fix(graph): preserve viewport across reloads

include/widgets/investigation_graph_view.h

@@ -247,6 +247,26 @@ void investigation_graph_view_reset_view(
     InvestigationGraphView *graph_view
 );
 
+/**
+ * @brief Lit le zoom et le déplacement courants du canvas.
+ *
+ * @return TRUE lorsqu'un graphe est actuellement présenté.
+ */
+gboolean investigation_graph_view_get_view_transform(
+    const InvestigationGraphView *graph_view,
+    double *zoom,
+    double *offset_x,
+    double *offset_y
+);
+
+/** @brief Restaure un zoom et un déplacement précédemment lus. */
+void investigation_graph_view_set_view_transform(
+    InvestigationGraphView *graph_view,
+    double zoom,
+    double offset_x,
+    double offset_y
+);
+
 /**
  * @brief Restaure la disposition déterministe initiale des nœuds.
  *

src/widgets/investigation_graph_view.c

@@ -12,6 +12,7 @@
 #include "models/social_platform.h"
 
 #include <glib.h>
+#include <math.h>
 #include <pango/pangocairo.h>
 
 #define INVESTIGATION_GRAPH_VIEW_MARGIN 32.0
@@ -4642,6 +4643,39 @@ void investigation_graph_view_reset_view(
     }
 }
 
+gboolean investigation_graph_view_get_view_transform(
+    const InvestigationGraphView *graph_view,
+    double *zoom,
+    double *offset_x,
+    double *offset_y)
+{
+    if (graph_view == NULL || graph_view->graph_model == NULL ||
+        zoom == NULL || offset_x == NULL || offset_y == NULL)
+        return FALSE;
+    *zoom = graph_view->zoom;
+    *offset_x = graph_view->offset_x;
+    *offset_y = graph_view->offset_y;
+    return TRUE;
+}
+
+void investigation_graph_view_set_view_transform(
+    InvestigationGraphView *graph_view,
+    double zoom,
+    double offset_x,
+    double offset_y)
+{
+    if (graph_view == NULL ||
+        zoom < INVESTIGATION_GRAPH_VIEW_MIN_ZOOM ||
+        zoom > INVESTIGATION_GRAPH_VIEW_MAX_ZOOM ||
+        !isfinite(zoom) || !isfinite(offset_x) || !isfinite(offset_y))
+        return;
+    graph_view->zoom = zoom;
+    graph_view->offset_x = offset_x;
+    graph_view->offset_y = offset_y;
+    if (graph_view->drawing_area != NULL)
+        gtk_widget_queue_draw(graph_view->drawing_area);
+}
+
 void investigation_graph_view_reset_layout(
     InvestigationGraphView *graph_view
 )

src/widgets/workspace.c

@@ -180,6 +180,10 @@ struct Workspace
     OsintActionCatalog *osint_action_catalog;
 
     WorkspaceGraphState graph_state;
+    gboolean saved_graph_transform_valid;
+    double saved_graph_zoom;
+    double saved_graph_offset_x;
+    double saved_graph_offset_y;
 };
 
 /**
@@ -3051,6 +3055,13 @@ void workspace_set_graph_loading(
         workspace->entity_details_panel
     );
 
+    workspace->saved_graph_transform_valid =
+        investigation_graph_view_get_view_transform(
+            workspace->graph_view,
+            &workspace->saved_graph_zoom,
+            &workspace->saved_graph_offset_x,
+            &workspace->saved_graph_offset_y);
+
     investigation_graph_view_clear(
         workspace->graph_view
     );
@@ -3156,6 +3167,16 @@ void workspace_set_graph(
         graph_model
     );
 
+    if (workspace->saved_graph_transform_valid)
+    {
+        investigation_graph_view_set_view_transform(
+            workspace->graph_view,
+            workspace->saved_graph_zoom,
+            workspace->saved_graph_offset_x,
+            workspace->saved_graph_offset_y);
+        workspace->saved_graph_transform_valid = FALSE;
+    }
+
     workspace->graph_state =
         WORKSPACE_GRAPH_STATE_READY;