feat: comeback workspace button

include/views/application_message_dialog.h

@@ -18,6 +18,20 @@ typedef enum
     APPLICATION_MESSAGE_DIALOG_INFORMATION
 } ApplicationMessageDialogType;
 
+/**
+ * @brief Callback appelé à la fermeture d'un dialogue de confirmation.
+ *
+ * Le callback est appelé une seule fois après un clic sur l'un des boutons
+ * ou après une fermeture manuelle de la fenêtre.
+ *
+ * @param confirmed TRUE si l'utilisateur confirme, sinon FALSE.
+ * @param user_data Données empruntées fournies par l'appelant.
+ */
+typedef void (*ApplicationMessageDialogConfirmationCallback)(
+    gboolean confirmed,
+    gpointer user_data
+);
+
 /**
  * @brief Affiche une fenêtre modale contenant un message.
  *
@@ -35,4 +49,31 @@ void application_message_dialog_present(
     const char *message
 );
 
+/**
+ * @brief Affiche un dialogue modal demandant une confirmation.
+ *
+ * Le bouton d'annulation transmet FALSE. Le bouton de confirmation transmet
+ * TRUE. Fermer la fenêtre manuellement équivaut à une annulation.
+ *
+ * callback et user_data sont empruntés jusqu'à la fermeture du dialogue.
+ * confirm_label peut être NULL ou vide pour utiliser « Confirmer ».
+ *
+ * @param parent_window Fenêtre parente, ou NULL.
+ * @param message_type Type de message.
+ * @param title Titre de la fenêtre, ou NULL.
+ * @param message Message principal, ou NULL.
+ * @param confirm_label Libellé du bouton de confirmation, ou NULL.
+ * @param callback Callback facultatif recevant la réponse.
+ * @param user_data Données empruntées transmises au callback.
+ */
+void application_message_dialog_present_confirmation(
+    GtkWindow *parent_window,
+    ApplicationMessageDialogType message_type,
+    const char *title,
+    const char *message,
+    const char *confirm_label,
+    ApplicationMessageDialogConfirmationCallback callback,
+    gpointer user_data
+);
+
 #endif

include/views/main_window.h

@@ -49,6 +49,15 @@ typedef void (*MainWindowImportEvidenceCallback)(
     gpointer user_data
 );
 
+/**
+ * @brief Callback appelé lorsque l'utilisateur revient au graphe.
+ *
+ * @param user_data Données utilisateur associées au callback.
+ */
+typedef void (*MainWindowShowGraphCallback)(
+    gpointer user_data
+);
+
 /**
  * @brief Callback appelé lorsqu'une preuve est sélectionnée.
  *
@@ -432,6 +441,21 @@ void main_window_set_import_evidence_callback(
     gpointer user_data
 );
 
+/**
+ * @brief Définit le callback du bouton « Revenir au graphe ».
+ *
+ * MainWindow transmet uniquement la demande au contrôleur.
+ *
+ * @param main_window Fenêtre principale.
+ * @param callback Fonction appelée lors du clic, ou NULL.
+ * @param user_data Données transmises au callback.
+ */
+void main_window_set_show_graph_callback(
+    MainWindow *main_window,
+    MainWindowShowGraphCallback callback,
+    gpointer user_data
+);
+
 /**
  * @brief Active ou désactive l'action d'import d'une preuve.
  *

src/core/application.c

@@ -4278,17 +4278,15 @@ static void application_on_graph_node_moved(
 }
 
 /**
- * @brief Ferme proprement l'application.
+ * @brief Supprime les positions persistées et restaure la grille automatique.
  *
- * @param user_data Pointeur vers Application.
+ * Cette fonction est appelée uniquement après une confirmation explicite.
+ * L'affichage et le modèle en mémoire restent inchangés en cas d'échec SQLite.
  */
-static void application_on_reset_graph_layout_requested(
-    gpointer user_data
+static void application_reset_graph_layout(
+    Application *application
 )
 {
-    Application *application =
-        user_data;
-
     Database *database =
         NULL;
 
@@ -4402,6 +4400,98 @@ static void application_on_reset_graph_layout_requested(
     );
 }
 
+/**
+ * @brief Traite la réponse du dialogue de confirmation.
+ */
+static void application_on_reset_graph_layout_confirmed(
+    gboolean confirmed,
+    gpointer user_data
+)
+{
+    Application *application =
+        user_data;
+
+    if (!confirmed)
+    {
+        return;
+    }
+
+    application_reset_graph_layout(
+        application
+    );
+}
+
+/**
+ * @brief Demande confirmation avant toute suppression de position.
+ */
+static void application_on_show_graph_requested(
+    gpointer user_data
+)
+{
+    Application *application =
+        user_data;
+
+    if (application == NULL ||
+        application->main_window == NULL ||
+        application->graph_model == NULL)
+    {
+        return;
+    }
+
+    application_set_selected_evidence_identifier(
+        application,
+        NULL
+    );
+
+    /*
+     * Passer NULL restaure l'état principal du Workspace. Quand le graphe
+     * est prêt, workspace_show_default() affiche automatiquement le canvas.
+     */
+    main_window_set_selected_evidence(
+        application->main_window,
+        NULL
+    );
+
+    main_window_set_status(
+        application->main_window,
+        "Graphe de l'enquête affiché."
+    );
+}
+
+/**
+ * @brief Demande confirmation avant toute suppression de position.
+ */
+static void application_on_reset_graph_layout_requested(
+    gpointer user_data
+)
+{
+    Application *application =
+        user_data;
+
+    if (application == NULL ||
+        application->main_window == NULL ||
+        application->session == NULL ||
+        application->graph_model == NULL ||
+        application->graph_layout == NULL)
+    {
+        return;
+    }
+
+    application_message_dialog_present_confirmation(
+        main_window_get_window(
+            application->main_window
+        ),
+        APPLICATION_MESSAGE_DIALOG_WARNING,
+        "Réinitialiser la disposition du graphe",
+        "Toutes les positions personnalisées des nœuds seront supprimées. "
+        "Le graphe retrouvera sa disposition automatique.\n\n"
+        "Cette action ne peut pas être annulée.",
+        "Réinitialiser",
+        application_on_reset_graph_layout_confirmed,
+        application
+    );
+}
+
 /**
  * @brief Ferme proprement l'application.
  *
@@ -4504,6 +4594,12 @@ static void application_on_activate(
         application
     );
 
+    main_window_set_show_graph_callback(
+        application->main_window,
+        application_on_show_graph_requested,
+        application
+    );
+
     main_window_set_new_investigation_callback(
         application->main_window,
         application_on_new_investigation_requested,

src/views/application_message_dialog.c

@@ -16,6 +16,25 @@
 #define APPLICATION_MESSAGE_DIALOG_DEFAULT_MESSAGE \
     "Aucun détail supplémentaire n'est disponible."
 
+/**
+ * @brief Libellé par défaut du bouton de confirmation.
+ */
+#define APPLICATION_MESSAGE_DIALOG_DEFAULT_CONFIRM_LABEL \
+    "Confirmer"
+
+/**
+ * @brief État privé d'un dialogue de confirmation.
+ */
+typedef struct
+{
+    GtkWindow *dialog_window;
+
+    ApplicationMessageDialogConfirmationCallback callback;
+    gpointer user_data;
+
+    gboolean completed;
+} ApplicationMessageDialogConfirmationContext;
+
 /**
  * @brief Retourne le libellé correspondant au type de message.
  *
@@ -335,3 +354,528 @@ void application_message_dialog_present(
         dialog_window
     );
 }
+
+/**
+ * @brief Libère le contexte associé à une fenêtre de confirmation.
+ */
+static void application_message_dialog_confirmation_context_free(
+    gpointer data
+)
+{
+    ApplicationMessageDialogConfirmationContext *context =
+        data;
+
+    if (context == NULL)
+    {
+        return;
+    }
+
+    context->dialog_window =
+        NULL;
+
+    context->callback =
+        NULL;
+
+    context->user_data =
+        NULL;
+
+    g_free(
+        context
+    );
+}
+
+/**
+ * @brief Termine une confirmation et transmet son résultat une seule fois.
+ *
+ * Lorsque destroy_window vaut TRUE, la fenêtre est détruite avant l'appel
+ * du callback. Les valeurs du callback sont donc copiées localement avant
+ * la destruction du contexte attaché à la fenêtre.
+ */
+static void application_message_dialog_complete_confirmation(
+    ApplicationMessageDialogConfirmationContext *context,
+    gboolean confirmed,
+    gboolean destroy_window
+)
+{
+    ApplicationMessageDialogConfirmationCallback callback =
+        NULL;
+
+    gpointer user_data =
+        NULL;
+
+    GtkWindow *dialog_window =
+        NULL;
+
+    if (context == NULL ||
+        context->completed)
+    {
+        return;
+    }
+
+    context->completed =
+        TRUE;
+
+    callback =
+        context->callback;
+
+    user_data =
+        context->user_data;
+
+    dialog_window =
+        context->dialog_window;
+
+    context->callback =
+        NULL;
+
+    context->user_data =
+        NULL;
+
+    if (destroy_window &&
+        dialog_window != NULL)
+    {
+        gtk_window_destroy(
+            dialog_window
+        );
+    }
+
+    if (callback != NULL)
+    {
+        callback(
+            confirmed,
+            user_data
+        );
+    }
+}
+
+/**
+ * @brief Annule le dialogue depuis son bouton.
+ */
+static void application_message_dialog_on_cancel_clicked(
+    GtkButton *button,
+    gpointer user_data
+)
+{
+    ApplicationMessageDialogConfirmationContext *context =
+        user_data;
+
+    (void) button;
+
+    application_message_dialog_complete_confirmation(
+        context,
+        FALSE,
+        TRUE
+    );
+}
+
+/**
+ * @brief Confirme le dialogue depuis son bouton principal.
+ */
+static void application_message_dialog_on_confirm_clicked(
+    GtkButton *button,
+    gpointer user_data
+)
+{
+    ApplicationMessageDialogConfirmationContext *context =
+        user_data;
+
+    (void) button;
+
+    application_message_dialog_complete_confirmation(
+        context,
+        TRUE,
+        TRUE
+    );
+}
+
+/**
+ * @brief Traite la fermeture manuelle comme une annulation.
+ */
+static gboolean application_message_dialog_on_confirmation_close_requested(
+    GtkWindow *dialog_window,
+    gpointer user_data
+)
+{
+    ApplicationMessageDialogConfirmationContext *context =
+        user_data;
+
+    (void) dialog_window;
+
+    application_message_dialog_complete_confirmation(
+        context,
+        FALSE,
+        FALSE
+    );
+
+    /*
+     * FALSE laisse GTK poursuivre la fermeture normale de la fenêtre.
+     */
+    return FALSE;
+}
+
+void application_message_dialog_present_confirmation(
+    GtkWindow *parent_window,
+    ApplicationMessageDialogType message_type,
+    const char *title,
+    const char *message,
+    const char *confirm_label,
+    ApplicationMessageDialogConfirmationCallback callback,
+    gpointer user_data
+)
+{
+    GtkWindow *dialog_window =
+        NULL;
+
+    GtkWidget *main_box =
+        NULL;
+
+    GtkWidget *type_label =
+        NULL;
+
+    GtkWidget *title_label =
+        NULL;
+
+    GtkWidget *message_label =
+        NULL;
+
+    GtkWidget *button_box =
+        NULL;
+
+    GtkWidget *cancel_button =
+        NULL;
+
+    GtkWidget *confirm_button =
+        NULL;
+
+    ApplicationMessageDialogConfirmationContext *context =
+        NULL;
+
+    const char *safe_title =
+        NULL;
+
+    const char *safe_message =
+        NULL;
+
+    const char *safe_confirm_label =
+        NULL;
+
+    const char *type_text =
+        NULL;
+
+    safe_title =
+        application_message_dialog_get_safe_title(
+            message_type,
+            title
+        );
+
+    safe_message =
+        application_message_dialog_get_safe_message(
+            message
+        );
+
+    safe_confirm_label =
+        confirm_label != NULL &&
+        confirm_label[0] != '\0'
+            ? confirm_label
+            : APPLICATION_MESSAGE_DIALOG_DEFAULT_CONFIRM_LABEL;
+
+    type_text =
+        application_message_dialog_get_type_label(
+            message_type
+        );
+
+    context =
+        g_try_new0(
+            ApplicationMessageDialogConfirmationContext,
+            1
+        );
+
+    if (context == NULL)
+    {
+        return;
+    }
+
+    dialog_window =
+        GTK_WINDOW(
+            gtk_window_new()
+        );
+
+    context->dialog_window =
+        dialog_window;
+
+    context->callback =
+        callback;
+
+    context->user_data =
+        user_data;
+
+    context->completed =
+        FALSE;
+
+    g_object_set_data_full(
+        G_OBJECT(
+            dialog_window
+        ),
+        "application-message-dialog-confirmation-context",
+        context,
+        application_message_dialog_confirmation_context_free
+    );
+
+    gtk_window_set_title(
+        dialog_window,
+        safe_title
+    );
+
+    gtk_window_set_default_size(
+        dialog_window,
+        APPLICATION_MESSAGE_DIALOG_DEFAULT_WIDTH,
+        -1
+    );
+
+    gtk_window_set_modal(
+        dialog_window,
+        TRUE
+    );
+
+    gtk_window_set_destroy_with_parent(
+        dialog_window,
+        TRUE
+    );
+
+    gtk_window_set_resizable(
+        dialog_window,
+        FALSE
+    );
+
+    if (parent_window != NULL)
+    {
+        gtk_window_set_transient_for(
+            dialog_window,
+            parent_window
+        );
+    }
+
+    main_box =
+        gtk_box_new(
+            GTK_ORIENTATION_VERTICAL,
+            12
+        );
+
+    gtk_widget_set_margin_start(
+        main_box,
+        20
+    );
+
+    gtk_widget_set_margin_end(
+        main_box,
+        20
+    );
+
+    gtk_widget_set_margin_top(
+        main_box,
+        20
+    );
+
+    gtk_widget_set_margin_bottom(
+        main_box,
+        20
+    );
+
+    type_label =
+        gtk_label_new(
+            type_text
+        );
+
+    gtk_widget_set_halign(
+        type_label,
+        GTK_ALIGN_START
+    );
+
+    gtk_label_set_xalign(
+        GTK_LABEL(
+            type_label
+        ),
+        0.0F
+    );
+
+    title_label =
+        gtk_label_new(
+            safe_title
+        );
+
+    gtk_widget_set_halign(
+        title_label,
+        GTK_ALIGN_START
+    );
+
+    gtk_label_set_xalign(
+        GTK_LABEL(
+            title_label
+        ),
+        0.0F
+    );
+
+    gtk_label_set_wrap(
+        GTK_LABEL(
+            title_label
+        ),
+        TRUE
+    );
+
+    gtk_widget_add_css_class(
+        title_label,
+        "title-2"
+    );
+
+    message_label =
+        gtk_label_new(
+            safe_message
+        );
+
+    gtk_widget_set_halign(
+        message_label,
+        GTK_ALIGN_FILL
+    );
+
+    gtk_label_set_xalign(
+        GTK_LABEL(
+            message_label
+        ),
+        0.0F
+    );
+
+    gtk_label_set_wrap(
+        GTK_LABEL(
+            message_label
+        ),
+        TRUE
+    );
+
+    gtk_label_set_wrap_mode(
+        GTK_LABEL(
+            message_label
+        ),
+        PANGO_WRAP_WORD_CHAR
+    );
+
+    gtk_label_set_selectable(
+        GTK_LABEL(
+            message_label
+        ),
+        TRUE
+    );
+
+    gtk_label_set_max_width_chars(
+        GTK_LABEL(
+            message_label
+        ),
+        70
+    );
+
+    button_box =
+        gtk_box_new(
+            GTK_ORIENTATION_HORIZONTAL,
+            8
+        );
+
+    gtk_widget_set_halign(
+        button_box,
+        GTK_ALIGN_END
+    );
+
+    cancel_button =
+        gtk_button_new_with_label(
+            "Annuler"
+        );
+
+    confirm_button =
+        gtk_button_new_with_label(
+            safe_confirm_label
+        );
+
+    gtk_widget_add_css_class(
+        confirm_button,
+        "destructive-action"
+    );
+
+    g_signal_connect(
+        cancel_button,
+        "clicked",
+        G_CALLBACK(
+            application_message_dialog_on_cancel_clicked
+        ),
+        context
+    );
+
+    g_signal_connect(
+        confirm_button,
+        "clicked",
+        G_CALLBACK(
+            application_message_dialog_on_confirm_clicked
+        ),
+        context
+    );
+
+    g_signal_connect(
+        dialog_window,
+        "close-request",
+        G_CALLBACK(
+            application_message_dialog_on_confirmation_close_requested
+        ),
+        context
+    );
+
+    gtk_box_append(
+        GTK_BOX(
+            button_box
+        ),
+        cancel_button
+    );
+
+    gtk_box_append(
+        GTK_BOX(
+            button_box
+        ),
+        confirm_button
+    );
+
+    gtk_box_append(
+        GTK_BOX(
+            main_box
+        ),
+        type_label
+    );
+
+    gtk_box_append(
+        GTK_BOX(
+            main_box
+        ),
+        title_label
+    );
+
+    gtk_box_append(
+        GTK_BOX(
+            main_box
+        ),
+        message_label
+    );
+
+    gtk_box_append(
+        GTK_BOX(
+            main_box
+        ),
+        button_box
+    );
+
+    gtk_window_set_child(
+        dialog_window,
+        main_box
+    );
+
+    gtk_widget_grab_focus(
+        cancel_button
+    );
+
+    gtk_window_present(
+        dialog_window
+    );
+}

src/views/main_window.c

@@ -59,6 +59,7 @@ struct MainWindow
     GtkWidget *new_investigation_button;
     GtkWidget *open_investigation_button;
     GtkWidget *import_evidence_button;
+    GtkWidget *show_graph_button;
     GtkWidget *content_paned;
     GtkWidget *main_paned;
     GtkWidget *status_label;
@@ -86,6 +87,12 @@ struct MainWindow
     gpointer
         import_evidence_user_data;
 
+    MainWindowShowGraphCallback
+        show_graph_callback;
+
+    gpointer
+        show_graph_user_data;
+
     MainWindowVerifyEvidenceCallback
         verify_evidence_callback;
 
@@ -190,6 +197,33 @@ static void main_window_on_import_evidence_clicked(
     );
 }
 
+/**
+ * @brief Transmet la demande de fermeture au contrôleur.
+ *
+ * @param button Bouton ayant reçu le clic.
+ * @param user_data Pointeur vers MainWindow.
+ */
+static void main_window_on_show_graph_clicked(
+    GtkButton *button,
+    gpointer user_data
+)
+{
+    MainWindow *main_window =
+        user_data;
+
+    (void) button;
+
+    if (main_window == NULL ||
+        main_window->show_graph_callback == NULL)
+    {
+        return;
+    }
+
+    main_window->show_graph_callback(
+        main_window->show_graph_user_data
+    );
+}
+
 /**
  * @brief Transmet la demande de fermeture au contrôleur.
  *
@@ -436,6 +470,12 @@ MainWindow *main_window_new(
             "Importer une preuve"
         );
 
+    main_window->show_graph_button =
+        main_window_create_action_button(
+            "go-previous-symbolic",
+            "Revenir au graphe"
+        );
+
     main_window->quit_button =
         main_window_create_action_button(
             "application-exit-symbolic",
@@ -461,6 +501,11 @@ MainWindow *main_window_new(
         FALSE
     );
 
+    gtk_widget_set_sensitive(
+        main_window->show_graph_button,
+        FALSE
+    );
+
     gtk_box_append(
         GTK_BOX(main_window->action_bar),
         main_window->new_investigation_button
@@ -476,6 +521,11 @@ MainWindow *main_window_new(
         main_window->import_evidence_button
     );
 
+    gtk_box_append(
+        GTK_BOX(main_window->action_bar),
+        main_window->show_graph_button
+    );
+
     gtk_box_append(
         GTK_BOX(main_window->action_bar),
         action_spacer
@@ -513,6 +563,15 @@ MainWindow *main_window_new(
         main_window
     );
 
+    g_signal_connect(
+        main_window->show_graph_button,
+        "clicked",
+        G_CALLBACK(
+            main_window_on_show_graph_clicked
+        ),
+        main_window
+    );
+
     g_signal_connect(
         main_window->quit_button,
         "clicked",
@@ -937,6 +996,11 @@ void main_window_set_graph_loading(
         return;
     }
 
+    gtk_widget_set_sensitive(
+        main_window->show_graph_button,
+        FALSE
+    );
+
     workspace_set_graph_loading(
         main_window->workspace
     );
@@ -958,6 +1022,11 @@ void main_window_set_graph(
         graph_model,
         graph_layout
     );
+
+    gtk_widget_set_sensitive(
+        main_window->show_graph_button,
+        graph_model != NULL
+    );
 }
 
 void main_window_set_graph_error(
@@ -970,6 +1039,11 @@ void main_window_set_graph_error(
         return;
     }
 
+    gtk_widget_set_sensitive(
+        main_window->show_graph_button,
+        FALSE
+    );
+
     workspace_set_graph_error(
         main_window->workspace,
         message
@@ -985,6 +1059,11 @@ void main_window_clear_graph(
         return;
     }
 
+    gtk_widget_set_sensitive(
+        main_window->show_graph_button,
+        FALSE
+    );
+
     workspace_clear_graph(
         main_window->workspace
     );
@@ -1113,6 +1192,24 @@ void main_window_set_import_evidence_callback(
         user_data;
 }
 
+void main_window_set_show_graph_callback(
+    MainWindow *main_window,
+    MainWindowShowGraphCallback callback,
+    gpointer user_data
+)
+{
+    if (main_window == NULL)
+    {
+        return;
+    }
+
+    main_window->show_graph_callback =
+        callback;
+
+    main_window->show_graph_user_data =
+        user_data;
+}
+
 void main_window_set_import_evidence_enabled(
     MainWindow *main_window,
     gboolean enabled
@@ -1324,6 +1421,12 @@ void main_window_free(
         main_window->reset_graph_layout_user_data =
             NULL;
 
+        main_window->show_graph_callback =
+            NULL;
+
+        main_window->show_graph_user_data =
+            NULL;
+
         main_window_clear_graph(
             main_window
         );
@@ -1354,3 +1457,4 @@ void main_window_free(
         main_window
     );
 }
+

src/widgets/workspace.c

@@ -49,6 +49,8 @@ struct Workspace
     GtkWidget *graph_view_page;
     GtkWidget *graph_toolbar;
     GtkWidget *reset_graph_layout_button;
+    GtkWidget *graph_help_button;
+    GtkWidget *graph_help_popover;
 
     InvestigationGraphView *graph_view;
     EntityDetailsPanel *entity_details_panel;
@@ -1174,6 +1176,175 @@ Workspace *workspace_new(void)
         TRUE
     );
 
+    workspace->graph_help_button =
+        gtk_menu_button_new();
+
+    workspace->graph_help_popover =
+        gtk_popover_new();
+
+    GtkWidget *graph_help_content =
+        gtk_box_new(
+            GTK_ORIENTATION_VERTICAL,
+            8
+        );
+
+    GtkWidget *graph_help_title =
+        gtk_label_new(
+            "Commandes du graphe"
+        );
+
+    GtkWidget *graph_help_text =
+        gtk_label_new(
+            "• Clic : sélectionner un nœud\n"
+            "• Glisser un nœud : le déplacer\n"
+            "• Maj + glisser : déplacer la vue\n"
+            "• Ctrl + molette : zoomer\n"
+            "• Pincement : zoomer"
+        );
+
+    if (workspace->graph_help_button == NULL ||
+        workspace->graph_help_popover == NULL ||
+        graph_help_content == NULL ||
+        graph_help_title == NULL ||
+        graph_help_text == NULL)
+    {
+        workspace_free(
+            workspace
+        );
+
+        return NULL;
+    }
+
+    gtk_menu_button_set_label(
+        GTK_MENU_BUTTON(
+            workspace->graph_help_button
+        ),
+        "?"
+    );
+
+    gtk_widget_add_css_class(
+        workspace->graph_help_button,
+        "flat"
+    );
+
+    gtk_widget_set_tooltip_text(
+        workspace->graph_help_button,
+        "Afficher les commandes du graphe"
+    );
+
+    gtk_widget_set_can_target(
+        workspace->graph_help_button,
+        TRUE
+    );
+
+    gtk_widget_set_halign(
+        workspace->graph_help_button,
+        GTK_ALIGN_END
+    );
+
+    gtk_widget_set_valign(
+        workspace->graph_help_button,
+        GTK_ALIGN_START
+    );
+
+    gtk_widget_set_margin_end(
+        workspace->graph_help_button,
+        12
+    );
+
+    gtk_widget_set_margin_top(
+        workspace->graph_help_button,
+        12
+    );
+
+    gtk_widget_set_margin_start(
+        graph_help_content,
+        16
+    );
+
+    gtk_widget_set_margin_end(
+        graph_help_content,
+        16
+    );
+
+    gtk_widget_set_margin_top(
+        graph_help_content,
+        14
+    );
+
+    gtk_widget_set_margin_bottom(
+        graph_help_content,
+        14
+    );
+
+    gtk_label_set_xalign(
+        GTK_LABEL(
+            graph_help_title
+        ),
+        0.0F
+    );
+
+    gtk_widget_add_css_class(
+        graph_help_title,
+        "heading"
+    );
+
+    gtk_label_set_xalign(
+        GTK_LABEL(
+            graph_help_text
+        ),
+        0.0F
+    );
+
+    gtk_label_set_wrap(
+        GTK_LABEL(
+            graph_help_text
+        ),
+        TRUE
+    );
+
+    gtk_label_set_wrap_mode(
+        GTK_LABEL(
+            graph_help_text
+        ),
+        PANGO_WRAP_WORD_CHAR
+    );
+
+    gtk_label_set_max_width_chars(
+        GTK_LABEL(
+            graph_help_text
+        ),
+        44
+    );
+
+    gtk_box_append(
+        GTK_BOX(
+            graph_help_content
+        ),
+        graph_help_title
+    );
+
+    gtk_box_append(
+        GTK_BOX(
+            graph_help_content
+        ),
+        graph_help_text
+    );
+
+    gtk_popover_set_child(
+        GTK_POPOVER(
+            workspace->graph_help_popover
+        ),
+        graph_help_content
+    );
+
+    gtk_menu_button_set_popover(
+        GTK_MENU_BUTTON(
+            workspace->graph_help_button
+        ),
+        workspace->graph_help_popover
+    );
+
     gtk_overlay_add_overlay(
         GTK_OVERLAY(
             workspace->graph_view_page
@@ -1193,6 +1364,22 @@ Workspace *workspace_new(void)
         TRUE
     );
 
+    gtk_overlay_add_overlay(
+        GTK_OVERLAY(
+            workspace->graph_view_page
+        ),
+        workspace->graph_help_button
+    );
+
+    gtk_overlay_set_clip_overlay(
+        GTK_OVERLAY(
+            workspace->graph_view_page
+        ),
+        workspace->graph_help_button,
+        TRUE
+    );
+
+
     gtk_stack_add_named(
         GTK_STACK(workspace->stack),
         workspace->graph_view_page,
@@ -2022,6 +2209,12 @@ void workspace_free(Workspace *workspace)
     workspace->reset_graph_layout_button =
         NULL;
 
+    workspace->graph_help_button =
+        NULL;
+
+    workspace->graph_help_popover =
+        NULL;
+
     g_clear_pointer(
         &workspace->selected_evidence_identifier,
         g_free