Commit: Initial Update

internal/ui/layout/responsive.go

@@ -0,0 +1,93 @@
+// Package layout provides responsive dimension calculations for the Nebara OS TUI.
+// All functions operate on terminal cell dimensions, not pixels.
+package layout
+
+// Constraints holds calculated layout values for a given terminal size.
+type Constraints struct {
+	TermWidth  int
+	TermHeight int
+
+	// Outer horizontal margin in cells (applied to both left and right sides).
+	MarginH int
+	// Outer vertical margin in cells (applied to top and bottom).
+	MarginV int
+
+	// ContentWidth is the usable width between the two horizontal margins.
+	ContentWidth int
+
+	// AppInfoLines is the number of rows reserved for appliance information
+	// (product title + 4 metadata rows).
+	AppInfoLines int
+
+	// MessageVisible indicates whether the message row should be shown.
+	// On very compact terminals it may be suppressed.
+	MessageVisible bool
+
+	// MenuInnerPad is the horizontal padding inside the menu border.
+	MenuInnerPad int
+
+	// FooterLines is the number of rows occupied by the footer (description + shortcuts).
+	FooterLines int
+
+	// IsMinimum flags terminals smaller than the supported minimum.
+	IsMinimum bool
+}
+
+// MinWidth is the smallest terminal width the application supports gracefully.
+const MinWidth = 60
+
+// MinHeight is the smallest terminal height the application supports gracefully.
+const MinHeight = 20
+
+// Calculate derives layout constraints from terminal dimensions.
+// Reference: Figma frame 1920×1080 with 80px outer margins (4.17% of width)
+// and 60px vertical margins (5.56% of height).
+func Calculate(termW, termH int) Constraints {
+	if termW < MinWidth || termH < MinHeight {
+		return Constraints{
+			TermWidth:  termW,
+			TermHeight: termH,
+			IsMinimum:  true,
+		}
+	}
+
+	// Horizontal margin: ~4.17% of width, min 4 cells, max 12 cells.
+	marginH := clamp(termW*417/10000, 4, 12)
+
+	// Vertical margin: ~5.56% of height, min 1 cell, max 4 cells.
+	marginV := clamp(termH*556/10000, 1, 4)
+
+	contentWidth := termW - marginH*2
+
+	// Menu inner horizontal padding (space between border char and text).
+	menuInnerPad := 2
+	if termW < 100 {
+		menuInnerPad = 1
+	}
+
+	// Message row visibility: suppress on very compact terminals.
+	messageVisible := termH >= 24
+
+	return Constraints{
+		TermWidth:      termW,
+		TermHeight:     termH,
+		MarginH:        marginH,
+		MarginV:        marginV,
+		ContentWidth:   contentWidth,
+		AppInfoLines:   6, // blank + product title + blank + 4 metadata rows
+		MessageVisible: messageVisible,
+		MenuInnerPad:   menuInnerPad,
+		FooterLines:    2,
+		IsMinimum:      false,
+	}
+}
+
+func clamp(v, lo, hi int) int {
+	if v < lo {
+		return lo
+	}
+	if v > hi {
+		return hi
+	}
+	return v
+}

internal/ui/layout/responsive_test.go

@@ -0,0 +1,73 @@
+package layout_test
+
+import (
+	"testing"
+
+	"github.com/nebara/nebara-os/internal/ui/layout"
+)
+
+func TestCalculate_Normal(t *testing.T) {
+	c := layout.Calculate(120, 40)
+	if c.IsMinimum {
+		t.Error("120×40 should not be minimum")
+	}
+	if c.ContentWidth <= 0 {
+		t.Error("ContentWidth should be positive")
+	}
+	if c.MarginH <= 0 {
+		t.Error("MarginH should be positive")
+	}
+	if c.ContentWidth != c.TermWidth-c.MarginH*2 {
+		t.Errorf("ContentWidth mismatch: got %d, expected %d", c.ContentWidth, c.TermWidth-c.MarginH*2)
+	}
+}
+
+func TestCalculate_TooSmall(t *testing.T) {
+	c := layout.Calculate(40, 10)
+	if !c.IsMinimum {
+		t.Error("40×10 should be flagged as minimum/too-small")
+	}
+}
+
+func TestCalculate_BoundaryMinWidth(t *testing.T) {
+	c := layout.Calculate(layout.MinWidth, layout.MinHeight)
+	if c.IsMinimum {
+		t.Errorf("exact minimum %dx%d should not be flagged as too small", layout.MinWidth, layout.MinHeight)
+	}
+}
+
+func TestCalculate_MarginClamps(t *testing.T) {
+	// Very wide terminal: margin should not exceed 12.
+	cWide := layout.Calculate(400, 80)
+	if cWide.MarginH > 12 {
+		t.Errorf("MarginH should not exceed 12 on very wide terminal, got %d", cWide.MarginH)
+	}
+
+	// Narrow but valid terminal: margin should not go below 4.
+	cNarrow := layout.Calculate(60, 20)
+	if cNarrow.MarginH < 4 {
+		t.Errorf("MarginH should be at least 4 on narrow terminal, got %d", cNarrow.MarginH)
+	}
+}
+
+func TestCalculate_MessageVisibility(t *testing.T) {
+	cCompact := layout.Calculate(80, 23)
+	if cCompact.MessageVisible {
+		t.Error("message should be hidden on terminals shorter than 24 rows")
+	}
+	cNormal := layout.Calculate(80, 24)
+	if !cNormal.MessageVisible {
+		t.Error("message should be visible at 24 rows")
+	}
+}
+
+func TestCalculate_MenuInnerPad(t *testing.T) {
+	cNarrow := layout.Calculate(80, 24)
+	if cNarrow.MenuInnerPad != 1 {
+		t.Errorf("expected menu inner pad 1 for narrow terminal, got %d", cNarrow.MenuInnerPad)
+	}
+	cWide := layout.Calculate(120, 40)
+	if cWide.MenuInnerPad != 2 {
+		t.Errorf("expected menu inner pad 2 for wide terminal, got %d", cWide.MenuInnerPad)
+	}
+}