Added "Toggle alias", conflict panel, descriptions; refactored intentions.

python/src/META-INF/python-plugin-common.xml

@@ -76,6 +76,12 @@
       <descriptionDirectoryName>ImportFromToImportIntention</descriptionDirectoryName>
     </intentionAction>
 
+    <intentionAction>
+      <className>com.jetbrains.python.codeInsight.intentions.ImportToggleAliasIntention</className>
+      <category>Python</category>
+      <descriptionDirectoryName>ImportToggleAliasIntention</descriptionDirectoryName>
+    </intentionAction>
+
     <fileStructureGroupRuleProvider implementation="com.jetbrains.python.codeInsight.intentions.PyRefGroupRuleProvider"/>
 
     <stubElementTypeHolder class="com.jetbrains.python.PyElementTypes"/>

python/src/com/jetbrains/python/PyBundle.properties

@@ -33,7 +33,9 @@ QFIX.action.failed=Action failed
 QFIX.remove.trailing.semicolon=Remove trailing semicolon
 
 # Intentions: INTN
-INTN.Family.convert.import=Convert import
+INTN.Family.convert.import.unqualify=Convert 'import' to 'from ... import'
+INTN.Family.convert.import.qualify=Convert 'from ... import' to 'import'
+INTN.Family.toggle.import.alias=Toggle import alias
 
 INTN.convert.to.from.$0.import=Convert to ''from {0} import ...''
 

python/src/com/jetbrains/python/PyNames.java

@@ -5,9 +5,10 @@ import org.jetbrains.annotations.NonNls;
 import java.util.HashSet;
 import java.util.Set;
 import java.util.Collections;
+import java.util.regex.Pattern;
 
 /**
- * @author yole
+ * @author dcheryasov
  */
 public class PyNames {
   private PyNames() {
@@ -122,4 +123,68 @@ public class PyNames {
 
   // canonical names, not forced by interpreter
   public static final String CANONICAL_SELF = "self";
+  
+  @NonNls private static final Set<String> _Keywords = new HashSet<String>();
+  static {
+    _Keywords.add("and");
+    _Keywords.add("del");
+    _Keywords.add("from");
+    _Keywords.add("not");
+    _Keywords.add("while");
+    _Keywords.add("as");
+    _Keywords.add("elif");
+    _Keywords.add("global");
+    _Keywords.add("or");
+    _Keywords.add("with");
+    _Keywords.add("assert");
+    _Keywords.add("else");
+    _Keywords.add("if");
+    _Keywords.add("pass");
+    _Keywords.add("yield");
+    _Keywords.add("break");
+    _Keywords.add("except");
+    _Keywords.add("import");
+    _Keywords.add("print");
+    _Keywords.add("class");
+    _Keywords.add("exec");
+    _Keywords.add("in");
+    _Keywords.add("raise");
+    _Keywords.add("continue");
+    _Keywords.add("finally");
+    _Keywords.add("is");
+    _Keywords.add("return");
+    _Keywords.add("def");
+    _Keywords.add("for");
+    _Keywords.add("lambda");
+    _Keywords.add("try");
+  }
+
+  /**
+   * Contains keywords as of CPython 2.5.
+   */
+  public static Set<String> Keywords = Collections.unmodifiableSet(_Keywords);
+
+  /**
+   * TODO: dependency on language level.
+   * @param name what to check
+   * @return true iff the name is either a keyword or a reserved name, like None.
+   *
+   */
+  public static boolean isReserved(@NonNls String name) {
+    return Keywords.contains(name) || NONE.equals(name) || "as".equals(name) || "with".equals(name);
+  }
+
+  // NOTE: includes unicode only good for py3k
+  private final static Pattern IDENTIFIER_PATTERN = Pattern.compile("\\p{javaJavaIdentifierStart}\\p{javaJavaIdentifierPart}*");
+
+  /**
+   * TODO: dependency on language level.
+   * @param name what to check
+   * @return true iff name is not reserved and is a well-formed identifier.
+   */
+  public static boolean isIdentifier(@NonNls String name) {
+    return ! isReserved(name) && IDENTIFIER_PATTERN.matcher(name).matches(); 
+  }
+
+
 }

python/src/com/jetbrains/python/codeInsight/intentions/AskNameDialog.form

@@ -0,0 +1,43 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<form xmlns="http://www.intellij.com/uidesigner/form/" version="1" bind-to-class="com.jetbrains.python.codeInsight.intentions.AskNameDialog">
+  <grid id="cbd77" binding="contentPane" layout-manager="GridLayoutManager" row-count="1" column-count="1" same-size-horizontally="false" same-size-vertically="false" hgap="-1" vgap="-1">
+    <margin top="10" left="10" bottom="10" right="10"/>
+    <constraints>
+      <xy x="48" y="254" width="436" height="64"/>
+    </constraints>
+    <properties/>
+    <border type="none"/>
+    <children>
+      <grid id="e3588" layout-manager="GridLayoutManager" row-count="1" column-count="2" same-size-horizontally="false" same-size-vertically="false" hgap="-1" vgap="-1">
+        <margin top="0" left="0" bottom="0" right="0"/>
+        <constraints>
+          <grid row="0" column="0" row-span="1" col-span="1" vsize-policy="3" hsize-policy="3" anchor="0" fill="3" indent="0" use-parent-layout="false"/>
+        </constraints>
+        <properties/>
+        <border type="none"/>
+        <children>
+          <component id="409e3" class="javax.swing.JLabel">
+            <constraints>
+              <grid row="0" column="0" row-span="1" col-span="1" vsize-policy="0" hsize-policy="0" anchor="8" fill="0" indent="0" use-parent-layout="false"/>
+            </constraints>
+            <properties>
+              <labelFor value="8af36"/>
+              <text value="&amp;Alias:"/>
+            </properties>
+          </component>
+          <component id="8af36" class="javax.swing.JTextField" binding="myAliasTextField" default-binding="true">
+            <constraints>
+              <grid row="0" column="1" row-span="1" col-span="1" vsize-policy="0" hsize-policy="6" anchor="8" fill="1" indent="0" use-parent-layout="false">
+                <preferred-size width="150" height="-1"/>
+              </grid>
+            </constraints>
+            <properties/>
+            <clientProperties>
+              <caretAspectRatio class="java.lang.Float" value="0.04"/>
+            </clientProperties>
+          </component>
+        </children>
+      </grid>
+    </children>
+  </grid>
+</form>

python/src/com/jetbrains/python/codeInsight/intentions/AskNameDialog.java

@@ -0,0 +1,40 @@
+package com.jetbrains.python.codeInsight.intentions;
+
+import com.intellij.openapi.project.Project;
+import com.intellij.openapi.ui.DialogWrapper;
+import com.jetbrains.python.PyNames;
+
+import javax.swing.*;
+import java.awt.event.ActionEvent;
+import java.awt.event.ActionListener;
+
+public class AskNameDialog extends DialogWrapper {
+  private JPanel contentPane;
+  private JTextField myAliasTextField;
+
+  protected AskNameDialog(Project project) {
+    super(project);
+    myAliasTextField.addActionListener(
+      new ActionListener() {
+        public void actionPerformed(ActionEvent actionEvent) {
+          AskNameDialog.this.setOKActionEnabled(PyNames.isIdentifier(myAliasTextField.getText()));
+        }
+      }
+    );
+    init();
+  }
+
+  @Override
+  protected JComponent createCenterPanel() {
+    return contentPane;
+  }
+
+  @Override
+  public JComponent getPreferredFocusedComponent() {
+    return myAliasTextField;
+  }
+
+  public String getAlias() {
+    return myAliasTextField.getText();
+  }
+}

python/src/com/jetbrains/python/codeInsight/intentions/DeclarationConflictChecker.java

@@ -0,0 +1,88 @@
+package com.jetbrains.python.codeInsight.intentions;
+
+import com.intellij.openapi.project.Project;
+import com.intellij.openapi.util.Pair;
+import com.intellij.psi.PsiElement;
+import com.intellij.psi.PsiReference;
+import com.intellij.usages.Usage;
+import com.intellij.usages.UsageTarget;
+import com.intellij.usages.UsageViewManager;
+import com.intellij.usages.UsageViewPresentation;
+import com.jetbrains.python.psi.NameDefiner;
+import com.jetbrains.python.psi.resolve.PyResolveUtil;
+import com.jetbrains.python.psi.resolve.ResolveProcessor;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.List;
+
+/**
+ * An utility class that checks local definitions of a given name and can show a conflicts panel.
+ * User: dcheryasov
+ * Date: Oct 11, 2009 5:59:12 AM
+ */
+public class DeclarationConflictChecker {
+  private DeclarationConflictChecker() { /* Don't instantiate */ }
+
+  /**
+   * For each reference in the collection, finds a definition of name visible from the point of the reference. Returns a list of
+   * such definitions.
+   * @param name what to look for.
+   * @param references references to check.
+   * @param ignored if an element defining the name is also listed here, ignore it.
+   * @return a list of pairs (referring element, element that defines name).
+   */
+  @NotNull
+  public static List<Pair<PsiElement, PsiElement>> findDefinitions(
+    String name, Collection<? extends PsiReference> references, @Nullable Collection<? extends PsiElement> ignored
+  ) {
+    List<Pair<PsiElement, PsiElement>> conflicts = new ArrayList<Pair<PsiElement, PsiElement>>();
+    REF_LOOP:
+    for (PsiReference ref : references) {
+      ResolveProcessor processor = new ResolveProcessor(name);
+      PyResolveUtil.treeCrawlUp(processor, ref.getElement());
+      PsiElement result = processor.getResult();
+      if (result != null) {
+        List<NameDefiner> definers = processor.getDefiners();
+        if (definers != null && definers.size() > 0) {
+          result = definers.get(0); // in this case, processor's result is one hop of resolution too far from what we want.
+        }
+        if (ignored != null) for (PsiElement ignorable : ignored) {
+          if (result == ignorable) continue REF_LOOP;
+        }
+        conflicts.add(new Pair<PsiElement, PsiElement>(ref.getElement(), result));
+      }
+    }
+    return conflicts;
+  }
+
+  /**
+   * Shows a panel with name redefinition conflicts, if needed.
+   * @param project
+   * @param conflicts what {@link #findDefinitions} would return
+   * @param obscured name or its topmost qualifier that is obscured, used at top of pane.
+   * @param name full name (maybe qualified) to show as obscured and display as qualifier in "would be" chunks.
+   * @return true iff conflicts is not empty and the panel is shown.
+   */
+  public static boolean showConflicts(Project project, List<Pair<PsiElement, PsiElement>> conflicts, String obscured, @Nullable String name) {
+    if (conflicts.size() > 0) {
+      Usage[] usages = new Usage[conflicts.size()];
+      int i = 0;
+      for (Pair<PsiElement, PsiElement> pair : conflicts) {
+        usages[i] = new NameUsage(pair.getFirst(), pair.getSecond(), name != null? name : obscured, name != null);
+        i += 1;
+      }
+      UsageViewPresentation prsnt = new UsageViewPresentation();
+      prsnt.setTabText("Name '" + obscured + "' obscured by local redefinitions. ");
+      prsnt.setCodeUsagesString("Name '" + obscured + "' obscured. Cannot convert import.");
+      prsnt.setUsagesWord("occurrence");
+      prsnt.setUsagesString("occurrences");
+      UsageViewManager.getInstance(project).showUsages(UsageTarget.EMPTY_ARRAY, usages, prsnt);
+      return true;
+    }
+    return false;
+  }
+}
+

python/src/com/jetbrains/python/codeInsight/intentions/ImportFromToImportIntention.java

@@ -1,39 +1,29 @@
 package com.jetbrains.python.codeInsight.intentions;
 
 import com.intellij.codeInsight.intention.IntentionAction;
-import com.intellij.ide.util.EditSourceUtil;
 import com.intellij.lang.ASTNode;
 import com.intellij.lang.Language;
 import com.intellij.openapi.editor.Editor;
-import com.intellij.openapi.editor.markup.TextAttributes;
-import com.intellij.openapi.fileEditor.FileEditorLocation;
 import com.intellij.openapi.project.Project;
 import com.intellij.openapi.ui.MessageType;
-import com.intellij.openapi.util.Pair;
-import com.intellij.pom.Navigatable;
 import com.intellij.psi.PsiElement;
 import com.intellij.psi.PsiFile;
 import com.intellij.psi.PsiReference;
 import com.intellij.psi.ResolveResult;
 import com.intellij.psi.search.PsiElementProcessor;
 import com.intellij.psi.util.PsiTreeUtil;
-import com.intellij.usages.*;
-import com.intellij.usages.rules.PsiElementUsage;
 import com.intellij.util.IncorrectOperationException;
 import com.intellij.util.containers.HashMap;
 import com.jetbrains.python.PyBundle;
 import com.jetbrains.python.PythonLanguage;
+import static com.jetbrains.python.codeInsight.intentions.DeclarationConflictChecker.findDefinitions;
+import static com.jetbrains.python.codeInsight.intentions.DeclarationConflictChecker.showConflicts;
 import com.jetbrains.python.psi.*;
 import static com.jetbrains.python.psi.PyUtil.sure;
 import com.jetbrains.python.psi.resolve.PyResolveUtil;
-import com.jetbrains.python.psi.resolve.ResolveProcessor;
 import org.jetbrains.annotations.NotNull;
-import org.jetbrains.annotations.Nullable;
 
-import javax.swing.*;
-import java.awt.*;
-import java.util.ArrayList;
-import java.util.List;
+import java.util.Arrays;
 import java.util.Map;
 
 /**
@@ -50,11 +40,6 @@ public class ImportFromToImportIntention implements IntentionAction {
   private PyReferenceExpression myModuleReference = null;
   private String myModuleName = null;
 
-  @Nullable
-  private static PyFromImportStatement findStatement(Editor editor, PsiFile file) {
-    return PsiTreeUtil.getParentOfType(file.findElementAt(editor.getCaretModel().getOffset()), PyFromImportStatement.class);
-  }
-
   @NotNull
   public String getText() {
     String name = myModuleName != null? myModuleName : "...";
@@ -63,11 +48,11 @@ public class ImportFromToImportIntention implements IntentionAction {
 
   @NotNull
   public String getFamilyName() {
-    return PyBundle.message("INTN.Family.convert.import");
+    return PyBundle.message("INTN.Family.convert.import.qualify");
   }
 
   public boolean isAvailable(@NotNull Project project, Editor editor, PsiFile file) {
-    myFromImportStatement = findStatement(editor, file);
+    myFromImportStatement = PsiTreeUtil.getParentOfType(file.findElementAt(editor.getCaretModel().getOffset()), PyFromImportStatement.class);
     if (myFromImportStatement != null) {
       myModuleReference = myFromImportStatement.getImportSource();
       if (myModuleReference != null) myModuleName = PyResolveUtil.toPath(myModuleReference, ".");
@@ -111,33 +96,14 @@ public class ImportFromToImportIntention implements IntentionAction {
         feeler = top_qualifier.getQualifier();
       } while (feeler != null);
       String top_name = top_qualifier.getName();
-      List<Pair<PsiElement, PsiElement>> conflicts = new ArrayList<Pair<PsiElement, PsiElement>>();
-      for (PsiReference ref : references.keySet()) {
-        ResolveProcessor processor = new ResolveProcessor(top_name);
-        PyResolveUtil.treeCrawlUp(processor, ref.getElement());
-        PsiElement result = processor.getResult();
-        if (result != null) {
-          List<NameDefiner> definers = processor.getDefiners();
-          if (definers != null && definers.size() > 0) {
-            result = definers.get(0); // in this case, processor's result is one hop of resolution too far from what we want.
-          }
-          conflicts.add(new Pair<PsiElement, PsiElement>(ref.getElement(), result));
-        }
-      }
-      if (conflicts.size() > 0) {
-        Usage[] usages = new Usage[conflicts.size()];
-        int i = 0;
-        for (Pair<PsiElement, PsiElement> pair : conflicts) {
-          usages[i] = new UUsage(pair.getFirst(), pair.getSecond(), myModuleName);
-          i += 1;
-        }
-        UsageViewPresentation prsnt = new UsageViewPresentation();
-        prsnt.setTabText("Name '" + top_name + "' obscured by local redefinitions. ");
-        prsnt.setCodeUsagesString("Name '" + top_name + "' obscured. Cannot convert import.");
-        prsnt.setUsagesWord("occurrence");
-        prsnt.setUsagesString("occurrences");
-        UsageViewManager.getInstance(project).showUsages(UsageTarget.EMPTY_ARRAY, usages, prsnt);
-        return;
+      if (
+        showConflicts(
+          project,
+          findDefinitions(top_name, references.keySet(), Arrays.asList(myFromImportStatement.getImportElements())), 
+          top_name, myModuleName
+        )
+      ) {
+        return; // got conflicts
       }
 
       // add qualifiers
@@ -183,90 +149,3 @@ public class ImportFromToImportIntention implements IntentionAction {
   }
 }
 
-class UUsage implements PsiElementUsage {
-
-  private final PsiElement myElement;
-  private final PsiElement myCulprit;
-
-  static final TextAttributes SLANTED;
-  private final String myPrefix;
-
-  static {
-    SLANTED = TextAttributes.ERASE_MARKER.clone();
-    SLANTED.setFontType(Font.ITALIC);
-  }
-
-
-  public UUsage(PsiElement element, PsiElement culprit, String prefix) {
-    myElement = element;
-    myCulprit = culprit;
-    myPrefix = prefix;
-  }
-
-  public FileEditorLocation getLocation() {
-    return null;
-  }
-
-  @NotNull
-  public UsagePresentation getPresentation() {
-    return new UsagePresentation() {
-      @Nullable
-      public Icon getIcon() {
-        return myElement.getIcon(0);
-      }
-
-      @NotNull
-      public TextChunk[] getText() {
-        TextChunk[] chunks = new TextChunk[3];
-        PsiFile file = myElement.getContainingFile();
-        int lineno = file.getViewProvider().getDocument().getLineNumber(myElement.getTextOffset());
-        chunks[0] = new TextChunk(SLANTED, "(" + lineno + ") ");
-        chunks[1] = new TextChunk(TextAttributes.ERASE_MARKER, myElement.getText());
-        chunks[2] = new TextChunk(SLANTED, " would become " + myPrefix + "." + myElement.getText());
-        return chunks;
-      }
-
-      @NotNull
-      public String getPlainText() {
-        return myElement.getText();
-      }
-
-      public String getTooltipText() {
-        return myElement.getText();
-      }
-    };
-  }
-
-  public boolean isValid() {
-    return true;
-  }
-
-  public boolean isReadOnly() {
-    return false;
-  }
-
-  public void selectInEditor() { }
-
-  public void highlightInEditor() { }
-
-  public void navigate(boolean requestFocus) {
-    Navigatable descr = EditSourceUtil.getDescriptor(myElement);
-    if (descr != null) descr.navigate(requestFocus);
-  }
-
-  public boolean canNavigate() {
-    return EditSourceUtil.canNavigate(myElement);
-  }
-
-  public boolean canNavigateToSource() {
-    return false; 
-  }
-
-  public PsiElement getElement() {
-    return myCulprit;
-  }
-
-  public boolean isNonCodeUsage() {
-    return false;
-  }
-}

python/src/com/jetbrains/python/codeInsight/intentions/ImportToImportFromIntention.java

@@ -53,7 +53,7 @@ public class ImportToImportFromIntention implements IntentionAction {
 
   @NotNull
   public String getFamilyName() {
-    return PyBundle.message("INTN.Family.convert.import");
+    return PyBundle.message("INTN.Family.convert.import.unqualify");
   }
 
   @Nullable
@@ -94,7 +94,7 @@ public class ImportToImportFromIntention implements IntentionAction {
               if (myQualifierName.equals(PyResolveUtil.toPath(ref, "."))) {  // filter out other names that might resolve to our target
                 PsiElement elt = ref.getElement();
                 PsiElement parent_elt = elt.getParent();
-                if (parent_elt != null && parent_elt instanceof PyQualifiedExpression) { // really qualified by us, not just referencing?
+                if (parent_elt instanceof PyQualifiedExpression) { // really qualified by us, not just referencing?
                   PsiElement resolved = ref.resolve();
                   if (resolved == myReferee) references.add(ref);
                 }

python/src/com/jetbrains/python/codeInsight/intentions/ImportToggleAliasIntention.java

@@ -0,0 +1,169 @@
+package com.jetbrains.python.codeInsight.intentions;
+
+import com.intellij.codeInsight.intention.IntentionAction;
+import com.intellij.lang.ASTNode;
+import com.intellij.lang.Language;
+import com.intellij.openapi.editor.Editor;
+import com.intellij.openapi.project.Project;
+import com.intellij.openapi.ui.MessageType;
+import com.intellij.psi.PsiElement;
+import com.intellij.psi.PsiFile;
+import com.intellij.psi.PsiReference;
+import com.intellij.psi.search.PsiElementProcessor;
+import com.intellij.psi.util.PsiTreeUtil;
+import com.intellij.util.IncorrectOperationException;
+import com.jetbrains.python.PyBundle;
+import com.jetbrains.python.PythonLanguage;
+import static com.jetbrains.python.codeInsight.intentions.DeclarationConflictChecker.findDefinitions;
+import static com.jetbrains.python.codeInsight.intentions.DeclarationConflictChecker.showConflicts;
+import com.jetbrains.python.psi.*;
+import static com.jetbrains.python.psi.PyUtil.sure;
+import com.jetbrains.python.psi.resolve.PyResolveUtil;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.ArrayList;
+import java.util.Collection;
+
+/**
+ * Adds an alias to "import foo" or "from foo import bar" import elements, or removes it if it's already present. 
+ * User: dcheryasov
+ * Date: Oct 9, 2009 6:07:19 PM
+ */
+public class ImportToggleAliasIntention implements IntentionAction {
+
+  private PyImportElement myImportElement;
+  private PyFromImportStatement myFromImportStatement;
+  private PyImportStatement myImportStatement;
+  private String myAlias;
+
+
+  @NotNull
+  public String getText() {
+    String add_name = "Add alias";
+    if (myImportElement != null) {
+      PyReferenceExpression refex = myImportElement.getImportReference();
+      if (refex != null) {
+        String name = refex.getReferencedName();
+        if (name != null && !"".equals(name)) {
+          add_name = "Add alias to '" + name + "'";
+        }
+      }
+    }
+    return myAlias == null? add_name : "Remove alias '" + myAlias + "'";
+  }
+
+  @NotNull
+  public String getFamilyName() {
+    return PyBundle.message("INTN.Family.toggle.import.alias");
+  }
+
+  public boolean isAvailable(@NotNull Project project, Editor editor, PsiFile file) {
+    myImportElement  = PsiTreeUtil.getParentOfType(file.findElementAt(editor.getCaretModel().getOffset()), PyImportElement.class);
+    if (myImportElement != null && myImportElement .isValid()) {
+      PyTargetExpression target = myImportElement.getAsName();
+      if (target != null && target.isValid()) myAlias = target.getName();
+      else myAlias = null;
+      myFromImportStatement = PsiTreeUtil.getParentOfType(myImportElement, PyFromImportStatement.class);
+      if (myFromImportStatement != null && myFromImportStatement.isValid()) {
+        return true;
+      }
+      else {
+        myImportStatement = PsiTreeUtil.getParentOfType(myImportElement, PyImportStatement.class);
+        return myImportStatement != null && myImportStatement.isValid();
+      }
+    }
+    return false;
+  }
+
+  public void invoke(@NotNull Project project, Editor editor, PsiFile file) throws IncorrectOperationException {
+    // sanity check: isAvailable must have set it.
+    assert myImportElement != null;
+    assert myImportStatement != null || myFromImportStatement != null;
+    //
+    final String target_name; // we set in in the source
+    final String remove_name; // we replace it in the source
+    PyReferenceExpression reference = sure(myImportElement.getImportReference());
+    // search for references to us with the right name
+    try {
+      String imported_name = PyResolveUtil.toPath(reference, ".");
+      if (myAlias != null) {
+        // have to remove alias, rename everything to original
+        target_name = imported_name;
+        remove_name = myAlias;
+      }
+      else {
+        // ask for and add alias
+        AskNameDialog dialog = new AskNameDialog(project);
+        dialog.setTitle("Alias for '" + imported_name + "'?");
+        dialog.show();
+        if (!dialog.isOK()) return; // 'Cancel' button cancels everything
+        target_name = dialog.getAlias();
+        remove_name = imported_name;
+      }
+      final PsiElement referee = reference.resolve();
+      if (referee != null && imported_name != null) {
+        final Collection<PsiReference> references = new ArrayList<PsiReference>();
+        PsiTreeUtil.processElements(file, new PsiElementProcessor() {
+          public boolean execute(PsiElement element) {
+            if (element instanceof PyReferenceExpression && PsiTreeUtil.getParentOfType(element, PyImportElement.class) == null) {
+              PyReferenceExpression ref = (PyReferenceExpression)element;
+              if (remove_name.equals(PyResolveUtil.toPath(ref, "."))) {  // filter out other names that might resolve to our target
+                PsiElement resolved = ref.resolve();
+                if (resolved == referee) references.add(ref);
+              }
+            }
+            return true;
+          }
+        });
+        // no references here is OK by us.
+        if (showConflicts(project, findDefinitions(target_name, references, null), target_name, null)) {
+          return; // got conflicts
+        }
+
+        // alter the import element
+        Language language = myImportElement.getLanguage();
+        assert language instanceof PythonLanguage;
+        PythonLanguage pythonLanguage = (PythonLanguage)language;
+        PyElementGenerator generator = pythonLanguage.getElementGenerator();
+        if (myAlias != null) {
+          // remove alias
+          ASTNode node = sure(myImportElement.getNode());
+          ASTNode parent = sure(node.getTreeParent());
+          node = sure(node.getFirstChildNode()); // this is the reference
+          node = sure(node.getTreeNext()); // things past the reference: space, 'as', and alias
+          parent.removeRange(node, null);
+        }
+        else {
+          // add alias
+          ASTNode my_ielt_node = sure(myImportElement.getNode());
+          PyImportElement fountain = generator.createFromText(project, PyImportElement.class, "import foo as "+target_name, new int[]{0,2});
+          ASTNode graft_node = sure(fountain.getNode()); // at import elt
+          graft_node = sure(graft_node.getFirstChildNode()); // at ref
+          graft_node = sure(graft_node.getTreeNext()); // space
+          my_ielt_node.addChild((ASTNode)graft_node.clone());
+          graft_node = sure(graft_node.getTreeNext()); // 'as'
+          my_ielt_node.addChild((ASTNode)graft_node.clone());
+          graft_node = sure(graft_node.getTreeNext()); // space
+          my_ielt_node.addChild((ASTNode)graft_node.clone());
+          graft_node = sure(graft_node.getTreeNext()); // alias
+          my_ielt_node.addChild((ASTNode)graft_node.clone());
+        }
+        // alter references
+        for (PsiReference ref : references) {
+          ASTNode ref_name_node = sure(sure(ref.getElement()).getNode());
+          ASTNode parent = sure(ref_name_node.getTreeParent());
+          ASTNode new_name_node = generator.createExpressionFromText(project, target_name).getNode();
+          assert new_name_node != null;
+          parent.replaceChild(ref_name_node, new_name_node);
+        }
+      }
+    }
+    catch (IncorrectOperationException ignored) {
+      PyUtil.showBalloon(project, PyBundle.message("QFIX.action.failed"), MessageType.WARNING);
+    }
+  }
+
+  public boolean startInWriteAction() {
+    return true;
+  }
+}

python/src/com/jetbrains/python/codeInsight/intentions/NameUsage.java

@@ -0,0 +1,127 @@
+package com.jetbrains.python.codeInsight.intentions;
+
+import com.intellij.ide.util.EditSourceUtil;
+import com.intellij.openapi.editor.Document;
+import com.intellij.openapi.editor.markup.TextAttributes;
+import com.intellij.openapi.fileEditor.FileEditorLocation;
+import com.intellij.pom.Navigatable;
+import com.intellij.psi.PsiElement;
+import com.intellij.psi.PsiFile;
+import com.intellij.usages.TextChunk;
+import com.intellij.usages.UsagePresentation;
+import com.intellij.usages.rules.PsiElementUsage;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+import javax.swing.*;
+import java.awt.*;
+
+/**
+ * Simplistic usage object for demonstration of name clashes, etc.
+ * User: dcheryasov
+ * Date: Oct 11, 2009 6:24:05 AM
+ */
+class NameUsage implements PsiElementUsage {
+
+  private final PsiElement myElement;
+  private final PsiElement myCulprit;
+
+  static final TextAttributes SLANTED;
+  private final String myName;
+  private final boolean myIsPrefix;
+
+  static {
+    SLANTED = TextAttributes.ERASE_MARKER.clone();
+    SLANTED.setFontType(Font.ITALIC);
+  }
+
+  /**
+   * Creates a conflict search panel usage.
+   * @param element where conflict happens.
+   * @param culprit where name is redefined; usages with the same culprit are grouped.
+   * @param name redefinition of it is what the conflict is about.
+   * @param prefix if true, show name as a prefix to element's name in "would be" part.
+   */
+  public NameUsage(PsiElement element, PsiElement culprit, String name, boolean prefix) {
+    myElement = element;
+    myCulprit = culprit;
+    myName = name;
+    myIsPrefix = prefix;
+  }
+
+  public FileEditorLocation getLocation() {
+    return null;
+  }
+
+  @NotNull
+  public UsagePresentation getPresentation() {
+    return new UsagePresentation() {
+      @Nullable
+      public Icon getIcon() {
+        return myElement.getIcon(0);
+      }
+
+      @NotNull
+      public TextChunk[] getText() {
+        if (myElement.isValid()) {
+          TextChunk[] chunks = new TextChunk[3];
+          PsiFile file = myElement.getContainingFile();
+          String line_id = "...";
+          final Document document = file.getViewProvider().getDocument();
+          if (document != null) {
+            line_id = String.valueOf(document.getLineNumber(myElement.getTextOffset()));
+          }
+          chunks[0] = new TextChunk(SLANTED, "(" + line_id + ") ");
+          chunks[1] = new TextChunk(TextAttributes.ERASE_MARKER, myElement.getText());
+          StringBuilder sb = new StringBuilder(" would become ").append(myName);
+          if (myIsPrefix) sb.append(".").append(myElement.getText());
+          chunks[2] = new TextChunk(SLANTED, sb.toString());
+          return chunks;
+        }
+        else return new TextChunk[]{new TextChunk(SLANTED, "?")}; 
+      }
+
+      @NotNull
+      public String getPlainText() {
+        return myElement.getText();
+      }
+
+      public String getTooltipText() {
+        return myElement.getText();
+      }
+    };
+  }
+
+  public boolean isValid() {
+    return true;
+  }
+
+  public boolean isReadOnly() {
+    return false;
+  }
+
+  public void selectInEditor() { }
+
+  public void highlightInEditor() { }
+
+  public void navigate(boolean requestFocus) {
+    Navigatable descr = EditSourceUtil.getDescriptor(myElement);
+    if (descr != null) descr.navigate(requestFocus);
+  }
+
+  public boolean canNavigate() {
+    return EditSourceUtil.canNavigate(myElement);
+  }
+
+  public boolean canNavigateToSource() {
+    return false;
+  }
+
+  public PsiElement getElement() {
+    return myCulprit;
+  }
+
+  public boolean isNonCodeUsage() {
+    return false;
+  }
+}

python/src/com/jetbrains/python/psi/resolve/PyResolveUtil.java

@@ -19,8 +19,8 @@ package com.jetbrains.python.psi.resolve;
 import com.intellij.openapi.progress.ProgressManager;
 import com.intellij.psi.PsiElement;
 import com.intellij.psi.PsiFile;
-import com.intellij.psi.ResolveState;
 import com.intellij.psi.PsiNamedElement;
+import com.intellij.psi.ResolveState;
 import com.intellij.psi.scope.PsiScopeProcessor;
 import com.intellij.psi.util.PsiTreeUtil;
 import com.jetbrains.python.psi.*;