onload image

var canvas = null;
var context = null;

setup = function(){
	canvas = document.getElementById("my_canvas");
	context = canvas.getContext('2d');
	canvas.width = window.innerWidth;
	canvas.height = window.innerHeight;
	// var img = document.getElementById("scream");
	// ctx.drawImage(img,10,10);
	img = new Image();
	img.onload = onImageLoad;
	img.src =　"ralphyrobot.png";
};

onImageLoad = function(){
	console.log("IMAGE!!");
};

onImageLoad

var onImageLoad = function(){
	console.log("IMAGE!!!");
	context.drawImage(img,192,192)
};

Strong password

at least n characters
combination of upper- and lower-case characters
one or more digits
not related to other user data (name, address, username, …)
not a dictionary word

<script type="text/javascript">

	function checkForm(form)
	{
		if(form.username.value == ""){
			alert("Error: Username cannot be blank!");
			form.username.focus();
			return false;
		}
		re = /^\w+$/;
		if(!re.test(form.username.value)){
			alert("Error: Username must only letters, numbers and undersocres!");
			form.username.focus();
			return false;
		}

		if(form.pwd1.value != "" && form.pwd1.value == form.pwd2.value){
			if(form.pwd1.value.length < 6){
				alert("Error: Password must contain at least six characters!");
				form.pwd1.focus();
				return false;
			}
			if(form.pwd1.value == form.username.value){
				alert("Error: Password must be different from Username!");
				form.pwd1.focus();
				return false;
			}
			re = /&#91;0-9&#93;/;
			if(!re.test(form.pwd1.value)){
				alert("Error: password must contain at least one number(0-9)!");
				form.pwd1.focus();
				return false;
			}
			re = /&#91;a-z&#93;/;
			if(!re.test(form.pwd1.value)){
				alert("Error: password must contain at least one lowercase letter(a-z"!);
				form.pwd1.focus();
				return false;
			}
			re = /&#91;A-Z&#93;/;
			if(!re.test(form.pwd1.value)){
				alert("Error: password must contain at least one uppercase letter(A-Z");
				form.pwd1.focus();
				return false;
			}
		} else {
			alert("Error: Please check that you've entered and confirmed your password!");
			form.pwd1.focus();
			return false;
		}
		alert("You entered a valid password: " + form.pwd1.value);
		return true;
	}
</script>
<form ... onsubmit="return checkForm(this);">
<p>Username: <input type="text" name="username"></p>
<p>Password: <input type="password" name="pwd1"></p>
<p>Confirm Password: <input type="password" name="pwd2"></p>
<p><input type="submit"></p>
</form>

Event holder

<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <title>Quiz - Placeholder</title>
</head>
<body>
    <form action="#">
        <label for="event-name">
            <span>Enter the name of your event:</span>
            <input type="text" id="event-name" placeholder="Event Name">
        </label>
    </form>
</body>
</html>

autocomplete
The autocomplete attribute specifies whether or not an input field should have autocomplete enabled.
Autocomplete allows the browser to predict the value. When a user starts to type in a field, the browser should display options to fill in the field, based on earlier typed values.

<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <title>Quiz - Autocomplete</title>
</head>
<body>
    <form action="#">
        <label for="email">
            <span>Email:</span>
            <input type="email" id="email" placeholder="example@gmail.com" autocomplete="email">
        </label>
    </form>
</body>
</html>

contact-form

Check input type with mozilla.
https://developer.mozilla.org/en-US/docs/Web/HTML/Element/input

<form class="date-and-time-picker">
	<label for="date">
		<span>what day do you want to leave?</span>
		<input id="date" type="date">
	</label>
	<label for="time">
		<span>What time do you want to leave?</span>
		<input id="time" type="date-time">
	</label>
</form>

data list

<input list="nano">
<datalist id="nano">
	<option value="Android"></option>
	<option value="Data Analyst"></option>
	<option value="Front End"></option>
	<option value="Full Stack"></option>
	<option value="Intro to Programming"></option>
	<option value="iOS"></option>
	<option value="Tech Entrepreneur"></option>
</datalist>

Another datalist

<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Quiz - Datalists</title>
</head>
<body>
    <p>What kind of event are you hosting?</p>
    <input list="event">
    <datalist id="event">
        <option>Party</option>
        <option>Meeting</option>
        <option>Conference Talk</option>
        <option>Sports Game</option>
    </datalist>
</body>
</html>

<form>
	<label for="use-billing">
		<span>Same as billing address</span>
	</label>
	<input type="checkbox" id="use-billing">

	<br>

	<label for="tel-number">
		<span>Telephone Number</span>
		<input type="tel" id="tel-number">
	</label>
</form>

Camera and Audio Input

<input type="file" accept="image/*;capture=camera">
<input type="file" accept="image/*;capture=camcorder">
<input type="file" accept="image/*;capture=microphone">

problems with file input capture
-only works on mobile
-file open button is unstylable
-different app can break the flow

navigator.getUserMedia(constraints, successCallback, errorCallback);

function openCameraPane(callback, fullscreen) {
	if (fullscreen)
		document.body.webkitRequestFullscreen();
	_myVideoCallback = callback;
	var constraints = {video: true};
    
	navigator.getUserMedia(constraints,successCallback,errorCallback);
}

function successCallback(stream) {
	var video = createVideoUserInterface();
	video.src = window.URL.createObjectURL(stream);
    
}

function snapshot(ev) {
	var video = document.querySelector('.camera-video');
	var canvas = document.querySelector('.camera-picture');
	var ctx = canvas.getContext('2d');

  ctx.drawImage(video, 0, 0);
}

MediaStreamTrack.getSources(gotSources);
<element>.requestFullscreen();

html5 geolocation API
maps, augmented reality, geocaching, nearby features

navigator.geolocation.getCurrentPosition(
	function(position){
		do_something(
			position.coords.latitude,
			position.coords.longitude )
	});

Vibration API
navigator.vibrate(1000)

viewport and media query

<meta name="viewport" content="width=device-width">

start this tag.

<meta name="viewport" content="width=device-width,initial-scale=1">

1vmin = 1vm or 1vh, whichever is smallest
1vmax = 1vm or 1vh, whichever is largest

available media query expressions
width, height, device-width, device-height, orientation, aspect-ratio,
device-aspect-ratio, grid, color, color-index, monochrome, resolution, scan

.menu-items-grid {
    display: flex;
    flex-wrap: wrap;
    flex-direction: row;
    justify-content: space-around;
    padding: 0 1%
}

@media (orientation:portrait){
  .menu-items-grid {
    flex-direction: column;
  }
}

window.devicePixelRatio

@media (min-pixel-ratio:2){
  .pretteybackground {
    background: url('images/hires_bkg.png');
  }
}

cellular radio lifecycle
Idle -> active -> short sleep -> long sleep

-lifecycle of an HTTP request
DNS lookup -> socket connect -> HTTP request -> Data download

avoid redirect
minimize or eliminate render-blocking resources (stylesheets, fonts, unknown-size, image)

animation framework
settimeout, setInterval -> requestAnimationFrame

touch UI
hover does not rely on
use large hit target
do not disable mouse support

touch events
->touchstart, touchmove, touchend, touch cancel

Input
html5 has tel input type.

<input type="tel">

<label>
  <input type="checkbox">
  "Do you love lemurs?"
</label>

interface

public interface Drawable
{
	void draw();
}

public class House implements Drawable
{
	public void draw(){...}
}

for (Drawable d : elements) { d.draw();}

public interface Moveable
{
	void move(int seconds);
}

public class Car implements Drawable, Moveable

setter and getter

publi class Person
{
	private String name;

	public String getName(){ return name; }
	public void setName(String newName)
	{
		if(newName.length() > 0) { name = newName; }
	}
}

getter はprivate instance field を getできるようにするもの。
setter はpublic (String/double/picture..) getHogeの値をセットするものです。

    public void setDriverName(String newName)
    {
      driverName = newName;
    }

    public String getDriverName()
    {
      return driverName;
    }

static method:staticメソッドはインスタンスではなく「クラスに属するメソッド」のため、インスタンスを作らずに直接呼び出すことができる。

    public Person(String name)
    {
        this.name = name;
        friends = new ArrayList<Person>();
        lastAssignedId++;
        id = lastAssignedId;
    }

public boolean tryToAdd(Person p)
{
    if(passengers.size() + 2 < numberOfSeats && p.getDestination() <= destination);
    {
        passengers.add(p);
        return true;
    }
    else
    {
        return false;
    }
}

public void drive()
{
    location++;
    while (i < passengers.size())
    {
      Person p = passengers.get(i);
      if (p.getDestination() == location)
      {
        passengers.remove(i);
      }
      else
      {
        i++;
      }
    }
}

public void loadPassengers()
{
    for (Person p : people)
    {
      boolean added = false;
      for (int i = 0; !added && i < cars.size(); i++)
      {
        added = cars.get(i).tryToAdd(p);
      }
    }
}

public void driveCars()
{
  while (cars.size() > 0)
  {
    for (int i = 0; i < cars.size(); i++)
    {
      Car c = cars.get(i);
      c.drive();
      if (c.hasArrived())
      {
        cars.remove(i);
      }
      else
      {
        i++;
      }
    }
  }
}