How to impement a displaying of a text selecting?

[NikitaFeodonit]

I would like to implement the selection of text by mouse or via Ctrl-A. Can the litehtml display a text selection at the click position?

[NikitaFeodonit]

Or display of a selecting of the whole text by pressing a hotkey?

And how to get the selected text?

[tordex]

Sorry litehtml doesn't support selection. You have to write your own code for this. Selection should be implemented via :selection selector. See the implementation of litehtml::html_tag::on_mouse_over and litehtml::html_tag::on_mouse_leave as example. These functions set/remove hover pseudo class for element. The same can be used for selection.

[matzipan]

Hi,

Litehtml is a really cool library, thanks for your awesome work. I am interested in using litehtml for an email client I am building.

I will be looking to implement text selection in the container. I was just wondering - are you aware of any good code bases where I could find such an implementation for Pango? The only ones that I'm aware are webkit and GTK which are way too complex and flexible.

Thanks so much Andrei

[mmanyen]

Have you looked at freetype?

[matzipan]

I'm trying something out with pango atm. Any pointers about free type?

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On 12 Oct 2019, at 21:53, Mark Manyen [email protected] wrote:

 Have you looked at freetype?

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[matzipan]

Ok, using pango I managed to mark the start position. Next I'm gonna work for the simple case where the end position is in the same el_text node.

How would the :selection work? Should I introduce a virtual element for the selection, and then render that using the :selection pseudo class? This begs the question, what do I do in the case where the selection spans multiple lines? Do I create one of these virtual elements for each line?

Or should it be entirely in the rendering, ie. pango markup for the text, and :selection styling for the elements?

I will push a merge request when I have something more substantial to show.

[matzipan]

Also very important question: what is the algorithm for selecting text over multiple elements? How does the layout come into play? I can get some intuition by playing a bit with some browsers, but I couldn't find any RFCs or anything describing this in more detail

[matzipan]

Some interesting documentation:

• https://go.tiny.cloud/blog/a-quick-guide-to-browser-selection-models/
• https://docs.google.com/document/d/19sakBLZnnU0GPCQS3-EuaohvR56A4TopVrI2MfxK-RI/edit#heading=h.ar8dxx954ldu
• https://www.w3.org/TR/DOM-Level-2-Traversal-Range/ranges.html

[matzipan]

I pushed https://github.com/litehtml/litehtml/pull/111. It's currently in early stages, but any input is welcome. I will also push demo code which is not meant to be merged.

[cristianadam]

Qt Creator 4.11 comes with a Litehtml Help plugin, which has selection implemented.

Bare in mind that Qt Creator is GPL licensed.

You can download a snapshot from here: https://download.qt.io/snapshots/qtcreator/4.11/

[matzipan]

Seeing as litehtml is BSD licensed, I'm not sure how to navigate the licensing issues that this brings up, so I won't delve in it too deep, but it seems I went along a similar track. Thanks for the pointer!

[deacomm]

@matzipan You also might want to look at Claws Mail mail client, there's a relatively new plugin for using Litehtml to display HTML email there.

[matzipan]

@matzipan You also might want to look at Claws Mail mail client, there's a relatively new plugin for using Litehtml to display HTML email there.

Interesting. It seems really nice, thanks.

However, on the text selection front, I'm not seeing any code.

[deacomm]

No, I guess I mentioned it mostly because it also uses Pango for fonts.