                "android:id=\"@+id/android_logo2\" android:layout_width=\"wrap_content\"" +
+                " android:layout_heigh...\"",
+                lintProject("res/layout/broken.xml"));
+    }
+}
diff --git a/lint/libs/lint_checks/tests/src/com/android/tools/lint/checks/data/res/layout/broken.xml b/lint/libs/lint_checks/tests/src/com/android/tools/lint/checks/data/res/layout/broken.xml
new file mode 100644
index 0000000..5dd9d2d
--- /dev/null
+++ b/lint/libs/lint_checks/tests/src/com/android/tools/lint/checks/data/res/layout/broken.xml
@@ -0,0 +1,8 @@
+<?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">
+    <Button android:text="Button" android:id="@+id/button1" android:layout_width="wrap_content" android:layout_height="wrap_content"></Button>
+    <ImageView 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" />
+    ImageButton android:id="@+id/android_logo2" 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" />
+    <Button android:text="Button" android:id="@+id/button2" android:layout_width="wrap_content" android:layout_height="wrap_content"></Button>
+    <Button android:id="@+android:id/summary" android:contentDescription="@string/label" />
+</LinearLayout>