Use Hyperlink widget for links in message info popup.

[theViz343]

What does this PR do, and why?

This PR introduces the Hyperlink widget for message links in message information popups. This solves the issue of long urls being force-wrapped which results in them not being clickable from ZT.

Outstanding aspect(s)

• The focus on the currently selected link is a bit off. It doesn't cover the link.

External discussion & connections

• Discussed in #zulip-terminal in Hyperlink support using OSC-8 escape sequences
• Fully fixes #
• Partially fixes issue Support OSC 8 hyperlinks in messages #1368
• Builds upon previous unmerged work in PR #
• Is a follow-up to work in PR #
• Requires merge of PR #
• Merge will enable work on #

How did you test this?

• Manually - Behavioral changes
• Manually - Visual changes
• Adapting existing automated tests
• Adding automated tests for new behavior (or missing tests)
• Existing automated tests should already cover this (only a refactor of tested code)

Self-review checklist for each commit

• It is a minimal coherent idea
• It has a commit summary following the documented style (title & body)
• It has a commit summary describing the motivation and reasoning for the change
• It individually passes linting and tests
• It contains test additions for any new behavior
• It flows clearly from a previous branch commit, and/or prepares for the next commit

Visual changes

[Subhasish-Behera]

Hey @theViz343 ,I am getting the error

 File "/home/subhasishbehera/zulip-terminal/zulipterminal/ui_tools/buttons.py", line 11, in <module>
    import urwidgets
ModuleNotFoundError: No module named 'urwidgets'

[neiljp]

@Subhasish-Behera If you're using make then run that and it should check you have the required dependencies, or reinstall the editable zt package over the top (if not using make).

@theViz343 It would be useful to have the dependency change visible as a separate small commit, as we do when we change other requirements.

[neiljp]

Having the rendering of the link defined in the link button like this would be cleaner, and it may be reasonable to refactor the layout into the button as a prep refactor for this.

However, right now this overall change affects the rendering quite a lot: links are not styled in the same way as the background of the button, or when selected. That makes it difficult to visually identify that the link and number/title are related to the link when many links are present.

I'm not sure if that's a limitation of the Hyperlink?

[AnonymouX47]

Hello!

However, right now this overall change affects the rendering quite a lot: links are not styled in the same way as the background of the button, or when selected. That makes it difficult to visually identify that the link and number/title are related to the link when many links are present.

I'm not sure if that's a limitation of the Hyperlink?

Yes, it was.

I just released v0.2.0 which allows the use of Attrmaps (and other means) over Hyperlink widgets (and the rendered canvases). See AnonymouX47/urwidgets#3.

[AnonymouX47]

Replace with:

        hyperlink = urwidgets.Hyperlink(uri=self.link)
        icon = urwid.Pile(
            widget_list=[
                urwid.SelectableIcon(caption, cursor_position=len(caption) + 1),
                # using `hyperlink.pack()[0]` instead of `len(self.link)` in case of wide characters
                urwidgets.TextEmbed((hyperlink.pack()[0], hyperlink)),
            ]
        )

to wrap the URL across lines instead of clipping with ellipsis.

The OSC 8 feature will still work perfectly on any terminal emulator with a spec-compliant implementation and behaviour will remain the same as before this PR on terminal emulators that don't support the feature.