diff --git a/textarea/textarea.go b/textarea/textarea.go index 2865e1a9..a7de53f2 100644 --- a/textarea/textarea.go +++ b/textarea/textarea.go @@ -135,6 +135,11 @@ type Model struct { // General settings. // Prompt is printed at the beginning of each line. + // + // When changing the value of Prompt after the model has been + // initialized, ensure that SetWidth() gets called afterwards. + // + // See also SetPromptFunc(). Prompt string // Placeholder is the text displayed when the user @@ -168,6 +173,13 @@ type Model struct { // accept. If 0 or less, there's no limit. CharLimit int + // If promptFunc is set, it replaces Prompt as a generator for + // prompt strings at the beginning of each line. + promptFunc func(line int) string + + // promptWidth is the width of the prompt. + promptWidth int + // width is the maximum number of characters that can be displayed at once. // If 0 or less this setting is ignored. width int @@ -785,10 +797,26 @@ func (m *Model) SetWidth(w int) { // Account for base style borders and padding. inputWidth -= m.style.Base.GetHorizontalFrameSize() - inputWidth -= rw.StringWidth(m.Prompt) + if m.promptFunc == nil { + m.promptWidth = rw.StringWidth(m.Prompt) + } + + inputWidth -= m.promptWidth m.width = clamp(inputWidth, minWidth, maxWidth) } +// SetPromptFunc supersedes the Prompt field and sets a dynamic prompt +// instead. +// If the function returns a prompt that is shorter than the +// specified promptWidth, it will be padded to the left. +// If it returns a prompt that is longer, display artifacts +// may occur; the caller is responsible for computing an adequate +// promptWidth. +func (m *Model) SetPromptFunc(promptWidth int, fn func(lineIdx int) string) { + m.promptFunc = fn + m.promptWidth = promptWidth +} + // Height returns the current height of the textarea. func (m Model) Height() int { return m.height @@ -950,6 +978,7 @@ func (m Model) View() string { var newLines int + displayLine := 0 for l, line := range m.value { wrappedLines := wrap(line, m.width) @@ -960,7 +989,10 @@ func (m Model) View() string { } for wl, wrappedLine := range wrappedLines { - s.WriteString(style.Render(m.style.Prompt.Render(m.Prompt))) + prompt := m.getPromptString(displayLine) + prompt = m.style.Prompt.Render(prompt) + s.WriteString(style.Render(prompt)) + displayLine++ if m.ShowLineNumbers { if wl == 0 { @@ -1009,7 +1041,10 @@ func (m Model) View() string { // Always show at least `m.Height` lines at all times. // To do this we can simply pad out a few extra new lines in the view. for i := 0; i < m.height; i++ { - s.WriteString(m.style.Prompt.Render(m.Prompt)) + prompt := m.getPromptString(displayLine) + prompt = m.style.Prompt.Render(prompt) + s.WriteString(prompt) + displayLine++ if m.ShowLineNumbers { lineNumber := m.style.EndOfBuffer.Render((fmt.Sprintf(m.lineNumberFormat, string(m.EndOfBufferCharacter)))) @@ -1022,6 +1057,19 @@ func (m Model) View() string { return m.style.Base.Render(m.viewport.View()) } +func (m Model) getPromptString(displayLine int) (prompt string) { + prompt = m.Prompt + if m.promptFunc == nil { + return prompt + } + prompt = m.promptFunc(displayLine) + pl := rw.StringWidth(prompt) + if pl < m.promptWidth { + prompt = fmt.Sprintf("%*s%s", m.promptWidth-pl, "", prompt) + } + return prompt +} + // placeholderView returns the prompt and placeholder view, if any. func (m Model) placeholderView() string { var ( @@ -1030,7 +1078,8 @@ func (m Model) placeholderView() string { style = m.style.Placeholder.Inline(true) ) - prompt := m.style.Prompt.Render(m.Prompt) + prompt := m.getPromptString(0) + prompt = m.style.Prompt.Render(prompt) s.WriteString(m.style.CursorLine.Render(prompt)) if m.ShowLineNumbers { @@ -1047,6 +1096,8 @@ func (m Model) placeholderView() string { // The rest of the new lines for i := 1; i < m.height; i++ { s.WriteRune('\n') + prompt := m.getPromptString(i) + prompt = m.style.Prompt.Render(prompt) s.WriteString(prompt) if m.ShowLineNumbers {