diff options
Diffstat (limited to 'src/librustdoc/html/static/js/scrape-examples.js')
-rw-r--r-- | src/librustdoc/html/static/js/scrape-examples.js | 106 |
1 files changed, 106 insertions, 0 deletions
diff --git a/src/librustdoc/html/static/js/scrape-examples.js b/src/librustdoc/html/static/js/scrape-examples.js new file mode 100644 index 000000000..fd7a14497 --- /dev/null +++ b/src/librustdoc/html/static/js/scrape-examples.js @@ -0,0 +1,106 @@ +/* global addClass, hasClass, removeClass, onEachLazy */ + +"use strict"; + +(function() { + // Number of lines shown when code viewer is not expanded + const MAX_LINES = 10; + + // Scroll code block to the given code location + function scrollToLoc(elt, loc) { + const lines = elt.querySelector(".line-numbers"); + let scrollOffset; + + // If the block is greater than the size of the viewer, + // then scroll to the top of the block. Otherwise scroll + // to the middle of the block. + if (loc[1] - loc[0] > MAX_LINES) { + const line = Math.max(0, loc[0] - 1); + scrollOffset = lines.children[line].offsetTop; + } else { + const wrapper = elt.querySelector(".code-wrapper"); + const halfHeight = wrapper.offsetHeight / 2; + const offsetMid = (lines.children[loc[0]].offsetTop + + lines.children[loc[1]].offsetTop) / 2; + scrollOffset = offsetMid - halfHeight; + } + + lines.scrollTo(0, scrollOffset); + elt.querySelector(".rust").scrollTo(0, scrollOffset); + } + + function updateScrapedExample(example) { + const locs = JSON.parse(example.attributes.getNamedItem("data-locs").textContent); + let locIndex = 0; + const highlights = Array.prototype.slice.call(example.querySelectorAll(".highlight")); + const link = example.querySelector(".scraped-example-title a"); + + if (locs.length > 1) { + // Toggle through list of examples in a given file + const onChangeLoc = changeIndex => { + removeClass(highlights[locIndex], "focus"); + changeIndex(); + scrollToLoc(example, locs[locIndex][0]); + addClass(highlights[locIndex], "focus"); + + const url = locs[locIndex][1]; + const title = locs[locIndex][2]; + + link.href = url; + link.innerHTML = title; + }; + + example.querySelector(".prev") + .addEventListener("click", () => { + onChangeLoc(() => { + locIndex = (locIndex - 1 + locs.length) % locs.length; + }); + }); + + example.querySelector("next") + .addEventListener("click", () => { + onChangeLoc(() => { + locIndex = (locIndex + 1) % locs.length; + }); + }); + } + + const expandButton = example.querySelector(".expand"); + if (expandButton) { + expandButton.addEventListener("click", () => { + if (hasClass(example, "expanded")) { + removeClass(example, "expanded"); + scrollToLoc(example, locs[0][0]); + } else { + addClass(example, "expanded"); + } + }); + } + + // Start with the first example in view + scrollToLoc(example, locs[0][0]); + } + + const firstExamples = document.querySelectorAll(".scraped-example-list > .scraped-example"); + onEachLazy(firstExamples, updateScrapedExample); + onEachLazy(document.querySelectorAll(".more-examples-toggle"), toggle => { + // Allow users to click the left border of the <details> section to close it, + // since the section can be large and finding the [+] button is annoying. + onEachLazy(toggle.querySelectorAll(".toggle-line, .hide-more"), button => { + button.addEventListener("click", () => { + toggle.open = false; + }); + }); + + const moreExamples = toggle.querySelectorAll(".scraped-example"); + toggle.querySelector("summary").addEventListener("click", () => { + // Wrapping in setTimeout ensures the update happens after the elements are actually + // visible. This is necessary since updateScrapedExample calls scrollToLoc which + // depends on offsetHeight, a property that requires an element to be visible to + // compute correctly. + setTimeout(() => { + onEachLazy(moreExamples, updateScrapedExample); + }); + }, {once: true}); + }); +})(); |