Closed
Description
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
Widgets that take a while to set up cause this race condition on wasm.
panic: syscall/js: call of Value.Call on null
wasm_exec.js:22
wasm_exec.js:22 goroutine 1 [running]:
wasm_exec.js:22 syscall/js.Value.Call({{}, 0x7ff8000000000002, 0x0}, {0x19ca0b, 0x8}, {0x1433b38, 0x4, 0x4})
wasm_exec.js:22 /usr/lib/go/src/syscall/js/js.go:438 +0x3f
wasm_exec.js:22 github.com/fyne-io/gl-js.Viewport(...)
wasm_exec.js:22 /home/hayden/Development/Go/pkg/mod/github.com/fyne-io/gl-js@v0.1.0/gl_webgl_wasm.go:824
wasm_exec.js:22 fyne.io/fyne/v2/internal/painter/gl.(*xjsContext).Viewport(0x12b1140, 0x0, 0x0, 0xf00, 0x4d6)
wasm_exec.js:22 /home/hayden/Development/Go/src/github.com/hkparker/fyne/internal/painter/gl/gl_wasm.go:238 +0x4
wasm_exec.js:22 fyne.io/fyne/v2/internal/painter/gl.(*painter).SetOutputSize(0x15aa700, 0xf00, 0x4d6)
wasm_exec.js:22 /home/hayden/Development/Go/src/github.com/hkparker/fyne/internal/painter/gl/painter.go:103 +0x6
wasm_exec.js:22 fyne.io/fyne/v2/internal/driver/glfw.updateGLContext(0x1400fc0)
wasm_exec.js:22 /home/hayden/Development/Go/src/github.com/hkparker/fyne/internal/driver/glfw/loop.go:228 +0x1d
wasm_exec.js:22 fyne.io/fyne/v2/internal/driver/glfw.(*gLDriver).repaintWindow.func1()
wasm_exec.js:22 /home/hayden/Development/Go/src/github.com/hkparker/fyne/internal/driver/glfw/loop.go:197 +0xa
wasm_exec.js:22 fyne.io/fyne/v2/internal/driver/glfw.(*window).RunWithContext(0x1400fc0, 0x1433cc0)
wasm_exec.js:22 /home/hayden/Development/Go/src/github.com/hkparker/fyne/internal/driver/glfw/window.go:899 +0x18
wasm_exec.js:22 fyne.io/fyne/v2/internal/driver/glfw.(*gLDriver).repaintWindow(0x15e3d90, 0x1400fc0)
wasm_exec.js:22 /home/hayden/Development/Go/src/github.com/hkparker/fyne/internal/driver/glfw/loop.go:191 +0x4
wasm_exec.js:22 fyne.io/fyne/v2/internal/driver/glfw.(*gLDriver).drawSingleFrame(0x15e3d90)
wasm_exec.js:22 /home/hayden/Development/Go/src/github.com/hkparker/fyne/internal/driver/glfw/loop.go:89 +0x1b
wasm_exec.js:22 fyne.io/fyne/v2/internal/driver/glfw.(*gLDriver).runGL(0x15e3d90)
wasm_exec.js:22 /home/hayden/Development/Go/src/github.com/hkparker/fyne/internal/driver/glfw/loop.go:167 +0x76
wasm_exec.js:22 fyne.io/fyne/v2/internal/driver/glfw.(*gLDriver).Run(0x15e3d90)
wasm_exec.js:22 /home/hayden/Development/Go/src/github.com/hkparker/fyne/internal/driver/glfw/driver.go:162 +0x6
wasm_exec.js:22 fyne.io/fyne/v2/app.(*fyneApp).Run(0x15e3e40)
wasm_exec.js:22 /home/hayden/Development/Go/src/github.com/hkparker/fyne/app/app.go:72 +0xf
wasm_exec.js:22 fyne.io/fyne/v2/internal/driver/glfw.(*window).ShowAndRun(0x1400fc0)
wasm_exec.js:22 /home/hayden/Development/Go/src/github.com/hkparker/fyne/internal/driver/glfw/window.go:221 +0xc
wasm_exec.js:22 main.main()
wasm_exec.js:22 /home/hayden/Development/Go/src/github.com/hkparker/fyne-dev/main.go:82 +0x3a
How to reproduce
fyne serve the example code and click the button while looking at the javascript console
Screenshots
No response
Example code
package main
import (
"fyne.io/fyne/v2"
"fyne.io/fyne/v2/app"
"fyne.io/fyne/v2/container"
"fyne.io/fyne/v2/widget"
"time"
)
type slowLabel struct {
widget.Label
}
func newSlowLabel(str string) *slowLabel {
sl := &slowLabel{
Label: widget.Label{Text: str},
}
sl.ExtendBaseWidget(sl)
return sl
}
func (sl *slowLabel) MinSize() fyne.Size {
time.Sleep(50 * time.Millisecond)
return sl.Label.MinSize()
}
func main() {
a := app.New()
w := a.NewWindow("crash")
var mainContent fyne.CanvasObject
mainContent = container.NewVBox(
newSlowLabel("click this button to crash"),
widget.NewButton("Crash", func() {
w.SetContent(mainContent)
}))
w.SetContent(mainContent)
w.ShowAndRun()
}Fyne version
develop
Go compiler version
go 1.24.1 linux/amd64
Operating system and version
Arch Linux / Chrome
Additional Information
No response