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
+}