Viewer: read the data-analysis algorithm documentation from Help

Adds Help > Data Analysis Algorithms, showing docs/CPU_DATA_ANALYSIS.md in a
window. The document is baked into the binary through the Qt resource system
(aliased to :/cpu_data_analysis.md), so it needs no docs/ directory at runtime
and cannot drift from the build it shipped with. Same shape as the existing
third-party licences window, created once and raised thereafter.

Limitation worth knowing: QTextBrowser::setMarkdown renders the headings, lists,
emphasis and inline code well, but it has no math support, so the inline LaTeX in
the more quantitative sections appears as raw "$...$" source. The descriptive
material - which is most of the 744 lines - reads fine. Fixing that properly
means either pre-rendering the document to HTML with a math filter at build time,
or sending the user to the Read The Docs copy instead; neither seemed worth doing
without knowing which you would prefer.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

viewer/CMakeLists.txt

@@ -87,6 +87,8 @@ ADD_EXECUTABLE(jfjoch_viewer jfjoch_viewer.cpp JFJochViewerWindow.cpp JFJochView
         windows/JFJochHelperWindow.h
         windows/JFJochLicenseWindow.cpp
         windows/JFJochLicenseWindow.h
+        windows/JFJochAlgorithmDocWindow.cpp
+        windows/JFJochAlgorithmDocWindow.h
         image_viewer/JFJochImage.cpp
         image_viewer/JFJochImage.h
         image_viewer/JFJochFollowerImage.cpp

viewer/JFJochViewerMenu.cpp

@@ -17,6 +17,7 @@
 #include <QDockWidget>
 
 #include "JFJochViewerWindow.h"
+#include "windows/JFJochAlgorithmDocWindow.h"
 #include "windows/JFJochLicenseWindow.h"
 #include "../common/GitInfo.h"
 #include "../common/CUDAWrapper.h"
@@ -81,6 +82,9 @@ JFJochViewerMenu::JFJochViewerMenu(QWidget *parent) : QMenuBar(parent) {
     const QAction *aboutAction = helpMenu->addAction("About");
     connect(aboutAction, &QAction::triggered, this, &JFJochViewerMenu::aboutSelected);
 
+    const QAction *algorithmDocAction = helpMenu->addAction("Data Analysis Algorithms");
+    connect(algorithmDocAction, &QAction::triggered, this, &JFJochViewerMenu::algorithmDocSelected);
+
     const QAction *licensesAction = helpMenu->addAction("Third-party Licenses");
     connect(licensesAction, &QAction::triggered, this, &JFJochViewerMenu::licensesSelected);
 }
@@ -148,6 +152,15 @@ void JFJochViewerMenu::licensesSelected() {
     licenseWindow->activateWindow();
 }
 
+void JFJochViewerMenu::algorithmDocSelected() {
+    // Same pattern as the licence window: created once, then raised.
+    if (algorithmDocWindow == nullptr)
+        algorithmDocWindow = new JFJochAlgorithmDocWindow(window());
+    algorithmDocWindow->show();
+    algorithmDocWindow->raise();
+    algorithmDocWindow->activateWindow();
+}
+
 void JFJochViewerMenu::openSelected() {
     QString fileName = QFileDialog::getOpenFileName(
         this,

viewer/JFJochViewerMenu.h

@@ -7,6 +7,7 @@
 
 #include "windows/JFJochHelperWindow.h"
 
+class JFJochAlgorithmDocWindow;
 class JFJochLicenseWindow;
 class QDockWidget;
 
@@ -21,6 +22,7 @@ class JFJochViewerMenu : public QMenuBar {
 
     QMenu *windowMenu = nullptr;
     JFJochLicenseWindow *licenseWindow = nullptr;
+    JFJochAlgorithmDocWindow *algorithmDocWindow = nullptr;
 public:
     explicit JFJochViewerMenu(QWidget *parent = nullptr);
     ~JFJochViewerMenu() override = default;
@@ -50,6 +52,7 @@ signals:
 private slots:
     void aboutSelected();
     void licensesSelected();
+    void algorithmDocSelected();
     void quitSelected();
     void closeSelected();
 

viewer/resources/resources.qrc

@@ -7,6 +7,9 @@
     <qresource prefix="/">
         <file>jfjoch.png</file>
         <file>third_party_licenses.html</file>
+        <!-- The algorithm documentation is shown in-app (Help > Data Analysis Algorithms);
+             aliased so the viewer does not depend on the docs/ directory at runtime. -->
+        <file alias="cpu_data_analysis.md">../../docs/CPU_DATA_ANALYSIS.md</file>
         <file>psi_01.png</file>
         <file>psi_02.png</file>
         <file>psi_03.png</file>

viewer/windows/JFJochAlgorithmDocWindow.cpp

@@ -0,0 +1,23 @@
+// SPDX-FileCopyrightText: 2026 Filip Leonarski, Paul Scherrer Institute <filip.leonarski@psi.ch>
+// SPDX-License-Identifier: GPL-3.0-only
+
+#include "JFJochAlgorithmDocWindow.h"
+
+#include <QFile>
+#include <QTextBrowser>
+#include <QVBoxLayout>
+
+JFJochAlgorithmDocWindow::JFJochAlgorithmDocWindow(QWidget *parent) : QDialog(parent) {
+    setWindowTitle("Data Analysis Algorithms");
+    resize(900, 700);
+
+    auto *browser = new QTextBrowser(this);
+    browser->setOpenExternalLinks(true);
+
+    QFile file(":/cpu_data_analysis.md");
+    if (file.open(QIODevice::ReadOnly | QIODevice::Text))
+        browser->setMarkdown(QString::fromUtf8(file.readAll()));
+
+    auto *layout = new QVBoxLayout(this);
+    layout->addWidget(browser);
+}

viewer/windows/JFJochAlgorithmDocWindow.h

@@ -0,0 +1,15 @@
+// SPDX-FileCopyrightText: 2026 Filip Leonarski, Paul Scherrer Institute <filip.leonarski@psi.ch>
+// SPDX-License-Identifier: GPL-3.0-only
+
+#pragma once
+
+#include <QDialog>
+
+// Modeless window showing the data-analysis algorithm documentation, rendered from the copy of
+// docs/CPU_DATA_ANALYSIS.md baked into the binary (:/cpu_data_analysis.md), so it is available
+// wherever the viewer runs and always matches the build.
+class JFJochAlgorithmDocWindow : public QDialog {
+    Q_OBJECT
+public:
+    explicit JFJochAlgorithmDocWindow(QWidget *parent = nullptr);
+};