public static PsiFile insertDummyIdentifier(final Editor editor, PsiFile file) {
   boolean selection = editor.getSelectionModel().hasSelection();
   final int startOffset =
       selection
           ? editor.getSelectionModel().getSelectionStart()
           : editor.getCaretModel().getOffset();
   final int endOffset = selection ? editor.getSelectionModel().getSelectionEnd() : startOffset;
   return insertDummyIdentifierIfNeeded(
       file, startOffset, endOffset, CompletionUtil.DUMMY_IDENTIFIER_TRIMMED);
 }
  public static List<TemplateImpl> listApplicableTemplateWithInsertingDummyIdentifier(
      Editor editor, PsiFile file, boolean selectionOnly) {
    int startOffset = editor.getSelectionModel().getSelectionStart();
    file = insertDummyIdentifier(editor, file);

    return listApplicableTemplates(file, startOffset, selectionOnly);
  }
 public void startTemplateWithPrefix(
     final Editor editor,
     final TemplateImpl template,
     final int templateStart,
     @Nullable final PairProcessor<String, String> processor,
     @Nullable final String argument) {
   final int caretOffset = editor.getCaretModel().getOffset();
   final TemplateState templateState = initTemplateState(editor);
   CommandProcessor commandProcessor = CommandProcessor.getInstance();
   commandProcessor.executeCommand(
       myProject,
       () -> {
         editor.getDocument().deleteString(templateStart, caretOffset);
         editor.getCaretModel().moveToOffset(templateStart);
         editor.getScrollingModel().scrollToCaret(ScrollType.RELATIVE);
         editor.getSelectionModel().removeSelection();
         Map<String, String> predefinedVarValues = null;
         if (argument != null) {
           predefinedVarValues = new HashMap<String, String>();
           predefinedVarValues.put(TemplateImpl.ARG, argument);
         }
         templateState.start(template, processor, predefinedVarValues);
       },
       CodeInsightBundle.message("insert.code.template.command"),
       null);
 }
  @Nullable
  public Runnable prepareTemplate(
      final Editor editor,
      char shortcutChar,
      @Nullable final PairProcessor<String, String> processor) {
    if (editor.getSelectionModel().hasSelection()) {
      return null;
    }

    PsiFile file = PsiUtilBase.getPsiFileInEditor(editor, myProject);
    if (file == null) return null;

    Map<TemplateImpl, String> template2argument =
        findMatchingTemplates(file, editor, shortcutChar, TemplateSettings.getInstance());

    List<CustomLiveTemplate> customCandidates =
        ContainerUtil.findAll(
            CustomLiveTemplate.EP_NAME.getExtensions(),
            customLiveTemplate ->
                shortcutChar == customLiveTemplate.getShortcut()
                    && (editor.getCaretModel().getCaretCount() <= 1
                        || supportsMultiCaretMode(customLiveTemplate)));
    if (!customCandidates.isEmpty()) {
      int caretOffset = editor.getCaretModel().getOffset();
      PsiFile fileCopy = insertDummyIdentifierIfNeeded(file, caretOffset, caretOffset, "");
      Document document = editor.getDocument();

      for (final CustomLiveTemplate customLiveTemplate : customCandidates) {
        if (isApplicable(customLiveTemplate, editor, fileCopy)) {
          final String key =
              customLiveTemplate.computeTemplateKey(new CustomTemplateCallback(editor, fileCopy));
          if (key != null) {
            int offsetBeforeKey = caretOffset - key.length();
            CharSequence text = document.getImmutableCharSequence();
            if (template2argument == null
                || !containsTemplateStartingBefore(
                    template2argument, offsetBeforeKey, caretOffset, text)) {
              return () -> customLiveTemplate.expand(key, new CustomTemplateCallback(editor, file));
            }
          }
        }
      }
    }

    return startNonCustomTemplates(template2argument, editor, processor);
  }
  private void startTemplate(
      final Editor editor,
      final String selectionString,
      final Template template,
      boolean inSeparateCommand,
      TemplateEditingListener listener,
      final PairProcessor<String, String> processor,
      final Map<String, String> predefinedVarValues) {
    final TemplateState templateState = initTemplateState(editor);

    //noinspection unchecked
    templateState.getProperties().put(ExpressionContext.SELECTION, selectionString);

    if (listener != null) {
      templateState.addTemplateStateListener(listener);
    }
    Runnable r =
        () -> {
          if (selectionString != null) {
            ApplicationManager.getApplication()
                .runWriteAction(() -> EditorModificationUtil.deleteSelectedText(editor));
          } else {
            editor.getSelectionModel().removeSelection();
          }
          templateState.start((TemplateImpl) template, processor, predefinedVarValues);
        };
    if (inSeparateCommand) {
      CommandProcessor.getInstance()
          .executeCommand(
              myProject, r, CodeInsightBundle.message("insert.code.template.command"), null);
    } else {
      r.run();
    }

    if (shouldSkipInTests()) {
      if (!templateState.isFinished()) templateState.gotoEnd(false);
    }
  }