There are a few things that need to be done, to make this work.
First, we need to register `Enter` as another hotkey that opens the
selected item.
However, by default the `KeyboardHandler` will override all default
actions. That might make sense for any other key, but for the `Enter`
key, we want to keep the default behavior (i.e. follow a selected link
or press a button). So for this single key event, we do not call
`preventDefault()`.
I see this as unproblematic for the following reasons.
1. With the changes from #2348, when we're in a list of items (articles,
categories, feeds), there is no link selected. This is what made the
`Enter` key work _implicitly_ in the past. With nothing selected, the
`Enter` key will do nothing by default.
2. If we have **any** link selected (including when we are in a view
with a list of selectable items), we'll get the default action of
`Enter` (i.e. follow a link), which is exactly what we had before.
Lastly, we need to update the list of keyboard shortcuts displayed when
pressing `?`.
This fixes#2366.
# Change HTML tag to button
Replace the link tag with an HTML button to prevent some screen readers from having confusing announcements. By using the HTML button, users can use the Enter and Space keys to activate actions by default, instead of implementing them in JavaScript.
# Differentiate links and buttons visually
When activating the link element, the user may expect the web page to navigate to the URL and the page will refresh; when activating the button element, the user may expect the web page to still be on the same page, so that their current state, such as: input value, won't disappear.
Links and buttons should have different styles visually, so that users can't expect what will happen when they activate a link or a button.
I added the underline to the links, because that is the common pattern. Buttons have border and background color in a common pattern. But I think that will change the current layout drastically. So I added the focus, hover and active classes to the buttons instead.
The recent HTTP client refactor in 14e25ab9fe
introduced a bug in which the global default User-Agent is no longer
used for requests. Unless a per-feed User-Agent exists, the Go standard
library's default User-Agent is used, which looks something like
"Go-http-client/1.1". To fix this, make RequestBuilder.WithUserAgent
take an additional argument, the default User-Agent, which will be used
if there is no per-feed User-Agent (i.e. it is an empty string).
Fixes#2188Fixes#2189
