textinput: Prompt length not taken into account for width

[mikelorant]

When creating a textinput, the prompt width is added to the width of the entire textinput. This means that two text inputs with a width of 20, will have different lengths based on the length of the prompt. This is visible when adding a border.

func initialModel() model {
	tiA := makeTextInput("1234")
	tiB := makeTextInput("1234567890")

	return model{
		textInputA: tiA,
		textInputB: tiB,
	}
}

func makeTextInput(str string) textinput.Model {
	ti := textinput.New()
	ti.Prompt = str
	ti.Focus()
	ti.CharLimit = 156
	ti.Width = 20

	return ti
}

I have an example of this bug here:
https://github.com/mikelorant/bubbles-textinput-prompt

Looking at the textinput code, it is clear that the prompt length is never subtracted from the width. I believe the width is actually shorter than it should be but I am unclear what the intended width is meant to represent.

[mikelorant]

@meowgorithm Can we get some clarification of what the width is meant to mean. You were the last person to touch this field so I am hoping you know the reasons behind why 😄

// Width is the maximum number of characters that can be displayed at once.
// It essentially treats the text field like a horizontally scrolling
// viewport. If 0 or less this setting is ignored.
Width int

https://github.com/charmbracelet/bubbles/blob/master/textinput/textinput.go#L113-L116

I have two possible interpretations:

1. The width is the entire textinput component.
2. The width is just the visible area for user input space. Prompts and extra padding add to this width.

Whatever the answer is, I believe we should update the documentation clarifying this field. If there is a bug, I will put up the appropriate pull request to fix this.

[meowgorithm]

Okay, jumping back in on this one: Width here is the width of the textinput input area only — so not including margins, borders, padding and so on.

[mikelorant]

@meowgorithm Thanks for the clarification. Will close this issue as it seems everything is working as expected.