From 97ffabda0e3eabfa6831e124fe0df99fff022b8c Mon Sep 17 00:00:00 2001
From: Axel Kohlmeyer <akohlmey@gmail.com>
Date: Sun, 21 Jul 2024 17:51:46 -0400
Subject: [PATCH] add (text) file viewer class

---
 tools/lammps-gui/CMakeLists.txt |   2 +
 tools/lammps-gui/fileviewer.cpp | 100 ++++++++++++++++++++++++++++++++
 tools/lammps-gui/fileviewer.h   |  39 +++++++++++++
 3 files changed, 141 insertions(+)
 create mode 100644 tools/lammps-gui/fileviewer.cpp
 create mode 100644 tools/lammps-gui/fileviewer.h

diff --git a/tools/lammps-gui/CMakeLists.txt b/tools/lammps-gui/CMakeLists.txt
index 74ceddacde..30e9fc824f 100644
--- a/tools/lammps-gui/CMakeLists.txt
+++ b/tools/lammps-gui/CMakeLists.txt
@@ -135,6 +135,8 @@ set(PROJECT_SOURCES
   linenumberarea.h
   logwindow.cpp
   logwindow.h
+  fileviewer.cpp
+  fileviewer.h
   preferences.cpp
   preferences.h
   setvariables.cpp
diff --git a/tools/lammps-gui/fileviewer.cpp b/tools/lammps-gui/fileviewer.cpp
new file mode 100644
index 0000000000..f93039d809
--- /dev/null
+++ b/tools/lammps-gui/fileviewer.cpp
@@ -0,0 +1,100 @@
+/* ----------------------------------------------------------------------
+   LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
+   https://www.lammps.org/, Sandia National Laboratories
+   LAMMPS development team: developers@lammps.org
+
+   Copyright (2003) Sandia Corporation.  Under the terms of Contract
+   DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government retains
+   certain rights in this software.  This software is distributed under
+   the GNU General Public License.
+
+   See the README file in the top-level LAMMPS directory.
+------------------------------------------------------------------------- */
+
+#include "fileviewer.h"
+
+#include "lammpsgui.h"
+
+#include <QAction>
+#include <QApplication>
+#include <QByteArray>
+#include <QFile>
+#include <QIcon>
+#include <QKeySequence>
+#include <QSettings>
+#include <QShortcut>
+#include <QString>
+#include <QTextCursor>
+#include <QTextStream>
+
+FileViewer::FileViewer(const QString &_filename, QWidget *parent) :
+    QPlainTextEdit(parent), fileName(_filename)
+{
+    auto *action = new QShortcut(QKeySequence(Qt::CTRL | Qt::Key_Q), this);
+    connect(action, &QShortcut::activated, this, &FileViewer::quit);
+    action = new QShortcut(QKeySequence(Qt::CTRL | Qt::Key_Slash), this);
+    connect(action, &QShortcut::activated, this, &FileViewer::stop_run);
+
+    installEventFilter(this);
+
+    // open and read file. Set editor to read-only.
+    QFile file(fileName);
+    if (file.open(QIODevice::Text | QIODevice::ReadOnly)) {
+        QTextStream in(&file);
+        QString content = in.readAll();
+        file.close();
+
+        QFont text_font;
+        QSettings settings;
+        text_font.fromString(settings.value("textfont", text_font.toString()).toString());
+        document()->setDefaultFont(text_font);
+
+        document()->setPlainText(content);
+        moveCursor(QTextCursor::Start, QTextCursor::MoveAnchor);
+        setReadOnly(true);
+        setLineWrapMode(NoWrap);
+        setMinimumSize(800, 500);
+        setWindowIcon(QIcon(":/icons/lammps-icon-128x128.png"));
+        setWindowTitle("LAMMPS-GUI - Viewer - " + fileName);
+    }
+}
+
+void FileViewer::quit()
+{
+    LammpsGui *main = nullptr;
+    for (QWidget *widget : QApplication::topLevelWidgets())
+        if (widget->objectName() == "LammpsGui") main = dynamic_cast<LammpsGui *>(widget);
+    if (main) main->quit();
+}
+
+void FileViewer::stop_run()
+{
+    LammpsGui *main = nullptr;
+    for (QWidget *widget : QApplication::topLevelWidgets())
+        if (widget->objectName() == "LammpsGui") main = dynamic_cast<LammpsGui *>(widget);
+    if (main) main->stop_run();
+}
+
+// event filter to handle "Ambiguous shortcut override" issues
+bool FileViewer::eventFilter(QObject *watched, QEvent *event)
+{
+    if (event->type() == QEvent::ShortcutOverride) {
+        auto *keyEvent = dynamic_cast<QKeyEvent *>(event);
+        if (!keyEvent) return QWidget::eventFilter(watched, event);
+        if (keyEvent->modifiers().testFlag(Qt::ControlModifier) && keyEvent->key() == '/') {
+            stop_run();
+            event->accept();
+            return true;
+        }
+        if (keyEvent->modifiers().testFlag(Qt::ControlModifier) && keyEvent->key() == 'W') {
+            close();
+            event->accept();
+            return true;
+        }
+    }
+    return QWidget::eventFilter(watched, event);
+}
+
+// Local Variables:
+// c-basic-offset: 4
+// End:
diff --git a/tools/lammps-gui/fileviewer.h b/tools/lammps-gui/fileviewer.h
new file mode 100644
index 0000000000..d52fa15a12
--- /dev/null
+++ b/tools/lammps-gui/fileviewer.h
@@ -0,0 +1,39 @@
+/* -*- c++ -*- ----------------------------------------------------------
+   LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
+   https://www.lammps.org/, Sandia National Laboratories
+   LAMMPS development team: developers@lammps.org
+
+   Copyright (2003) Sandia Corporation.  Under the terms of Contract
+   DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government retains
+   certain rights in this software.  This software is distributed under
+   the GNU General Public License.
+
+   See the README file in the top-level LAMMPS directory.
+------------------------------------------------------------------------- */
+
+#ifndef FILEVIEWER_H
+#define FILEVIEWER_H
+
+#include <QPlainTextEdit>
+
+class FileViewer : public QPlainTextEdit {
+    Q_OBJECT
+
+public:
+    FileViewer(const QString &filename, QWidget *parent = nullptr);
+
+private slots:
+    void quit();
+    void stop_run();
+
+protected:
+    bool eventFilter(QObject *watched, QEvent *event) override;
+
+private:
+    QString fileName;
+};
+
+#endif
+// Local Variables:
+// c-basic-offset: 4
+// End: