From d94e9eeb3d10557ff3bea3c7c9489f651e0a1e66 Mon Sep 17 00:00:00 2001
From: Julian Mutter <julian.mutter@comumail.de>
Date: Thu, 5 Feb 2026 18:47:28 +0100
Subject: [PATCH] Allow free zoom and pan in drawing mode

---
 .../sheet_viewer/drawing/drawing_board.dart   | 38 +++++++++++++------
 1 file changed, 26 insertions(+), 12 deletions(-)

diff --git a/lib/features/sheet_viewer/drawing/drawing_board.dart b/lib/features/sheet_viewer/drawing/drawing_board.dart
index 56a25d8..c13efe2 100644
--- a/lib/features/sheet_viewer/drawing/drawing_board.dart
+++ b/lib/features/sheet_viewer/drawing/drawing_board.dart
@@ -96,18 +96,32 @@ class _DrawingBoardState extends State<DrawingBoard> {
     }
 
     // Drawing mode: wrap with InteractiveViewer for zoom/pan
-    return Align(
-      alignment: widget.alignment,
-      child: InteractiveViewer(
-        transformationController: _transformationController,
-        minScale: widget.minScale,
-        maxScale: widget.maxScale,
-        boundaryMargin: EdgeInsets.zero,
-        constrained: true,
-        panEnabled: !_isDrawing,
-        scaleEnabled: !_isDrawing,
-        child: content,
-      ),
+    // Use LayoutBuilder to get available size and center content manually
+    return LayoutBuilder(
+      builder: (context, constraints) {
+        // Calculate padding to center the content
+        final horizontalPadding =
+            (constraints.maxWidth - widget.boardSize.width) / 2;
+        final verticalPadding =
+            (constraints.maxHeight - widget.boardSize.height) / 2;
+
+        return InteractiveViewer(
+          transformationController: _transformationController,
+          minScale: widget.minScale,
+          maxScale: widget.maxScale,
+          boundaryMargin: const EdgeInsets.all(double.infinity),
+          constrained: false,
+          panEnabled: !_isDrawing,
+          scaleEnabled: !_isDrawing,
+          child: Padding(
+            padding: EdgeInsets.only(
+              left: horizontalPadding > 0 ? horizontalPadding : 0,
+              top: verticalPadding > 0 ? verticalPadding : 0,
+            ),
+            child: content,
+          ),
+        );
+      },
     );
   }