Before this commit chat was applying a fixed height on everything under the `/chat` route. It's only really needed on the channel page with the composer at the bottom of the page.
This commits makes the following changes:
- moves height limitation from `#main-outlet-wrapper` to `.chat-channel`
- makes browse channel page and members list page full height and rely on main document scrollbar
- adds height computation for draft header and direct message creator block to ensure the height is correct when creating a draft channel
- makes chat index full height to rely on the browser scrollbar. As a result the <kbd> + </kbd> button used on mobile to create a direct message as been moved out of `<ChannelsList>` into the chat index template
- sidebar height was relying on chat setting a max height, as a result the height computation of sidebar has been changed to work correctly, especially with an opened keyboard on mobile or ipad
This commit adds an initial thread list UI. There are several limitations
with this that will be addressed in future PRs:
* There is no MessageBus reactivity, so e.g. if someone edits the original
message of the thread it will not be reflected in the list. However if
the thread title is updated the original message indicator will be updated.
* There is no unread functionality for threads in the list, if new messages
come into the thread there is no indicator in the UI.
* There is no unread indicator on the actual button to open the thread list.
* No pagination.
In saying that, this is the functionality so far:
* We show a list of the 50 threads that the user has most recently participated
in (i.e. sent a message) for the channel in descending order.
* Each thread we show a rich excerpt, the title, and the user who is the OM creator.
* The title is editable by staff and by the OM creator.
* Thread indicators show a title. We also replace emojis in the titles.
* Thread list works in the drawer/mobile.
`.chat-channel` had `300px` min width, when `.chat-drawer` was `250px`, resulting in overflowing channel when in drawer. This commits ensures the limits are always set at `250px`.
This pull request is a full overhaul of the chat-composer and contains various improvements to the thread panel. They have been grouped in the same PR as lots of improvements/fixes to the thread panel needed an improved composer. This is meant as a first step.
### New features included in this PR
- A resizable side panel
- A clear dropzone area for uploads
- A simplified design for image uploads, this is only a first step towards more redesign of this area in the future
### Notable fixes in this PR
- Correct placeholder in thread panel
- Allows to edit the last message of a thread with arrow up
- Correctly focus composer when replying to a message
- The reply indicator is added instantly in the channel when starting a thread
- Prevents a large variety of bug where the composer could bug and prevent sending message or would clear your input while it has content
### Technical notes
To achieve this PR, three important changes have been made:
- `<ChatComposer>` has been fully rewritten and is now a glimmer component
- The chat composer now takes a `ChatMessage` as input which can directly be used in other operations, it simplifies a lot of logic as we are always working a with a `ChatMessage`
- `TextareaInteractor` has been created to wrap the existing `TextareaTextManipulation` mixin, it will make future migrations easier and allow us to have a less polluted `<ChatComposer>`
Note ".chat-live-pane" has been renamed ".chat-channel"
Design for upload dropzone is from @chapoi
