package.src.display.update_lines.js Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of codemirror Show documentation
Basic configuration for the CodeMirror code editor
The newest version!
import { heightAtLine } from "../line/spans.js"
import { getLine, lineAtHeight, updateLineHeight } from "../line/utils_line.js"
import { paddingTop, charWidth } from "../measurement/position_measurement.js"
import { ie, ie_version } from "../util/browser.js"

// Read the actual heights of the rendered lines, and update their
// stored heights to match.
export function updateHeightsInViewport(cm) {
  let display = cm.display
  let prevBottom = display.lineDiv.offsetTop
  let viewTop = Math.max(0, display.scroller.getBoundingClientRect().top)
  let oldHeight = display.lineDiv.getBoundingClientRect().top
  let mustScroll = 0
  for (let i = 0; i < display.view.length; i++) {
    let cur = display.view[i], wrapping = cm.options.lineWrapping
    let height, width = 0
    if (cur.hidden) continue
    oldHeight += cur.line.height
    if (ie && ie_version < 8) {
      let bot = cur.node.offsetTop + cur.node.offsetHeight
      height = bot - prevBottom
      prevBottom = bot
    } else {
      let box = cur.node.getBoundingClientRect()
      height = box.bottom - box.top
      // Check that lines don't extend past the right of the current
      // editor width
      if (!wrapping && cur.text.firstChild)
        width = cur.text.firstChild.getBoundingClientRect().right - box.left - 1
    }
    let diff = cur.line.height - height
    if (diff > .005 || diff < -.005) {
      if (oldHeight < viewTop) mustScroll -= diff
      updateLineHeight(cur.line, height)
      updateWidgetHeight(cur.line)
      if (cur.rest) for (let j = 0; j < cur.rest.length; j++)
        updateWidgetHeight(cur.rest[j])
    }
    if (width > cm.display.sizerWidth) {
      let chWidth = Math.ceil(width / charWidth(cm.display))
      if (chWidth > cm.display.maxLineLength) {
        cm.display.maxLineLength = chWidth
        cm.display.maxLine = cur.line
        cm.display.maxLineChanged = true
      }
    }
  }
  if (Math.abs(mustScroll) > 2) display.scroller.scrollTop += mustScroll
}

// Read and store the height of line widgets associated with the
// given line.
function updateWidgetHeight(line) {
  if (line.widgets) for (let i = 0; i < line.widgets.length; ++i) {
    let w = line.widgets[i], parent = w.node.parentNode
    if (parent) w.height = parent.offsetHeight
  }
}

// Compute the lines that are visible in a given viewport (defaults
// the the current scroll position). viewport may contain top,
// height, and ensure (see op.scrollToPos) properties.
export function visibleLines(display, doc, viewport) {
  let top = viewport && viewport.top != null ? Math.max(0, viewport.top) : display.scroller.scrollTop
  top = Math.floor(top - paddingTop(display))
  let bottom = viewport && viewport.bottom != null ? viewport.bottom : top + display.wrapper.clientHeight

  let from = lineAtHeight(doc, top), to = lineAtHeight(doc, bottom)
  // Ensure is a {from: {line, ch}, to: {line, ch}} object, and
  // forces those lines into the viewport (if possible).
  if (viewport && viewport.ensure) {
    let ensureFrom = viewport.ensure.from.line, ensureTo = viewport.ensure.to.line
    if (ensureFrom < from) {
      from = ensureFrom
      to = lineAtHeight(doc, heightAtLine(getLine(doc, ensureFrom)) + display.wrapper.clientHeight)
    } else if (Math.min(ensureTo, doc.lastLine()) >= to) {
      from = lineAtHeight(doc, heightAtLine(getLine(doc, ensureTo)) - display.wrapper.clientHeight)
      to = ensureTo
    }
  }
  return {from: from, to: Math.max(to, from + 1)}
}