This document explains why [tview ](https://github.com/rivo/tview ) was forked to
create [cview ](https://code.rocketnine.space/tslocum/cview ). It also explains any
differences between the projects and tracks which tview pull requests have been
merged into cview.
# Why fork?
[rivo ](https://github.com/rivo ), the creator and sole maintainer of tview,
explains his reviewing and merging process in a [GitHub comment ](https://github.com/rivo/tview/pull/298#issuecomment-559373851 ).
He states that he does not have the necessary time or interest to review,
discuss and merge pull requests:
>this project is quite low in priority. It doesn't generate any income for me
>and, unfortunately, reviewing issues and PRs is also not much "fun".
>But some other people submitted large PRs which will cost me many hours to
>review. (I had to chuckle a bit when I saw [this comment ](https://github.com/rivo/tview/pull/363#issuecomment-555484734 ).)
>Lastly, I'm the one who ends up maintaining this code. I have to be 100%
>behind it, understand it 100%, and be able to make changes to it later if
> necessary.
cview aims to solve these issues by increasing the number of project
maintainers and allowing code changes which may be outside of tview's scope.
# Differences
## Primitive methods do not return the primitive they belong to
When chaining multiple primitive method calls together, application developers
might accidentally end the chain with a different return type than the first
method call. This could result in unexpected return types. For example, ending
a chain with `SetTitle` would result in a `Box` rather than the original primitive.
## cview is [thread-safe](https://docs.rocketnine.space/code.rocketnine.space/tslocum/cview/#hdr-Concurrency)
tview [is not thread-safe ](https://godoc.org/github.com/rivo/tview#hdr-Concurrency ).
## [Application.QueueUpdate](https://docs.rocketnine.space/code.rocketnine.space/tslocum/cview/#Application.QueueUpdate) and [Application.QueueUpdateDraw](https://docs.rocketnine.space/code.rocketnine.space/tslocum/cview/#Application.QueueUpdateDraw) do not block
tview [blocks until the queued function returns ](https://github.com/rivo/tview/blob/fe3052019536251fd145835dbaa225b33b7d3088/application.go#L510 ).
## `Primitive` has two additional fields, `SetVisible` and `GetVisible`
Widgets embedding `Box` require the addition of the following at the beginning
of their `Draw` routine to handle visibility changes.
```go
func (w *Widget) Draw(screen tcell.Screen) {
if !w.GetVisible() {
return
}
// ...
}
```
## Setting a primitive's background color to `tcell.ColorDefault` does not result in transparency
Call [Box.SetBackgroundTransparent ](https://docs.rocketnine.space/code.rocketnine.space/tslocum/cview/#Box.SetBackgroundTransparent )
to enable background transparency.
## Double clicks are not handled by default
All clicks are handled as single clicks until an interval is set with [Application.SetDoubleClickInterval ](https://docs.rocketnine.space/code.rocketnine.space/tslocum/cview/#Application.SetDoubleClickInterval ).
## Tables are sorted when a fixed row is clicked by default
Call [Table.SetSortClicked ](https://docs.rocketnine.space/code.rocketnine.space/tslocum/cview/#Table.SetSortClicked )
to disable this behavior.
## Lists and Forms do not wrap around by default
Call `SetWrapAround` to wrap around when navigating.
## Tables do not wrap around when selecting a cell
Attempting to move outside of the range of the table results in the selection
remaining unchanged.
## TextViews store their text as []byte instead of string
This greatly improves buffer efficiency. [TextView.Write ](https://docs.rocketnine.space/code.rocketnine.space/tslocum/cview/#TextView.Write )
is 90% faster and [TextView.Draw ](https://docs.rocketnine.space/code.rocketnine.space/tslocum/cview/#TextView.Draw )
is 50% faster.
## `Pages` has been renamed as `Panels`
This is for consistency with `TabbedPanels` , which is built on top of `Panels` .
## `Panels.AddPanel` preserves order of panels when updating existing panel
tview moves the updated panel to the end.
## `Application.Draw` may be used to draw the entire screen or a set of primitives
When calling `Application.Draw` without providing any primitives, the entire
screen is drawn. This behavior matches tview.
When using cview, you may provide one or more primitives to limit drawing.
## `Application.ForceDraw` has been removed
Because cview is [thread-safe ](https://docs.rocketnine.space/code.rocketnine.space/tslocum/cview/#hdr-Concurrency ),
application draws must be queued. Call `Application.QueueUpdateDraw` to queue
an update that requires the application to be drawn when completed.
# Merged pull requests
The following tview pull requests have been merged into cview:
- [#378 Throttle resize handling ](https://github.com/rivo/tview/pull/378 )
- [#368 Add support for displaying text next to a checkbox ](https://github.com/rivo/tview/pull/368 )
- [#353 Add window size change handler ](https://github.com/rivo/tview/pull/353 )
- [#347 Handle ANSI code 39 and 49 ](https://github.com/rivo/tview/pull/347 )
- [#336 Don't skip regions at end of line ](https://github.com/rivo/tview/pull/336 )
- [#296 Fixed TextView's reset [-] setting the wrong color ](https://github.com/rivo/tview/pull/296 )
