added simple documentation stub generation for python functions

python/src/com/jetbrains/python/documentation/PythonDocumentationProvider.java

@@ -53,12 +53,16 @@ import java.util.regex.Pattern;
 
 /**
  * Provides quick docs for classes, methods, and functions.
+ * Generates documentation stub
  */
 public class PythonDocumentationProvider extends AbstractDocumentationProvider implements ExternalDocumentationProvider {
 
   @NonNls private static final String LINK_TYPE_CLASS = "#class#";
   @NonNls private static final String LINK_TYPE_PARENT = "#parent#";
 
+  @NonNls private static final String RST_PREFIX = ":";
+  @NonNls private static final String EPYDOC_PREFIX = "@";
+
   // provides ctrl+hover info
   public String getQuickNavigateInfo(final PsiElement element, PsiElement originalElement) {
     if (element instanceof PyFunction) {
@@ -799,4 +803,31 @@ public class PythonDocumentationProvider extends AbstractDocumentationProvider i
     }
     return ret;
   }
+
+  public String generateDocumentationContentStub(PyFunction element, String substring, String offset) {
+    Project project = element.getProject();
+    PyDocumentationSettings documentationSettings = PyDocumentationSettings.getInstance(project);
+    String result = "";
+    if (documentationSettings.isEpydocFormat())
+      result += generateContent(element, offset, EPYDOC_PREFIX);
+    else if (documentationSettings.isReSTFormat())
+      result += generateContent(element, offset, RST_PREFIX);
+    result += substring;
+    return result;
+  }
+
+  private String generateContent(PyFunction element, String offset, String prefix) {
+    PyParameter[] list = element.getParameterList().getParameters();
+    StringBuilder builder = new StringBuilder();
+    for(PyParameter p : list) {
+      builder.append(prefix);
+      builder.append("param ");
+      builder.append(p.getName());
+      builder.append(": ");
+      builder.append(offset);
+    }
+    builder.append(prefix).append("return:").append(offset);
+    return builder.toString();
+  }
+
 }

python/src/com/jetbrains/python/editor/PythonEnterHandler.java

@@ -1,5 +1,6 @@
 package com.jetbrains.python.editor;
 
+import com.intellij.codeInsight.CodeInsightSettings;
 import com.intellij.codeInsight.editorActions.AutoHardWrapHandler;
 import com.intellij.codeInsight.editorActions.enter.EnterHandlerDelegate;
 import com.intellij.ide.DataManager;
@@ -12,6 +13,7 @@ import com.intellij.openapi.util.Ref;
 import com.intellij.psi.*;
 import com.intellij.psi.util.PsiTreeUtil;
 import com.jetbrains.python.PyTokenTypes;
+import com.jetbrains.python.documentation.PythonDocumentationProvider;
 import com.jetbrains.python.psi.*;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
@@ -58,6 +60,20 @@ public class PythonEnterHandler implements EnterHandlerDelegate {
     if (element == null) {
       return Result.Continue;
     }
+    CodeInsightSettings codeInsightSettings = CodeInsightSettings.getInstance();
+    if (codeInsightSettings.JAVADOC_STUB_ON_ENTER && inDocComment(element)) {
+      PythonDocumentationProvider provider = new PythonDocumentationProvider();
+      PyFunction fun = PsiTreeUtil.getParentOfType(element, PyFunction.class);
+      if (fun != null) {
+        PsiWhiteSpace whitespace = PsiTreeUtil.getPrevSiblingOfType(fun.getStatementList(), PsiWhiteSpace.class);
+        String docStub = provider.generateDocumentationContentStub(fun, element.getParent().getText().substring(0,3), whitespace.getText());
+        if (docStub != null && docStub.length() != 0) {
+          editor.getDocument().insertString(editor.getCaretModel().getOffset(), docStub);
+          return Result.Continue;
+        }
+      }
+    }
+
     if (offset > 0) {
       final PsiElement beforeCaret = file.findElementAt(offset-1);
       if (beforeCaret instanceof PsiWhiteSpace && beforeCaret.getText().indexOf('\\') > 0) {
@@ -117,6 +133,27 @@ public class PythonEnterHandler implements EnterHandlerDelegate {
     return Result.Continue;
   }
 
+  private boolean inDocComment(PsiElement element) {
+    PyStringLiteralExpression string = PsiTreeUtil.getParentOfType(element, PyStringLiteralExpression.class);
+    if (string != null) {
+      PyFunction func = PsiTreeUtil.getParentOfType(element, PyFunction.class);
+      if (func != null) {
+        String text = string.getText();
+        if (text.startsWith("\"\"\"") || text.startsWith("'''")) {
+          if (!text.endsWith("\"\"\"") && !text.endsWith("'''"))
+            return true;
+          PsiErrorElement error = PsiTreeUtil.getNextSiblingOfType(string, PsiErrorElement.class);
+          if (error != null)
+            return true;
+          error = PsiTreeUtil.getNextSiblingOfType(string.getParent(), PsiErrorElement.class);
+          if (error != null)
+            return true;
+        }
+      }
+    }
+    return false;
+  }
+
   @Nullable
   private static PsiElement findWrappable(PsiFile file, int offset, boolean before) {
     PsiElement wrappable = before