introduce "word selectioner" for path parts in a string literal

platform/lang-impl/src/com/intellij/codeInsight/editorActions/wordSelection/InjectedReferenceSelectioner.java

@@ -0,0 +1,54 @@
+/*
+ * Copyright 2000-2015 JetBrains s.r.o.
+ *
+ * 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.intellij.codeInsight.editorActions.wordSelection;
+
+import com.intellij.openapi.editor.Editor;
+import com.intellij.openapi.util.Conditions;
+import com.intellij.openapi.util.TextRange;
+import com.intellij.psi.PsiElement;
+import com.intellij.psi.PsiLanguageInjectionHost;
+import com.intellij.psi.PsiReference;
+import com.intellij.psi.impl.source.resolve.reference.impl.PsiMultiReference;
+import com.intellij.psi.util.PsiTreeUtil;
+import com.intellij.util.Function;
+import com.intellij.util.containers.JBIterable;
+
+import java.util.Collections;
+import java.util.List;
+
+public class InjectedReferenceSelectioner extends AbstractWordSelectioner {
+  @Override
+  public boolean canSelect(PsiElement e) {
+    return PsiTreeUtil.getParentOfType(e, PsiLanguageInjectionHost.class) != null;
+  }
+
+  @Override
+  public List<TextRange> select(PsiElement e, CharSequence editorText, final int cursorOffset, Editor editor) {
+    PsiReference ref = e.findReferenceAt(cursorOffset - e.getTextRange().getStartOffset());
+    if (ref == null) return Collections.emptyList();
+    JBIterable<PsiReference> it = ref instanceof PsiMultiReference ? JBIterable.of(((PsiMultiReference)ref).getReferences()) : JBIterable.of(ref);
+    return it.transform(new Function<PsiReference, TextRange>() {
+      @Override
+      public TextRange fun(PsiReference ref) {
+        TextRange base = ref.getElement().getTextRange();
+        TextRange r = ref.getRangeInElement().shiftRight(base.getStartOffset());
+        return r.containsOffset(cursorOffset) ? r : null;
+      }
+    }).filter(Conditions.notNull()).toList();
+  }
+
+}

platform/platform-resources/src/META-INF/LangExtensions.xml

@@ -587,6 +587,7 @@
     <extendWordSelectionHandler implementation="com.intellij.codeInsight.editorActions.wordSelection.NaturalLanguageTextSelectioner"/>
     <extendWordSelectionHandler implementation="com.intellij.codeInsight.editorActions.wordSelection.WordSelectioner"/>
     <extendWordSelectionHandler implementation="com.intellij.codeInsight.editorActions.wordSelection.LineCommentSelectioner"/>
+    <extendWordSelectionHandler implementation="com.intellij.codeInsight.editorActions.wordSelection.InjectedReferenceSelectioner"/>
     <extendWordSelectionHandler implementation="com.intellij.ide.highlighter.custom.impl.CustomFileTypeSelectWordHandler"/>
 
     <basicWordSelectionFilter implementation="com.intellij.lang.parser.DummyBlockWordSelectionFilter"/>