internal virtual bool HandlePreExec()

in vsintegration/src/FSharp.LanguageService.Base/ExpansionProvider.cs [129:186]
56 lines of code
18 McCabe index (conditional complexity)

        internal virtual bool HandlePreExec(ref Guid guidCmdGroup, uint nCmdId, uint nCmdexecopt, IntPtr pvaIn, IntPtr pvaOut) {
            if (!this.expansionActive || this.expansionSession == null) {
				return false;
            }

            this.completorActiveDuringPreExec = this.IsCompletorActive(this.view);            

            if (guidCmdGroup == typeof(VsCommands2K).GUID) {
                VsCommands2K cmd = (VsCommands2K)nCmdId;
#if TRACE_EXEC
                Trace.WriteLine(String.Format("ExecCommand: {0}", cmd.ToString()));
#endif
                switch (cmd) {
                    case VsCommands2K.CANCEL:
                        if (this.completorActiveDuringPreExec)
                            return false;
                        EndTemplateEditing(true);
                        return true;
                    case VsCommands2K.RETURN:
                        bool leaveCaret = false;
                        int line = 0, col = 0;
                        if (NativeMethods.Succeeded(this.view.GetCaretPos(out line, out col))) {
                            TextSpan span = GetExpansionSpan();
                            if (!TextSpanHelper.ContainsExclusive(span, line, col)) {
                                leaveCaret = true;
                            }
                        }
                        if (this.completorActiveDuringPreExec)
                            return false;
                        if (this.completorActiveDuringPreExec)
                            return false;
                        EndTemplateEditing(leaveCaret);
                        if (leaveCaret)
                            return false;
                        return true;
                    case VsCommands2K.BACKTAB:
                        if (this.completorActiveDuringPreExec)
                            return false;
                        this.expansionSession.GoToPreviousExpansionField();
                        return true;
                    case VsCommands2K.TAB:
                        if (this.completorActiveDuringPreExec)
                            return false;
                        this.expansionSession.GoToNextExpansionField(0); // fCommitIfLast=false
                        return true;
#if TRACE_EXEC
                    case VsCommands2K.TYPECHAR:
                        if (pvaIn != IntPtr.Zero) {
                            Variant v = Variant.ToVariant(pvaIn);
                            char ch = v.ToChar();
                            Trace.WriteLine(String.Format("TYPECHAR: {0}, '{1}', {2}", cmd.ToString(), ch.ToString(), (int)ch));
                        }
                        return true;
#endif
                }
            }
            return false;
        }