Kannada characters not rendering correctly

[ravihara]

Describe the bug:

I was following the example given at https://developer.fyne.io/tour/binding/twoway. I changed my keyboard layout to Kannada-itrans. I'm using Ubuntu 20.04 LTS 64 bit system and have install ibus-m17n and fonts-indic packages. While running the application via go run main.go, after typing couple of characters, the application crashed with the following error.

panic: runtime error: slice bounds out of range [15:14]

goroutine 9 [running]:
fyne.io/fyne/v2/widget.(*RichText).insertAt(0xc000618000, 0xf, {0xc000353f30, 0x3})
	/home/ravihara/.asdf/installs/golang/1.17.3/packages/pkg/mod/fyne.io/fyne/v2@v2.1.1/widget/richtext.go:222 +0x2b8
fyne.io/fyne/v2/widget.(*Entry).TypedRune(0xc0001a4000, 0xccd)
	/home/ravihara/.asdf/installs/golang/1.17.3/packages/pkg/mod/fyne.io/fyne/v2@v2.1.1/widget/entry.go:743 +0x11b
fyne.io/fyne/v2/internal/driver/glfw.(*window).charInput.func1()
	/home/ravihara/.asdf/installs/golang/1.17.3/packages/pkg/mod/fyne.io/fyne/v2@v2.1.1/internal/driver/glfw/window.go:1226 +0x25
fyne.io/fyne/v2/internal/driver/common.(*Window).RunEventQueue(0xc00045c200)
	/home/ravihara/.asdf/installs/golang/1.17.3/packages/pkg/mod/fyne.io/fyne/v2@v2.1.1/internal/driver/common/window.go:58 +0x56
created by fyne.io/fyne/v2/internal/driver/glfw.(*gLDriver).createWindow.func1
	/home/ravihara/.asdf/installs/golang/1.17.3/packages/pkg/mod/fyne.io/fyne/v2@v2.1.1/internal/driver/glfw/window.go:1395 +0x15b
exit status 2

To Reproduce:

Steps to reproduce the behaviour:

1. Go to 'https://developer.fyne.io/tour/binding/twoway' and create a sample project as per the guide. In my case, the sample code was in main.go in main package.
2. Export the required font file so as to get the Kannada font to render properly in the InputEntry box
   export FYNE_FONT=/usr/share/fonts/truetype/Gubbi/Gubbi.ttf
3. Run the fyne application using go run main.go
4. See error

Screenshots:

Example code:

Device (please complete the following information):

• OS: Ubuntu Linux 20.04 LTS 64-Bit (x86-64)
• Version: 20.04 LTS
• Go version: 1.17.3
• Fyne version: 2.1.1

[andydotxyz]

• Run the fyne application using go run main.go
• See error

I think this is missing some steps - didn't you have to type something into one of the fields? It would be helpful to get the characters so we can replicate correctly.

[ravihara]

• Run the fyne application using go run main.go
• See error

I think this is missing some steps - didn't you have to type something into one of the fields? It would be helpful to get the characters so we can replicate correctly.

Yes. The issue happens once you start typing couple of Kannada (IN_Kn) characters. I use ibus-m17n engine with itrans keyboard layout for Kannada, in order to type the characters. An Example string in Kannada could be - ಕನ್ನಡ ಒಂದು ಸುಂದರ ಭಾಷೆ

[andydotxyz]

Is the font you are using this one: https://github.com/aravindavk/Gubbi?

[ravihara]

Is the font you are using this one: https://github.com/aravindavk/Gubbi?

Yes.. Do you see an issue in the font?

[andydotxyz]

It would be good if you could outline the specific steps required to replicate the crash - that way I can know if we have fixed the problem,

[ravihara]

It would be good if you could outline the specific steps required to replicate the crash - that way I can know if we have fixed the problem,

• mkdir check-fyne
• cd check-fyne
• go mod init github.com/ravihara/check-fyne
• go get fyne.io/fyne/v2
• Create the file main.go with the code sample as given in https://developer.fyne.io/tour/binding/twoway
• go mod tidy
• export FYNE_FONT=/usr/share/fonts/truetype/Gubbi/Gubbi.ttf
• go run main.go
• Clear the type in the text box
• Switch to Kannada (IN_kn) keyboard layout and start typing random characters. If you need a proper string type ಕನ್ನಡ ಒಂದು ಸುಂದರ ಭಾಷೆ

[ravihara]

Today I retried again and the app hung instead of crashing. When I tried running again, it went fine. In all the cases, the font rendering is not proper too.

[andydotxyz]

I think we need more details replication steps for:

Switch to Kannada (IN_kn) keyboard layout and start typing random characters. If you need a proper string type ಕನ್ನಡ ಒಂದು ಸುಂದರ ಭಾಷೆ

Because I tried and it seemed to work OK, so I am clearly missing something.

[andydotxyz]

Just for posterity this was the code that created the screenshot above:

package main

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

func main() {
	a := app.New()
	w := a.NewWindow("Hello")

	str := binding.NewString()
	str.Set("ಕನ್ನಡ ಒಂದು ಸುಂದರ ಭಾಷೆ")

	e := widget.NewEntryWithData(str)
	w.SetContent(container.NewVBox(
		widget.NewLabelWithData(str),
		e,
	))

	w.Resize(fyne.NewSize(180, 20))
	w.ShowAndRun()
}

[ravihara]

Just for posterity this was the code that created the screenshot above:

package main

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

func main() {
	a := app.New()
	w := a.NewWindow("Hello")

	str := binding.NewString()
	str.Set("ಕನ್ನಡ ಒಂದು ಸುಂದರ ಭಾಷೆ")

	e := widget.NewEntryWithData(str)
	w.SetContent(container.NewVBox(
		widget.NewLabelWithData(str),
		e,
	))

	w.Resize(fyne.NewSize(180, 20))
	w.ShowAndRun()
}

Hi, thanks for trying it out. As I mentioned in my last comment, I couldn't reproduce the crash error due to slice size, again. Now, the only issue that remains is the font rendering. You can easily compare the rendered output in the fyne app and how it renders in the github in the code snippet that you posted. I mean, the value of str.set(...) method. We may close this issue, if font-rendering is a separate problem space.

[andydotxyz]

You can easily compare the rendered output in the fyne app and how it renders in the github in the code snippet that you posted.

It is not as easy as you think - the string rendered in GitHub is system dependent, I do not normally have "Gubbi" font running, so I just see squares. If you want to compare rendering output please post screenshots so we can see exactly what you expect.

[ravihara]

You can easily compare the rendered output in the fyne app and how it renders in the github in the code snippet that you posted.

It is not as easy as you think - the string rendered in GitHub is system dependent, I do not normally have "Gubbi" font running, so I just see squares. If you want to compare rendering output please post screenshots so we can see exactly what you expect.

Sorry about that! i missed the point. Please find the screenshot of the Kannada font rendering for your reference. You may compare it with #2654 (comment) to understand the rendering issue.