| /* |
| * Copyright (C) 2015 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.idea.lang.databinding; |
| |
| import com.android.annotations.Nullable; |
| import com.android.tools.idea.lang.databinding.parser.DbParser; |
| import com.android.tools.idea.lang.databinding.psi.DbTokenType; |
| import com.android.tools.idea.lang.databinding.psi.DbTokenTypes; |
| import com.android.tools.idea.lang.databinding.psi.PsiDbConstantValue; |
| import com.android.tools.idea.lang.databinding.psi.PsiDbDefaults; |
| import com.intellij.openapi.util.Ref; |
| import com.intellij.psi.PsiElement; |
| import com.intellij.psi.PsiFile; |
| import com.intellij.psi.PsiLanguageInjectionHost; |
| import com.intellij.psi.impl.source.tree.injected.InjectedLanguageUtil; |
| import com.intellij.psi.util.PsiTreeUtil; |
| import com.intellij.psi.xml.XmlAttribute; |
| import com.intellij.psi.xml.XmlAttributeValue; |
| import org.jetbrains.annotations.NotNull; |
| |
| import java.util.List; |
| import java.util.regex.Matcher; |
| import java.util.regex.Pattern; |
| |
| /** |
| * Helper methods for data binding. |
| */ |
| public class DbUtil { |
| |
| @Nullable |
| public static String getBindingExprDefault(@NotNull XmlAttribute psiAttribute) { |
| XmlAttributeValue attrValue = psiAttribute.getValueElement(); |
| if (attrValue instanceof PsiLanguageInjectionHost) { |
| final Ref<PsiElement> injections = Ref.create(); |
| InjectedLanguageUtil.enumerate(attrValue, new PsiLanguageInjectionHost.InjectedPsiVisitor() { |
| @Override |
| public void visit(@NotNull PsiFile injectedPsi, @NotNull List<PsiLanguageInjectionHost.Shred> places) { |
| if (injectedPsi instanceof DbFile) { |
| injections.set(injectedPsi); |
| } |
| } |
| }); |
| if (injections.get() != null) { |
| PsiDbDefaults defaults = PsiTreeUtil.getChildOfType(injections.get(), PsiDbDefaults.class); |
| if (defaults != null) { |
| // TODO: extract value from literals and resolve variable values if needed. |
| PsiDbConstantValue constantValue = defaults.getConstantValue(); |
| if (constantValue.getNode().getElementType() == DbTokenTypes.STRING_LITERAL) { |
| String text = constantValue.getText(); |
| return text.substring(1, text.length() -1); // return unquoted string literal. |
| } |
| return constantValue.getText(); |
| } |
| } |
| } |
| return null; |
| } |
| |
| /** |
| * @param exprn Data binding expression enclosed in @{} |
| * @return |
| */ |
| @Nullable |
| public static String getBindingExprDefault(@NotNull String exprn) { |
| if (!exprn.contains(DbTokenTypes.DEFAULT_KEYWORD.toString())) { |
| // A fast check since many expressions would likely not have a default. |
| return null; |
| } |
| Pattern defaultCheck = Pattern.compile(",\\s*default\\s*=\\s*"); |
| int index = 0; |
| Matcher matcher = defaultCheck.matcher(exprn); |
| while (matcher.find()) { |
| index = matcher.end(); |
| } |
| String def = exprn.substring(index, exprn.length() - 1).trim(); // remove the trailing "}" |
| if (def.startsWith("\"") && def.endsWith("\"")) { |
| def = def.substring(1, def.length() - 1); // Unquote the string. |
| } |
| return def; |
| } |
| |
| /** Disallow instances. */ |
| private DbUtil() { |
| } |
| } |