Excellent resources...reading through them both first. I'd obviously seen the SVG implementation specs before, but didn't even think application-related events would tie in. Should've looked first. Diving in once again, this is great material.
Michael -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Sent: Monday, October 24, 2005 5:00 PM To: [email protected] Cc: [email protected] Subject: RE: Efficient way of "selecting" an element? Hi Michael, "Bishop, Michael W. CONTR J9C880" <[EMAIL PROTECTED]> wrote on 10/24/2005 04:05:27 PM: > I draw a rectangle with x,y,w,h and no fill color. I can only ?capture? this > element as the event target if I click on the rectangle itself; I cannot click > inside of it. If I create a rectangle WITH a fill color, I can click inside > of it. Is there anyway to trigger the event in the case without a fill color? > Should I set the fill color as the background color??? That seems kind of like a hack. You need to review Section 16.6 of the SVG specification "The 'pointer-events' property": http://www.w3.org/TR/SVG11/interact.html#PointerEventsProperty In particular the value 'visible' is most likely what you want, however the other values are useful in a number of situations as well. So it is likely going to be useful for you to review them. BTW you might be interested in reading my ApacheCON 2003 presentation which covers some of these issues as well: http://people.apache.org/~deweese/ac2003/ > From: Andres Toussaint [mailto:[EMAIL PROTECTED] > Sent: Monday, October 24, 2005 3:26 PM > To: [email protected] > Subject: Re: Efficient way of "selecting" an element? > > You can do the following to retrieve the element that triggered the action: > > Element trigger = (Element)evt.getTarget(); > > The SVGLocatable gives you access to matrix information about the specific > Element. (to transform from screen coordinates to SVG coordinates) > > You do not need to check for your elements unless you have "live" and > "sleeping" elements in the same group that has the listener, if not, only when > you are over an element within the group, the event will be triggered. > > The Listener will listen for events within its scope (a listener in a G > element will only listen for events that happen to its children) so if there > is no object indicated as background, no event will be triggered. > > Some case scenario, in case you want to capture DE-SELECT click also: > > Sample SVG snippet (not well formed): > > <svg ...> > <rect x=0 y=0 width=100% height=100% fill=red /> -- May be a background inert object > <g id=selectableItems onmouseover activated via DOM> > <rect id=background x=0 y=0 width=100% height=100% fill=none pointer-events=fill /> > <rect id=object1 ... /> > <rect id=object2 ... /> > <rect id=object2 ... /> > </g> > </svg> > > public class OnClickAction implements EventListener { > public void handleEvent(Event evt) { > Element theActionEvent = (Element)evt.getTarget(); > if (theActionEvent.getAttribute("id")="background") { > > //The user clicked on the "background" object, perform > //Deselect options > } else { > > // Convert the screen coordinates into SVG coordinate space > SVGLocatable thisNode = (SVGLocatable)evt.getTarget(); > > DOMMouseEvent elEvt = (DOMMouseEvent)evt; > int nowToX = elEvt.getClientX(); > int nowToY = elEvt.getClientY(); > > // Convert Screen coordinates to Document Coordinates. > SVGOMPoint pt = new SVGOMPoint(nowToX, nowToY); > SVGMatrix mat = thisNode.getScreenCTM(); // elem -> screen > mat = mat.inverse(); // screen -> elem > initialDragPoint = (SVGOMPoint)pt.matrixTransform(mat); > > //initialDragPoint has the mouseEvent coordinates in the SVG > //coordinate space. > > // At this point you can do whatever you what with your selected > // Element, for instance, change its opacity, to denote the selection: > theActionEvent.setAttribute("opacity","0.5"); > } > } > > > regards, > > Andres. > > On Oct 24, 2005, at 2:23 PM, Bishop, Michael W. CONTR J9C880 wrote: > > OK, well thanks to the two of you, I'm on the path to implementing this > functionality. I do use ALWAYS_DYNAMIC for my document since I'm > consistently adding and removing elements from it. I do have one > question about this tutorial at: > > http://wiki.apache.org/xmlgraphics-batik/DragTutorial > > How do I get which Element I'm clicking in? There's a commented area > that says "This is where you set your selected element, validate, etc." > but I don't know how to do that. > > If I click on a JSVGCanvas, I need to know if I'm inside one of my > Elements. If I am, I can drag it, if I'm not (i.e. a blank piece of > JSVGCanvas), there's nothing to drag. > > I think this is based on the SVGLocatable which is defined as > "thisNode", but how do I get from it to an Element? What happens if > there is no element where I click? Is there documentation I can read > about this? There is none in the JavaDoc for SVGLocatable, so > understanding precisely what that object is, is my stumbling block. > > Michael Bishop > > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] > Sent: Monday, October 24, 2005 1:51 PM > To: [email protected] > Cc: [email protected] > Subject: RE: Efficient way of "selecting" an element? > > Hi Michael, > > "Bishop, Michael W. CONTR J9C880" <[EMAIL PROTECTED]> wrote on > > 10/24/2005 01:46:18 PM: > > Just to be clear, I?m doing this in Java, not the SVG-supported > JavaScript. > Nonetheless, this drag tutorial seems to be precisely what I?m looking > > for. > Does it require JavaScript (or anything else extra) to be present in > the > document? > > All of the dynamic stuff is fully available in Java as well as in > JavaScript > (EcmaScript). If you don't have any obvious dynamic elements in your > document > then you need to inform Batik to treat your document as dynamic, using > JSVGComponent.setDocumentState(ALWAYS_DYNAMIC). > > You will have to add your listeners using the DOM interfaces > (addEventListener) instead of using the event attributes > (on click etc). > > From: Andres Toussaint [mailto:[EMAIL PROTECTED] > Sent: Monday, October 24, 2005 1:19 PM > To: [email protected] > Subject: Re: Efficient way of "selecting" an element? > > SVG has the ability to dispatch events based on mouse actions, and the > > event > holds the object that triggered the event (which is not necessarily > the > object > holding the listener, in case it is a group), for example: > > <g onMouseClick="doEvent(evt)" > > <rect id="object 1" ...../> > <rect id="object 2" ...../> > <rect id="object 3" ...../> > <rect id="object 4" ...../> > </g> > > the event will be activated and dispatched only when the click is > inside > any > of the rect objects, and the evt.target will tell you what is the > clicked object. > > You may also see the dragTutorial in the batik wiki to see how to add > listeners in the code: > http://wiki.apache.org/xmlgraphics-batik/DragTutorial > > regards, > Andres. > > p.s. the same is true for all other mouse events. > > On Oct 24, 2005, at 1:04 PM, Bishop, Michael W. CONTR J9C880 wrote: > > I have a scenario where I?d like to click in the JSVGCanvas and > ?select? > the > SVG element I?m clicking inside of. Short of iterating through the > document > and creating Java2D objects in which to check to see if my clicked > point > is > ?inside? of, is there a way in Batik to see which elements a point > resides in? > > Michael Bishop > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: [EMAIL PROTECTED] > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: [EMAIL PROTECTED] > --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
