godoc: generate TOC from server-side for search page

Currently, we generate the TOC for a page dynamically after page load
through javascript. This is fine for pages with static content.

But for pages with dynamic output like /search, sometimes this causes a
noticeable page jump due to extensive DOM traversal. Also, the heuristics
to calculate the no. of columns is very rudimentary and fills the entire
above-the-fold area if the no. of results is very large.

Therefore, we generate the TOC from server side itself. And improve
the no. of columns heuristic further to accomodate up to 4 columns.

This improves page performance and utilizes real estate appropriately
according to the input.

Some screenshots at laptop (1366x768) resolution.
https://snag.gy/AXz2rP.jpg
https://snag.gy/th3Nn8.jpg

More can be found in the CL comments.

Fixes golang/go#21685
Updates golang/go#21686

Change-Id: Ia9b6dd1e67231d992709e4ba10ebdbedfe38b564
Reviewed-on: https://go-review.googlesource.com/c/129135
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
6 files changed
tree: 1d3d61eb69bc494ea7639117478eff55289d421a
  1. benchmark/
  2. blog/
  3. cmd/
  4. container/
  5. cover/
  6. go/
  7. godoc/
  8. imports/
  9. internal/
  10. playground/
  11. present/
  12. refactor/
  13. third_party/
  14. .gitattributes
  15. .gitignore
  16. AUTHORS
  17. codereview.cfg
  18. CONTRIBUTING.md
  19. CONTRIBUTORS
  20. LICENSE
  21. PATENTS
  22. README.md
README.md

Go Tools

This subrepository holds the source for various packages and tools that support the Go programming language.

Some of the tools, godoc and vet for example, are included in binary Go distributions.

Others, including the Go guru and the test coverage tool, can be fetched with go get.

Packages include a type-checker for Go and an implementation of the Static Single Assignment form (SSA) representation for Go programs.

Download/Install

The easiest way to install is to run go get -u golang.org/x/tools/.... You can also manually git clone the repository to $GOPATH/src/golang.org/x/tools.

Report Issues / Send Patches

This repository uses Gerrit for code changes. To learn how to submit changes to this repository, see https://golang.org/doc/contribute.html.

The main issue tracker for the tools repository is located at https://github.com/golang/go/issues. Prefix your issue with “x/tools/(your subdir):” in the subject line, so it is easy to find.