From 6c7dad0a4251dfea364f57cfd60c04d7d860db1b Mon Sep 17 00:00:00 2001
From: Allan CORNET <nelson.numerical.computation@gmail.com>
Date: Sat, 4 Jan 2025 09:32:43 +0100
Subject: [PATCH] fix(display_format): allow interrupting DisplayCell function
 Fixes #1324 (#1326)

---
 CHANGELOG.md                                  |  4 ++++
 .../display_format/src/cpp/DisplayCell.cpp    | 23 +++++++++++++++----
 .../tests/bug_github_issue_#1324.m            | 20 ++++++++++++++++
 3 files changed, 43 insertions(+), 4 deletions(-)
 create mode 100644 modules/display_format/tests/bug_github_issue_#1324.m

diff --git a/CHANGELOG.md b/CHANGELOG.md
index df7961ba2b..663684812c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -24,6 +24,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Advanced terminal updated (common for all platforms without GUI, auto completion, search history).
 - Python 3.13.1 supported.
 
+### Fixed
+
+- [#1324](http://github.com/nelson-lang/nelson/issues/1324) Cell display could not be interrupted.
+
 ## 1.10.0 (2024-12-14)
 
 ### Added
diff --git a/modules/display_format/src/cpp/DisplayCell.cpp b/modules/display_format/src/cpp/DisplayCell.cpp
index 2c54a686ed..be0eeb4d57 100644
--- a/modules/display_format/src/cpp/DisplayCell.cpp
+++ b/modules/display_format/src/cpp/DisplayCell.cpp
@@ -17,6 +17,7 @@
 #include "NelsonConfiguration.hpp"
 #include "DisplayVariableHelpers.hpp"
 #include "FormatHelpers.hpp"
+#include "nlsBuildConfig.h"
 //=============================================================================
 namespace Nelson {
 //=============================================================================
@@ -81,7 +82,10 @@ Display2dCell(size_t evaluatorID, Interface* io, const ArrayOf& A, const std::ws
 
     indexType v = 0;
     bool isColumnsVector = A.isColumnVector();
-    for (indexType k = 0; k < nbElements; ++k) {
+#if WITH_OPENMP
+#pragma omp parallel for
+#endif
+    for (ompIndexType k = 0; k < (ompIndexType)nbElements; ++k) {
         if (v >= columns) {
             v = 0;
         }
@@ -169,7 +173,12 @@ DisplayNdCell(size_t evaluatorID, Interface* io, const ArrayOf& A, const std::ws
     if (currentLineSpacing == NLS_LINE_SPACING_LOOSE) {
         io->outputMessage(L"\n");
     }
-    while (wdims.inside(dims)) {
+    bool continueDisplay = true;
+    while (wdims.inside(dims) && continueDisplay) {
+        if (NelsonConfiguration::getInstance()->getInterruptPending(evaluatorID)) {
+            continueDisplay = false;
+            break;
+        }
         if (offset != 0) {
             if (currentLineSpacing == NLS_LINE_SPACING_LOOSE) {
                 io->outputMessage(L"\n");
@@ -191,7 +200,11 @@ DisplayNdCell(size_t evaluatorID, Interface* io, const ArrayOf& A, const std::ws
         std::vector<size_t> vSize(columns, (size_t)0);
         indexType nbElements = rows * columns;
         wstringVector cellSummarize(nbElements, L"");
-        for (indexType k = 0; k < nbElements; ++k) {
+
+#if WITH_OPENMP
+#pragma omp parallel for
+#endif
+        for (ompIndexType k = 0; k < (ompIndexType)nbElements; ++k) {
             cellSummarize[k] = getAsFormattedString(
                 elements, k + offset, currentNumericFormat, termWidth, false);
             vSize[k / rows] = std::max(vSize[k / rows], cellSummarize[k].length());
@@ -218,7 +231,9 @@ DisplayNdCell(size_t evaluatorID, Interface* io, const ArrayOf& A, const std::ws
                 }
                 io->outputMessage(msg);
             }
-            for (indexType i = 0; i < rows; i++) {
+            for (indexType i = 0;
+                 i < rows && !NelsonConfiguration::getInstance()->getInterruptPending(evaluatorID);
+                 i++) {
                 for (indexType j = 0; j < colsInThisPage
                      && !NelsonConfiguration::getInstance()->getInterruptPending(evaluatorID);
                      j++) {
diff --git a/modules/display_format/tests/bug_github_issue_#1324.m b/modules/display_format/tests/bug_github_issue_#1324.m
new file mode 100644
index 0000000000..02ca27c205
--- /dev/null
+++ b/modules/display_format/tests/bug_github_issue_#1324.m
@@ -0,0 +1,20 @@
+%=============================================================================
+% Copyright (c) 2017 Allan CORNET (Nelson)
+%=============================================================================
+% This file is part of the Nelson.
+%=============================================================================
+% LICENCE_BLOCK_BEGIN
+% SPDX-License-Identifier: LGPL-3.0-or-later
+% LICENCE_BLOCK_END
+%=============================================================================
+% <-- Issue URL -->
+% https://github.com/nelson-lang/nelson/issues/1324
+% <-- Short Description -->
+% Cell display could not be interrupted.
+%=============================================================================
+% <--INTERACTIVE TEST-->
+%=============================================================================
+A = 1:10
+cell(A)
+% and press Ctrl+C
+%=============================================================================