Add EdzArchive: extract EPLAN .edz packages (M0)

First piece of native EPLAN Data Portal (.edz) import. A .edz is a 7-Zip
archive; QET previously had no archive handling. EdzArchive unpacks one to a
temporary directory and locates the contained part.xml.

The extraction backend is isolated behind extractWithSevenZipCli() so it can be
replaced with a bundled decompressor later without touching callers; this M0
step shells out to a 7-Zip CLI via QProcess. Verified on three ifm sample
parts (KG6000, MFH200, R1D200 — all 7z), plus the corrupt/missing-file paths.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

cmake/qet_compilation_vars.cmake

@@ -107,6 +107,8 @@ set(QET_RES_FILES
   ${QET_DIR}/sources/ui/configpage/generalconfigurationpage.ui
   )
 set(QET_SRC_FILES
+  ${QET_DIR}/sources/import/edz/edzarchive.cpp
+  ${QET_DIR}/sources/import/edz/edzarchive.h
   ${QET_DIR}/sources/borderproperties.cpp
   ${QET_DIR}/sources/borderproperties.h
   ${QET_DIR}/sources/bordertitleblock.cpp

sources/import/edz/edzarchive.cpp

@@ -0,0 +1,154 @@
+/*
+	Copyright 2006 The QElectroTech Team
+	This file is part of QElectroTech.
+
+	QElectroTech is free software: you can redistribute it and/or modify
+	it under the terms of the GNU General Public License as published by
+	the Free Software Foundation, either version 2 of the License, or
+	(at your option) any later version.
+
+	QElectroTech is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+	GNU General Public License for more details.
+
+	You should have received a copy of the GNU General Public License
+	along with QElectroTech. If not, see <http://www.gnu.org/licenses/>.
+*/
+#include "edzarchive.h"
+
+#include <QDir>
+#include <QDirIterator>
+#include <QFileInfo>
+#include <QProcess>
+#include <QStandardPaths>
+#include <QTemporaryDir>
+
+EdzArchive::EdzArchive() = default;
+EdzArchive::~EdzArchive() = default;
+
+/**
+	Extract the .edz at @a edz_path into a fresh temporary directory.
+	@return true on success; extractedDir()/partXmlPath() are then valid.
+*/
+bool EdzArchive::extract(const QString &edz_path)
+{
+	m_error.clear();
+
+	const QFileInfo fi(edz_path);
+	if (!fi.exists() || !fi.isFile()) {
+		m_error = QStringLiteral("File not found: %1").arg(edz_path);
+		return false;
+	}
+
+	m_dir.reset(new QTemporaryDir);
+	if (!m_dir->isValid()) {
+		m_error = QStringLiteral("Could not create a temporary directory: %1")
+				  .arg(m_dir->errorString());
+		return false;
+	}
+
+	if (!extractWithSevenZipCli(fi.absoluteFilePath(), m_dir->path())) {
+		return false;
+	}
+
+	if (partXmlPath().isEmpty()) {
+		m_error = QStringLiteral("No *.part.xml found inside the .edz");
+		return false;
+	}
+	return true;
+}
+
+/** @return the temporary folder holding the extracted tree (empty if none). */
+QString EdzArchive::extractedDir() const
+{
+	return m_dir ? m_dir->path() : QString();
+}
+
+/** @return absolute path to the first *.part.xml in the extracted tree. */
+QString EdzArchive::partXmlPath() const
+{
+	const QString root = extractedDir();
+	if (root.isEmpty()) {
+		return QString();
+	}
+	QDirIterator it(root, QStringList{QStringLiteral("*.part.xml")},
+			QDir::Files, QDirIterator::Subdirectories);
+	return it.hasNext() ? it.next() : QString();
+}
+
+QString EdzArchive::errorString() const
+{
+	return m_error;
+}
+
+/**
+	M0 backend: run a 7-Zip command-line tool to extract the archive.
+	Placeholder for a bundled decompressor in a later milestone.
+*/
+bool EdzArchive::extractWithSevenZipCli(const QString &edz_path,
+					const QString &dest)
+{
+	const QString exe = findSevenZip();
+	if (exe.isEmpty()) {
+		m_error = QStringLiteral(
+			"7-Zip not found. A .edz is a 7z archive; install 7-Zip or "
+			"put 7z on PATH.");
+		return false;
+	}
+
+	QProcess proc;
+	proc.start(exe, QStringList{QStringLiteral("x"), edz_path,
+				    QStringLiteral("-o%1").arg(dest),
+				    QStringLiteral("-y")});
+	if (!proc.waitForStarted()) {
+		m_error = QStringLiteral("Could not start 7-Zip: %1").arg(exe);
+		return false;
+	}
+	proc.waitForFinished(-1);
+
+	if (proc.exitStatus() != QProcess::NormalExit || proc.exitCode() != 0) {
+		QString detail;
+		const QString out = QString::fromLocal8Bit(proc.readAllStandardOutput());
+		for (const QString &line : out.split('\n')) {
+			const QString t = line.trimmed();
+			if (t.startsWith(QStringLiteral("ERROR"))
+			    || t.startsWith(QStringLiteral("Cannot"))
+			    || t.startsWith(QStringLiteral("Can't"))) {
+				detail += (detail.isEmpty() ? QString() : QStringLiteral(" ")) + t;
+			}
+		}
+		if (detail.isEmpty()) {
+			detail = QStringLiteral("7-Zip exit code %1").arg(proc.exitCode());
+		}
+		m_error = QStringLiteral("7-Zip could not extract the archive: %1")
+				  .arg(detail);
+		return false;
+	}
+	return true;
+}
+
+/** Locate a 7-Zip executable: PATH first, then the usual install locations. */
+QString EdzArchive::findSevenZip()
+{
+	for (const QString &name : {QStringLiteral("7z"), QStringLiteral("7za"),
+				    QStringLiteral("7zr")}) {
+		const QString found = QStandardPaths::findExecutable(name);
+		if (!found.isEmpty()) {
+			return found;
+		}
+	}
+	const QStringList candidates {
+		QStringLiteral("C:/Program Files/7-Zip/7z.exe"),
+		QStringLiteral("C:/Program Files (x86)/7-Zip/7z.exe"),
+		QStringLiteral("/usr/bin/7z"),
+		QStringLiteral("/usr/local/bin/7z"),
+		QStringLiteral("/opt/homebrew/bin/7z"),
+	};
+	for (const QString &c : candidates) {
+		if (QFileInfo::exists(c)) {
+			return c;
+		}
+	}
+	return QString();
+}

sources/import/edz/edzarchive.h

@@ -0,0 +1,62 @@
+/*
+	Copyright 2006 The QElectroTech Team
+	This file is part of QElectroTech.
+
+	QElectroTech is free software: you can redistribute it and/or modify
+	it under the terms of the GNU General Public License as published by
+	the Free Software Foundation, either version 2 of the License, or
+	(at your option) any later version.
+
+	QElectroTech is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+	GNU General Public License for more details.
+
+	You should have received a copy of the GNU General Public License
+	along with QElectroTech. If not, see <http://www.gnu.org/licenses/>.
+*/
+#ifndef EDZARCHIVE_H
+#define EDZARCHIVE_H
+
+#include <QString>
+#include <QScopedPointer>
+
+class QTemporaryDir;
+
+/**
+	@brief Extracts an EPLAN Data Portal package (.edz) to a temporary folder.
+
+	A .edz is a 7-Zip archive holding a part definition (part.xml), an EPLAN
+	macro, a product image and metadata. EdzArchive unpacks it so the rest of the
+	import pipeline can read the (portable) part.xml.
+
+	The extraction backend sits behind a single private method so it can be
+	swapped without touching callers: this M0 spike shells out to a 7-Zip CLI via
+	QProcess; a later milestone replaces that with a bundled decompressor so no
+	external tool is required at runtime.
+
+	The extracted tree lives in a QTemporaryDir owned by this object and is
+	removed when the EdzArchive is destroyed.
+*/
+class EdzArchive
+{
+	public:
+		EdzArchive();
+		~EdzArchive();
+
+		bool extract(const QString &edz_path);
+
+		QString extractedDir() const;
+		QString partXmlPath() const;
+		QString errorString() const;
+
+	private:
+		bool extractWithSevenZipCli(const QString &edz_path,
+					    const QString &dest);
+		static QString findSevenZip();
+
+		QScopedPointer<QTemporaryDir> m_dir;
+		QString m_error;
+};
+
+#endif // EDZARCHIVE_H