infinite_lazy_grid
Code Issues

support for lazy building widgets within viewport

Browse Source
This commit is contained in:
ruinivist
2025-07-05 20:09:52 +00:00
parent 7cfb9457a2
commit b81b99c55c
10 changed files with 392 additions and 194 deletions
Download Patch File Download Diff File Expand all files Collapse all files
lib/core/render.dart
+38 -39
View File
@@ -1,6 +1,6 @@
import 'package:flutter/material.dart';
import 'package:flutter/rendering.dart';
import 'package:infinite_lazy_2d_grid/core/controller.dart';
import 'package:infinite_lazy_2d_grid/core/controller/controller.dart';
import 'package:infinite_lazy_2d_grid/utils/offset_extensions.dart';
import 'package:infinite_lazy_2d_grid/utils/styles.dart';
@@ -15,45 +15,42 @@ class CanvasView extends StatelessWidget {
@override
Widget build(BuildContext context) {
return Container(
color: canvasBackground.bgColor,
child: GestureDetector(
behavior: HitTestBehavior.translucent,
onScaleUpdate: controller.onScaleUpdate,
onScaleStart: controller.onScaleStart,
child: ListenableBuilder(
listenable: controller,
builder: (_, _) {
final childrenWithPositions = controller.widgetsWithScreenPositions();
final ssPositions = childrenWithPositions.map((e) => e.ssPosition).toList();
final children = childrenWithPositions.map((e) => e.child).toList();
final canvas = _CanvasRenderObject(
canvasBackground: canvasBackground,
ssPositions: ssPositions,
scale: controller.scale,
onCanvasSizeChange: controller.onCanvasSizeChange,
children: children,
);
return GestureDetector(
behavior: HitTestBehavior.translucent,
onScaleUpdate: controller.onScaleUpdate,
onScaleStart: controller.onScaleStart,
child: ListenableBuilder(
listenable: controller,
builder: (_, _) {
final childrenWithPositions = controller.widgetsWithScreenPositions();
final ssPositions = childrenWithPositions.map((e) => e.ssPosition).toList();
final children = childrenWithPositions.map((e) => e.child).toList();
final canvas = _CanvasRenderObject(
canvasBackground: canvasBackground,
ssPositions: ssPositions,
scale: controller.scale,
onCanvasSizeChange: controller.onCanvasSizeChange,
children: children,
);
if (controller.debug) {
return Stack(
children: [
canvas,
Positioned(
top: 16,
left: 16,
child: Text(
'Offset: ${controller.offset.coord()}\nScale: ${controller.scale.toStringAsFixed(1)}',
style: monospaceStyle,
),
if (controller.debug) {
return Stack(
children: [
canvas,
Positioned(
top: 16,
left: 16,
child: Text(
'Offset: ${controller.offset.coord()}\nScale: ${controller.scale.toStringAsFixed(1)}',
style: monospaceStyle,
),
],
);
} else {
return canvas;
}
},
),
),
],
);
} else {
return canvas;
}
},
),
);
}
@@ -122,7 +119,9 @@ class _CanvasRenderBox extends RenderBox
}
set ssPositions(List<Offset> ssPositions) {
assert(ssPositions.length == childCount);
// at this point childCount may not be equal to ssPositions.length
// but since we are only marking for layout this is fine
// at the actual performLayout this will be asserted
if (_ssPositions != ssPositions) {
_ssPositions = ssPositions;
markNeedsLayout();