Develop Reference

error with arrays in javascript

To fully understand this note this; `when the page loads it gets the area of the image (width * height) and creates all the x,y positions for all the positions in the area.
This works fine.
When I have another area from pos x,y and with also an area (width * height) should pop the positions from the first list so it can separate the two areas.
Little bug I noticed is I get little lines that are horizontal to the selected area and they don't extend far from that. I believe the reason is instead of making a clean square inside the image every line is offseted by a pixel or two.
Here's a video of the behaviour https://youtu.be/v1b6dEmfxQw
so since there's already an all positions list this code created a clone of the array and removes the positions.
var drop_boxes = $('.drop-box');
var area_grid = [];
var image_width = $('.img-class')[0].naturalWidth;
var image_height = $('.img-class')[0].naturalHeight;
drop_boxes.each(function() {
var position = $(this).position();
var width = $(this).width();
var height = $(this).height();
var positions_clone = positions.slice(0);
//console.log(positions_clone.length);
var top_offset = parseInt((position['top'] * image_width)/img_width);
var left_offset = parseInt((position['left'] * image_height)/img_height);
position['top'] = top_offset;
position['left'] = left_offset;
var width_offset = parseInt((width * image_width)/img_width);
var height_offset = parseInt((height * image_height)/img_height);
var width_counter = 0;
var height_counter = 0;
var area = width_offset * height_offset;
console.log(position);
console.log(width_offset);
console.log(height_offset);
if (position['top'] < image_height-1 && position['left'] < image_width) {
for (counter = 0; counter < area; counter++) {
var pos = [parseInt(position['left']+width_counter), parseInt(position['top']+height_counter)];
var index = positions.findIndex(function(item) {
// return result of comparing `data` with `item`
// This simple implementation assumes that all `item`s will be Arrays.
return pos.length === item.length && item.every(function(n, i) { return n === pos[i] });
});
//console.log(pos);
if (index > -1) {
positions_clone.splice(index, 1);
}
//area_grid.push(pos);
if (width_counter == width_offset) {
width_counter = 0;
height_counter += 1;
}
if (counter%100 == 0) {
var percentage = Math.round((counter/area)*100, 2);
console.log("Percentage: "+percentage+"%" + " "+counter);
}
width_counter += 1;
}
console.log(positions_clone.length);
console.log(area_grid.length);
areas[area_counter] = {'area': area_grid, 'positions': positions_clone};
parent.find('.area').text(area_counter);
area_counter += 1;
}
any clues in fixing it will be appreciated. I've showed how it behaves after commenting out certain parts of the code in the video.

Change
var index = positions.findIndex(function(item) {
to
var index = positions_clone.findIndex(function(item) {
Because after each splice, the indices of the original positions doesn't change but you are still using those indices to splice the clone.

Pixi.js keeps accelerating on page refresh

These are my references created in pixi.js here:
http://brekalo.info/en/reference
If we go to references it loads pixiJS and everything works fine on first load! Then, if we go to another page let's say: http://brekalo.info/en/contact, and the go back to references again - now my references have accelerated text movement and rotation and it keeps accelerate on each reference page load!
Here is my javascript/pixi code below:
function initiatePixi() {
Object.keys(PIXI.utils.TextureCache).forEach(function(texture) {
PIXI.utils.TextureCache[texture].destroy(true);}
);
// create an new instance of a pixi stage
var container = new PIXI.Container();
// create a renderer instance.
renderer = PIXI.autoDetectRenderer(frameWidth, frameHeight, transparent = false, antialias = true);
// set renderer frame background color
renderer.backgroundColor = 0xFFFFFF;
// add the renderer view element to the DOM
document.getElementById('pixi-frame').appendChild(renderer.view);
// create references
createReferences(animate); // callback to animate frame
function createReferences(callback) {
// Create text container
textContainer = new PIXI.Container();
textContainer.x = 0;
textContainer.y = 0;
for (i = 0; i < references.length; i++) {
var style = {
font:"22px Verdana",
fill:getRandomColor()
};
var text = new PIXI.Text(references[i], style);
text.x = getRandomInteger(20, 440); // text position x
text.y = getRandomInteger(20, 440); // text position y
text.anchor.set(0.5, 0.5); // set text anchor point to the center of text
text.rotation = getRandomInteger(0, rotationLockDeg) * 0.0174532925; // set text rotation
// make the text interactive
text.interactive = true;
// create urls on text click
text.on("click", function (e) {
var win = window.open("http://" + this.text, '_blank');
win.focus();
});
textContainer.addChild(text);
rotateText(); // rotate text each second
}
container.addChild(textContainer);
// callback
if (callback && typeof(callback) === "function") {
callback();
}
}
function animate() {
requestAnimationFrame(animate);
// render the stage
renderer.render(container);
}
function rotateText() {
var rotateTimer = setInterval(function () {
for (var key in textContainer.children) { // loop each text object
var text = textContainer.children[key];
if(text.rotation / 0.0174532925 < -rotationLockDeg || text.rotation / 0.0174532925 > rotationLockDeg) {
if(text.rotation / 0.0174532925 < -rotationLockDeg)
text.rotation = -rotationLockRad;
if(text.rotation / 0.0174532925 > rotationLockDeg)
text.rotation = rotationLockRad;
rotation = -rotation;
}
text.rotation += rotation; // rotate text by rotate speed in degree
if(text.x < 0 || text.x > 460)
dx = -dx;
if(text.y < 0 || text.y > 460)
dy = -dy;
text.x += dx;
text.y += dy;
}
}, 75);
}
// get random integer between given range (eg 1-10)
function getRandomInteger(min, max) {
return Math.floor(Math.random() * (max - min + 1)) + min;
}
// random hex color generator
function getRandomColor() {
var letters = '0123456789ABCDEF'.split('');
var color = '#';
for (var i = 0; i < 6; i++ ) {
color += letters[Math.floor(Math.random() * 16)];
}
return color;
}
Thanks in advance!
:: cheers ::
Josip

To expand #Cristy's comment to an answer:
The answer lies in the same reason as why your question title is wrong: There is indeed NO page refresh when doing what you describe. If there were, you wouldn't have that problem in the first place. Try it out, hit F5 a few times on you animated page, it will stay the same speed.
The reason is that you are running a angular based single page application, and only exchange the loaded view content on a route change. This does not stop your already running animation code from continuing to run in the background while you navigate to another view, so that when you return to the animated tab you will create another set of interval timers for your animation, which will result in more executions and thus a visually faster animation.

#Cristy thanks for the advice!
Here is how I manage to solve this..
I put one property in my pixi-parameters.js:
pixiWasLoaded = false;
Then, when I call initiatePixi() function, I set:
pixiWasLoaded = true;
Now in my controllers.js I have this piece of code:
.run( function($rootScope, $location, $window) {
$rootScope.$watch(function() {
return $location.path();
},
function(page){
if(page == "/hr/reference" || page == "/en/references"){
if($window.pixiWasLoaded)
$window.addRendererElementToDOM();
else
loadReferences();
}
});
});
It checks if references page is loaded and then uses $window to find my global variable "pixiWasLoaded" and if it's not loaded then it loads PixiJS using loadReferences() function.. and if is already loaded it calls my part of code to add render-view to DOM so my animate function can render it..
:: cheers ::
Josip

For Loop MovieClip Grid not showing on stage

So I'm a newbie and should obviously spend time in the tuts, but I'm looking for a quick answer. Basically, I've created a grid of movie clips with AS3. When I 'preview' the flash (as a flash or HTML) it shows up fine. Success. Yet, the stage remains empty.
Q1) Will the stage remain empty as I have used AS3 to dynamically 'draw' the grid of mc's? Or is there a slit of code I am missing to make this baby show up on the stage?
Q2) I've managed to use alpha to make the MC's 'fade' on hover - but I want to make them change color (to red) when hovered over. I've searched everywhere and can't seem to find the right script.
Here is my code:
var stage = new createjs.Stage("canvas");
var image = new createjs.Bitmap("images/square.png");
stage.addChild(image);
createjs.Ticker.addEventListener("tick", handleTick);
function handleTick(event) {
image.x += 10;
stage.update();
}
var x0:Number = 0;
var y0:Number = 0;
var nt:Number = 72;
var nc = 10;
var vd:Number = 12;
var hd:Number = 12;
for (var i = 1; i <= nt; i++) {
var mc = this.attachMovie("square", "square" + i, i);
var aprox = Math.floor((i - 1) / nc);
mc._x = x0 + hd * ((i - aprox * nc) - 1);
mc._y = y0 + aprox * vd;
mc.useHandCursor = true;
// fade in
mc.onRollOver = function()
{
this.onEnterFrame = function()
{
if (this._alpha > 0) {
this._alpha -= 10;
} else {
this._alpha = 0;
delete this.onEnterFrame;
}
};
};
// fade out
mc.onRollOut = function()
{
this.onEnterFrame = function()
{
if (this._alpha < 100) {
this._alpha += 10;
} else {
this._alpha = 100;
delete this.onEnterFrame;
}
};
};
}
Thanks in advance - sorry I am a noob.

This will never work. 1/3 of your code is in AS3, 2/3 in AS2. Considering you haven't been thrown any error, I assume you exported it as AS2.

Javascript Color Animation

I want to animate (transition) from 1 color to another in raw javascript.
I dont want to use any framework (jquery, mootools) or css3. plain raw javascript.
I have been really having trouble to do this, can someone help me out ? :)

maybe something like this:
lerp = function(a, b, u) {
return (1 - u) * a + u * b;
};
fade = function(element, property, start, end, duration) {
var interval = 10;
var steps = duration / interval;
var step_u = 1.0 / steps;
var u = 0.0;
var theInterval = setInterval(function() {
if (u >= 1.0) {
clearInterval(theInterval);
}
var r = Math.round(lerp(start.r, end.r, u));
var g = Math.round(lerp(start.g, end.g, u));
var b = Math.round(lerp(start.b, end.b, u));
var colorname = 'rgb(' + r + ',' + g + ',' + b + ')';
el.style.setProperty(property, colorname);
u += step_u;
}, interval);
};
You can play around an try it out as a jsfiddle or check out the full working example below. You might want to improve this by using HSL/HSV colors, which gives you a prettier transition, but i'll leave that up to you.
<html>
<head>
<title>Fade</title>
<style type="text/css">
#box {
width: 100px;
height: 100px;
background-color: rgb(255,0,0);
}
</style>
</head>
<body>
<div id="box"></div>
<script type="text/javascript" charset="utf-8">
// linear interpolation between two values a and b
// u controls amount of a/b and is in range [0.0,1.0]
lerp = function(a,b,u) {
return (1-u) * a + u * b;
};
fade = function(element, property, start, end, duration) {
var interval = 10;
var steps = duration/interval;
var step_u = 1.0/steps;
var u = 0.0;
var theInterval = setInterval(function(){
if (u >= 1.0){ clearInterval(theInterval) }
var r = parseInt(lerp(start.r, end.r, u));
var g = parseInt(lerp(start.g, end.g, u));
var b = parseInt(lerp(start.b, end.b, u));
var colorname = 'rgb('+r+','+g+','+b+')';
el.style.setProperty(property, colorname);
u += step_u;
}, interval);
};
// in action
el = document.getElementById('box'); // your element
property = 'background-color'; // fading property
startColor = {r:255, g: 0, b: 0}; // red
endColor = {r: 0, g:128, b:128}; // dark turquoise
fade(el,'background-color',startColor,endColor,1000);
// fade back after 2 secs
setTimeout(function(){
fade(el,'background-color',endColor,startColor,1000);
},2000);
</script>
</body>
</html>

Here is also my solution:
<html><head>
<script type="text/javascript">
<!--
function animate(id,color0,color1,duration){
//public attributes
this.elem = document.getElementById(id);
//private attributes
var r0= parseInt(color0.substring(0,2),16);
var g0= parseInt(color0.substring(2,4),16);
var b0= parseInt(color0.substring(4,6),16);
var r1= parseInt(color1.substring(0,2),16);
var g1= parseInt(color1.substring(2,4),16);
var b1= parseInt(color1.substring(4,6),16);
var wait = 100; //100ms
var steps = duration/wait;
var rstep = (r1 - r0) / (steps);
var gstep = (g1 - g0) / (steps);
var bstep = (b1 - b0) / (steps);
var self = this;
//public functions
this.step = function() {
steps--;
if ( steps>0 ) {
r0 = Math.floor(r0 + rstep);
g0 = Math.floor(g0 + gstep);
b0 = Math.floor(b0 + bstep);
elem.style.backgroundColor = 'rgb('+r0+','+g0+','+b0+')';
//alert(steps + ' ; ' + elem.style.backgroundColor);
window.setTimeout(function(){self.step();}, wait);
} else {
elem.style.backgroundColor = '#'+color1;
}
}
step();
//alert(this.r0);
}
//-->
</script>
</head><body>
<div id="anim" style="width:100px; height:100px; background-color:#ff0000"></div>
<input type="button" onclick="animate('anim','1122ff','ff2211',1000)" value="test" />
</body>
</html>
html at pastebin, how to call the timeout function - see for example 1, 2

if canvas would be ok you could try doing it like this ;)
var context = document.getElementsByTagName('canvas')[0].getContext('2d');
var hue = 0;
function bgcolor() {
hue = hue + Math.random() * 3 ;
context.fillStyle = 'hsl(' + hue + ', 100%, 50%)';
context.fillRect(0, 0, context.canvas.width, context.canvas.height);
}
setInterval(bgcolor, 20 );
Yes ;) it`s not perfect and just an excample but give it a try. Here is the complete pen on codepen.

One way might be to use setTimeout to call some function which incrementally changes the colour (I'm assuming background-color) by some small amount each time it's called. At each iteration, just check to see if you've arrived at your target colour and if not, increase or decrease your RGB value as necessary.

Finding number of lines in an html textarea

I'm writing a mobile web application where scrollbars are not displayed on the device's browser. Due to this, I'm trying to dynamically modify the height of the textarea to make it bigger, however I don't know of any way to actually get the line count on an html textarea. Any help would be greatly appreciated!
EDIT
So I realize now that it's not newlines per se, but actual line wrapping. So when one line finishes it wraps the text to the next line. It appears as if it is a new line. Any way to count the number of these? Thanks!

The number of lines in the textarea would be
textarea.value.match(/\n/g).length + 1

I have created a plugin to handle line counting and wrap detection in a <textarea>.
I hope someone can use it.
Code on BitBucket
Sample Usage
var result = $.countLines("#textarea");
result.actual // The number of lines in the textarea.
result.wraps // The number of lines in the textarea that wrap at least once.
result.wrapped // The total number of times all lines wrap.
result.blank // The number of blank lines.
result.visual // The approximate number of lines that the user actually sees in the textarea
Working Demonstration
/*! Textarea Line Count - v1.4.1 - 2012-12-06
* https://bitbucket.org/MostThingsWeb/textarea-line-count
* Copyright (c) 2012 MostThingsWeb (Chris Laplante); Licensed MIT */
(function($) {
$.countLines = function(ta, options) {
var defaults = {
recalculateCharWidth: true,
charsMode: "random",
fontAttrs: ["font-family", "font-size", "text-decoration", "font-style", "font-weight"]
};
options = $.extend({}, defaults, options);
var masterCharacters = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890";
var counter;
if (!ta.jquery) {
ta = $(ta);
}
var value = ta.val();
switch (options.charsMode) {
case "random":
// Build a random collection of characters
options.chars = "";
masterCharacters += ".,?!-+;:'\"";
for (counter = 1; counter <= 12; counter++) {
options.chars += masterCharacters[(Math.floor(Math.random() * masterCharacters.length))];
}
break;
case "alpha":
options.chars = masterCharacters;
break;
case "alpha_extended":
options.chars = masterCharacters + ".,?!-+;:'\"";
break;
case "from_ta":
// Build a random collection of characters from the textarea
if (value.length < 15) {
options.chars = masterCharacters;
} else {
for (counter = 1; counter <= 15; counter++) {
options.chars += value[(Math.floor(Math.random() * value.length))];
}
}
break;
case "custom":
// Already defined in options.chars
break;
}
// Decode chars
if (!$.isArray(options.chars)) {
options.chars = options.chars.split("");
}
// Generate a span after the textarea with a random ID
var id = "";
for (counter = 1; counter <= 10; counter++) {
id += (Math.floor(Math.random() * 10) + 1);
}
ta.after("<span id='s" + id + "'></span>");
var span = $("#s" + id);
// Hide the span
span.hide();
// Apply the font properties of the textarea to the span class
$.each(options.fontAttrs, function(i, v) {
span.css(v, ta.css(v));
});
// Get the number of lines
var lines = value.split("\n");
var linesLen = lines.length;
var averageWidth;
// Check if the textarea has a cached version of the average character width
if (options.recalculateCharWidth || ta.data("average_char") == null) {
// Get a pretty good estimation of the width of a character in the textarea. To get a better average, add more characters and symbols to this list
var chars = options.chars;
var charLen = chars.length;
var totalWidth = 0;
$.each(chars, function(i, v) {
span.text(v);
totalWidth += span.width();
});
// Store average width on textarea
ta.data("average_char", Math.ceil(totalWidth / charLen));
}
averageWidth = ta.data("average_char");
// We are done with the span, so kill it
span.remove();
// Determine missing width (from padding, margins, borders, etc); this is what we will add to each line width
var missingWidth = (ta.outerWidth() - ta.width()) * 2;
// Calculate the number of lines that occupy more than one line
var lineWidth;
var wrappingLines = 0;
var wrappingCount = 0;
var blankLines = 0;
$.each(lines, function(i, v) {
// Calculate width of line
lineWidth = ((v.length + 1) * averageWidth) + missingWidth;
// Check if the line is wrapped
if (lineWidth >= ta.outerWidth()) {
// Calculate number of times the line wraps
var wrapCount = Math.floor(lineWidth / ta.outerWidth());
wrappingCount += wrapCount;
wrappingLines++;
}
if ($.trim(v) === "") {
blankLines++;
}
});
var ret = {};
ret["actual"] = linesLen;
ret["wrapped"] = wrappingLines;
ret["wraps"] = wrappingCount;
ret["visual"] = linesLen + wrappingCount;
ret["blank"] = blankLines;
return ret;
};
}(jQuery));
result = jQuery.countLines("#textarea");
jQuery('#display').html(
'<span>Actual: ' + result.actual + '</span>' +
'<span>Blank: ' + result.blank + '</span>' +
'<span>Visual: ' + result.visual + '</span>' +
'<span>Wrapped: ' + result.wrapped + '</span>' +
'<span>Wraps: ' + result.wraps + '</span>'
);
#textarea {
width: 150px;
height: 80px;
}
#display span {
display: block;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<textarea id="textarea">text
here
this is a longer line so that it will wrap in the box longer longer longer</textarea>
<div id="display"></div>

This is an efficient and accurate method to count the number of lines in a text area, including wrapped lines.
/** #type {HTMLTextAreaElement} */
var _buffer;
/**
* Returns the number of lines in a textarea, including wrapped lines.
*
* __NOTE__:
* [textarea] should have an integer line height to avoid rounding errors.
*/
function countLines(textarea) {
if (_buffer == null) {
_buffer = document.createElement('textarea');
_buffer.style.border = 'none';
_buffer.style.height = '0';
_buffer.style.overflow = 'hidden';
_buffer.style.padding = '0';
_buffer.style.position = 'absolute';
_buffer.style.left = '0';
_buffer.style.top = '0';
_buffer.style.zIndex = '-1';
document.body.appendChild(_buffer);
}
var cs = window.getComputedStyle(textarea);
var pl = parseInt(cs.paddingLeft);
var pr = parseInt(cs.paddingRight);
var lh = parseInt(cs.lineHeight);
// [cs.lineHeight] may return 'normal', which means line height = font size.
if (isNaN(lh)) lh = parseInt(cs.fontSize);
// Copy content width.
_buffer.style.width = (textarea.clientWidth - pl - pr) + 'px';
// Copy text properties.
_buffer.style.font = cs.font;
_buffer.style.letterSpacing = cs.letterSpacing;
_buffer.style.whiteSpace = cs.whiteSpace;
_buffer.style.wordBreak = cs.wordBreak;
_buffer.style.wordSpacing = cs.wordSpacing;
_buffer.style.wordWrap = cs.wordWrap;
// Copy value.
_buffer.value = textarea.value;
var result = Math.floor(_buffer.scrollHeight / lh);
if (result == 0) result = 1;
return result;
}
Demo here

I haven't tried using the function discussed in this blog, but you may find it useful.
http://kirblog.idetalk.com/2010/03/calculating-cursor-position-in-textarea.html
Basically, if you create a div and then copy the text into that div, with the same width and font characteristics, you can then get the information you need, such as the number of lines. The number of lines in this example would be easy, in that if you know how many pixels high a single line would be, then just find the width of the test div and you can get a pretty accurate idea as to how many lines are in your textarea.

Get scrollHeight, subtract top+bottom padding, divide by lineHeight.

I'm pretty sure there is no reasonable way to count the number of lines as displayed in the browser especially considering some browsers (Safari) allow the user to resize textareas.
It'd be hacky, but your best bet might be to just estimate based on the total characters divided by average number of characters per line. :-/

Maybe there is a way to get the "raw" number of "visual" lines. You should read the scrollHeight property of the textarea and divide it by the height of a line. Let's try.
Start with this HTML:
<textarea id="ta" cols="50" rows="10"></textarea>
Then:
var line_height = Math.floor($("#ta").height() / parseInt($("#ta").attr("rows")));
var dirty_number_of_lines = Math.ceil($("#ta")[0].scrollHeight / line_height);
I am not sure if that really works, just a mad theory.

You can calculate is as so:
var length = $('#textarea').val().split("\n").length;

The number of characters allowed per line is dictated by the "cols" attribute of the textarea.
<textarea rows="10" cols="80"></textarea>
Assuming 80 characters per line, a good estimate may be:
var approxNumLines = textareaElement.value.length / textareaElement.cols ;
Doesn't account for word-break and word-wrap.