feat(inputfield): Add ability to show a note below the inputfield

checkbox.go

@@ -215,6 +215,11 @@ func (c *CheckBox) SetFormAttributes(labelWidth int, bgColor, labelColor, labelC
 	return c
 }
 
+// GetFieldHeight returns the height of the field.
+func (c *CheckBox) GetFieldHeight() int {
+	return 1
+}
+
 // GetFieldWidth returns this primitive's field width.
 func (c *CheckBox) GetFieldWidth() int {
 	c.RLock()

demos/form/main.go

@@ -11,6 +11,10 @@ func main() {
 		AddDropDownSimple("Title", 0, nil, "Mr.", "Ms.", "Mrs.", "Dr.", "Prof.").
 		AddInputField("First name", "", 20, nil, nil).
 		AddInputField("Last name", "", 20, nil, nil).
+		AddFormItem(cview.NewInputField().
+			SetLabel("Address").
+			SetFieldWidth(30).
+			SetFieldNote("Your complete address")).
 		AddPasswordField("Password", "", 10, '*', nil).
 		AddCheckBox("", "Age 18+", false, nil).
 		AddButton("Save", nil).

dropdown.go

@@ -403,6 +403,11 @@ func (d *DropDown) SetFieldWidth(width int) *DropDown {
 	return d
 }
 
+// GetFieldHeight returns the height of the field.
+func (d *DropDown) GetFieldHeight() int {
+	return 1
+}
+
 // GetFieldWidth returns this primitive's field screen width.
 func (d *DropDown) GetFieldWidth() int {
 	d.RLock()

form.go

@@ -28,6 +28,9 @@ type FormItem interface {
 	// required.
 	GetFieldWidth() int
 
+	// GetFieldHeight returns the height of the form item.
+	GetFieldHeight() int
+
 	// SetFinishedFunc sets the handler function for when the user finished
 	// entering data into the item. The handler may receive events for the
 	// Enter key (we're done), the Escape key (cancel input), the Tab key (move to
@@ -640,7 +643,7 @@ func (f *Form) Draw(screen tcell.Screen) {
 		if f.horizontal {
 			x += itemWidth + f.itemPadding
 		} else {
-			y += 1 + f.itemPadding
+			y += item.GetFieldHeight() + f.itemPadding
 		}
 	}
 

inputfield.go

@@ -79,6 +79,12 @@ type InputField struct {
 	// The text color of the suggestion.
 	autocompleteSuggestionTextColor tcell.Color
 
+	// The text color of the note below the input field.
+	fieldNoteTextColor tcell.Color
+
+	// The note to show below the input field.
+	fieldNote string
+
 	// The screen width of the label area. A value of 0 means use the width of
 	// the label text.
 	labelWidth int
@@ -147,6 +153,7 @@ func NewInputField() *InputField {
 		autocompleteListSelectedTextColor:       Styles.PrimitiveBackgroundColor,
 		autocompleteListSelectedBackgroundColor: Styles.PrimaryTextColor,
 		autocompleteSuggestionTextColor:         Styles.ContrastPrimaryTextColor,
+		fieldNoteTextColor:                      Styles.SecondaryTextColor,
 	}
 }
 
@@ -321,6 +328,30 @@ func (i *InputField) SetAutocompleteSuggestionTextColor(color tcell.Color) *Inpu
 	return i
 }
 
+// SetFieldNoteTextColor sets the text color of the note.
+func (i *InputField) SetFieldNoteTextColor(color tcell.Color) *InputField {
+	i.Lock()
+	defer i.Unlock()
+	i.fieldNoteTextColor = color
+	return i
+}
+
+// SetFieldNote sets the text to show below the input field, e.g. when the input is invalid.
+func (i *InputField) SetFieldNote(note string) *InputField {
+	i.Lock()
+	defer i.Unlock()
+	i.fieldNote = note
+	return i
+}
+
+// ResetFieldNote sets the note to an empty string.
+func (i *InputField) ResetFieldNote() *InputField {
+	i.Lock()
+	defer i.Unlock()
+	i.fieldNote = ""
+	return i
+}
+
 // SetFormAttributes sets attributes shared by all form items.
 func (i *InputField) SetFormAttributes(labelWidth int, bgColor, labelColor, labelColorFocused, fieldTextColor, fieldTextColorFocused, fieldBgColor, fieldBgColorFocused tcell.Color) FormItem {
 	i.Lock()
@@ -355,6 +386,16 @@ func (i *InputField) GetFieldWidth() int {
 	return i.fieldWidth
 }
 
+// GetFieldHeight returns the height of the field.
+func (i *InputField) GetFieldHeight() int {
+	i.RLock()
+	defer i.RUnlock()
+	if i.fieldNote == "" {
+		return 1
+	}
+	return 2
+}
+
 // GetCursorPosition returns the cursor position.
 func (i *InputField) GetCursorPosition() int {
 	i.RLock()
@@ -630,6 +671,11 @@ func (i *InputField) Draw(screen tcell.Screen) {
 		}
 	}
 
+	// Draw field note
+	if i.fieldNote != "" {
+		Print(screen, i.fieldNote, x, y+1, fieldWidth, AlignLeft, i.fieldNoteTextColor)
+	}
+
 	// Draw autocomplete list.
 	if i.autocompleteList != nil {
 		// How much space do we need?