/*
	scripts.js
	JavaScript examples
	
	Sparisoma Viridi | dudung@gmail.com
	
	20180116
	Create some examples.
*/

// Execute a test function
test_temperature_conversion();

// 20180120.1919 !ok
function test_temperature_conversion() {
	// Define some temperature references in oC and oF
	var THC = 100;
	var TCC = 0;
	var THF = 212;
	var TCF = 32;
	
	// Convert oC to oF and then back to oC
	var TC = 20;
	var TF = C2F(TC);
	console.log("T = " + TF + " oF");
	var TC2 = F2C(TF);
	console.log("T = " + TC2 + " oC");
	
	// Convert from oC to oF
	function C2F(TC) {
		var TF = (TC - TCC) / (THC - TCC) * (THF - TCF) + TCF;
		return TF;
	}
	
	// Convert from oF to oC
	function F2C(TF) {
		var TC = (TF - TCF) / (THF - TCF) * (THC - TCC) + TCC;
		return TC;
	}
}

// 20180116.0950 ok
function test_table() {
	var table = document.createElement("table");
	table.border = "1";
	document.body.appendChild(table);
	
	var row1 = document.createElement("tr");
	table.appendChild(row1);
	
	var col11 = document.createElement("td");
	row1.appendChild(col11);
	col11.innerHTML = "(1,1) A";

	var col12 = document.createElement("td");
	row1.appendChild(col12);
	col12.innerHTML = "(1,2) B";
	
	var row2 = document.createElement("tr");
	table.appendChild(row2);
	
	var col21 = document.createElement("td");
	row2.appendChild(col21);
	col21.innerHTML = "(2,1) C";

	var col22 = document.createElement("td");
	row2.appendChild(col22);
	col22.innerHTML = "(2,2) D";
}

// 20180116.0941 ok
function test_canvas_circles() {
	var c = document.createElement("canvas");
	c.width = 300;
	c.height = 200;
	c.style.background = "#eee";
	var cx = c.getContext("2d");
	for(var x = 50; x < 300; x += 50) {
		for(var y = 50; y < 200; y += 50) {
			var R = parseInt(Math.random() * 256);
			var G = parseInt(Math.random() * 256);
			var B = parseInt(Math.random() * 256);
			var colorRGB = "rgb(" + R + "," + G + "," + B + ")";
			cx.strokeStyle = colorRGB;
			cx.beginPath();
			cx.arc(x, y, 20, 0, 2 * Math.PI);
			cx.stroke()
		}
	}
	document.body.appendChild(c);
}


// 20180116.0936 ok
function test_canvas() {
	var c = document.createElement("canvas");
	c.width = 300;
	c.height = 200;
	c.style.background = "#eee";
	var cx = c.getContext("2d");
	cx.strokeStyle = "#f00";
	cx.beginPath();
	cx.arc(150, 100, 50, 0, 2 * Math.PI);
	cx.stroke()
	document.body.appendChild(c);
}

// 20180116.0927 !ok
function test_bilangan_acak() {
	var N = 10;
	for(var i = 0; i < N; i++) {
		var x = Math.random();
		var y = parseInt(x * 10);
		console.log(i + "\t"  + x + "\t" + y);
	}
}

// 20180116.0918
function test_create_button_from_parent() {
	// Define first id
	var id = "10";
	
	// Create first button
	var btn = document.createElement("button");
	btn.id = 10 + parseInt(Math.random() * 90);
	btn.innerHTML = btn.id;
	document.body.appendChild(btn);
	
	// Add event
	btn.addEventListener("click", createButton);
	
	// Create a button
	function createButton() {
		var btn = document.createElement("button");
		var id = 10 + parseInt(Math.random() * 90);
		var parentId = event.target.id;
		while(id == parentId) {
			id = 10 + parseInt(Math.random() * 90);
		}
		btn.id = id;
		btn.innerHTML = btn.id + " [" + parentId + "]";
		document.body.appendChild(btn);
		btn.addEventListener("click", createButton);
	}
}

// 20180116.0850 ok
function test_button_create_button() {
	// Define button number
	var buttonNumber = 1;
	// Create first visible button
	var btn = document.createElement("button");
	btn.innerHTML = "Create another";
	document.body.appendChild(btn);
	
	// Add an event only to to first button
	btn.addEventListener("click", createAnotherButton);
	
	// Create another button
	function createAnotherButton() {
		var btn = document.createElement("button");
		btn.innerHTML = "Another button " + buttonNumber;
		document.body.appendChild(btn);
		buttonNumber++;
	}
}

// 20180116.0842 ok
function test_hello_button() {
	// Create element of type button, which is <button></button>
	// in a HTML page
	var b = document.createElement("button");
	b.innerHTML = "Hello, World!";
	document.body.appendChild(b);
}

// 20180116.0840
function test_hello_paragraph() {
	// Create element of type paragraph, which is <p></p>
	// in a HTML page
	var p = document.createElement("p");
	p.innerHTML = "Hello, World!";
	document.body.appendChild(p);
}

// 20180116.0824 ok
function test_hello_title() {
	// Tags <title></title> inside section <head></head> should
	// already be defined
	var title = document.getElementsByTagName("title");
	title[0].text = "Hello, Wordl!";
}

// 20180116.0818 ok
function test_hello_console() {
	// Open concole in internet browser
	// Google Chrome: Ctrl+Shift+I, Ctrl+Shift+J
	// Mozilla Firefox: Ctrl+Shift+I
	// Internet Explorer: F12 then Ctrl+2
	console.log("Hello, World!");
}