Re: [Devel] NUMA Support - GUI Technical Session

Hi Gilad, to my understanding, we already use _HTML5_ Drag'n'Drop support (exposed by GWT API since 2.4) in "Setup Host Networks" dialog. To utilize HTML5 Drag'n'Drop support in GWT widget, just extend FocusPanel and mark your widget's DOM element as "draggable". For example, in UnassignedNetworksPanel constructor: getElement().setDraggable( ... ); addBitlessDomHandler(new DragEnterHandler() { ... }); addBitlessDomHandler(new DragOverHandler() { ... }); addBitlessDomHandler(new DragLeaveHandler() { ... }); addBitlessDomHandler(new DropHandler() { ... }); In other words, GWT already exposes API for working with HTML5 Drag'n'Drop spec, so you don't need any 3rd party libraries. The downside is that HTML5 Drag'n'Drop spec is supported only in recent browsers (but this isn't an issue for us, AFAIK): http://caniuse.com/#feat=dragndrop So in general we have two alternatives: 1, use standard HTML5 Drag'n'Drop spec pros: + no need for 3rd party library + compliant with existing code, i.e. "Setup Host Networks" cons (not too relevant IMHO): - requires browser support of HTML5 Drag'n'Drop spec - HTML5 Drag'n'Drop spec deals with dragging data, not widgets themselves (no HTML DOM re-parenting after drag finish) 2, use 3rd party gwt-dnd library pros (which I don't think we really need): + emulate Drag'n'Drop support in older browsers + more advanced functionality, i.e. allows dragging widgets so that HTML DOM is dynamically updated cons: - dependency on 3rd party library - this would mean we need to revisit existing code (we should do Drag'n'Drop in one consistent way) It's possible that I might be missing something, but I'd suggest to try using HTML5 Drag'n'Drop via GWT API as the first approach. If we find out that HTML5 Drag'n'Drop doesn't work for us in given browser(s) or if we need extra functionality, we can always add gwt-dnd dependency. Few more comments inline, let me know what you think. Regards, Vojtech ----- Original Message ----- Yeah, but the downside is adding 3rd party dependency which predates GWT's support for (API exposure of) HTML5 Drag'n'Drop spec. GWT's HTML5 Drag'n'Drop API works directly on DOM element level, it's just a thin API overlay on top of HTML5Drag'n'Drop spec. Do we really need custom DnD infra on top of that? Can't we just use GWT APIs like Element.setDraggable, Drag*Handler, Drop*Handler? I agree, there should be one consistent way to do DnD in oVirt UI. I'm just saying we should consider existing GWT HTML5 Drag'n'Drop API before jumping into gwt-dnd 3rd party dependency. If it turns out that GWT DnD API is too basic (lacks functionality) or has issues with some browser(s) - we can add gwt-dnd dependency anytime.