canvas

Align objects to curve with canvas

Is it possible? I'm learning canvas at the moment, and while it's fun to position objects programmatically, it would be most interesting to come up with a way to align them to a curve. E.g. align a series of squares back to back along a wavy line or a circle. ...

Canvas maximization bug?

I must've killed over an hour on what seems to me like strange behaviour that happens in Firefox, Safari and Chrome. Here is some code: <!doctype html> <html> <head> <title>Watch me grow scrollbars!</title> </head> <body onload="resizeCanvas()"> <canvas id="canvas"></canvas> </body> </html> <script type=...

Why aren't these Canvases rendering?

I'm creating a web app that allows users to enter a number of colors, by specifying RGB values. Upon submission, the user will see a canvas with a solid rectangle drawn in the color chosen. On this page, I have 7 canvases. The first one draws just fine, but none of the rest show up. The browser is Safari. Here's the relevant code: Fir...

Making Firefox render canvas text the same as CSS text

I've been experimenting with the canvas tag and Javascript. I've made a page that takes Tweets from the Twitter public timeline and animates them into view. It works by using a canvas element in the background for the animation. When the animation is complete, it creates a div element with the same text over the top. I do this so that th...

Android Custom View - Optimizing Redrawing while Fling

I have a custom view that represents something like a photo-collage. I need to support the following: Fling Zoom In Zoom Out Here's what I currently do: onDraw: Look out for the number of images to be drawn. Look out for the images to be drawn and their locations and angles If the image had been downloaded (from the ser...

Android ImageView draw

Hi, i have the following problem. I am working with a library of maps which paints the icons on the map using drawables and canvas. Now, i'm trying to modify it in order to the user can click on icons. So i want to attach drawables into different ImageView with a onClickListener. However, i don't know how i can paint the ImageView ...

HTML5 canvas object events

Hi, Is there a way to attach an event handler to a object drawn on HTML5 Canvas, without tracking the points? Cheers, I ...

<Tabcontrol and Canvas

Hello, I have following situation <stackpanel > <ViewBox height=25/ > <tabcontrol> <tabitem> <Canvas /> </tabitem> </tabcontrol> </stackpanel> Q1. I want stackpanel to fill the screen, tabcontrol to fill the remain portion after viewbox. How do I do that ? How do I avoid the tabcontrol shrinking based on the s...

How to superpose two GwtCanvas ?

Hi, I'm trying to superpose two GwtCanvas (which use an Html5 canvas). I am able to get this effect by using an absolute panel. But by doing this, I can't get my object to fill my panel. I would like to this so I can do a whiteboard in GWT. So far, I'm pretty advance but I would like to have multiple canvas overlay to support undo or pre...

How to bring a menu to front of a navigation frame in silverlight?

The situation: I Have a silverlight page with a header menu, a navigation frame and a footer. In my header menu I want to put a drop down menu, but when I open the menu, it goes backward of the frame. Theres a way to put it forward? Canvas.ZIndex make no difference at all. thanks in advice ...

How do I attach event bindings to items on a canvas using Tkinter?

If I'm using a canvas to display data and I want the user to be able to click on various items on the canvas in order to get more information or interact with it in some way, whats the best way of going about this? Searching online I can find information about how to bind events to tags but that seems to be more indirect then what I wa...

Does HTML5/Canvas Support Double Buffering?

What I'd like to do is draw my graphics on a buffer and then be able to copy it as is to the canvas so I can do animation and avoid flickering. But I couldn't find this option. Anyone know how I can go about this? ...

[Tkinter/Python] Different line widths with canvas.create_line?

Does anyone have any idea why I get different line widths on the canvas in the following example? from Tkinter import * bigBoxSize = 150 class cFrame(Frame): def __init__(self, master, cwidth=450, cheight=450): Frame.__init__(self, master, relief=RAISED, height=550, width=600, bg = "grey") self.canvasWidth = cwidth ...

Bind event to shape on canvas

How can I bind an event to a shape drawn on a canvas? I presumed this would work but I get an error. <html> <head> <script type="application/javascript"> function draw() { var canvas = document.getElementById("canvas"); var ctx = canvas.getContext("2d"); ctx.fillStyle = "rgb(200,0,0)"; ...

HTML5 Canvas + select / drag-and-drop features in a JS lib?

Hi, I'd like to use HTML5 Canvas, but I'd like to use it in terms of shapes, texts and curves, able to attach traditional DOM events like onClick or drag-and-drop functions. Is there any Javascript library that is able to do that for me? I've seen that gwt-canvas is close to this approach, but haven't looked it in details. Thanks, I...

Save a <canvas> as a file in a form

Using Canvas method toDataURL, I would like to be able to save the image on the server side (using Rails). With toDataURL string, how to use it in a form that can be seen as a file attachment in a HTML form ? ...

Canvas Animation

I'm making a graph script using canvas, i'm adding animation to a chart but i don't like the way that it's look, i use setInterval for X function adding height to a rectangle to make a bar chart for example, but i wanna an animation more fluid, is another way to do an animation? ...

jquery remove issue in IE, canvas tag

hi, I am creating a line in canvas tag using jquery drawing library. After the line drawn the <div id="cool"><canvas id="canid"></canvas></div> Then on click the below code executed. $('#canid').remove(); What happens in IE after removing, dom with canvas end tag and also line is not removed. Please help me out!. ...

How do you retrieve WebGL bitmap data?

It is possible to retrieve the bitmap data HTML Canvas 2D element, is it also possible to access the rendered content of a Canvas 3D / WebGL element as bitmap data? ...

Problem with large Canvas in Silverlight

Hi, I am developing (using Silvelight 3) an aplication that creates some kind of timeline and places objects on it. For this purpose I need a really large Canvas (up to 2000000 pixels width) with long lines on it, but whenever I create Canvas even 40000 pixels width it behaves very strangely, randomly disappearing. I have found a post ...