com.android.tools.lint.checks.GridLayoutDetector Maven / Gradle / Ivy
/*
* 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 static com.android.SdkConstants.ANDROID_NS_NAME;
import static com.android.SdkConstants.ANDROID_URI;
import static com.android.SdkConstants.ATTR_COLUMN_COUNT;
import static com.android.SdkConstants.ATTR_LAYOUT_COLUMN;
import static com.android.SdkConstants.ATTR_LAYOUT_COLUMN_SPAN;
import static com.android.SdkConstants.ATTR_LAYOUT_GRAVITY;
import static com.android.SdkConstants.ATTR_LAYOUT_ROW;
import static com.android.SdkConstants.ATTR_LAYOUT_ROW_SPAN;
import static com.android.SdkConstants.ATTR_ORIENTATION;
import static com.android.SdkConstants.ATTR_ROW_COUNT;
import static com.android.SdkConstants.ATTR_USE_DEFAULT_MARGINS;
import static com.android.SdkConstants.AUTO_URI;
import static com.android.SdkConstants.FQCN_GRID_LAYOUT_V7;
import static com.android.SdkConstants.GRID_LAYOUT;
import static com.android.SdkConstants.XMLNS_PREFIX;
import com.android.annotations.NonNull;
import com.android.annotations.Nullable;
import com.android.tools.lint.detector.api.Category;
import com.android.tools.lint.detector.api.Implementation;
import com.android.tools.lint.detector.api.Issue;
import com.android.tools.lint.detector.api.LayoutDetector;
import com.android.tools.lint.detector.api.LintUtils;
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.TextFormat;
import com.android.tools.lint.detector.api.XmlContext;
import org.w3c.dom.Attr;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;
import java.util.Arrays;
import java.util.Collection;
/**
* Check which looks for potential errors in declarations of GridLayouts, such as specifying
* row/column numbers outside the declared dimensions of the grid.
*/
public class GridLayoutDetector extends LayoutDetector {
/** The main issue discovered by this detector */
public static final Issue ISSUE = Issue.create(
"GridLayout", //$NON-NLS-1$
"GridLayout validation",
"Declaring a layout_row or layout_column that falls outside the declared size " +
"of a GridLayout's `rowCount` or `columnCount` is usually an unintentional error.",
Category.CORRECTNESS,
4,
Severity.FATAL,
new Implementation(
GridLayoutDetector.class,
Scope.RESOURCE_FILE_SCOPE));
/** Constructs a new {@link GridLayoutDetector} check */
public GridLayoutDetector() {
}
@NonNull
@Override
public Speed getSpeed() {
return Speed.FAST;
}
@Override
public Collection getApplicableElements() {
return Arrays.asList(
GRID_LAYOUT,
FQCN_GRID_LAYOUT_V7
);
}
private static int getInt(Element element, String attribute, int defaultValue) {
String valueString = element.getAttributeNS(ANDROID_URI, attribute);
if (valueString != null && !valueString.isEmpty()) {
try {
return Integer.decode(valueString);
} catch (NumberFormatException nufe) {
// Ignore - error in user's XML
}
}
return defaultValue;
}
@Override
public void visitElement(@NonNull XmlContext context, @NonNull Element element) {
int declaredRowCount = getInt(element, ATTR_ROW_COUNT, -1);
int declaredColumnCount = getInt(element, ATTR_COLUMN_COUNT, -1);
if (declaredColumnCount != -1 || declaredRowCount != -1) {
for (Element child : LintUtils.getChildren(element)) {
if (declaredColumnCount != -1) {
int column = getInt(child, ATTR_LAYOUT_COLUMN, -1);
if (column >= declaredColumnCount) {
Attr node = child.getAttributeNodeNS(ANDROID_URI, ATTR_LAYOUT_COLUMN);
context.report(ISSUE, node, context.getLocation(node),
String.format("Column attribute (%1$d) exceeds declared grid column count (%2$d)",
column, declaredColumnCount));
}
}
if (declaredRowCount != -1) {
int row = getInt(child, ATTR_LAYOUT_ROW, -1);
if (row > declaredRowCount) {
Attr node = child.getAttributeNodeNS(ANDROID_URI, ATTR_LAYOUT_ROW);
context.report(ISSUE, node, context.getLocation(node),
String.format("Row attribute (%1$d) exceeds declared grid row count (%2$d)",
row, declaredRowCount));
}
}
}
}
if (element.getTagName().equals(FQCN_GRID_LAYOUT_V7)) {
// Make sure that we're not using android: namespace attributes where we should
// be using app namespace attributes!
ensureAppNamespace(context, element, ATTR_COLUMN_COUNT);
ensureAppNamespace(context, element, ATTR_ORIENTATION);
ensureAppNamespace(context, element, ATTR_ROW_COUNT);
ensureAppNamespace(context, element, ATTR_USE_DEFAULT_MARGINS);
ensureAppNamespace(context, element, "alignmentMode");
ensureAppNamespace(context, element, "columnOrderPreserved");
ensureAppNamespace(context, element, "rowOrderPreserved");
for (Element child : LintUtils.getChildren(element)) {
ensureAppNamespace(context, child, ATTR_LAYOUT_COLUMN);
ensureAppNamespace(context, child, ATTR_LAYOUT_COLUMN_SPAN);
ensureAppNamespace(context, child, ATTR_LAYOUT_GRAVITY);
ensureAppNamespace(context, child, ATTR_LAYOUT_ROW);
ensureAppNamespace(context, child, ATTR_LAYOUT_ROW_SPAN);
}
}
}
private static void ensureAppNamespace(XmlContext context, Element element, String name) {
Attr attribute = element.getAttributeNodeNS(ANDROID_URI, name);
if (attribute != null) {
String prefix = getNamespacePrefix(element.getOwnerDocument(), AUTO_URI);
boolean haveNamespace = prefix != null;
if (!haveNamespace) {
prefix = "app";
}
StringBuilder sb = new StringBuilder();
sb.append("Wrong namespace; with v7 `GridLayout` you should use ").append(prefix)
.append(":").append(name);
if (!haveNamespace) {
sb.append(" (and add `xmlns:app=\"").append(AUTO_URI)
.append("\"` to your root element.)");
}
String message = sb.toString();
context.report(ISSUE, attribute, context.getLocation(attribute), message);
}
}
@Nullable
private static String getNamespacePrefix(Document document, String uri) {
Element root = document.getDocumentElement();
if (root == null) {
return null;
}
NamedNodeMap attributes = root.getAttributes();
for (int i = 0, n = attributes.getLength(); i < n; i++) {
Node attribute = attributes.item(i);
if (attribute.getNodeName().startsWith(XMLNS_PREFIX) &&
attribute.getNodeValue().equals(uri)) {
return attribute.getNodeName().substring(XMLNS_PREFIX.length());
}
}
return null;
}
/**
* Given an error message produced by this lint detector,
* returns the old value to be replaced in the source code.
*
* Intended for IDE quickfix implementations.
*
* @param errorMessage the error message associated with the error
* @param format the format of the error message
* @return the corresponding old value, or null if not recognized
*/
@Nullable
public static String getOldValue(@NonNull String errorMessage,
@NonNull TextFormat format) {
errorMessage = format.toText(errorMessage);
String attribute = LintUtils.findSubstring(errorMessage, " should use ", " ");
if (attribute == null) {
attribute = LintUtils.findSubstring(errorMessage, " should use ", null);
}
if (attribute != null) {
int index = attribute.indexOf(':');
if (index != -1) {
return ANDROID_NS_NAME + attribute.substring(index);
}
}
return null;
}
/**
* Given an error message produced by this lint detector,
* returns the new value to be put into the source code.
*
* Intended for IDE quickfix implementations.
*
* @param errorMessage the error message associated with the error
* @param format the format of the error message
* @return the corresponding new value, or null if not recognized
*/
@Nullable
public static String getNewValue(@NonNull String errorMessage,
@NonNull TextFormat format) {
errorMessage = format.toText(errorMessage);
String attribute = LintUtils.findSubstring(errorMessage, " should use ", " ");
if (attribute == null) {
attribute = LintUtils.findSubstring(errorMessage, " should use ", null);
}
return attribute;
}
}