widget.ToolbarItem SetIcon

[xines]

Is your feature request related to a problem? Please describe:

At the moment ToolBarItem does not have a SetIcon function like widget buttons even tho toolbars are buttons under the hood.
So as a workaround to set the icon it's required to store the fyne.resource icon into variable and re-update content accordingly.

Is it possible to construct a solution with the existing API?

Yes

Describe the solution you'd like to see:

toolBarItem = widget.NewToolbarAction(theme.FyneLogo(), func() {})
toolBarItem.SetIcon(theme.QuestionIcon())

[andydotxyz]

You can currently do this:

toolbarItem.Icon = theme.QuestionIcon()
toolbar.Refresh()

[xines]

You can currently do this:

toolbarItem.Icon = theme.QuestionIcon()
toolbar.Refresh()

Using newest dev branch i get this.

Interface have no icon so explains why.
https://developer.fyne.io/api/v2.0/widget/toolbaritem.html

[andydotxyz]

I'm sorry - I forgot that the return type is the interface.

toolbarItem.(*widget.ToolbarAction).Icon = theme.QuestionIcon()
toolbar.Refresh()

[xines]

Yes i see, tyvm @andydotxyz

• I still believe SetIcon to be a great addition. 👍

[adzo261]

I would like to do this one.

Describe the solution you'd like to see:

toolBarItem = widget.NewToolbarAction(theme.FyneLogo(), func() {})
toolBarItem.SetIcon(theme.QuestionIcon())

@xines I think this way it won't be possible since ToolbarItem is an interface and not a struct.

Also, we can't add SetIcon to the ToolbarItem interface since multiple toolbar items are of the same type (e.g spacers, separators, etc.)
A workaround can be something like -
func SetIcon(toolbarItem ToolbarItem , icon fyne.Resource){...}

But I think since we have SetIcon in different packages and it is invoked by some struct object, it would be inconsistent with that pattern.

Another thing we can do is to implement SetIcon on t *ToolbarAction as follows:

func (t *ToolbarAction) SetIcon(icon fyne.Resource) {
	t.Icon = icon
	t.ToolbarObject().Refresh()
}

But then we will have to cast the interface to specific type while using it -

toolbarItem.(*widget.ToolbarAction).SetIcon(theme.QuestionIcon())

@andydotxyz @xines Any pointers on how can we implement this ?

[andydotxyz]

Or NewToolbarAction could return a ToolbarAction instead of ToolbarItem...? That could have a SetIcon() function

[adzo261]

Or NewToolbarAction could return a ToolbarAction instead of ToolbarItem...? That could have a SetIcon() function

Yes, we can do that too as NewToolbar accepts any instance implmentingToolbarItems. But again, it is inconsistent with the existing code. Currently, every concrete toolbar item constructor(For spacer and separator) is returning a generic ToolbarItem interface. -
Can I know what is the idea behind such a design, as I am fairly new to Golang?
Meanwhile, I will implement it as you said and run tests to see if anything else breaks.

[andydotxyz]

Can I know what is the idea behind such a design, as I am fairly new to Golang?

I was also very new to Go when I wrote that code, so it may not be the right way to do it ;).
In general I think they promote accepting interfaces (in function parameters) and return concrete types.

[xines]

In general I think they promote accepting interfaces (in function parameters) and return concrete types.

Yeah indeed they do.

• Just stay away from 'interface pollution' hehe.

as I am fairly new to Golang

Id highly recommend giving this a look :) https://go-proverbs.github.io/

[andydotxyz]

On develop for testing, thanks :)