Add packaging and release automation

vendor/github.com/charmbracelet/bubbles/viewport/viewport.go

@@ -0,0 +1,544 @@
+package viewport
+
+import (
+	"math"
+	"strings"
+
+	"github.com/charmbracelet/bubbles/key"
+	tea "github.com/charmbracelet/bubbletea"
+	"github.com/charmbracelet/lipgloss"
+	"github.com/charmbracelet/x/ansi"
+)
+
+// New returns a new model with the given width and height as well as default
+// key mappings.
+func New(width, height int) (m Model) {
+	m.Width = width
+	m.Height = height
+	m.setInitialValues()
+	return m
+}
+
+// Model is the Bubble Tea model for this viewport element.
+type Model struct {
+	Width  int
+	Height int
+	KeyMap KeyMap
+
+	// Whether or not to respond to the mouse. The mouse must be enabled in
+	// Bubble Tea for this to work. For details, see the Bubble Tea docs.
+	MouseWheelEnabled bool
+
+	// The number of lines the mouse wheel will scroll. By default, this is 3.
+	MouseWheelDelta int
+
+	// YOffset is the vertical scroll position.
+	YOffset int
+
+	// xOffset is the horizontal scroll position.
+	xOffset int
+
+	// horizontalStep is the number of columns we move left or right during a
+	// default horizontal scroll.
+	horizontalStep int
+
+	// YPosition is the position of the viewport in relation to the terminal
+	// window. It's used in high performance rendering only.
+	YPosition int
+
+	// Style applies a lipgloss style to the viewport. Realistically, it's most
+	// useful for setting borders, margins and padding.
+	Style lipgloss.Style
+
+	// HighPerformanceRendering bypasses the normal Bubble Tea renderer to
+	// provide higher performance rendering. Most of the time the normal Bubble
+	// Tea rendering methods will suffice, but if you're passing content with
+	// a lot of ANSI escape codes you may see improved rendering in certain
+	// terminals with this enabled.
+	//
+	// This should only be used in program occupying the entire terminal,
+	// which is usually via the alternate screen buffer.
+	//
+	// Deprecated: high performance rendering is now deprecated in Bubble Tea.
+	HighPerformanceRendering bool
+
+	initialized      bool
+	lines            []string
+	longestLineWidth int
+}
+
+func (m *Model) setInitialValues() {
+	m.KeyMap = DefaultKeyMap()
+	m.MouseWheelEnabled = true
+	m.MouseWheelDelta = 3
+	m.initialized = true
+}
+
+// Init exists to satisfy the tea.Model interface for composability purposes.
+func (m Model) Init() tea.Cmd {
+	return nil
+}
+
+// AtTop returns whether or not the viewport is at the very top position.
+func (m Model) AtTop() bool {
+	return m.YOffset <= 0
+}
+
+// AtBottom returns whether or not the viewport is at or past the very bottom
+// position.
+func (m Model) AtBottom() bool {
+	return m.YOffset >= m.maxYOffset()
+}
+
+// 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 > m.maxYOffset()
+}
+
+// ScrollPercent returns the amount scrolled as a float between 0 and 1.
+func (m Model) ScrollPercent() float64 {
+	if m.Height >= len(m.lines) {
+		return 1.0
+	}
+	y := float64(m.YOffset)
+	h := float64(m.Height)
+	t := float64(len(m.lines))
+	v := y / (t - h)
+	return math.Max(0.0, math.Min(1.0, v))
+}
+
+// HorizontalScrollPercent returns the amount horizontally scrolled as a float
+// between 0 and 1.
+func (m Model) HorizontalScrollPercent() float64 {
+	if m.xOffset >= m.longestLineWidth-m.Width {
+		return 1.0
+	}
+	y := float64(m.xOffset)
+	h := float64(m.Width)
+	t := float64(m.longestLineWidth)
+	v := y / (t - h)
+	return math.Max(0.0, math.Min(1.0, v))
+}
+
+// SetContent set the pager's text content.
+func (m *Model) SetContent(s string) {
+	s = strings.ReplaceAll(s, "\r\n", "\n") // normalize line endings
+	m.lines = strings.Split(s, "\n")
+	m.longestLineWidth = findLongestLineWidth(m.lines)
+
+	if m.YOffset > len(m.lines)-1 {
+		m.GotoBottom()
+	}
+}
+
+// maxYOffset returns the maximum possible value of the y-offset based on the
+// viewport's content and set height.
+func (m Model) maxYOffset() int {
+	return max(0, len(m.lines)-m.Height+m.Style.GetVerticalFrameSize())
+}
+
+// visibleLines returns the lines that should currently be visible in the
+// viewport.
+func (m Model) visibleLines() (lines []string) {
+	h := m.Height - m.Style.GetVerticalFrameSize()
+	w := m.Width - m.Style.GetHorizontalFrameSize()
+
+	if len(m.lines) > 0 {
+		top := max(0, m.YOffset)
+		bottom := clamp(m.YOffset+h, top, len(m.lines))
+		lines = m.lines[top:bottom]
+	}
+
+	if (m.xOffset == 0 && m.longestLineWidth <= w) || w == 0 {
+		return lines
+	}
+
+	cutLines := make([]string, len(lines))
+	for i := range lines {
+		cutLines[i] = ansi.Cut(lines[i], m.xOffset, m.xOffset+w)
+	}
+	return cutLines
+}
+
+// scrollArea returns the scrollable boundaries for high performance rendering.
+//
+// Deprecated: high performance rendering is deprecated in Bubble Tea.
+func (m Model) scrollArea() (top, bottom int) {
+	top = max(0, m.YPosition)
+	bottom = max(top, top+m.Height)
+	if top > 0 && bottom > top {
+		bottom--
+	}
+	return top, bottom
+}
+
+// SetYOffset sets the Y offset.
+func (m *Model) SetYOffset(n int) {
+	m.YOffset = clamp(n, 0, m.maxYOffset())
+}
+
+// ViewDown moves the view down by the number of lines in the viewport.
+// Basically, "page down".
+//
+// Deprecated: use [Model.PageDown] instead.
+func (m *Model) ViewDown() []string {
+	return m.PageDown()
+}
+
+// PageDown moves the view down by the number of lines in the viewport.
+func (m *Model) PageDown() []string {
+	if m.AtBottom() {
+		return nil
+	}
+
+	return m.ScrollDown(m.Height)
+}
+
+// ViewUp moves the view up by one height of the viewport.
+// Basically, "page up".
+//
+// Deprecated: use [Model.PageUp] instead.
+func (m *Model) ViewUp() []string {
+	return m.PageUp()
+}
+
+// PageUp moves the view up by one height of the viewport.
+func (m *Model) PageUp() []string {
+	if m.AtTop() {
+		return nil
+	}
+
+	return m.ScrollUp(m.Height)
+}
+
+// HalfViewDown moves the view down by half the height of the viewport.
+//
+// Deprecated: use [Model.HalfPageDown] instead.
+func (m *Model) HalfViewDown() (lines []string) {
+	return m.HalfPageDown()
+}
+
+// HalfPageDown moves the view down by half the height of the viewport.
+func (m *Model) HalfPageDown() (lines []string) {
+	if m.AtBottom() {
+		return nil
+	}
+
+	return m.ScrollDown(m.Height / 2) //nolint:mnd
+}
+
+// HalfViewUp moves the view up by half the height of the viewport.
+//
+// Deprecated: use [Model.HalfPageUp] instead.
+func (m *Model) HalfViewUp() (lines []string) {
+	return m.HalfPageUp()
+}
+
+// HalfPageUp moves the view up by half the height of the viewport.
+func (m *Model) HalfPageUp() (lines []string) {
+	if m.AtTop() {
+		return nil
+	}
+
+	return m.ScrollUp(m.Height / 2) //nolint:mnd
+}
+
+// LineDown moves the view down by the given number of lines.
+//
+// Deprecated: use [Model.ScrollDown] instead.
+func (m *Model) LineDown(n int) (lines []string) {
+	return m.ScrollDown(n)
+}
+
+// ScrollDown moves the view down by the given number of lines.
+func (m *Model) ScrollDown(n int) (lines []string) {
+	if m.AtBottom() || n == 0 || len(m.lines) == 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.
+	m.SetYOffset(m.YOffset + n)
+
+	// Gather lines to send off for performance scrolling.
+	//
+	// XXX: high performance rendering is deprecated in Bubble Tea.
+	bottom := clamp(m.YOffset+m.Height, 0, len(m.lines))
+	top := clamp(m.YOffset+m.Height-n, 0, bottom)
+	return m.lines[top:bottom]
+}
+
+// LineUp moves the view down by the given number of lines. Returns the new
+// lines to show.
+//
+// Deprecated: use [Model.ScrollUp] instead.
+func (m *Model) LineUp(n int) (lines []string) {
+	return m.ScrollUp(n)
+}
+
+// ScrollUp moves the view down by the given number of lines. Returns the new
+// lines to show.
+func (m *Model) ScrollUp(n int) (lines []string) {
+	if m.AtTop() || n == 0 || len(m.lines) == 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 are from the top.
+	m.SetYOffset(m.YOffset - n)
+
+	// Gather lines to send off for performance scrolling.
+	//
+	// XXX: high performance rendering is deprecated in Bubble Tea.
+	top := max(0, m.YOffset)
+	bottom := clamp(m.YOffset+n, 0, m.maxYOffset())
+	return m.lines[top:bottom]
+}
+
+// SetHorizontalStep sets the default amount of columns to scroll left or right
+// with the default viewport key map.
+//
+// If set to 0 or less, horizontal scrolling is disabled.
+//
+// On v1, horizontal scrolling is disabled by default.
+func (m *Model) SetHorizontalStep(n int) {
+	m.horizontalStep = max(n, 0)
+}
+
+// SetXOffset sets the X offset.
+func (m *Model) SetXOffset(n int) {
+	m.xOffset = clamp(n, 0, m.longestLineWidth-m.Width)
+}
+
+// ScrollLeft moves the viewport to the left by the given number of columns.
+func (m *Model) ScrollLeft(n int) {
+	m.SetXOffset(m.xOffset - n)
+}
+
+// ScrollRight moves viewport to the right by the given number of columns.
+func (m *Model) ScrollRight(n int) {
+	m.SetXOffset(m.xOffset + n)
+}
+
+// TotalLineCount returns the total number of lines (both hidden and visible) within the viewport.
+func (m Model) TotalLineCount() int {
+	return len(m.lines)
+}
+
+// VisibleLineCount returns the number of the visible lines within the viewport.
+func (m Model) VisibleLineCount() int {
+	return len(m.visibleLines())
+}
+
+// GotoTop sets the viewport to the top position.
+func (m *Model) GotoTop() (lines []string) {
+	if m.AtTop() {
+		return nil
+	}
+
+	m.SetYOffset(0)
+	return m.visibleLines()
+}
+
+// GotoBottom sets the viewport to the bottom position.
+func (m *Model) GotoBottom() (lines []string) {
+	m.SetYOffset(m.maxYOffset())
+	return m.visibleLines()
+}
+
+// Sync tells the renderer where the viewport will be located and requests
+// a render of the current state of the viewport. It should be called for the
+// first render and after a window resize.
+//
+// For high performance rendering only.
+//
+// Deprecated: high performance rendering is deprecated in Bubble Tea.
+func Sync(m Model) tea.Cmd {
+	if len(m.lines) == 0 {
+		return nil
+	}
+	top, bottom := m.scrollArea()
+	return tea.SyncScrollArea(m.visibleLines(), top, bottom)
+}
+
+// ViewDown is a high performance command that moves the viewport up by a given
+// number of lines. Use Model.ViewDown to get the lines that should be rendered.
+// For example:
+//
+//	lines := model.ViewDown(1)
+//	cmd := ViewDown(m, lines)
+//
+// Deprecated: high performance rendering is deprecated in Bubble Tea.
+func ViewDown(m Model, lines []string) tea.Cmd {
+	if len(lines) == 0 {
+		return nil
+	}
+	top, bottom := m.scrollArea()
+
+	// XXX: high performance rendering is deprecated in Bubble Tea. In a v2 we
+	// won't need to return a command here.
+	return tea.ScrollDown(lines, top, bottom)
+}
+
+// ViewUp is a high performance command the moves the viewport down by a given
+// number of lines height. Use Model.ViewUp to get the lines that should be
+// rendered.
+//
+// Deprecated: high performance rendering is deprecated in Bubble Tea.
+func ViewUp(m Model, lines []string) tea.Cmd {
+	if len(lines) == 0 {
+		return nil
+	}
+	top, bottom := m.scrollArea()
+
+	// XXX: high performance rendering is deprecated in Bubble Tea. In a v2 we
+	// won't need to return a command here.
+	return tea.ScrollUp(lines, top, bottom)
+}
+
+// Update handles standard message-based viewport updates.
+func (m Model) Update(msg tea.Msg) (Model, tea.Cmd) {
+	var cmd tea.Cmd
+	m, cmd = m.updateAsModel(msg)
+	return m, cmd
+}
+
+// Author's note: this method has been broken out to make it easier to
+// potentially transition Update to satisfy tea.Model.
+func (m Model) updateAsModel(msg tea.Msg) (Model, tea.Cmd) {
+	if !m.initialized {
+		m.setInitialValues()
+	}
+
+	var cmd tea.Cmd
+
+	switch msg := msg.(type) {
+	case tea.KeyMsg:
+		switch {
+		case key.Matches(msg, m.KeyMap.PageDown):
+			lines := m.PageDown()
+			if m.HighPerformanceRendering {
+				cmd = ViewDown(m, lines)
+			}
+
+		case key.Matches(msg, m.KeyMap.PageUp):
+			lines := m.PageUp()
+			if m.HighPerformanceRendering {
+				cmd = ViewUp(m, lines)
+			}
+
+		case key.Matches(msg, m.KeyMap.HalfPageDown):
+			lines := m.HalfPageDown()
+			if m.HighPerformanceRendering {
+				cmd = ViewDown(m, lines)
+			}
+
+		case key.Matches(msg, m.KeyMap.HalfPageUp):
+			lines := m.HalfPageUp()
+			if m.HighPerformanceRendering {
+				cmd = ViewUp(m, lines)
+			}
+
+		case key.Matches(msg, m.KeyMap.Down):
+			lines := m.ScrollDown(1)
+			if m.HighPerformanceRendering {
+				cmd = ViewDown(m, lines)
+			}
+
+		case key.Matches(msg, m.KeyMap.Up):
+			lines := m.ScrollUp(1)
+			if m.HighPerformanceRendering {
+				cmd = ViewUp(m, lines)
+			}
+
+		case key.Matches(msg, m.KeyMap.Left):
+			m.ScrollLeft(m.horizontalStep)
+
+		case key.Matches(msg, m.KeyMap.Right):
+			m.ScrollRight(m.horizontalStep)
+		}
+
+	case tea.MouseMsg:
+		if !m.MouseWheelEnabled || msg.Action != tea.MouseActionPress {
+			break
+		}
+		switch msg.Button { //nolint:exhaustive
+		case tea.MouseButtonWheelUp:
+			if msg.Shift {
+				// Note that not every terminal emulator sends the shift event for mouse actions by default (looking at you Konsole)
+				m.ScrollLeft(m.horizontalStep)
+			} else {
+				lines := m.ScrollUp(m.MouseWheelDelta)
+				if m.HighPerformanceRendering {
+					cmd = ViewUp(m, lines)
+				}
+			}
+
+		case tea.MouseButtonWheelDown:
+			if msg.Shift {
+				m.ScrollRight(m.horizontalStep)
+			} else {
+				lines := m.ScrollDown(m.MouseWheelDelta)
+				if m.HighPerformanceRendering {
+					cmd = ViewDown(m, lines)
+				}
+			}
+		// Note that not every terminal emulator sends the horizontal wheel events by default (looking at you Konsole)
+		case tea.MouseButtonWheelLeft:
+			m.ScrollLeft(m.horizontalStep)
+		case tea.MouseButtonWheelRight:
+			m.ScrollRight(m.horizontalStep)
+		}
+	}
+
+	return m, cmd
+}
+
+// View renders the viewport into a string.
+func (m Model) View() string {
+	if m.HighPerformanceRendering {
+		// Just send newlines since we're going to be rendering the actual
+		// content separately. We still need to send something that equals the
+		// height of this view so that the Bubble Tea standard renderer can
+		// position anything below this view properly.
+		return strings.Repeat("\n", max(0, m.Height-1))
+	}
+
+	w, h := m.Width, m.Height
+	if sw := m.Style.GetWidth(); sw != 0 {
+		w = min(w, sw)
+	}
+	if sh := m.Style.GetHeight(); sh != 0 {
+		h = min(h, sh)
+	}
+	contentWidth := w - m.Style.GetHorizontalFrameSize()
+	contentHeight := h - m.Style.GetVerticalFrameSize()
+	contents := lipgloss.NewStyle().
+		Width(contentWidth).      // pad to width.
+		Height(contentHeight).    // pad to height.
+		MaxHeight(contentHeight). // truncate height if taller.
+		MaxWidth(contentWidth).   // truncate width if wider.
+		Render(strings.Join(m.visibleLines(), "\n"))
+	return m.Style.
+		UnsetWidth().UnsetHeight(). // Style size already applied in contents.
+		Render(contents)
+}
+
+func clamp(v, low, high int) int {
+	if high < low {
+		low, high = high, low
+	}
+	return min(high, max(low, v))
+}
+
+func findLongestLineWidth(lines []string) int {
+	w := 0
+	for _, l := range lines {
+		if ww := ansi.StringWidth(l); ww > w {
+			w = ww
+		}
+	}
+	return w
+}