Develop Reference

Explain "SLIDER" drag and drop on protractor with a proper example

browser.actions().dragAndDrop(elem, target).perform();
I can clearly understand the above code but I cannot get how to specify this element and target.
Take this example
browser.actions().dragAndDrop(slider,{x:100, y:0}).perform();
In the website in which I'm working on, I cannot find any x, y or anything I can match with that and develop.
So it will be helpful if someone explains with some example for x and y so that I can relate to it and make I work.

The dragAndDrop() has two ways to work.
One starts with the element to drag. Here elem works as normal ElementFinder, so something like dragAndDrop(element(by.css('div.my-class')), target).perform();.
Now the target works in two ways: Either as another ElementFinder like in elem or as coordinates to move, starting from the position of elem, moving x pixels horizontally and y pixels vertically (plus to the right or top, minus to the left or bottom). So {x:100, y:0} will move your slider 100 pixels to the right from the starting position.
dragAndDrop(element(by.css('div.my-class')), {x:100, y:0}).perform(); will therefore move the element(by.css('div.my-class')) 100 pixels to the right.

Getting CSS left and top when div is rotated

I'm trying to get the style.left and style.top of a rectangular div, after it has been rotated using style.transform=rotate(90deg).
I understand how the div is being rotated, with it being rotated around a 'transform point'. And I also understand that a div could be rotated by 45 degrees, so giving the new top/left of that would be awkward (In effect giving the bounding box left/top).
But back to the original question, rotating the rectangular div by 90 degrees, is there a way to get the 'new' left/top?
The reason I need this, is for a project im working on to upload images, allow the user to zoom, rotate etc, but currently having to do it with PHP to keep all the dimensions correct for the final image (Which is obviously bad, because I'm having to keep loading a new image once PHP has done the rotating/zooming etc)
I've also made a little jsfiddle showing that the top/left position doesn't change when it is rotated

Okay, thanks to the comment left above, I managed to throw together an answer.
Basically using:
newleft = parseInt(div.style.top) + Math.cos(90) * parseInt(div.style.height);
newtop = parseInt(div.style.left) + Math.sin(90) * parseInt(div.style.height);
after the div had been rotated.
I've updated my jsfiddle aswell, because the one in the comment above uses jQuery, but this way uses only javascript.

Canvas: pointer based viewport / contain mouse pointer

There doesn't seem to be a good way to base the <canvas> viewport on the location of the mouse pointer and being able to move around freely. Basically, like every other first-person game on the market.
There is no way to capture the mouse
inside a <canvas> element.
There is no way to set the position
of the mouse pointer.
It is not possible to go full screen
with <canvas>, and even if, once the edge has been reached, functionality will be broken.
For good reasons, too. Imagine what possible scenarios could (and definitely would) be employed by malicious persons.
Perhaps it's too early to be thinking of something that is almost only of any use in a 3D environment, something that there isn't yet a spec for.
What's your take or solution?

You can get the mouse position inside of a canvas.
function getCursorPosition(e) {
var x;
var y;
if (e.pageX != undefined && e.pageY != undefined) {
x = e.pageX;
y = e.pageY;
}
else {
x = e.clientX + document.body.scrollLeft +
document.documentElement.scrollLeft;
y = e.clientY + document.body.scrollTop +
document.documentElement.scrollTop;
}
x -= gCanvasElement.offsetLeft;
y -= gCanvasElement.offsetTop;
var cell = new Cell(Math.floor(y/kPieceHeight),
Math.floor(x/kPieceWidth));
return cell;
}
From Dive Into HTML5: Let's Call it a Draw(ing Surface)

I don't think there is a good solution for this -- at least, not until we get mouse locking. No matter how elegant your solution, if you make a twitchy mouselook driven game, the user is going to twitch outside the canvas area at some point. Even if they don't accidentally click a link, their immersion will be broken when the view stops responding to their mouse.
For slower paced games, you could:
Use click and drag to turn. Once user starts dragging within the canvas, you use the mouse delta from the point where they started dragging to determine how far to turn. Because the user is holding down the button, they won't accidentally click things.
Hover cursor near the edges of the canvas to turn, similar to an RTS. This would turn more slowly, but is probably the most intuitive, and easiest for a user to accidentally discover.
Use the keyboard to look, like pre-mouse FPS games (such as Doom).
It's worth noting that there is an open feature request in Firefox for mouse locking. But, unfortunately, neither this, nor mouse hiding or fullscreen are part of the WebGL spec.
All of these features are supported by Unity, so that may be a path to look at if you really need FPS controls.

Spot the ball game, zooming problems, jQuery

I am trying to create a spot the ball game, so it will (eventually) be an image of a player kicking a ball but the ball has been removed and the player needs to click where the ball should be.
The first version went well and works.
http://enjoythespace.com/sites/game/test.html
But what I need to add is some sort of zooming so you can see more accurately where you are clicking. I been playing around and have come up with this
http://enjoythespace.com/sites/v2/demo.html
But once you click it looks great when zoomed in but when you go back to the image its way off.
I think its todo with how the image is setup, the #webpage is half the original size of the image and the #retina uses the full size of the image.
Any help?

The first problem is that you aren't setting the retina backgroundPosition correctly.
This code works (I added a zoom variable to make it clear how changing the zoom would change the calculation, but it would need other changes too):
/* Moving the retina div with the mouse
(and scrolling the background) */
zoom = 2.0;
retina.css({
left : left - sizes.retina.width/2,
top : top - sizes.retina.height/2,
backgroundPosition : ""+(-zoom*left+sizes.retina.width/2)+'px '+(-zoom*top+sizes.retina.height/2)+'px'
});
Test this by checking that all four corners are seen correctly in the retina, i.e. when you're over the corner of the main image, the corner should be in the center of the retina circle.
The second problem is if you resize the browser the position calculations are out because the offset variable isn't updated for the new size. A simple way to do this is to put this as the first line of webpage.mousemove() so the offsets are updated every time:
var offset = { left: webpage.offset().left, top: webpage.offset().top };

It looks like you are passing the top/left position click point of the zoomed image to highlight where you have clicked. What you will need to do is alter your top/left position based on whether the fisheye is over the image or not.
Does the un-zoomed image have to be part of the news page or can it be a standalone image?
If it can be standalone then the solution should be quite simple. If the zoomed in image is twice the size of the unzoomed one then you can just set the top/left values of the highlight to half the value of the zoomed, when looking at the unzoomed.
Jquery position will allow you to accurately get the position.
jQuery Position()

Click on given element in canvas

Is there any trick to determine if user clicks on given element rendered in canvas? For example I'm displaying rhombus from .png file with transparent background and i want to know if user click inside or outside that figure (like mouse-element collision).

There is no concept of individual elements in a canvas - it is simply just an area that you're drawing pixels onto. SVG on the other hand is made up of elements which you can then bind events to. However there are a few approaches you can take to add click events to canvas:
Position an html element that overlays the area on the canvas you want to be clickable. A for a rectangular area or an image map for something more irregular.
Use separate canvases for each element that you want to be clickable.
CAKE - I haven't used this myself, but it's description is "SVG sans the XML". This may cover your needs. Demos here http://glimr.rubyforge.org/cake/canvas.html#EditableCurve

One idea is to draw the image to a temporary canvas, then use getImageDate() to receive data for the pixel you are interested in, and check if its alpha value is 0 ( = transparent).
The following is a sketch of a solution. It is assumed that...
x and y are the coordinates of the mouse click event
you are looping over gameObjects, the current object being stored in the variable gameObject
the game object has been initialized with an image, x and y coordinates
The following code would then check whether the click was on a transparent area:
var tempCanvas = document.createElement('canvas');
if (tempCanvas.getContext) {
tempContext = tempCanvas.getContext('2d');
}
tempContext.drawImage(gameObject.img, 0, 0);
var imgd = tempContext.getImageData(x - gameObject.x, y - gameObject.y, 1, 1);
var pix = imgd.data;
if (pix[3] == 0) {
// user clicked on transparent part of the image!
}
Note: This is probably quite inefficient. I'm sure someone can come up with a better solution.

I have solve this problem using kintech.js, tutorials and examples can be found: http://www.html5canvastutorials.com/kineticjs/html5-canvas-drag-and-drop-tutorial/