private List GetExecutionCommands()

in src/Trinity.VSExtension/TrinityVSExtension/EditorExtension/AutoCompletion/CompletionHandler.cs [115:213]
87 lines of code
25 McCabe index (conditional complexity)

        private List<ExecutionCommand> GetExecutionCommands(Guid cmdGroup, uint nCmdID, IntPtr pvaIn, out char? typedChar)
        {
            typedChar = null;
            List<ExecutionCommand> ret = new List<ExecutionCommand>();
            /* If there's automation, or we can't recognize cmdGroup, just pass on. */
            if (VsShellUtilities.IsInAutomationFunction(provider.ServiceProvider) ||
               (cmdGroup != VSConstants.VSStd2K))
            {
                ret.Add(ExecutionCommand.CMD_PassToNextHandler);
                return ret;
            }
            bool sessionActive = (session != null && !session.IsDismissed);
            bool sessionSelectionActive = (sessionActive && session.SelectedCompletionSet.SelectionStatus.IsSelected);
            switch ((VSConstants.VSStd2KCmdID)nCmdID)
            {
                case VSConstants.VSStd2KCmdID.AUTOCOMPLETE:
                case VSConstants.VSStd2KCmdID.COMPLETEWORD:
                    ret.Add(sessionActive ? ExecutionCommand.CMD_PassToNextHandler : ExecutionCommand.CMD_StartSession);
                    break;
                case VSConstants.VSStd2KCmdID.TYPECHAR:
                    typedChar = (char)(ushort)Marshal.GetObjectForNativeVariant(pvaIn);
                    bool commitChr = TypedCharLeadsToCommit(typedChar.Value);
                    bool triggerChr = TypedCharLeadsToTrigger(typedChar.Value);
                    if (commitChr && sessionActive)
                    {
                        /* Ready to commit the completion.
                         * We first check if we can commit something meaningful.
                         * If so, we then check if this commit will lead to another
                         * completion trigger.
                         * */
                        if (sessionSelectionActive)
                        {
                            ret.Add(ExecutionCommand.CMD_Commit);
                            ret.Add(ExecutionCommand.CMD_PassToNextHandler);
                            if (triggerChr)
                                ret.Add(ExecutionCommand.CMD_StartSession);
                        }
                        else
                        {
                            ret.Add(ExecutionCommand.CMD_Dismiss);
                            ret.Add(ExecutionCommand.CMD_PassToNextHandler);
                        }
                    }
                    else if (sessionActive)
                    {
                        /* Typed char doesn't lead to a commit. It leads to filter of completion results. */
                        ret.Add(ExecutionCommand.CMD_PassToNextHandler);
                        ret.Add(ExecutionCommand.CMD_Filter);
                    }
                    else
                    {
                        ret.Add(ExecutionCommand.CMD_PassToNextHandler);
                        /* Session not active, check if we have a trigger*/
                        if (triggerChr)
                        {
                            ret.Add(ExecutionCommand.CMD_StartSession);
                        }
                    }

                    /* At last, we issue a CheckInputChar command to see if we
                     * could do something about auto brackets completion, indention.
                     */
                    ret.Add(ExecutionCommand.CMD_CheckInputChar);
                    break;
                case VSConstants.VSStd2KCmdID.RETURN:
                case VSConstants.VSStd2KCmdID.TAB:
                    if (sessionActive)
                    {
                        if(!sessionSelectionActive)
                        {
                            session.SelectedCompletionSet.SelectBestMatch();
                        }
                        ret.Add(ExecutionCommand.CMD_Commit);
                    }
                    else
                    {
                        ret.Add(ExecutionCommand.CMD_PassToNextHandler);
                        if (nCmdID == (uint)(VSConstants.VSStd2KCmdID.RETURN))
                        {
                            typedChar = '\n';
                            ret.Add(ExecutionCommand.CMD_CheckInputChar);
                        }
                    }
                    break;
                case VSConstants.VSStd2KCmdID.BACKSPACE:
                case VSConstants.VSStd2KCmdID.DELETE:
                    ret.Add(ExecutionCommand.CMD_PassToNextHandler);
                    if (sessionActive)
                        ret.Add(ExecutionCommand.CMD_Filter);
                    break;
                case VSConstants.VSStd2KCmdID.CANCEL:
                    ret.Add(sessionActive ? ExecutionCommand.CMD_Dismiss : ExecutionCommand.CMD_PassToNextHandler);
                    break;
                default:
                    ret.Add(ExecutionCommand.CMD_PassToNextHandler);
                    break;
            }
            return ret;
        }