Add menu prompt

This makes it possible to add a prompt to a menu. It will be shown above the
menu items, separated from them by a blank line.

pkg/gui/context/menu_context.go

@@ -50,6 +50,8 @@ func NewMenuContext(
 type MenuViewModel struct {
 	c               *ContextCommon
 	menuItems       []*types.MenuItem
+	prompt          string
+	promptLines     []string
 	columnAlignment []utils.Alignment
 	*FilteredListViewModel[*types.MenuItem]
 }
@@ -73,6 +75,23 @@ func (self *MenuViewModel) SetMenuItems(items []*types.MenuItem, columnAlignment
 	self.columnAlignment = columnAlignment
 }
 
+func (self *MenuViewModel) GetPrompt() string {
+	return self.prompt
+}
+
+func (self *MenuViewModel) SetPrompt(prompt string) {
+	self.prompt = prompt
+	self.promptLines = nil
+}
+
+func (self *MenuViewModel) GetPromptLines() []string {
+	return self.promptLines
+}
+
+func (self *MenuViewModel) SetPromptLines(promptLines []string) {
+	self.promptLines = promptLines
+}
+
 // TODO: move into presentation package
 func (self *MenuViewModel) GetDisplayStrings(_ int, _ int) [][]string {
 	menuItems := self.FilteredListViewModel.GetItems()
@@ -94,14 +113,22 @@ func (self *MenuViewModel) GetDisplayStrings(_ int, _ int) [][]string {
 }
 
 func (self *MenuViewModel) GetNonModelItems() []*NonModelItem {
+	result := []*NonModelItem{}
+	result = append(result, lo.Map(self.promptLines, func(line string, _ int) *NonModelItem {
+		return &NonModelItem{
+			Index:   0,
+			Column:  0,
+			Content: line,
+		}
+	})...)
+
 	// Don't display section headers when we are filtering, and the filter mode
 	// is fuzzy. The reason is that filtering changes the order of the items
 	// (they are sorted by best match), so all the sections would be messed up.
 	if self.FilteredListViewModel.IsFiltering() && self.c.UserConfig.Gui.UseFuzzySearch() {
-		return []*NonModelItem{}
+		return result
 	}
 
-	result := []*NonModelItem{}
 	menuItems := self.FilteredListViewModel.GetItems()
 	var prevSection *types.MenuSection = nil
 	for i, menuItem := range menuItems {

pkg/gui/controllers/helpers/confirmation_helper.go

@@ -373,7 +373,9 @@ func (self *ConfirmationHelper) resizeMenu() {
 	itemCount := self.c.Contexts().Menu.UnfilteredLen()
 	offset := 3
 	panelWidth := self.getPopupPanelWidth()
-	x0, y0, x1, y1 := self.getPopupPanelDimensionsForContentHeight(panelWidth, itemCount+offset)
+	contentWidth := panelWidth - 2 // minus 2 for the frame
+	promptLinesCount := self.layoutMenuPrompt(contentWidth)
+	x0, y0, x1, y1 := self.getPopupPanelDimensionsForContentHeight(panelWidth, itemCount+offset+promptLinesCount)
 	menuBottom := y1 - offset
 	_, _ = self.c.GocuiGui().SetView(self.c.Views().Menu.Name(), x0, y0, x1, menuBottom, 0)
 
@@ -383,11 +385,39 @@ func (self *ConfirmationHelper) resizeMenu() {
 	if selectedItem != nil {
 		tooltip = self.TooltipForMenuItem(selectedItem)
 	}
-	contentWidth := panelWidth - 2                                     // minus 2 for the frame
 	tooltipHeight := getMessageHeight(true, tooltip, contentWidth) + 2 // plus 2 for the frame
 	_, _ = self.c.GocuiGui().SetView(self.c.Views().Tooltip.Name(), x0, tooltipTop, x1, tooltipTop+tooltipHeight-1, 0)
 }
 
+// Wraps the lines of the menu prompt to the available width and rerenders the
+// menu if neeeded. Returns the number of lines the prompt takes up.
+func (self *ConfirmationHelper) layoutMenuPrompt(contentWidth int) int {
+	oldPromptLines := self.c.Contexts().Menu.GetPromptLines()
+	var promptLines []string
+	prompt := self.c.Contexts().Menu.GetPrompt()
+	if len(prompt) > 0 {
+		promptLines = wrapMessageToWidth(true, prompt, contentWidth)
+		promptLines = append(promptLines, "")
+	}
+	self.c.Contexts().Menu.SetPromptLines(promptLines)
+	if len(oldPromptLines) != len(promptLines) {
+		// The number of lines in the prompt has changed; this happens either
+		// because we're now showing a menu that has a prompt, and the previous
+		// menu didn't (or vice versa), or because the user is resizing the
+		// terminal window while a menu with a prompt is open.
+
+		// We need to rerender to give the menu context a chance to update its
+		// non-model items, and reinitialize the data it uses for converting
+		// between view index and model index.
+		_ = self.c.Contexts().Menu.HandleRender()
+
+		// Then we need to refocus to ensure the cursor is in the right place in
+		// the view.
+		_ = self.c.Contexts().Menu.HandleFocus(types.OnFocusOpts{})
+	}
+	return len(promptLines)
+}
+
 func (self *ConfirmationHelper) resizeConfirmationPanel() {
 	suggestionsViewHeight := 0
 	if self.c.Views().Suggestions.Visible {

pkg/gui/menu_panel.go

@@ -42,6 +42,7 @@ func (gui *Gui) createMenu(opts types.CreateMenuOptions) error {
 	}
 
 	gui.State.Contexts.Menu.SetMenuItems(opts.Items, opts.ColumnAlignment)
+	gui.State.Contexts.Menu.SetPrompt(opts.Prompt)
 	gui.State.Contexts.Menu.SetSelection(0)
 
 	gui.Views.Menu.Title = opts.Title

pkg/gui/types/common.go

@@ -159,6 +159,7 @@ const (
 
 type CreateMenuOptions struct {
 	Title           string
+	Prompt          string // a message that will be displayed above the menu options
 	Items           []*MenuItem
 	HideCancel      bool
 	ColumnAlignment []utils.Alignment