update example

CHANGELOG.md

@@ -9,3 +9,7 @@
 ## 1.0.2
 
 -   Again update README ( -\_-)
+
+## 1.0.3
+
+-   Update example

example/lib/simple_example.dart

@@ -11,11 +11,14 @@ class SimpleExample extends StatefulWidget {
 }
 
 class _SimpleExampleState extends State<SimpleExample> {
-  final LazyCanvasController controller = LazyCanvasController(debug: true, buildCacheExtent: const Offset(50, 50));
+  late final LazyCanvasController controller;
-  final List<CanvasChildId> childIds = [];
 
   @override
   void initState() {
+    final cacheExtent = const Offset(50, 50);
+    controller = LazyCanvasController(debug: true, buildCacheExtent: cacheExtent);
+    final List<CanvasChildId> childIds = [];
+
     super.initState();
     for (int i = 0; i < 10; i++) {
       final id = controller.addChild(
@@ -30,7 +33,8 @@ class _SimpleExampleState extends State<SimpleExample> {
       );
       childIds.add(id);
     }
-    controller.addChild(
+
+    final trackId = controller.addChild(
       const Offset(0, 200),
       Container(
         width: 300,
@@ -52,6 +56,8 @@ class _SimpleExampleState extends State<SimpleExample> {
         ),
       ),
     );
+
+    controller.addChild(const Offset(330, 200), _PositionTracker(controller: controller, childId: trackId));
   }
 
   @override
@@ -97,3 +103,94 @@ class InfoContainer extends StatelessWidget {
     return Container(color: color, width: 50, height: 50);
   }
 }
+
+class _PositionTracker extends StatefulWidget {
+  final LazyCanvasController controller;
+  final CanvasChildId childId;
+  const _PositionTracker({required this.controller, required this.childId});
+
+  @override
+  State<_PositionTracker> createState() => _PositionTrackerState();
+}
+
+class _PositionTrackerState extends State<_PositionTracker> {
+  late final VoidCallback _listener;
+
+  @override
+  void initState() {
+    super.initState();
+    _listener = () {
+      if (mounted) setState(() {});
+    };
+    widget.controller.addListener(_listener);
+  }
+
+  @override
+  void dispose() {
+    widget.controller.removeListener(_listener);
+    super.dispose();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final childPosition = widget.controller
+        .widgetsWithScreenPositions()
+        .where((e) => e.id == widget.childId)
+        .firstOrNull;
+
+    final visible = childPosition != null;
+    final borderColor = visible ? Colors.green : Colors.red;
+    final icon = visible ? Icons.visibility : Icons.visibility_off;
+    final statusText = visible ? 'Visible' : 'Off screen';
+
+    return Container(
+      padding: const EdgeInsets.all(12),
+      decoration: BoxDecoration(
+        color: Theme.of(context).colorScheme.surface,
+        border: Border(left: BorderSide(color: borderColor, width: 4)),
+        borderRadius: BorderRadius.circular(12),
+        boxShadow: [BoxShadow(color: Colors.black.withAlpha(10), blurRadius: 8, offset: const Offset(0, 2))],
+      ),
+      child: Column(
+        mainAxisSize: MainAxisSize.min,
+        crossAxisAlignment: CrossAxisAlignment.start,
+        children: [
+          Text(
+            'This example uses tight build extents so you can see the text box get unmounted when its position ( top left ) goes off screen.\nIncrease it in your app.',
+            style: TextStyle(fontSize: 13, color: Theme.of(context).colorScheme.onSurface),
+          ),
+          const SizedBox(height: 8),
+          Row(
+            mainAxisSize: MainAxisSize.min,
+            children: [
+              Icon(icon, size: 16, color: borderColor),
+              const SizedBox(width: 6),
+              Text(
+                statusText,
+                style: TextStyle(color: borderColor, fontWeight: FontWeight.w600),
+              ),
+            ],
+          ),
+          const SizedBox(height: 8),
+          Text(
+            'Cache extent: ${widget.controller.buildCacheExtent}',
+            style: TextStyle(color: Theme.of(context).colorScheme.onSurface, fontSize: 13),
+          ),
+          const SizedBox(height: 6),
+          if (visible)
+            Text(
+              'Text box position: ${childPosition.ssPosition}',
+              style: TextStyle(color: Theme.of(context).colorScheme.onSurface, fontSize: 13),
+            )
+          else
+            const Text('Text box is off screen', style: TextStyle(fontSize: 13)),
+          const SizedBox(height: 16),
+          Text(
+            'Note: due to spatial hashing the offset is an approximate, not a pixel-perfect measure.',
+            style: TextStyle(fontSize: 11, color: Theme.of(context).colorScheme.onSurface.withAlpha(200)),
+          ),
+        ],
+      ),
+    );
+  }
+}

example/pubspec.lock

@@ -25,14 +25,6 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "1.4.0"
-  charcode:
-    dependency: transitive
-    description:
-      name: charcode
-      sha256: fb0f1107cac15a5ea6ef0a6ef71a807b9e4267c713bb93e00e92d737cc8dbd8a
-      url: "https://pub.dev"
-    source: hosted
-    version: "1.4.0"
   clock:
     dependency: transitive
     description:
@@ -57,14 +49,6 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "3.0.6"
-  csslib:
-    dependency: transitive
-    description:
-      name: csslib
-      sha256: "09bad715f418841f976c77db72d5398dc1253c21fb9c0c7f0b0b985860b2d58e"
-      url: "https://pub.dev"
-    source: hosted
-    version: "1.0.2"
   cupertino_icons:
     dependency: "direct main"
     description:
@@ -107,21 +91,13 @@ packages:
     description: flutter
     source: sdk
     version: "0.0.0"
-  html:
-    dependency: transitive
-    description:
-      name: html
-      sha256: "6d1264f2dffa1b1101c25a91dff0dc2daee4c18e87cd8538729773c073dbf602"
-      url: "https://pub.dev"
-    source: hosted
-    version: "0.15.6"
   infinite_lazy_grid:
     dependency: "direct main"
     description:
       path: ".."
       relative: true
     source: path
-    version: "0.0.1"
+    version: "1.0.2"
   leak_tracker:
     dependency: transitive
     description:
@@ -255,22 +231,6 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "1.4.0"
-  universal_html:
-    dependency: transitive
-    description:
-      name: universal_html
-      sha256: "56536254004e24d9d8cfdb7dbbf09b74cf8df96729f38a2f5c238163e3d58971"
-      url: "https://pub.dev"
-    source: hosted
-    version: "2.2.4"
-  universal_io:
-    dependency: transitive
-    description:
-      name: universal_io
-      sha256: "1722b2dcc462b4b2f3ee7d188dad008b6eb4c40bbd03a3de451d82c78bba9aad"
-      url: "https://pub.dev"
-    source: hosted
-    version: "2.2.2"
   uuid:
     dependency: transitive
     description:

lib/core/controller/controller.dart

@@ -80,6 +80,8 @@ class LazyCanvasController with ChangeNotifier {
   Offset get _ssCenter => Offset(_canvasSize.width / 2, _canvasSize.height / 2);
   Offset get _gsCenter => ssToGs(_ssCenter, _gsTopLeftOffset, _scale);
   bool get _renderCacheDirty => _lastProcessedOffset != _gsTopLeftOffset || _lastProcessedScale != _scale || _markDirty;
+  Offset get buildExtent => _buildExtent;
+  Offset? get buildCacheExtent => _buildCacheExtent;
 
   // ==================== Callback Functions ====================
 

pubspec.yaml

@@ -1,6 +1,6 @@
 name: infinite_lazy_grid
 description: "infinitely scrollable and zoomable grid layout with lazy loading capabilities."
-version: 1.0.2
+version: 1.0.3
 homepage: https://github.com/ruinivist/infinite_lazy_grid
 
 environment: