[Lazarus] SVG Object
steveg at nevets.com.au
Tue Jan 18 05:22:01 CET 2022
Thank you Mehmet -
Tried to follow the math within the svg (inkscape) on my first attempt(s)
got completely lost (which leads to questioning ones intelligence) on
the transforms, scales and differing units :)
So now fully fudging it by dividing the Svg source Height and Width by a
grid format and call each one a quadrant location (x,y).
Then do the same with the OnClick position of the viewer (so relative
quadrants / sizes), and find closest matching (for me) object. All
depends on granularity of grid for accuracy.
Works, but is very dependent on complexity of the svg (not a problem for
my use case so far)
On 18/1/22 9:53 am, Mehmet Erol Sanliturk wrote:
> On Tue, Jan 18, 2022 at 2:37 AM Steve Gatenby via lazarus
> <lazarus at lists.lazarus-ide.org <mailto:lazarus at lists.lazarus-ide.org>>
> Thanks Marc - seems I will need to stick with what I have then.
> Currently I am pulling all object info from the SVG into an array and
> assigning quadrant positions.
> Then do best guess by relative quadrant of mouse click position -
> fine, but feels sloppy :)
> If it is feasible for you , you may do the following :
> In an array of a record , define approximate "bounding boxes" of your
> SVG graphic ( You may generate a "bounding box" array conforming to
> the given SVG ) .
> In the "bounding box" array record , you may define a pointer showing
> the SVG object .
> When a mouse click is obtained , you may search "bounding box" array and
> if it is related with an element of the SVG , from it you reach to the
> SVG element and
> do whatever you want to do with it .
> Minimum bounding box
> ( Please see attached pages . )
> This idea may be considered as an alternative view which I can not say
> it is very suitable for you . Only you may decide its usefulness .
> Mehmet Erol Sanliturk
> On 17/1/22 8:55 pm, Marc Weustink via lazarus wrote:
> > I'm afraid there is no easy solution for that. SVGs are rendered
> > the first element to the last, where ever element (atleast in
> > can be a part of a given pixel. SVG elements do have a
> > x,y,width,height but they may also be part of one or more
> > transformations.
> > To give you an idea, the (browser)app I'm currently working on
> > displays several object, where every object has an origin(x,y)
> of 0,0
> > and they are finally placed by translations.
> > The easiest way (if you are in a browser context) is to add an
> > handler to your elements of interest.
> > Marc
> > On 16-1-2022 23:34, Steve Gatenby via lazarus wrote:
> >> Not sure if this is the right place to ask about this one -
> >> I am using the BCSVGViewer from bgra controls - for SVG viewing
> >> obviously :)
> >> Would anybody know if there is a method to retrieve the object
> >> (within the svg) at specified x,y ?
> >> or is it possible to use embedded links within the svg ?
> >> I am looking to find which object has been clicked on within
> the svg
> >> to create a 'clickable' map
> >> Any suggestions on a better place to post this also appreciated
> >> Regards SteveG
> lazarus mailing list
> lazarus at lists.lazarus-ide.org <mailto:lazarus at lists.lazarus-ide.org>
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