feat: LR graph view

SyntaxTutor.pro

@@ -31,8 +31,10 @@ SOURCES += \
     src/backend/lr0_item.cpp \
     src/backend/slr1_parser.cpp \
     src/backend/symbol_table.cpp \
+    src/widgets/automatonview.cpp \
     src/widgets/customtextedit.cpp \
     src/widgets/grammarview.cpp \
+    src/gui/automatonviewerdialog.cpp \
     src/gui/examreportdialog.cpp \
     src/gui/grammareditordialog.cpp \
     src/gui/lltabledialog.cpp \
@@ -54,8 +56,10 @@ HEADERS += \
     src/backend/slr1_parser.hpp \
     src/backend/state.hpp \
     src/backend/symbol_table.hpp \
+    src/widgets/automatonview.h \
     src/widgets/customtextedit.h \
     src/widgets/grammarview.h \
+    src/gui/automatonviewerdialog.h \
     src/gui/examreportdialog.h \
     src/gui/examsession.h \
     src/gui/grammareditordialog.h \

resources/styles/app.qss

@@ -846,3 +846,65 @@ QDialog[examReport="true"] QPushButton#examReportCloseButton:hover {
     color: #FFFFFF;
     border: 1px solid rgba(255, 255, 255, 0.12);
 }
+
+QPushButton#automatonButton {
+    background-color: rgba(17, 179, 188, 0.12);
+    color: #11B3BC;
+    border: 1px solid rgba(17, 179, 188, 0.35);
+    border-radius: 8px;
+    padding: 8px 14px;
+    font-size: 12px;
+    font-weight: 600;
+}
+
+QPushButton#automatonButton:hover {
+    background-color: rgba(17, 179, 188, 0.2);
+    color: #36C5CC;
+}
+
+QPushButton#automatonButton:pressed {
+    background-color: rgba(17, 179, 188, 0.28);
+}
+
+QPushButton#automatonButton:disabled {
+    background-color: #2A2E30;
+    color: #6F7A7E;
+    border: 1px solid #353D40;
+}
+
+QGraphicsView#slrAutomatonView {
+    background-color: #212526;
+    border: 1px solid #303638;
+    border-radius: 12px;
+}
+
+QDialog[automatonViewer="true"] {
+    background-color: #1F1F1F;
+}
+
+QDialog[automatonViewer="true"] QLabel#automatonViewerHint {
+    color: #6F7A7E;
+    font-size: 12px;
+}
+
+QDialog[automatonViewer="true"] QPushButton#automatonViewerToolButton {
+    background-color: #2B3133;
+    color: #E8ECEE;
+    border: 1px solid rgba(255, 255, 255, 0.1);
+    border-radius: 8px;
+    padding: 6px 12px;
+    font-size: 13px;
+    font-weight: 600;
+    min-width: 28px;
+}
+
+QDialog[automatonViewer="true"] QPushButton#automatonViewerToolButton:hover {
+    background-color: #343B3D;
+    border: 1px solid rgba(17, 179, 188, 0.4);
+    color: #36C5CC;
+}
+
+QDialog[automatonViewer="true"] QPushButton#automatonViewerToolButton:pressed {
+    background-color: #11B3BC;
+    color: #07343A;
+}

src/gui/automatonviewerdialog.cpp

@@ -0,0 +1,91 @@
+/*
+ * SyntaxTutor - Interactive Tutorial About Syntax Analyzers
+ * Copyright (C) 2025 Jose R. (jose-rzm)
+ *
+ * This program 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 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "automatonviewerdialog.h"
+#include "automatonview.h"
+
+#include <QHBoxLayout>
+#include <QLabel>
+#include <QPushButton>
+#include <QVBoxLayout>
+
+AutomatonViewerDialog::AutomatonViewerDialog(AutomatonView* view,
+                                             QWidget*       parent)
+    : QDialog(parent), view_(view) {
+    setObjectName("automatonViewerDialog");
+    setProperty("automatonViewer", true);
+    setWindowTitle(tr("Autómata LR(0)"));
+    setModal(false);
+    resize(820, 620);
+    setMinimumSize(520, 420);
+
+    auto* rootLayout = new QVBoxLayout(this);
+    rootLayout->setContentsMargins(16, 14, 16, 16);
+    rootLayout->setSpacing(12);
+
+    auto* toolbar = new QHBoxLayout();
+    toolbar->setSpacing(8);
+
+    auto* hint = new QLabel(
+        tr("Ctrl + rueda para acercar, arrastra para desplazar"), this);
+    hint->setObjectName("automatonViewerHint");
+    toolbar->addWidget(hint);
+    toolbar->addStretch(1);
+
+    auto makeToolButton = [this](const QString& text, const QString& tip) {
+        auto* button = new QPushButton(text, this);
+        button->setObjectName("automatonViewerToolButton");
+        button->setToolTip(tip);
+        button->setCursor(Qt::PointingHandCursor);
+        button->setAutoDefault(false);
+        button->setDefault(false);
+        return button;
+    };
+
+    auto* zoomOutButton = makeToolButton(QStringLiteral("−"), tr("Alejar"));
+    auto* zoomInButton  = makeToolButton(QStringLiteral("+"), tr("Acercar"));
+    auto* fitButton = makeToolButton(tr("Ajustar"), tr("Ajustar a la vista"));
+    auto* centerButton =
+        makeToolButton(tr("Centrar estado"), tr("Centrar el estado actual"));
+
+    toolbar->addWidget(zoomOutButton);
+    toolbar->addWidget(zoomInButton);
+    toolbar->addWidget(fitButton);
+    toolbar->addWidget(centerButton);
+    rootLayout->addLayout(toolbar);
+
+    view_->setParent(this);
+    rootLayout->addWidget(view_, 1);
+    view_->show();
+
+    connect(zoomOutButton, &QPushButton::clicked, view_,
+            &AutomatonView::zoomOut);
+    connect(zoomInButton, &QPushButton::clicked, view_, &AutomatonView::zoomIn);
+    connect(fitButton, &QPushButton::clicked, view_, &AutomatonView::fitToView);
+    connect(centerButton, &QPushButton::clicked, view_,
+            &AutomatonView::centerOnCurrentState);
+}
+
+AutomatonViewerDialog::~AutomatonViewerDialog() {
+    // The view is owned by the tutor, not by this dialog. Detach it so it
+    // survives the dialog and can be embedded again next time.
+    if (view_ != nullptr && view_->parent() == this) {
+        view_->hide();
+        view_->setParent(nullptr);
+    }
+}

src/gui/automatonviewerdialog.h

@@ -0,0 +1,57 @@
+/*
+ * SyntaxTutor - Interactive Tutorial About Syntax Analyzers
+ * Copyright (C) 2025 Jose R. (jose-rzm)
+ *
+ * This program 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 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef AUTOMATONVIEWERDIALOG_H
+#define AUTOMATONVIEWERDIALOG_H
+
+#include <QDialog>
+#include <QPointer>
+
+class AutomatonView;
+
+/**
+ * @class AutomatonViewerDialog
+ * @brief Non-modal floating window that hosts the LR(0) automaton view.
+ *
+ * The dialog is a thin shell: it embeds an externally-owned AutomatonView
+ * (so its progressive reveal state is preserved across open/close cycles)
+ * and adds a toolbar with zoom in/out, fit-to-view and center-current
+ * actions. It never owns the view: on destruction it reparents the view out
+ * so the tutor can keep reusing it. Being non-modal, the student can keep it
+ * open while continuing the exercise.
+ */
+class AutomatonViewerDialog : public QDialog {
+    Q_OBJECT
+  public:
+    /**
+     * @brief Builds the viewer around an existing automaton view.
+     *
+     * @param view The automaton view to embed; ownership is not taken.
+     * @param parent Parent widget.
+     */
+    explicit AutomatonViewerDialog(AutomatonView* view,
+                                   QWidget*       parent = nullptr);
+    ~AutomatonViewerDialog() override;
+
+  private:
+    // QPointer so the dialog never dereferences the borrowed view if it is
+    // destroyed first (e.g. by the tutor during teardown).
+    QPointer<AutomatonView> view_;
+};
+
+#endif // AUTOMATONVIEWERDIALOG_H