Develop Reference

How to animate from point till destination point and then blink the drawn path?

I have a situation where i need to draw on 2D picture (such as networking diagram) from position to destination position like path, once the path is established then I need to blink that highlighted RED color path.
I tried as following which is not animated how do i animate the start and end instead of static draw as below:
$.tpt.prototype.setDraw = function() {
var canvas = document.getElementById('maincanvas');
var context = canvas.getContext('2d');
context.beginPath();
context.moveTo(100,20);
// line 1
context.lineTo(200, 160);
// quadratic curve
context.quadraticCurveTo(0, 200, 250, 120);
// bezier curve
context.bezierCurveTo(290, -40, 300, 200, 400, 150);
// line 2
context.lineTo(500, 90);
context.lineWidth = 1;
context.strokeStyle = 'red';
context.stroke();
};

Change Color of Shape Mid Tween

I'm trying to make an event that changes my shapes stroke color for 5 seconds when a button is clicked, and then the shape returns to original color after the duration.
I am able to do this with clearing the entire stage and redrawing new shapes (which resets their position), but I can't figure it out with the current shapes.
Q. What's the best way to approach making a change to a shapes color, during a Tween?
I was also curious if there's a better way to handling tweening the shapes width? Currently I am relying on ScaleX and ScaleY - but this also changes the stroke's size - which is not desired.
JS Fiddle
HTML
<button id="change">Click to Change Color</button>
<canvas id="demoCanvas" width="500" height="500"></canvas>
JS
var stage,
circle;
function init() {
stage = new createjs.Stage("demoCanvas");
createjs.Ticker.setFPS(60);
createjs.Ticker.addEventListener("tick", stage);
}
function createCircle(){
circle = new createjs.Shape().set({name:"circle"});
circle.graphics.setStrokeStyle(1).beginStroke("#000").beginFill( "#FFF" ).drawCircle(0, 0, 20);
circle.x = 100;
circle.y = 100;
stage.addChild(circle);
createjs.Tween.get(circle, {loop: true})
.to({x: 225, y: 225}, 1000, createjs.Ease.getPowInOut(1))
.to({x: 100, y: 100}, 1000, createjs.Ease.getPowInOut(1));
circle2 = new createjs.Shape().set({name:"circle"});
circle2.graphics.setStrokeStyle(1).beginStroke("#000").beginFill( "#FFF" ).drawCircle(0, 0, 20);
circle2.x = 400;
circle2.y = 400;
stage.addChild(circle2);
createjs.Tween.get(circle2, {loop: true})
.to({scaleX: 2, scaleY: 2, x: 425, y: 125}, 1000, createjs.Ease.getPowInOut(1))
.to({scaleX: 1, scaleY: 1, x: 400, y: 400}, 1000, createjs.Ease.getPowInOut(1));
stage.update();
}
$( "#change" ).click(function() {
// change color
});
$(document).ready(function() {
init();
createCircle();
});

There are a few questions in this post, so I will try to answer them all:
First, a solution to most of your issues is Graphic commands. Commands provide a simple way to store graphic instructions, and change them later. Here is a simple example:
var shape = new createjs.Shape();
var colorCmd = shape.graphics.beginFill("red").command;
var rectCmd = shape.graphics.drawRect(0,0,100,100).command;
// Later
colorCmd.style = "blue";
rectCmd.w = 200;
stage.update(); // Remember to update the stage after changing properties
You can read more about commands on the createjs blog. All commands and their properties are documented in the EaselJS docs.
Change a color: I outlined this in the example above, but the short answer is to adjust the style property of a fill command. If you want to change it instantly, you can just set up a Tween.call:
Example:
createjs.Tween.get(circle, {loop: true})
.to({x: 225, y: 225}, 1000, createjs.Ease.getPowInOut(1))
.call(function(tween) {
colorCmd.style = "rgba(0, 0, 255, 0.5)"; // Change to 50% blue
})
.to({x: 100, y: 100}, 1000, createjs.Ease.getPowInOut(1));
If you want to tween the color, then you could check out the ColorPlugin, which is currently in a "Plugins" branch of TweenJS: https://github.com/CreateJS/TweenJS/tree/Plugins/extras/plugins
// Tween the color from its current value to blue.
// Note that only hex, short hex, HSL, and RGB formats are supported.
createjs.Tween.get(colorCmd).to({style:"#0000ff"});
Change the size: The example above also shows how to modify the values of a drawRect call. You can do the same with any other draw command (including moveTo, lineTo, polyStar, etc).
Scaling also works, and if you want to not scale the stroke, just set the ignoreScale parameter on the stroke style.
shape.graphics.setStrokeStyle(1, null, null, null, true);

Using arcTo() gives me an error in Kinetic.js

I am getting an error when using arcTo in the following code, using Kinetic.js 5.1.0.
The error is 'TypeError: context.arcTo is not a function'
myshape = new Kinetic.Shape({
sceneFunc: function(context) {
context.beginPath();
context.moveTo(10, 0);
context.lineTo(57, 0);
context.lineTo(47, 35);
context.lineTo(13, 35);
context.arcTo(3, 0, 10, 0, 3);
context.closePath();
context.fillStrokeShape(this);
},
fill: '#e2e4e3',
stroke: '#92278f',
strokeWidth: 1,
rotationDeg: 15,
x: 150,
y: 40
});

context parameter is not native 2d canvas context, it is KineticJS wrapper. You may use arc() function or use native canvas reference with context._context
context._context.arcTo(...);

Draw canvas shape as an oval lauout using fabric.js

On change event i am trying to draw canvas as oval shape, i am not getting proper property
of canvas to draw this canvas in oval format.I have set the following property in my code see the following code.I tried this with css and i am getting perfect out put but when i a am trying convert canvas as png image that canvas shapes not going to converted in image so that's why , i want it in this way.
$("#decalshap").change(function() {
alert("oval");
var shap = $(this).val();
if(shap=="oval")
{
canvas.set({
height:314,
width:500,
borderColor: 'red',
borderRadius: 314.5/157.25,
border:2,
});
}
Answer will be appreciate.

for this you have to clipTo property ,use this code for drawing an oval in canvas
//script
var w;
var h;
var ctx = canvas.getContext('2d');
w=canvas.width / 4;
h=canvas.height / 2.4;
canvas.clipTo = function(ctx) {
ctx.save();
ctx.scale(2, 1.2);
ctx.arc(w, h, 90, 0, 2 * Math.PI, true);
ctx.stroke();
ctx.restore();
//canvas.renderAll();
}
Here is the Fiddle DEMO

Drawing shapes and lines with HTML5 Canvas and jQuery

I have an upcoming project that I would like to use the HTML5 canvas element to accomplish what would have had to be done in the past with either images and absolutely paced div's or Flash. Here is a basic example of the concept
Here are my concerns:
I am ok with using div's with corner radius to create the circles as they will be styled, and I'm not sure if I can do that with a mix of svg and the canvas element.
My main concern is the stroke that joins the outer circles to the inner, I would like to do this with canvas but am not sure A) How to get multiple canvas elements on one page in one containing element (a wrapper div) and B) how to figure out the starting points, I would assume the ending point would just be the center of the wrapper div (IE if its 600x600 = x=300, y=300)
Can anyone shed some light on this and offer any suggestions? Is there an advantage to using any of the jQuery canvas plugiins over vanilla JS?
thank you!

The canvas API consists of some functions which seem to do the job just fine:
.moveTo/.lineTo for a line path
.arc for a circle path
.stroke to stroke a path (line)
.fill to fill a path (circle)
Here's a very trivial proof of concept: http://jsfiddle.net/eGjak/275/.
I've used (x, y) for both the lines and the circles, which means the lines go from and to the midpoint of two circles. r is the radius of a circle.
var ctx = $('#cv').get(0).getContext('2d');
var circles = [ // smaller circles
{ x: 50, y: 50, r: 25 },
{ x: 250, y: 50, r: 25 },
{ x: 250, y: 250, r: 25 },
{ x: 50, y: 250, r: 25 },
];
var mainCircle = { x: 150, y: 150, r: 50 }; // big circle
function drawCircle(data) {
ctx.beginPath();
ctx.arc(data.x, data.y, data.r, 0, Math.PI * 2); // 0 - 2pi is a full circle
ctx.fill();
}
function drawLine(from, to) {
ctx.beginPath();
ctx.moveTo(from.x, from.y);
ctx.lineTo(to.x, to.y);
ctx.stroke();
}
drawCircle(mainCircle); // draw big circle
$.each(circles, function() { // draw small circles and lines to them
drawCircle(this);
drawLine(mainCircle, this);
});​

You could just do all of these circles in CSS. Get some divs, style them as you like in CSS, and then apply border-radius: 100; to the object, and done. I hope this helped.