Re: [whatwg] Proposed addition to Drag and Drop API
I did a bit of reading about what the WhatWG spec says setDragImage should do and wanted to ensure I understand what the spec is saying and how Webkit is behaving. Spec: http://www.whatwg.org/specs/web-apps/current-work/multipage/dnd.html#dom-datatransfer-setdragimage The spec says defines setDragImage as: setDragImage(element, x, y) Element argument is defined as: If the element argument is an img element, then set the drag data store bitmap to the element's image (at its intrinsic size); otherwise, set the drag data store bitmap to an image generated from the given element (the exact mechanism for doing so is not currently specified). This says, if I'm understanding it correctly, that I can provide any element as the first argument and a bitmap image will be generated as a drag image. This would allow me to accomplish what I'm trying to do (setting a small drag element to represent a larger draggable container). However, in my testing, Webkit will not render anything unless the element specified is an image. Am I misunderstanding the spec, or might this be a bug in the implementation? Thanks, - Alex On Friday, June 29, 2012 at 4:37 PM, Alex Bain wrote: @Ryosuke - I do not have a concrete proposal but would be interested in helping to work one out. I had idly considered a content attribute but think that specifying an element (perhaps via a function called setDragElement()) would be a simple implementation. @Daniel - I had thought that was possible but in my testing I was not able to get it to work. I had tried referencing an existing element as well as creating a new element but neither were visible while dragging [in Chrome]. On Friday, June 29, 2012 at 4:30 PM, Daniel Cheng wrote: Can't you use setDragImage() and pass it the element that holds the post title? Daniel On Fri, Jun 29, 2012 at 4:27 PM, Ryosuke Niwa rn...@webkit.org (mailto:rn...@webkit.org) wrote: On Fri, Jun 29, 2012 at 4:24 PM, Alex Bain a...@alexba.in (mailto:a...@alexba.in) wrote: I would prefer not to visually drag the entire post around (which is what happens if I set draggable to true on the post container). My goal is to set draggable on a container element and only show a small element when the user starts dragging. Ah, that's an interesting use case. Thanks for clarification. Do you have a concrete proposal for this? (e.g. adding new content attribute / element). - Ryosuke
Re: [whatwg] Proposed addition to Drag and Drop API
I tested locally and it works for me--if I set a specific element as the drag image, it gets used instead of the entire draggable element. Daniel On Mon, Jul 2, 2012 at 10:06 AM, Alex Bain a...@alexba.in wrote: I did a bit of reading about what the WhatWG spec says setDragImage should do and wanted to ensure I understand what the spec is saying and how Webkit is behaving. Spec: http://www.whatwg.org/specs/web-apps/current-work/multipage/dnd.html#dom-datatransfer-setdragimage The spec says defines setDragImage as: setDragImage(element, x, y) Element argument is defined as: If the element argument is an img element, then set the drag data store bitmap to the element's image (at its intrinsic size); otherwise, set the drag data store bitmap to an image generated from the given element (the exact mechanism for doing so is not currently specified). This says, if I'm understanding it correctly, that I can provide any element as the first argument and a bitmap image will be generated as a drag image. This would allow me to accomplish what I'm trying to do (setting a small drag element to represent a larger draggable container). However, in my testing, Webkit will not render anything unless the element specified is an image. Am I misunderstanding the spec, or might this be a bug in the implementation? Thanks, - Alex On Friday, June 29, 2012 at 4:37 PM, Alex Bain wrote: @Ryosuke - I do not have a concrete proposal but would be interested in helping to work one out. I had idly considered a content attribute but think that specifying an element (perhaps via a function called setDragElement()) would be a simple implementation. @Daniel - I had thought that was possible but in my testing I was not able to get it to work. I had tried referencing an existing element as well as creating a new element but neither were visible while dragging [in Chrome]. On Friday, June 29, 2012 at 4:30 PM, Daniel Cheng wrote: Can't you use setDragImage() and pass it the element that holds the post title? Daniel On Fri, Jun 29, 2012 at 4:27 PM, Ryosuke Niwa rn...@webkit.org wrote: On Fri, Jun 29, 2012 at 4:24 PM, Alex Bain a...@alexba.in wrote: I would prefer not to visually drag the entire post around (which is what happens if I set draggable to true on the post container). My goal is to set draggable on a container element and only show a small element when the user starts dragging. Ah, that's an interesting use case. Thanks for clarification. Do you have a concrete proposal for this? (e.g. adding new content attribute / element). - Ryosuke
Re: [whatwg] Proposed addition to Drag and Drop API (Alex Bain)
I did a bit of reading about what the WhatWG spec says setDragImage should do and wanted to ensure I understand what the spec is saying and how Webkit is behaving. Spec: http://www.whatwg.org/specs/web-apps/current-work/multipage/dnd.html#dom-datatransfer-setdragimage The spec says defines setDragImage as: setDragImage(element, x, y) Element argument is defined as: If the element argument is an img element, then set the drag data store bitmap to the element's image (at its intrinsic size); otherwise, set the drag data store bitmap to an image generated from the given element (the exact mechanism for doing so is not currently specified). This says, if I'm understanding it correctly, that I can provide any element as the first argument and a bitmap image will be generated as a drag image. This would allow me to accomplish what I'm trying to do (setting a small drag element to represent a larger draggable container). However, in my testing, Webkit will not render anything unless the element specified is an image. Am I misunderstanding the spec, or might this be a bug in the implementation? I can't say which without an example of how you're using setDragImage, but I assure you that it works with non-img elements in WebKit browsers: http://jsfiddle.net/mZGP7/1/ Note, however, that (at least for WebKit-based browsers) the element must be in the document body, and it can't have visibility: hidden or display: none or even positioning that puts it outside of the window bounds. None of this is dictated by the spec, which simply declares that the mechanism for turning an element into a bitmap is unspecified. At this point, I would take your questions to StackOverflow rather than the WHATWG list (unless you would like to draft a proposal for making the setDragImage spec more precise). Best, Trevor
Re: [whatwg] Media queries, viewport dimensions, srcset and picture
In Scott Jehl's latest example of a responsive image polyfill (https://github.com/scottjehl/picturefill), he produced a variation that allows a non-retinae image to be downloaded by default with the user having the ability to then choose the download the retina version of image if then wanted. Which ever solution to the responsive image eventually get's incorporated into the spec I think we need to account for this behaviour at the user-agent level i.e. if the UA decides to download a non-retina image because the user is on a cell network, then they need a way of easily choosing to download the retina image if they want. Any thoughts? Andy
