Reorganized the JavaScript demo code for modularity and clarity without changing behavior.

javascript/qrcodegen-demo.js

@@ -26,18 +26,20 @@
 
 
 function redrawQrCode() {
-	// Get error correction level
-	var ecl;
+	// Returns a QrCode.Ecc object based on the radio buttons in the HTML form.
+	function getInputErrorCorrectionLevel() {
 		if (document.getElementById("errcorlvl-medium").checked)
-		ecl = qrcodegen.QrCode.Ecc.MEDIUM;
+			return qrcodegen.QrCode.Ecc.MEDIUM;
 		else if (document.getElementById("errcorlvl-quartile").checked)
-		ecl = qrcodegen.QrCode.Ecc.QUARTILE;
+			return qrcodegen.QrCode.Ecc.QUARTILE;
 		else if (document.getElementById("errcorlvl-high").checked)
-		ecl = qrcodegen.QrCode.Ecc.HIGH;
+			return qrcodegen.QrCode.Ecc.HIGH;
 		else  // In case no radio button is depressed
-		ecl = qrcodegen.QrCode.Ecc.LOW;
+			return qrcodegen.QrCode.Ecc.LOW;
+	}
 	
-	// Get text and compute QR Code
+	// Get form inputs and compute QR Code
+	var ecl = getInputErrorCorrectionLevel();
 	var text = document.getElementById("text-input").value;
 	var segs = qrcodegen.QrSegment.makeSegments(text);
 	var qr = qrcodegen.encodeSegments(segs, ecl);
@@ -63,40 +65,24 @@ function redrawQrCode() {
 		}
 	}
 	
-	// Show statistics
-	var stats = "QR Code version = " + qr.getVersion() + ", ";
-	stats += "mask pattern = " + qr.getMask() + ", ";
-	stats += "character count = " + countUnicodeChars(text) + ",\n";
-	stats += "encoding mode = ";
+	
+	// Returns a string to describe the given list of segments.
+	function describeSegments(segs) {
 		if (segs.length == 0)
-		stats += "none";
+			return "none";
 		else if (segs.length == 1) {
 			var mode = segs[0].getMode();
-		if (mode == qrcodegen.QrSegment.Mode.NUMERIC)
-			stats += "numeric";
-		else if (mode == qrcodegen.QrSegment.Mode.ALPHANUMERIC)
-			stats += "alphanumeric";
-		else if (mode == qrcodegen.QrSegment.Mode.BYTE)
-			stats += "byte";
-		else if (mode == qrcodegen.QrSegment.Mode.KANJI)
-			stats += "kanji";
-		else
-			stats += "unknown";
+			var Mode = qrcodegen.QrSegment.Mode;
+			if (mode == Mode.NUMERIC     )  return "numeric";
+			if (mode == Mode.ALPHANUMERIC)  return "alphanumeric";
+			if (mode == Mode.BYTE        )  return "byte";
+			if (mode == Mode.KANJI       )  return "kanji";
+			return "unknown";
 		} else
-		stats += "multiple";
-	stats += ", error correction = level " + "LMQH".charAt(qr.getErrorCorrectionLevel().ordinal) + ", ";
-	var databits = 0;
-	segs.forEach(function(seg) {
-		databits += 4 + seg.getMode().numCharCountBits(qr.getVersion()) + seg.getBits().length;
-	});
-	stats += "data bits = " + databits + ".";
-	var elem = document.getElementById("statistics-output");
-	while (elem.firstChild != null)
-		elem.removeChild(elem.firstChild);
-	elem.appendChild(document.createTextNode(stats));
+			return "multiple";
 	}
 	
-
+	// Returns the number of Unicode code points in the given UTF-16 string.
 	function countUnicodeChars(str) {
 		var result = 0;
 		for (var i = 0; i < str.length; i++, result++) {
@@ -114,5 +100,18 @@ function countUnicodeChars(str) {
 		return result;
 	}
 	
+	// Show the QR Code symbol's statistics as a string
+	var stats = "QR Code version = " + qr.getVersion() + ", ";
+	stats += "mask pattern = " + qr.getMask() + ", ";
+	stats += "character count = " + countUnicodeChars(text) + ",\n";
+	stats += "encoding mode = " + describeSegments(segs) + ", ";
+	stats += "error correction = level " + "LMQH".charAt(qr.getErrorCorrectionLevel().ordinal) + ", ";
+	stats += "data bits = " + qrcodegen.QrSegment.getTotalBits(segs, qr.getVersion()) + ".";
+	var elem = document.getElementById("statistics-output");
+	while (elem.firstChild != null)
+		elem.removeChild(elem.firstChild);
+	elem.appendChild(document.createTextNode(stats));
+}
+
 
 redrawQrCode();