Flutter Table size failed - flutter

Question

I need to create table which contains numbers and has square form.
The obvious solution would be to use widget Table, but...
When I use odd size it works, when I use even size it fails with rendering exception.
How to fix it?
void main() => runApp(
MaterialApp(
home: Scaffold(
appBar: new AppBar(title: Text("Table Shulte")),
body: tab(),
)
)
);
Widget tab(){
int N = 6;
Widget table = Table(
children: List.generate(N, (i){
return TableRow(children: List.generate(N, (j) =>
AspectRatio(child:Center(child: Text("${i*N+j+1}", textScaleFactor: 12.0/N,)), aspectRatio: 1.0,)
));
}),
border: TableBorder.all(),
);
return table;
}
I don't understand why this assert failes:
'package:flutter/src/rendering/table.dart': Failed assertion: line 883 pos 16: 'tableWidth >= targetWidth': is not true.
Another exception was thrown: 'package:flutter/src/rendering/table.dart': Failed assertion: line 1126 pos 12: '_rowTops.length == rows + 1': is not true.
Here the log.
I/flutter (10304): ══╡ EXCEPTION CAUGHT BY RENDERING LIBRARY ╞═════════════════════════════════════════════════════════
I/flutter (10304): The following assertion was thrown during performLayout():
I/flutter (10304): 'package:flutter/src/rendering/table.dart': Failed assertion: line 883 pos 16: 'tableWidth >=
I/flutter (10304): targetWidth': is not true.
I/flutter (10304): When the exception was thrown, this was the stack:
I/flutter (10304): #2 RenderTable._computeColumnWidths (package:flutter/src/rendering/table.dart)
I/flutter (10304): #3 RenderTable.performLayout (package:flutter/src/rendering/table.dart:1001:33)
I/flutter (10304): #4 RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7)
I/flutter (10304): #5 MultiChildLayoutDelegate.layoutChild (package:flutter/src/rendering/custom_layout.dart:141:11)
I/flutter (10304): #6 _ScaffoldLayout.performLayout (package:flutter/src/material/scaffold.dart:399:7)
I/flutter (10304): #7 MultiChildLayoutDelegate._callPerformLayout (package:flutter/src/rendering/custom_layout.dart:211:7)
I/flutter (10304): #8 RenderCustomMultiChildLayoutBox.performLayout (package:flutter/src/rendering/custom_layout.dart:355:14)
I/flutter (10304): #9 RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7)
I/flutter (10304): #10 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:109:13)
I/flutter (10304): #11 RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7)
I/flutter (10304): #12 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:109:13)
I/flutter (10304): #13 _RenderCustomClip.performLayout (package:flutter/src/rendering/proxy_box.dart:1143:11)
I/flutter (10304): #14 RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7)
I/flutter (10304): #15 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:109:13)
I/flutter (10304): #16 RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7)
I/flutter (10304): #17 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:109:13)
I/flutter (10304): This RenderObject had the following descendants (showing up to depth 5):
I/flutter (10304): RenderAspectRatio#eecef NEEDS-LAYOUT NEEDS-PAINT
I/flutter (10304): RenderPositionedBox#1f1ff NEEDS-LAYOUT NEEDS-PAINT
I/flutter (10304): RenderParagraph#8f8f7 NEEDS-LAYOUT NEEDS-PAINT
I/flutter (10304): Another exception was thrown: RenderBox was not laid out: RenderTable#babed relayoutBoundary=up1 NEEDS-PAINT
I/flutter (10304): Another exception was thrown: 'package:flutter/src/rendering/table.dart': Failed assertion: line 1126 pos 12: '_rowTops.length == rows + 1': is not true.

Answer 1

The problem causing the issue is textScaleFactor.
List.generate(index,...) method starts the index from (0).
When we call the textScaleFactor: 12.0/N is not returning a number for the widget therefore it causes an issue.
I simply, modified your tab method as follows and it returns a view now.
Widget tab(){
int N = 6;
Widget table = Table(
children: List.generate(N, (i){
return TableRow(children: List.generate(N+1, (j) =>
AspectRatio(child:Center(child: Text("${i*N+j+1}", textScaleFactor: 12.0/N)), aspectRatio: 1.0)
));
}),
border: TableBorder.all(),
);
return table;
}