QSvgWidget and URIs: Can I emit a signal by clicking on a link in an SVG image?
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wrote on 10 Feb 2019, 13:53 last edited by
What I would like to do is this:
I can display an SVG image of a graph, which is generated by the Graphviz library, in a QSvgWidget (no problem there). Nodes and edges of the graph can have tooltips as well as URL properties. When the SVG file is displayed in a browser, the link specified by the URL is followed if one clicks on it. Instead, since it is being displayed in a widget and not a browser, I want to emit a QObject signal which would be connected to the parent of the QSvgWidget and cause it to display a popup window with additional data related to the node or edge.What is the best way to do this?
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Hi
The only way know is to read the XML /with XML class) and find the Id that are links.
Then use
QRectF QSvgRenderer::boundsOnElement(const QString &id) const
to get the rects for the choosen Ids.
Then use this rect list for mousePress event on a QSvgWidget subclassI did not find any access methods for SVG properties in the SVG classes.
That said, Graphviz also supports HREF in the dot format so you can make labels
"hotlinked"
https://stackoverflow.com/questions/14155773/label-hyperlink-graphviz -
Hi
The only way know is to read the XML /with XML class) and find the Id that are links.
Then use
QRectF QSvgRenderer::boundsOnElement(const QString &id) const
to get the rects for the choosen Ids.
Then use this rect list for mousePress event on a QSvgWidget subclassI did not find any access methods for SVG properties in the SVG classes.
That said, Graphviz also supports HREF in the dot format so you can make labels
"hotlinked"
https://stackoverflow.com/questions/14155773/label-hyperlink-graphvizwrote on 10 Feb 2019, 17:44 last edited by@mrjj Thanks very much, this was very helpful!
In the meantime, I discovered that Graphviz can also output an HTML image map of a graph. Together with the information returned by QSvgRenderer::boundsOnElement function, I think I can do it.
As to the link ID: Is this the tag name, or is there an attribute "id" for each SVG element? (I don't know much about SVG except that it is a special kind of XML format.)
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@mrjj Thanks very much, this was very helpful!
In the meantime, I discovered that Graphviz can also output an HTML image map of a graph. Together with the information returned by QSvgRenderer::boundsOnElement function, I think I can do it.
As to the link ID: Is this the tag name, or is there an attribute "id" for each SVG element? (I don't know much about SVG except that it is a special kind of XML format.)
@Robert-Hairgrove
Yes Graphviz is very nice. Many ways to do things.
its the ID attribute all elements have.
<path id="lineBC" d="M 250 50 l 150 300" stroke="red"lineBC in this case.
Since the id allows us to get a rect to hit test with , it was possible to know it was clicked.
However, i did not find other way to read say text of a text element to get any URL
so i think you need to find out this by reading the XML/or the HTML.Well SVGs format is just plain XML. So it should not too complicated to dig out
some URLS. -
@Robert-Hairgrove
Yes Graphviz is very nice. Many ways to do things.
its the ID attribute all elements have.
<path id="lineBC" d="M 250 50 l 150 300" stroke="red"lineBC in this case.
Since the id allows us to get a rect to hit test with , it was possible to know it was clicked.
However, i did not find other way to read say text of a text element to get any URL
so i think you need to find out this by reading the XML/or the HTML.Well SVGs format is just plain XML. So it should not too complicated to dig out
some URLS.wrote on 10 Feb 2019, 18:12 last edited by@mrjj Thank you!
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@mrjj Thank you!
@Robert-Hairgrove
Np :)
Just as a note. I used inkscape to fiddle with the SVGs.
Its sorts of reverses the element Y pos if saved.
So just in case you did use InkScape as that fooled me for some time.
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