stack overflow when calling SetRowHeight in table UpdateCell callback

[MidnightSong]

Checklist

• I have searched the issue tracker for open issues that relate to the same problem, before opening a new one.
• This issue only relates to a single bug. I will open new issues for any other problems.

Describe the bug

I create a table widget . But the row height is uncertain when it created, only until use other variable return fields.

runtime: goroutine stack exceeds 1000000000-byte limit
runtime: sp=0x1407a780420 stack=[0x1407a780000, 0x1409a780000]
fatal error: stack overflow

runtime stack:
runtime.throw({0x104b739ce?, 0x16ee4adb8?})
/usr/local/go/src/runtime/panic.go:1023 +0x40 fp=0x16ee4ad50 sp=0x16ee4ad20 pc=0x103016420
runtime.newstack()
/usr/local/go/src/runtime/stack.go:1103 +0x478 fp=0x16ee4aef0 sp=0x16ee4ad50 pc=0x103030fa8
runtime.morestack()
/usr/local/go/src/runtime/asm_arm64.s:341 +0x70 fp=0x16ee4aef0 sp=0x16ee4aef0 pc=0x103049010

goroutine 115 gp=0x1400f26ce00 m=5 mp=0x14000100008 [running]:
fyne.io/fyne/v2/widget.splitLines(0x140002491f0)
/Users/xjy/go/pkg/mod/fyne.io/fyne/v2@v2.5.0/widget/richtext.go:1097 +0x3e8 fp=0x1407a780420 sp=0x1407a780420 pc=0x104999418
fyne.io/fyne/v2/widget.lineBounds(0x140002491f0, 0x0, 0x0, 0x436a0000, {0x436a0000, 0x4193e000}, 0x1407a780be8)
/Users/xjy/go/pkg/mod/fyne.io/fyne/v2@v2.5.0/widget/richtext.go:943 +0x54 fp=0x1407a780a20 sp=0x1407a780420 pc=0x104997714
fyne.io/fyne/v2/widget.(*RichText).updateRowBounds.func1({0x140104a03f0, 0x1, 0x1})

when i remove this code :

table.SetRowHeight(id.Row, 50).

Everything has become normal

How to reproduce

just use i provide code

Screenshots

Example code

when i use this code:

package main

import (
	"fyne.io/fyne/v2"
	"fyne.io/fyne/v2/app"
	"fyne.io/fyne/v2/container"
	"fyne.io/fyne/v2/widget"
)

var data = [][]string{
	{"this is a long string", "Row 1, Col 2"},
	{"Row 2, Col 1", "Row 2, Col 2"},
	{"Row 3, Col 1", "Row 3, Col 2"},
	{"Row 4, Col 1", "Row 4, Col 2"},
	{"Row 5, Col 1", "Row 5, Col 2"},
	{"Row 6, Col 1", "Row 6, Col 2"},
}

func main() {
	mainApp := app.NewWithID("a.b.c.d")
	mainWin := mainApp.NewWindow("test table")
	table := getTable()
	mainWin.SetContent(container.NewStack(table))
	mainWin.CenterOnScreen()
	mainWin.Resize(fyne.NewSize(600, 400))
	mainWin.ShowAndRun()
}

func getTable() *widget.Table {
	var table *widget.Table
	table = widget.NewTableWithHeaders(func() (int, int) { return len(data), 2 },
		func() fyne.CanvasObject {
			label := widget.NewLabel("unload")
			return label
		},
		func(id widget.TableCellID, cell fyne.CanvasObject) {
			c := cell.(*widget.Label)
			if len(data[id.Row][id.Col]) > 10 {
				table.SetRowHeight(id.Row, 50)
			}
			c.SetText(data[id.Row][id.Col])
		},
	)
	table.SetColumnWidth(0, 100)
	table.SetColumnWidth(1, 100)
	return table
}

Fyne version

v2.5.0

Go compiler version

1.21

Operating system and version

macOS Sonoma 14.5 Apple M2

Additional Information

No response

[andydotxyz]

Is it possible to please provide a code sample that actually replicates this issue? The snippet included does not compile.

[hfmrow]

Hi,

Personally, I don't use 'table.SetRowHeight' inside the 'update' function because it seems logical that an issue will occur, given that the row size increases in height, it will trigger a table update again and this will create an infinite loop that will ultimately result in a stack overflow (This is what I believe, but I might be mistaken).

So, to keep it simple, you put 'table.SetRowHeight' right after creating your table, something like this:

        var table *widget.Table
       
	// ...

	// ...

	table = widget.NewTable(length, create, update)

	for i := range items.EnvItems {
		table.SetRowHeight(i, rowHeight)
	}

	return table

And it works perfectly.

Here's a complete example:

package main

import (
	"fyne.io/fyne/v2"
	"fyne.io/fyne/v2/app"
	"fyne.io/fyne/v2/container"
	"fyne.io/fyne/v2/theme"
	"fyne.io/fyne/v2/widget"
)

var (
	// Dummy data
	chats = [][]string{
		{"title0", "content0", "author0"},
		{"title1", "content1", "author1"},
		{"title2", "content2", "author2"},
		{"title3verylongwithlotofwords", "content3", "author3"},
		{"title4", "content4", "author4"},
		{"title5", "content5", "author5"},
		{"title6verylongwithlotofwords", "content6", "author6"},
		{"title7verylongwithlotofwords", "content7", "author7"},
		{"title8", "content8", "author8"},
		{"title9verylongwithlotofwords", "content9", "author9"},
	}

	// Set to false to disable text truncation.
	// It will use manual width sizing instead.
	withTruncation bool = true
)

func main() {
	mainApp := app.NewWithID("a.b.c.d")
	mainWin := mainApp.NewWindow("test table")

	table := openedDialogs()

	mainWin.SetContent(container.NewStack(table))
	mainWin.CenterOnScreen()
	mainWin.Resize(fyne.NewSize(800, 400))

	mainWin.ShowAndRun()
}

func openedDialogs() *widget.Table {
	// Get length
	length := func() (int, int) { return len(chats), 3 }

	// Create label
	create := func() fyne.CanvasObject {
		return widget.NewLabel("O(∩_∩)O哈哈~")
	}

	// Update table
	update := func(id widget.TableCellID, cell fyne.CanvasObject) {
		label := cell.(*widget.Label)
		label.SetText(chats[id.Row][id.Col])
		if withTruncation {
			// auto truncation method (change 'withTruncation' to 'false' to disable it)
			label.Truncation = fyne.TextTruncateEllipsis
		}
	}

	// Create table
	table := widget.NewTableWithHeaders(length, create, update)

	// Adjust height/width
	for i, v := range chats {

		for col, text := range v {
			switch col {
			case 0:
				if len(text) > 25 {
					table.SetRowHeight(i, 50)
				}
			case 1:
				// do something
			case 2:
				// do...
			}

			if !withTruncation {
				// manual cell width sizing method (change 'withTruncation' to 'true' to disable it)
				width := fyne.MeasureText(text, theme.TextSize(), fyne.TextStyle{}).Width
				table.SetColumnWidth(col, width+theme.Padding()*5)
			}
		}
	}

	return table
}

[MidnightSong]

Hi,

Personally, I don't use 'table.SetRowHeight' inside the 'update' function because it seems logical that an issue will occur, given that the row size increases in height, it will trigger a table update again and this will create an infinite loop that will ultimately result in a stack overflow (This is what I believe, but I might be mistaken).

So, to keep it simple, you put 'table.SetRowHeight' right after creating your table, something like this:

        var table *widget.Table
       
	// ...

	// ...

	table = widget.NewTable(length, create, update)

	for i := range items.EnvItems {
		table.SetRowHeight(i, rowHeight)
	}

	return table

And it works perfectly.

Here's a complete example:

package main

import (
	"fyne.io/fyne/v2"
	"fyne.io/fyne/v2/app"
	"fyne.io/fyne/v2/container"
	"fyne.io/fyne/v2/theme"
	"fyne.io/fyne/v2/widget"
)

var (
	// Dummy data
	chats = [][]string{
		{"title0", "content0", "author0"},
		{"title1", "content1", "author1"},
		{"title2", "content2", "author2"},
		{"title3verylongwithlotofwords", "content3", "author3"},
		{"title4", "content4", "author4"},
		{"title5", "content5", "author5"},
		{"title6verylongwithlotofwords", "content6", "author6"},
		{"title7verylongwithlotofwords", "content7", "author7"},
		{"title8", "content8", "author8"},
		{"title9verylongwithlotofwords", "content9", "author9"},
	}

	// Set to false to disable text truncation.
	// It will use manual width sizing instead.
	withTruncation bool = true
)

func main() {
	mainApp := app.NewWithID("a.b.c.d")
	mainWin := mainApp.NewWindow("test table")

	table := openedDialogs()

	mainWin.SetContent(container.NewStack(table))
	mainWin.CenterOnScreen()
	mainWin.Resize(fyne.NewSize(800, 400))

	mainWin.ShowAndRun()
}

func openedDialogs() *widget.Table {
	// Get length
	length := func() (int, int) { return len(chats), 3 }

	// Create label
	create := func() fyne.CanvasObject {
		return widget.NewLabel("O(∩_∩)O哈哈~")
	}

	// Update table
	update := func(id widget.TableCellID, cell fyne.CanvasObject) {
		label := cell.(*widget.Label)
		label.SetText(chats[id.Row][id.Col])
		if withTruncation {
			// auto truncation method (change 'withTruncation' to 'false' to disable it)
			label.Truncation = fyne.TextTruncateEllipsis
		}
	}

	// Create table
	table := widget.NewTableWithHeaders(length, create, update)

	// Adjust height/width
	for i, v := range chats {

		for col, text := range v {
			switch col {
			case 0:
				if len(text) > 25 {
					table.SetRowHeight(i, 50)
				}
			case 1:
				// do something
			case 2:
				// do...
			}

			if !withTruncation {
				// manual cell width sizing method (change 'withTruncation' to 'true' to disable it)
				width := fyne.MeasureText(text, theme.TextSize(), fyne.TextStyle{}).Width
				table.SetColumnWidth(col, width+theme.Padding()*5)
			}
		}
	}

	return table
}

Thank you for your answer. This is indeed a temporary solution that can be used

[MidnightSong]

Is it possible to please provide a code sample that actually replicates this issue? The snippet included does not compile.

I have modified the example code. Could you please review it again

[andydotxyz]

Thanks, I can now replicate the issue. PR open

[JanVaya]

I had the same problem but could not use the proposed solution. I wordwrap Text in Cells and thus the columnHeight changes, if the contents or the columnWidth changes. Therefore I used SetRowHeight in the UpdateCell call. If fixed the initial problem with a simple variable based saveguard, preventing that I use SetRowHeight again during the Refresh, that it caused:
label.SetText(currentRSListe.Liste[id.Row].Beschreibung)
newHeight := label.MinSize().Height
if abs(newHeight-cell.Size().Height) > 0.1*newHeight {
if gateKeeper == 0 {
gateKeeper = 1
table.SetRowHeight(id.Row, newHeight)
gateKeeper = 0
}
}
But even with this fix it crashes, because SetRowHeight is changing the internal map rowHeights and this is also accessed heavily during other ongoing Refreshes and after some scrolling of the table the program will panic with concurrent map write...

I have fixed this with the introduction of a Mutex to guard all accesses the columnWidths and rowHeights maps in table.go and now it all runs smoothly. I tried to make a fork of fyne and made the changes to table.go there but failed to execute the tests as go test ..... FAILs in the canvas.go which I didn't touch :-(
--- FAIL: TestGlCanvas_ChildMinSizeChangesInDifferentScrollAffectAncestorsUpToScroll (0.33s)
canvas_test.go:117:
Error Trace: D:/Go/Projekte/fyne/internal/driver/glfw/canvas_test.go:117
Error: Not equal:
expected: fyne.Size{Width:76, Height:40}
actual : fyne.Size{Width:120, Height:40}

                            Diff:
                            --- Expected
                            +++ Actual
                            @@ -1,3 +1,3 @@
                             (fyne.Size) {
                            - Width: (float32) 76,
                            + Width: (float32) 120,
                              Height: (float32) 40
            Test:           TestGlCanvas_ChildMinSizeChangesInDifferentScrollAffectAncestorsUpToScroll

2024/07/25 21:52:08 Fyne error: Failed to focus object which is not part of the canvas’ content, menu or overlays.
2024/07/25 21:52:08 At: D:/Go/Projekte/fyne/internal/driver/common/canvas.go:182

Hope this helps anyone.

[andydotxyz]

Fixed on develop and will get picked into v2.5.1

[janmz]

Thank You!!