feat: add HP 12c Platinum g-shift key labels and backspace

calculator.go

@@ -21,14 +21,15 @@ type Display struct {
 // ---- service ---------------------------------------------------------------
 
 type CalcService struct {
-	e        *engine.Engine
-	hasEntry bool
-	buf      string
-	expBuf   string
-	hasDot   bool
-	hasSign  bool
-	inExp    bool
-	armed    string // "", "f", "g", "STO", "RCL"
+	e         *engine.Engine
+	hasEntry  bool
+	buf       string
+	expBuf    string
+	hasDot    bool
+	hasSign   bool
+	inExp     bool
+	armed     string // "", "f", "g", "STO", "RCL"
+	undoState *engine.EngineState
 }
 
 type KeyResult struct {
@@ -65,6 +66,12 @@ func (c *CalcService) PressKey(input KeyInput) KeyResult {
 		isDigit = true
 	}
 
+	// snapshot before every state-changing operation for single-level undo
+	if op != "f" && op != "g" && op != "STO" && op != "RCL" && !isDigit && op != "." && op != "CHS" && op != "EEX" && op != "ENTER" && op != "CLx" {
+		s := c.e.Snapshot()
+		c.undoState = &s
+	}
+
 	switch {
 	case c.armed == "f":
 		c.fPrefixed(op, arg, input.ArgS)
@@ -80,7 +87,6 @@ func (c *CalcService) PressKey(input KeyInput) KeyResult {
 		c.armed = ""
 	case op == "f" || op == "g":
 		c.armed = op
-		c.clearEntry()
 		return c.state()
 	case op == "STO" || op == "RCL":
 		c.armed = op
@@ -125,7 +131,6 @@ func (c *CalcService) PressKey(input KeyInput) KeyResult {
 		c.e.LastXRecall()
 	case op == "f" || op == "g":
 		c.armed = op
-		c.clearEntry()
 		return c.state()
 	case op == "STO" || op == "RCL":
 		c.armed = op
@@ -480,6 +485,31 @@ func (c *CalcService) gPrefixed(op string, arg float64, argS string) {
 	case "BST":
 	case "GTO":
 	case "R/S":
+	case "+":
+		c.finishEntry()
+		c.e.LastXRecall()
+	case "×":
+		c.finishEntry()
+		c.e.Sqr()
+	case "÷":
+		if c.undoState != nil {
+			c.e.Restore(*c.undoState)
+			c.undoState = nil
+		}
+	case "−":
+		c.backspace()
+	case "PMT":
+		c.finishEntry()
+		if c.e.FinCfCnt < 10 {
+			c.e.FinCFj[c.e.FinCfCnt] = c.e.X
+			c.e.FinCfCnt++
+		}
+	case "FV":
+		c.finishEntry()
+		n := int(c.e.X)
+		if n > 0 && c.e.FinCfCnt > 0 {
+			c.e.FinNj[c.e.FinCfCnt-1] = n
+		}
 	default:
 		_ = argS
 	}
@@ -565,6 +595,29 @@ func (c *CalcService) clearEntry() {
 	c.inExp = false
 }
 
+func (c *CalcService) backspace() {
+	if !c.hasEntry {
+		// not in an active entry; start editing the current X value
+		c.buf = strconv.FormatFloat(c.e.X, 'f', -1, 64)
+		if len(c.buf) > 0 {
+			c.buf = c.buf[:len(c.buf)-1]
+		}
+		c.hasEntry = true
+	} else {
+		if c.inExp && len(c.expBuf) > 0 {
+			c.expBuf = c.expBuf[:len(c.expBuf)-1]
+		} else if !c.inExp && len(c.buf) > 0 {
+			c.buf = c.buf[:len(c.buf)-1]
+		}
+	}
+	if c.buf == "" || c.buf == "-" || c.buf == "." || c.buf == "-." {
+		c.clearEntry()
+		c.e.X = 0
+	} else {
+		c.e.X = c.parseBuf()
+	}
+}
+
 func (c *CalcService) parseBuf() float64 {
 	s := c.buf
 	if c.inExp && c.expBuf != "" {
@@ -669,15 +722,13 @@ func trimZero(s string) string {
 		return s
 	}
 	i := 0
-	if s[0] == '-' {
+	neg := s[0] == '-'
+	if neg {
 		i = 1
 	}
 	for i < len(s)-1 && s[i] == '0' && s[i+1] != '.' {
 		i++
 	}
-	if i > 0 && s[0] == '-' {
-		return "-" + s[i:]
-	}
 	return s[i:]
 }
 

frontend/public/style.css

@@ -3,10 +3,10 @@
 :root {
   --calc-w: 856px;
   --calc-h: 486px;
-  --key-w: 62px;
-  --key-h: 46px;
+  --key-w: 66px;
+  --key-h: 50px;
   --col-gap: 9px;
-  --row-gap: 48px;
+  --row-gap: 52px;
   --gold: #e8892b;
   --blue: #4fb6da;
   --key-text: #eceae4;
@@ -204,17 +204,17 @@ body {
 
 /* primary label on key face */
 .key .prim {
-  font-size: 15px;
+  font-size: 17px;
   font-weight: 600;
   line-height: 1;
   color: var(--key-text);
 }
-.key .prim.sm { font-size: 12px; }
-.key .prim.xs { font-size: 10.5px; }
+.key .prim.sm { font-size: 14px; }
+.key .prim.xs { font-size: 12px; }
 
 /* blue (g) label under the primary, on the key face */
 .key .glabel {
-  font-size: 9px;
+  font-size: 13px;
   font-weight: 700;
   line-height: 1;
   color: var(--blue);
@@ -242,15 +242,15 @@ body {
     0 -3px 4px rgba(0,0,0,.28) inset,
     0 2px 3px rgba(0,0,0,.55);
 }
-.key.fkey .prim { color: #3a2408; font-weight: 800; font-size: 17px; }
+.key.fkey .prim { color: #3a2408; font-weight: 800; font-size: 19px; }
 .key.gkey {
   background: linear-gradient(180deg, #34bce6 0%, #159fce 100%);
   box-shadow:
     0 1px 0 rgba(255,255,255,.4) inset,
     0 -3px 4px rgba(0,0,0,.28) inset,
     0 2px 3px rgba(0,0,0,.55);
 }
-.key.gkey .prim { color: #0a2f3d; font-weight: 800; font-size: 17px; }
+.key.gkey .prim { color: #0a2f3d; font-weight: 800; font-size: 19px; }
 
 .key.armed { outline: 2px solid #f0b45a; outline-offset: 1px; }
 

frontend/src/main.js

@@ -20,7 +20,7 @@ const KEYS = [
   { r:1,c:7,  prim:"7",   f:"",      g:"BEG", op:"7",   fop:"FIX",   gop:"BEG", fixArg:7 },
   { r:1,c:8,  prim:"8",   f:"",      g:"END", op:"8",   fop:"FIX",   gop:"END", fixArg:8 },
   { r:1,c:9,  prim:"9",   f:"",      g:"MEM", op:"9",   fop:"FIX",   gop:"MEM", fixArg:9 },
-  { r:1,c:10, prim:"÷",   f:"",     g:"",    op:"÷",   fop:NOP,     gop:NOP },
+  { r:1,c:10, prim:"÷",   f:"",     g:"↩",  op:"÷",   fop:NOP,     gop:"÷" },
 
 
   // row 2
@@ -33,19 +33,19 @@ const KEYS = [
   { r:2,c:7,  prim:"4",   f:"",      g:"D.MY",op:"4",   fop:"FIX",   gop:"D.MY", fixArg:4 },
   { r:2,c:8,  prim:"5",   f:"",      g:"M.DY",op:"5",   fop:"FIX",   gop:"M.DY", fixArg:5 },
   { r:2,c:9,  prim:"6",   f:"",      g:"x̄w", op:"6",   fop:"FIX",   gop:"x̄w", fixArg:6 },
-  { r:2,c:10, prim:"×",   f:"",     g:"",    op:"×",   fop:NOP,     gop:NOP },
+  { r:2,c:10, prim:"×",   f:"",     g:"x²",  op:"×",   fop:NOP,     gop:"×" },
 
   // row 3
   { r:3,c:1,  prim:"R/S", f:"P/R",   g:"PSE", op:"R/S", fop:"P/R",   gop:"PSE", primClass:"sm" },
   { r:3,c:2,  prim:"SST", f:"Σ",     g:"BST", op:"SST", fop:"CLEAR Σ", gop:"BST", primClass:"sm" },
   { r:3,c:3,  prim:"R↓",  f:"PRGM",  g:"GTO", op:"R↓",  fop:"CLEAR PRGM", gop:"GTO" },
   { r:3,c:4,  prim:"x↔y", f:"FIN",   g:"x≤y", op:"x↔y", fop:"CLEAR FIN", gop:"x≤y", primClass:"xs" },
   { r:3,c:5,  prim:"CLx", f:"REG",   g:"x=0", op:"CLx", fop:"CLEAR REG", gop:"x=0", primClass:"sm" },
-  { enter:true, r:3, c:6, prim:"ENTER", f:"PREFIX", g:"LSTx", op:"ENTER", fop:"CLEAR PREFIX", gop:"LSTx" },
+  { enter:true, r:3, c:6, prim:"ENTER", f:"PREFIX", g:"",   op:"ENTER", fop:"CLEAR PREFIX", gop:NOP },
   { r:3,c:7,  prim:"1",   f:"",      g:"x̂,r", op:"1",  fop:NOP,     gop:NOP },
   { r:3,c:8,  prim:"2",   f:"",      g:"ŷ,r", op:"2",  fop:NOP,     gop:"ŷ,r" },
   { r:3,c:9,  prim:"3",   f:"",      g:"n!",  op:"3",   fop:NOP,     gop:"n!" },
-  { r:3,c:10, prim:"−",   f:"",     g:"",    op:"−",   fop:NOP,     gop:NOP },
+  { r:3,c:10, prim:"−",   f:"",     g:"←",   op:"−",   fop:NOP,     gop:"−" },
   // row 4
   { r:4,c:1,  prim:"ON",  f:"",      g:"",    op:"ON",  fop:NOP,     gop:NOP, primClass:"sm" },
   { r:4,c:2,  prim:"f",   f:"",      g:"",    op:"f",   special:"f" },
@@ -55,7 +55,7 @@ const KEYS = [
   { r:4,c:7,  prim:"0",   f:"",      g:"x̄",  op:"0",   fop:"FIX",   gop:"x̄", fixArg:0 },
   { r:4,c:8,  prim:".",   f:"",      g:"s",   op:".",   fop:NOP,     gop:"s" },
   { r:4,c:9,  prim:"Σ+",  f:"",      g:"Σ−",  op:"Σ+",  fop:NOP,     gop:NOP, primClass:"sm" },
-  { r:4,c:10, prim:"+",   f:"",      g:"",    op:"+",   fop:NOP,     gop:NOP },
+  { r:4,c:10, prim:"+",   f:"",      g:"LSTx", op:"+",   fop:NOP,     gop:"+" },
 ];
 
 // Groups drawn as gold brackets above the keys.
@@ -95,6 +95,7 @@ const ANNUN = ["f", "g", "BEGIN", "RAD", "D.MY", "PRGM"];
 function applyState(s) {
   const d = (s && s.display) || {};
   const sign = d.sign && d.sign.trim() ? d.sign : "";
+  signEl.textContent = sign;
   digitsEl.textContent = d.mantissa && d.mantissa.trim() ? d.mantissa.trim() : "0.00";
   const flags = (d.flags || []).map(f => String(f).toUpperCase());
   annunEl.innerHTML = ANNUN.map(a => {