Fix bug where scroll wheel could create duplicate lines on top and bottom

README.md

@@ -1,8 +1,33 @@
-# Tea Party
+# Bubbles
 
-Components for [Tea](https://github.com/charmbraclet/tea)
+Some components for [Bubble Tea](https://github.com/charmbraclet/bubbletea):
 
-⚠️  This project is a pre-release! Check back later.
+* Spinner
+* Text Input
+* Paginator
+* Viewport
+
+## Spinner
+
+A spinner, useful for indicating that some kind of invisible operation is
+happening. There are a couple default ones, but you can also pass your own
+”frames.”
+
+## Text Input
+
+A text input field, akin to an `<input type="text">` in HTML.
+
+## Paginator
+
+A component for handling pagination logic and optionally drawing pagination UI.
+
+## Viewport
+
+A viewport for vertically scrolling content which optionally includes standard
+pager keybindings and mouse wheel support. A high performance mode is available
+for applications which make use of the alterate screen buffer. This is
+generally only necessary when dealing with content with a very large amount of
+ANSI escape sequences.
 
 ## License
 

go.mod

@@ -3,10 +3,11 @@ module github.com/charmbracelet/bubbles
 go 1.13
 
 require (
-	github.com/charmbracelet/bubbletea v0.8.3-0.20200622174044-8bab4bce9a84
+	github.com/charmbracelet/bubbletea v0.9.1-0.20200713153904-2f53eeb54b90
 	github.com/mattn/go-runewidth v0.0.9
-	github.com/muesli/termenv v0.5.3-0.20200617154346-da5de72b61c0
+	github.com/muesli/termenv v0.5.3-0.20200625163851-04b5c30e4c04
-	golang.org/x/crypto v0.0.0-20200604202706-70a84ac30bf9 // indirect
+	golang.org/x/crypto v0.0.0-20200709230013-948cd5f35899 // indirect
+	golang.org/x/sys v0.0.0-20200625212154-ddb9806d33ae // indirect
 )
 
 replace github.com/charmbracelet/bubbletea => ../bubbletea

go.sum

@@ -6,19 +6,21 @@ github.com/mattn/go-isatty v0.0.12 h1:wuysRhFDzyxgEmMf5xjvJ2M9dZoWAXNNr5LSBS7uHX
 github.com/mattn/go-isatty v0.0.12/go.mod h1:cbi8OIDigv2wuxKPP5vlRcQ1OAZbq2CE4Kysco4FUpU=
 github.com/mattn/go-runewidth v0.0.9 h1:Lm995f3rfxdpd6TSmuVCHVb/QhupuXlYr8sCI/QdE+0=
 github.com/mattn/go-runewidth v0.0.9/go.mod h1:H031xJmbD/WCDINGzjvQ9THkh0rPKHF+m2gUSrubnMI=
-github.com/muesli/termenv v0.5.3-0.20200617154346-da5de72b61c0 h1:IASsj5pQ478TEN9TLiuhP+ugUQEotZ1QdzQvcJUQ1dM=
+github.com/muesli/termenv v0.5.3-0.20200625163851-04b5c30e4c04 h1:Wr876oXlAk6avTWi0daXAriOr+r5fqIuyDmtNc/KwY0=
-github.com/muesli/termenv v0.5.3-0.20200617154346-da5de72b61c0/go.mod h1:O1/I6sw+6KcrgAmcs6uiUVr7Lui+DNVbHTzt9Lm/PlI=
+github.com/muesli/termenv v0.5.3-0.20200625163851-04b5c30e4c04/go.mod h1:O1/I6sw+6KcrgAmcs6uiUVr7Lui+DNVbHTzt9Lm/PlI=
 github.com/pkg/term v0.0.0-20200520122047-c3ffed290a03 h1:pd4YKIqCB0U7O2I4gWHgEUA2mCEOENmco0l/bM957bU=
 github.com/pkg/term v0.0.0-20200520122047-c3ffed290a03/go.mod h1:Z9+Ul5bCbBKnbCvdOWbLqTHhJiYV414CURZJba6L8qA=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
-golang.org/x/crypto v0.0.0-20200510223506-06a226fb4e37 h1:cg5LA/zNPRzIXIWSCxQW10Rvpy94aQh3LT/ShoCpkHw=
-golang.org/x/crypto v0.0.0-20200510223506-06a226fb4e37/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
 golang.org/x/crypto v0.0.0-20200604202706-70a84ac30bf9 h1:vEg9joUBmeBcK9iSJftGNf3coIG4HqZElCPehJsfAYM=
 golang.org/x/crypto v0.0.0-20200604202706-70a84ac30bf9/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
+golang.org/x/crypto v0.0.0-20200709230013-948cd5f35899 h1:DZhuSZLsGlFL4CmhA8BcRA0mnthyA/nZ00AqCUo7vHg=
+golang.org/x/crypto v0.0.0-20200709230013-948cd5f35899/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
 golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
 golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20200116001909-b77594299b42/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20200620081246-981b61492c35 h1:wb/9mP8eUAmHfkM8RmpeLq6nUA7c2i5+bQOtcDftjaE=
+golang.org/x/sys v0.0.0-20200622214017-ed371f2e16b4 h1:5/PjkGUjvEU5Gl6BxmvKRPpqo2uNMv4rcHBMwzk/st8=
-golang.org/x/sys v0.0.0-20200620081246-981b61492c35/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20200622214017-ed371f2e16b4/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20200625212154-ddb9806d33ae h1:Ih9Yo4hSPImZOpfGuA4bR/ORKTAbhZo2AbWNRCnevdo=
+golang.org/x/sys v0.0.0-20200625212154-ddb9806d33ae/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=

paginator/paginator.go

@@ -28,6 +28,7 @@ type Model struct {
 	ActiveDot         string
 	InactiveDot       string
 	ArabicFormat      string
+	UsePgUpPgDownKeys bool
 	UseLeftRightKeys  bool
 	UseUpDownKeys     bool
 	UseHLKeys         bool
@@ -105,6 +106,7 @@ func NewModel() Model {
 		ActiveDot:         "•",
 		InactiveDot:       "○",
 		ArabicFormat:      "%d/%d",
+		UsePgUpPgDownKeys: true,
 		UseLeftRightKeys:  true,
 		UseUpDownKeys:     false,
 		UseHLKeys:         true,
@@ -116,6 +118,14 @@ func NewModel() Model {
 func Update(msg tea.Msg, m Model) (Model, tea.Cmd) {
 	switch msg := msg.(type) {
 	case tea.KeyMsg:
+		if m.UsePgUpPgDownKeys {
+			switch msg.String() {
+			case "pgup":
+				m.PrevPage()
+			case "pgdown":
+				m.NextPage()
+			}
+		}
 		if m.UseLeftRightKeys {
 			switch msg.String() {
 			case "left":

spinner/spinner.go

@@ -7,25 +7,17 @@ import (
 	"github.com/muesli/termenv"
 )
 
+const (
+	defaultFPS = time.Second / 10
+)
+
 // Spinner is a set of frames used in animating the spinner.
-type Spinner = int
+type Spinner = []string
-
-// Available types of spinners
-const (
-	Line Spinner = iota
-	Dot
-)
-
-const (
-	defaultFPS = 9
-)
 
 var (
-	// Spinner frames
+	// Some spinners to choose from. You could also make your own.
-	spinners = map[Spinner][]string{
+	Line = Spinner([]string{"|", "/", "-", "\\"})
-		Line: {"|", "/", "-", "\\"},
+	Dot  = Spinner([]string{"⣾ ", "⣽ ", "⣻ ", "⢿ ", "⡿ ", "⣟ ", "⣯ ", "⣷ "})
-		Dot:  {"⣾ ", "⣽ ", "⣻ ", "⢿ ", "⡿ ", "⣟ ", "⣯ ", "⣷ "},
-	}
 
 	color = termenv.ColorProfile().Color
 )
@@ -35,10 +27,10 @@ var (
 type Model struct {
 
 	// Type is the set of frames to use. See Spinner.
-	Type Spinner
+	Frames Spinner
 
 	// FPS is the speed at which the ticker should tick
-	FPS int
+	FPS time.Duration
 
 	// ForegroundColor sets the background color of the spinner. It can be a
 	// hex code or one of the 256 ANSI colors. If the terminal emulator can't
@@ -52,19 +44,13 @@ type Model struct {
 	// (per github.com/muesli/termenv).
 	BackgroundColor string
 
-	// CustomMsgFunc can be used to a custom message on tick. This can be
-	// useful when you have spinners in different parts of your application and
-	// want to differentiate between the messages for clarity and simplicity.
-	// If nil, this setting is ignored.
-	CustomMsgFunc func() tea.Msg
-
 	frame int
 }
 
 // NewModel returns a model with default values.
 func NewModel() Model {
 	return Model{
-		Type: Line,
+		Frames: Line,
 		FPS:    defaultFPS,
 	}
 }
@@ -76,43 +62,38 @@ type TickMsg struct{}
 // every time it's called, regardless the message passed, so be sure the logic
 // is setup so as not to call this Update needlessly.
 func Update(msg tea.Msg, m Model) (Model, tea.Cmd) {
+	if _, ok := msg.(TickMsg); ok {
 		m.frame++
-	if m.frame >= len(spinners[m.Type]) {
+		if m.frame >= len(m.Frames) {
 			m.frame = 0
 		}
-	if m.CustomMsgFunc != nil {
 		return m, Tick(m)
 	}
-	return m, Tick(m)
+	return m, nil
 }
 
 // View renders the model's view.
 func View(model Model) string {
-	s := spinners[model.Type]
+	if model.frame >= len(model.Frames) {
-	if model.frame >= len(s) {
+		return "error"
-		return "[error]"
 	}
 
-	str := s[model.frame]
+	frame := model.Frames[model.frame]
 
 	if model.ForegroundColor != "" || model.BackgroundColor != "" {
 		return termenv.
-			String(str).
+			String(frame).
 			Foreground(color(model.ForegroundColor)).
 			Background(color(model.BackgroundColor)).
 			String()
 	}
 
-	return str
+	return frame
 }
 
 // Tick is the command used to advance the spinner one frame.
-func Tick(model Model) tea.Cmd {
+func Tick(m Model) tea.Cmd {
-	return func() tea.Msg {
+	return tea.Tick(m.FPS, func(time.Time) tea.Msg {
-		time.Sleep(time.Second / time.Duration(model.FPS))
-		if model.CustomMsgFunc != nil {
-			return model.CustomMsgFunc()
-		}
 		return TickMsg{}
-	}
+	})
 }

textinput/textinput.go

@@ -361,7 +361,7 @@ func View(model tea.Model) string {
 	}
 
 	// Placeholder text
-	if m.value == nil && m.Placeholder != "" {
+	if len(m.value) == 0 && m.Placeholder != "" {
 		return placeholderView(m)
 	}
 

viewport/viewport.go

@@ -7,6 +7,10 @@ import (
 	tea "github.com/charmbracelet/bubbletea"
 )
 
+const (
+	spacebar = " "
+)
+
 // MODEL
 
 type Model struct {
@@ -53,9 +57,16 @@ func (m Model) AtTop() bool {
 	return m.YOffset <= 0
 }
 
-// AtBottom returns whether or not the viewport is at the very botom position.
+// AtBottom returns whether or not the viewport is at or past the very bottom
+// position.
 func (m Model) AtBottom() bool {
-	return m.YOffset >= len(m.lines)-m.Height-1
+	return m.YOffset >= len(m.lines)-1-m.Height
+}
+
+// PastBottom returns whether or not the viewport is scrolled beyond the last
+// line. This can happen when adjusting the viewport height.
+func (m Model) PastBottom() bool {
+	return m.YOffset > len(m.lines)-1-m.Height
 }
 
 // Scrollpercent returns the amount scrolled as a float between 0 and 1.
@@ -65,7 +76,7 @@ func (m Model) ScrollPercent() float64 {
 	}
 	y := float64(m.YOffset)
 	h := float64(m.Height)
-	t := float64(len(m.lines))
+	t := float64(len(m.lines) - 1)
 	v := y / (t - h)
 	return math.Max(0.0, math.Min(1.0, v))
 }
@@ -96,7 +107,7 @@ func (m *Model) ViewDown() []string {
 
 	m.YOffset = min(
 		m.YOffset+m.Height,      // target
-		len(m.lines)-m.Height, // fallback
+		len(m.lines)-1-m.Height, // fallback
 	)
 
 	return m.visibleLines()
@@ -124,7 +135,7 @@ func (m *Model) HalfViewDown() (lines []string) {
 
 	m.YOffset = min(
 		m.YOffset+m.Height/2,    // target
-		len(m.lines)-m.Height, // fallback
+		len(m.lines)-1-m.Height, // fallback
 	)
 
 	if len(m.lines) > 0 {
@@ -156,20 +167,26 @@ func (m *Model) HalfViewUp() (lines []string) {
 	return lines
 }
 
-// LineDown moves the view up by the given number of lines.
+// LineDown moves the view down by the given number of lines.
 func (m *Model) LineDown(n int) (lines []string) {
 	if m.AtBottom() || n == 0 {
 		return nil
 	}
 
+	// Make sure the number of lines by which we're going to scroll isn't
+	// greater than the number of lines we actually have left before we reach
+	// the bottom.
+	maxDelta := (len(m.lines) - 1) - (m.YOffset + m.Height) // number of lines - viewport bottom edge
+	n = min(n, maxDelta)
+
 	m.YOffset = min(
 		m.YOffset+n,             // target
-		len(m.lines)-m.Height, // fallback
+		len(m.lines)-1-m.Height, // fallback
 	)
 
 	if len(m.lines) > 0 {
-		top := max(0, m.YOffset+m.Height-n)
+		top := max(m.YOffset+m.Height-n, 0)
-		bottom := min(len(m.lines)-1, m.YOffset+m.Height)
+		bottom := min(m.YOffset+m.Height, len(m.lines)-1)
 		lines = m.lines[top:bottom]
 	}
 
@@ -183,11 +200,45 @@ func (m *Model) LineUp(n int) (lines []string) {
 		return nil
 	}
 
+	// Make sure the number of lines by which we're going to scroll isn't
+	// greater than the number of lines we are from the top.
+	n = min(n, m.YOffset)
+
 	m.YOffset = max(m.YOffset-n, 0)
 
 	if len(m.lines) > 0 {
 		top := max(0, m.YOffset)
-		bottom := min(len(m.lines)-1, m.YOffset+n)
+		bottom := min(m.YOffset+n, len(m.lines)-1)
+		lines = m.lines[top:bottom]
+	}
+
+	return lines
+}
+
+// GotoTop sets the viewport to the top position.
+func (m *Model) GotoTop() (lines []string) {
+	if m.AtTop() {
+		return nil
+	}
+
+	m.YOffset = 0
+
+	if len(m.lines) > 0 {
+		top := m.YOffset
+		bottom := min(m.YOffset+m.Height, len(m.lines)-1)
+		lines = m.lines[top:bottom]
+	}
+
+	return lines
+}
+
+// GotoTop sets the viewport to the bottom position.
+func (m *Model) GotoBottom() (lines []string) {
+	m.YOffset = max(len(m.lines)-1-m.Height, 0)
+
+	if len(m.lines) > 0 {
+		top := m.YOffset
+		bottom := max(len(m.lines)-1, 0)
 		lines = m.lines[top:bottom]
 	}
 
@@ -206,6 +257,8 @@ func Sync(m Model) tea.Cmd {
 		return nil
 	}
 
+	// TODO: we should probably use m.visibleLines() rather than these two
+	// expressions.
 	top := max(m.YOffset, 0)
 	bottom := min(m.YOffset+m.Height, len(m.lines)-1)
 
@@ -216,9 +269,9 @@ func Sync(m Model) tea.Cmd {
 	)
 }
 
-// ViewDown is a high performance command that moves the viewport up by one
+// ViewDown is a high performance command that moves the viewport up by a given
-// viewport height. Use Model.ViewDown to get the lines that should be
+// numer of lines. Use Model.ViewDown to get the lines that should be rendered.
-// rendered. For example:
+// For example:
 //
 //     lines := model.ViewDown(1)
 //     cmd := ViewDown(m, lines)
@@ -230,8 +283,8 @@ func ViewDown(m Model, lines []string) tea.Cmd {
 	return tea.ScrollDown(lines, m.YPosition, m.YPosition+m.Height)
 }
 
-// ViewUp is a high performance command the moves the viewport down by one
+// ViewUp is a high performance command the moves the viewport down by a given
-// viewport height. Use Model.ViewDown to get the lines that should be
+// number of lines height. Use Model.ViewDown to get the lines that should be
 // rendered.
 func ViewUp(m Model, lines []string) tea.Cmd {
 	if len(lines) == 0 {
@@ -240,46 +293,6 @@ func ViewUp(m Model, lines []string) tea.Cmd {
 	return tea.ScrollUp(lines, m.YPosition, m.YPosition+m.Height)
 }
 
-// HalfViewDown is a high performance command the moves the viewport down by
-// half of the height of the viewport. Use Model.HalfViewDown to get the lines
-// that should be rendered.
-func HalfViewDown(m Model, lines []string) tea.Cmd {
-	if len(lines) == 0 {
-		return nil
-	}
-	return tea.ScrollDown(lines, m.YPosition, m.YPosition+m.Height)
-}
-
-// HalfViewUp is a high performance command the moves the viewport up by
-// half of the height of the viewport. Use Model.HalfViewUp to get the lines
-// that should be rendered.
-func HalfViewUp(m Model, lines []string) tea.Cmd {
-	if len(lines) == 0 {
-		return nil
-	}
-	return tea.ScrollUp(lines, m.YPosition, m.YPosition+m.Height)
-}
-
-// LineDown is a high performance command the moves the viewport down by
-// a given number of lines. Use Model.LineDown to get the lines that should be
-// rendered.
-func LineDown(m Model, lines []string) tea.Cmd {
-	if len(lines) == 0 {
-		return nil
-	}
-	return tea.ScrollDown(lines, m.YPosition, m.YPosition+m.Height)
-}
-
-// LineDown is a high performance command the moves the viewport up by a given
-// number of lines. Use Model.LineDown to get the lines that should be
-// rendered.
-func LineUp(m Model, lines []string) tea.Cmd {
-	if len(lines) == 0 {
-		return nil
-	}
-	return tea.ScrollUp(lines, m.YPosition, m.YPosition+m.Height)
-}
-
 // UPDATE
 
 // Update runs the update loop with default keybindings similar to popular
@@ -293,20 +306,14 @@ func Update(msg tea.Msg, m Model) (Model, tea.Cmd) {
 	case tea.KeyMsg:
 		switch msg.String() {
 		// Down one page
-		case "pgdown":
+		case "pgdown", spacebar, "f":
-			fallthrough
-		case " ": // spacebar
-			fallthrough
-		case "f":
 			lines := m.ViewDown()
 			if m.HighPerformanceRendering {
 				cmd = ViewDown(m, lines)
 			}
 
 		// Up one page
-		case "pgup":
+		case "pgup", "b":
-			fallthrough
-		case "b":
 			lines := m.ViewUp()
 			if m.HighPerformanceRendering {
 				cmd = ViewUp(m, lines)
@@ -316,32 +323,44 @@ func Update(msg tea.Msg, m Model) (Model, tea.Cmd) {
 		case "d":
 			lines := m.HalfViewDown()
 			if m.HighPerformanceRendering {
-				cmd = HalfViewDown(m, lines)
+				cmd = ViewDown(m, lines)
 			}
 
 		// Up half page
 		case "u":
 			lines := m.HalfViewUp()
 			if m.HighPerformanceRendering {
-				cmd = HalfViewUp(m, lines)
+				cmd = ViewUp(m, lines)
 			}
 
 		// Down one line
-		case "down":
+		case "down", "j":
-			fallthrough
-		case "j":
 			lines := m.LineDown(1)
 			if m.HighPerformanceRendering {
-				cmd = LineDown(m, lines)
+				cmd = ViewDown(m, lines)
 			}
 
 		// Up one line
-		case "up":
+		case "up", "k":
-			fallthrough
-		case "k":
 			lines := m.LineUp(1)
 			if m.HighPerformanceRendering {
-				cmd = LineUp(m, lines)
+				cmd = ViewUp(m, lines)
+			}
+		}
+
+	case tea.MouseMsg:
+		switch msg.Button {
+
+		case tea.MouseWheelUp:
+			lines := m.LineUp(3)
+			if m.HighPerformanceRendering {
+				cmd = ViewUp(m, lines)
+			}
+
+		case tea.MouseWheelDown:
+			lines := m.LineDown(3)
+			if m.HighPerformanceRendering {
+				cmd = ViewDown(m, lines)
 			}
 		}
 	}