Add pager

cmd/show.go

@@ -86,7 +86,7 @@ func init() {
 	// and all subcommands, e.g.:
 	// showCmd.PersistentFlags().String("foo", "", "A help for foo")
 
-	showCmd.Flags().BoolVarP(&shouldShowPlain, "plain", "p", false, "Only print the raw contents, without terminal decorations")
+	showCmd.Flags().BoolVarP(&shouldShowPlain, "plain", "", false, "Only print the raw contents, without terminal decorations")
 
 	// Cobra supports local flags which will only run when this command
 	// is called directly, e.g.:

internal/changelog/show.go

@@ -1,10 +1,11 @@
 package changelog
 
 import (
-	"fmt"
+	// "fmt"
 	"os"
 
 	"github.com/charmbracelet/glamour"
+	"github.com/niclasvaneyk/keepac/internal/tui"
 	"golang.org/x/crypto/ssh/terminal"
 )
 
@@ -27,8 +28,10 @@ func Show(contents string) error {
 		return err
 	}
 
-	fmt.Print(out)
-	return nil
+	return tui.Paginate(out)
+
+	// fmt.Print(out)
+	// return nil
 }
 
 func getWordWrapLimit() int {

internal/tui/choice.go

@@ -12,7 +12,7 @@ import (
 )
 
 var (
-	titleStyle        = lipgloss.NewStyle().MarginLeft(2).MarginTop(1)
+	choiceTitleStyle  = lipgloss.NewStyle().MarginLeft(2).MarginTop(1)
 	itemStyle         = lipgloss.NewStyle().PaddingLeft(4)
 	selectedItemStyle = lipgloss.NewStyle().PaddingLeft(2).Bold(true)
 )
@@ -45,16 +45,16 @@ func (d itemDelegate) Render(w io.Writer, m list.Model, index int, listItem list
 	fmt.Fprint(w, fn(i.value))
 }
 
-type model struct {
+type choiceModel struct {
 	list     list.Model
 	onSelect func(item)
 }
 
-func (m model) Init() tea.Cmd {
+func (m choiceModel) Init() tea.Cmd {
 	return nil
 }
 
-func (m model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
+func (m choiceModel) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 	switch msg := msg.(type) {
 	case tea.WindowSizeMsg:
 		m.list.SetWidth(msg.Width)
@@ -79,7 +79,7 @@ func (m model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 	return m, cmd
 }
 
-func (m model) View() string {
+func (m choiceModel) View() string {
 	return m.list.View()
 }
 
@@ -99,11 +99,11 @@ func Choice(title string, options []string) (string, int) {
 	l.SetShowHelp(false)
 
 	l.Title = title
-	l.Styles.Title = titleStyle
+	l.Styles.Title = choiceTitleStyle
 
 	choice := ""
 	index := -1
-	m := model{list: l, onSelect: func(i item) {
+	m := choiceModel{list: l, onSelect: func(i item) {
 		choice = i.value
 		index = i.index
 	}}

internal/tui/pager.go

@@ -0,0 +1,105 @@
+package tui
+
+// An example program demonstrating the pager component from the Bubbles
+// component library.
+
+import (
+	"github.com/charmbracelet/bubbles/viewport"
+	tea "github.com/charmbracelet/bubbletea"
+)
+
+// You generally won't need this unless you're processing stuff with
+// complicated ANSI escape sequences. Turn it on if you notice flickering.
+//
+// Also keep in mind that high performance rendering only works for programs
+// that use the full size of the terminal. We're enabling that below with
+// tea.EnterAltScreen().
+const useHighPerformanceRenderer = false
+
+type pagerModel struct {
+	content  string
+	ready    bool
+	viewport viewport.Model
+}
+
+func (m pagerModel) Init() tea.Cmd {
+	return nil
+}
+
+func (m pagerModel) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
+	var (
+		cmd  tea.Cmd
+		cmds []tea.Cmd
+	)
+
+	switch msg := msg.(type) {
+	case tea.KeyMsg:
+		if k := msg.String(); k == "ctrl+c" || k == "q" || k == "esc" {
+			return m, tea.Quit
+		}
+
+	case tea.WindowSizeMsg:
+		if !m.ready {
+			// Since this program is using the full size of the viewport we
+			// need to wait until we've received the window dimensions before
+			// we can initialize the viewport. The initial dimensions come in
+			// quickly, though asynchronously, which is why we wait for them
+			// here.
+			m.viewport = viewport.New(msg.Width, msg.Height)
+			m.viewport.HighPerformanceRendering = useHighPerformanceRenderer
+			m.viewport.SetContent(m.content)
+			m.ready = true
+
+			// This is only necessary for high performance rendering, which in
+			// most cases you won't need.
+			//
+			// Render the viewport one line below the header.
+		} else {
+			m.viewport.Width = msg.Width
+			m.viewport.Height = msg.Height
+		}
+
+		if useHighPerformanceRenderer {
+			// Render (or re-render) the whole viewport. Necessary both to
+			// initialize the viewport and when the window is resized.
+			//
+			// This is needed for high-performance rendering only.
+			cmds = append(cmds, viewport.Sync(m.viewport))
+		}
+	}
+
+	// Handle keyboard and mouse events in the viewport
+	m.viewport, cmd = m.viewport.Update(msg)
+	cmds = append(cmds, cmd)
+
+	return m, tea.Batch(cmds...)
+}
+
+func (m pagerModel) View() string {
+	if !m.ready {
+		return "\n  Initializing..."
+	}
+
+	return m.viewport.View()
+}
+
+func max(a, b int) int {
+	if a > b {
+		return a
+	}
+	return b
+}
+
+func Paginate(content string) error {
+	p := tea.NewProgram(
+		pagerModel{content: content},
+		tea.WithAltScreen(),       // use the full size of the terminal in its "alternate screen buffer"
+		tea.WithMouseCellMotion(), // turn on mouse support so we can track the mouse wheel
+	)
+
+	if _, err := p.Run(); err != nil {
+		return err
+	}
+
+	return nil
+}