Carriage Return (\r) is rendered as space

[TUSF]

Describe the bug:

I've only tested the entry and label widgets so far, but it appears that when Fyne comes across \r, it is rendered as a space. Ideally, the application would NOT render it at all, while still potentially having the option to use \r\n for linebreaks, for compatibility with other Windows applications.

To Reproduce:

In my case, I merely edited the textedit example, and inserted this line into the Show() function:

editor.entry.SetText("A test\nwith\rcarriage return,\r\nAnd if it understands?")

I also added a \n\r into the "Cursor Row" label (which is backwards from how Windows apps normally handle it, but still demonstrates how Fyne labels handle the carriage return)

Screenshots:

Device (please complete the following information):

• OS: Windows
• Version: 10
• Go version: 1.17
• Fyne version: 2.0.4

[julieta-311]

I'm having issues with carriage return as well when executing a command in the background and writing the logs into a text grid. These logs contain a progress bar with carriage return at the beginning of each line. It prints out unexpected characters that are not printed out when writing to Stdout (prints out the outcome of fmt.Println("\u001b[1A")).

Here is minimal code to visualise it and compare to the output in the terminal:

package main

import (
	"fmt"
	"io"
	"os"
	"time"

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

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

	t := widget.NewTextGrid()
	b := widget.NewButton("read", func() {
		pipeToTextGrid(t)
	})

	w.SetContent(container.NewVBox(t, b))
	w.ShowAndRun()
}

func pipeToTextGrid(t *widget.TextGrid) {
	r, w := io.Pipe()
	go doRead(r, t)

	// Carriage return: \u001b[1A
	w.Write([]byte("Foo:\n"))
	for {
		w.Write([]byte("\u001b[1A Bar 1"))
		time.Sleep(time.Second)
		w.Write([]byte("\u001b[1A Bar 12"))
		time.Sleep(time.Second)
		w.Write([]byte("\u001b[1A Bar 123"))
		time.Sleep(time.Second)
		w.Write([]byte("\u001b[1A Bar 1234"))
		time.Sleep(time.Second)
		w.Write([]byte("\u001b[1A Bar 12345"))
		time.Sleep(time.Second)
		w.Write([]byte("\u001b[1A Bar 123456"))
		time.Sleep(time.Second)
		w.Write([]byte("\u001b[1A Bar 1234567\n"))
	}
}

func doRead(r *io.PipeReader, t *widget.TextGrid) {
	for {
		buf := make([]byte, 50)
		n, _ := r.Read(buf)
		line := string(buf[:n])
		t.SetText(line)
		fmt.Fprintf(os.Stdout, "\n%v", line)
	}
}

Device:
OS: Manjaro Linux.
Version: DISTRIB_RELEASE=21.2.2.
Go version: 1.17.6 linux/amd64
Fyne version: v2.1.2

[andydotxyz]

Your terminal interprets these control characters @julieta-311, but a text renderer does not.
You should either tell the software you are logging not to include colour code/style information or you will have to filter it in your own code. This is not a bug of our text rendering - you are asking it to print the "escape" character - which the font does not contain.

[andydotxyz]

This fix was landed for Bowmore

[julieta-311]

Your terminal interprets these control characters @julieta-311, but a text renderer does not.
You should either tell the software you are logging not to include colour code/style information or you will have to filter it in your own code. This is not a bug of our text rendering - you are asking it to print the "escape" character - which the font does not contain.

Thanks for the quick response! I'm filtering it out in my code at the moment, will try your other suggestion as well.