v0.1.0 initial commit

tui/status_bar.go

@@ -0,0 +1,210 @@
+package tui
+
+import "github.com/lixenwraith/terminal"
+
+// BarSection represents one segment of a status bar
+type BarSection struct {
+	Label      string
+	Value      string
+	LabelStyle Style
+	ValueStyle Style
+	Priority   int // Higher = survives truncation
+}
+
+// BarAlign specifies status bar alignment mode
+type BarAlign uint8
+
+const (
+	BarAlignRight      BarAlign = iota // Pack sections from right
+	BarAlignLeft                       // Pack sections from left
+	BarAlignDistribute                 // Evenly space sections
+	BarAlignCenter                     // Center all sections as a group
+)
+
+// BarOpts configures status bar rendering
+type BarOpts struct {
+	Separator string // Between sections, default " │ "
+	SepStyle  Style  // Separator styling
+	Bg        terminal.RGB
+	Align     BarAlign
+	Padding   int // Left/right padding, default 1
+}
+
+// DefaultBarOpts returns sensible defaults
+func DefaultBarOpts() BarOpts {
+	return BarOpts{
+		Separator: " │ ",
+		SepStyle:  Style{Fg: terminal.RGB{R: 80, G: 80, B: 100}},
+		Padding:   1,
+		Align:     BarAlignRight,
+	}
+}
+
+// StatusBar renders horizontal status bar on row y
+func (r Region) StatusBar(y int, sections []BarSection, opts BarOpts) {
+	if y < 0 || y >= r.H || len(sections) == 0 {
+		return
+	}
+
+	if opts.Separator == "" {
+		opts.Separator = " │ "
+	}
+	if opts.Padding == 0 {
+		opts.Padding = 1
+	}
+
+	// Fill background
+	for x := 0; x < r.W; x++ {
+		r.Cell(x, y, ' ', terminal.RGB{}, opts.Bg, terminal.AttrNone)
+	}
+
+	sepLen := RuneLen(opts.Separator)
+
+	// Calculate total width needed
+	totalW := 0
+	sectionWidths := make([]int, len(sections))
+	for i, sec := range sections {
+		w := RuneLen(sec.Label) + RuneLen(sec.Value)
+		sectionWidths[i] = w
+		totalW += w
+		if i < len(sections)-1 {
+			totalW += sepLen
+		}
+	}
+
+	availW := r.W - opts.Padding*2
+
+	// Truncate low-priority sections if needed
+	if totalW > availW {
+		sections, sectionWidths = truncateSections(sections, sectionWidths, sepLen, availW)
+		totalW = 0
+		for i, w := range sectionWidths {
+			totalW += w
+			if i < len(sectionWidths)-1 {
+				totalW += sepLen
+			}
+		}
+	}
+
+	// Calculate starting position based on alignment
+	var x int
+	switch opts.Align {
+	case BarAlignLeft:
+		x = opts.Padding
+	case BarAlignRight:
+		x = r.W - opts.Padding - totalW
+		if x < opts.Padding {
+			x = opts.Padding
+		}
+	case BarAlignDistribute:
+		x = opts.Padding
+		// Handled specially below
+	case BarAlignCenter:
+		x = (r.W - totalW) / 2
+		if x < opts.Padding {
+			x = opts.Padding
+		}
+	}
+
+	// Render sections
+	if opts.Align == BarAlignDistribute && len(sections) > 1 {
+		gap := (availW - totalW) / (len(sections) - 1)
+		if gap < 0 {
+			gap = 0
+		}
+		for i, sec := range sections {
+			x = r.renderBarSection(x, y, sec, opts)
+			if i < len(sections)-1 {
+				x += gap
+			}
+		}
+	} else {
+		for i, sec := range sections {
+			x = r.renderBarSection(x, y, sec, opts)
+			if i < len(sections)-1 {
+				// Separator
+				for j, ch := range opts.Separator {
+					if x+j < r.W-opts.Padding {
+						r.Cell(x+j, y, ch, opts.SepStyle.Fg, opts.Bg, opts.SepStyle.Attr)
+					}
+				}
+				x += sepLen
+			}
+		}
+	}
+}
+
+func (r Region) renderBarSection(x, y int, sec BarSection, opts BarOpts) int {
+	// Label
+	for _, ch := range sec.Label {
+		if x >= r.W-opts.Padding {
+			break
+		}
+		r.Cell(x, y, ch, sec.LabelStyle.Fg, opts.Bg, sec.LabelStyle.Attr)
+		x++
+	}
+	// Value
+	for _, ch := range sec.Value {
+		if x >= r.W-opts.Padding {
+			break
+		}
+		r.Cell(x, y, ch, sec.ValueStyle.Fg, opts.Bg, sec.ValueStyle.Attr)
+		x++
+	}
+	return x
+}
+
+// truncateSections removes lowest priority sections until fit
+func truncateSections(sections []BarSection, widths []int, sepLen, availW int) ([]BarSection, []int) {
+	// Copy to avoid modifying original
+	secs := make([]BarSection, len(sections))
+	copy(secs, sections)
+	ws := make([]int, len(widths))
+	copy(ws, widths)
+
+	for {
+		total := 0
+		for i, w := range ws {
+			total += w
+			if i < len(ws)-1 {
+				total += sepLen
+			}
+		}
+		if total <= availW || len(secs) <= 1 {
+			break
+		}
+
+		// Find lowest priority
+		minIdx := 0
+		minPrio := secs[0].Priority
+		for i, sec := range secs {
+			if sec.Priority < minPrio {
+				minPrio = sec.Priority
+				minIdx = i
+			}
+		}
+
+		// RemoveEntityAt it
+		secs = append(secs[:minIdx], secs[minIdx+1:]...)
+		ws = append(ws[:minIdx], ws[minIdx+1:]...)
+	}
+
+	return secs, ws
+}
+
+// QuickStatusBar renders simple label:value pairs right-aligned
+func (r Region) QuickStatusBar(y int, pairs [][2]string, labelFg, valueFg, bg terminal.RGB) {
+	sections := make([]BarSection, len(pairs))
+	for i, p := range pairs {
+		sections[i] = BarSection{
+			Label:      p[0],
+			Value:      p[1],
+			LabelStyle: Style{Fg: labelFg},
+			ValueStyle: Style{Fg: valueFg},
+		}
+	}
+	r.StatusBar(y, sections, BarOpts{
+		Bg:    bg,
+		Align: BarAlignRight,
+	})
+}