save work

static/filemanager/src/display/Display.js

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+import { gecko, ie, ie_version, mobile, webkit } from "../util/browser.js"
+import { elt, eltP } from "../util/dom.js"
+import { scrollerGap } from "../util/misc.js"
+import { getGutters, renderGutters } from "./gutters.js"
+
+// The display handles the DOM integration, both for input reading
+// and content drawing. It holds references to DOM nodes and
+// display-related state.
+
+export function Display(place, doc, input, options) {
+  let d = this
+  this.input = input
+
+  // Covers bottom-right square when both scrollbars are present.
+  d.scrollbarFiller = elt("div", null, "CodeMirror-scrollbar-filler")
+  d.scrollbarFiller.setAttribute("cm-not-content", "true")
+  // Covers bottom of gutter when coverGutterNextToScrollbar is on
+  // and h scrollbar is present.
+  d.gutterFiller = elt("div", null, "CodeMirror-gutter-filler")
+  d.gutterFiller.setAttribute("cm-not-content", "true")
+  // Will contain the actual code, positioned to cover the viewport.
+  d.lineDiv = eltP("div", null, "CodeMirror-code")
+  // Elements are added to these to represent selection and cursors.
+  d.selectionDiv = elt("div", null, null, "position: relative; z-index: 1")
+  d.cursorDiv = elt("div", null, "CodeMirror-cursors")
+  // A visibility: hidden element used to find the size of things.
+  d.measure = elt("div", null, "CodeMirror-measure")
+  // When lines outside of the viewport are measured, they are drawn in this.
+  d.lineMeasure = elt("div", null, "CodeMirror-measure")
+  // Wraps everything that needs to exist inside the vertically-padded coordinate system
+  d.lineSpace = eltP("div", [d.measure, d.lineMeasure, d.selectionDiv, d.cursorDiv, d.lineDiv],
+                    null, "position: relative; outline: none")
+  let lines = eltP("div", [d.lineSpace], "CodeMirror-lines")
+  // Moved around its parent to cover visible view.
+  d.mover = elt("div", [lines], null, "position: relative")
+  // Set to the height of the document, allowing scrolling.
+  d.sizer = elt("div", [d.mover], "CodeMirror-sizer")
+  d.sizerWidth = null
+  // Behavior of elts with overflow: auto and padding is
+  // inconsistent across browsers. This is used to ensure the
+  // scrollable area is big enough.
+  d.heightForcer = elt("div", null, null, "position: absolute; height: " + scrollerGap + "px; width: 1px;")
+  // Will contain the gutters, if any.
+  d.gutters = elt("div", null, "CodeMirror-gutters")
+  d.lineGutter = null
+  // Actual scrollable element.
+  d.scroller = elt("div", [d.sizer, d.heightForcer, d.gutters], "CodeMirror-scroll")
+  d.scroller.setAttribute("tabIndex", "-1")
+  // The element in which the editor lives.
+  d.wrapper = elt("div", [d.scrollbarFiller, d.gutterFiller, d.scroller], "CodeMirror")
+
+  // Work around IE7 z-index bug (not perfect, hence IE7 not really being supported)
+  if (ie && ie_version < 8) { d.gutters.style.zIndex = -1; d.scroller.style.paddingRight = 0 }
+  if (!webkit && !(gecko && mobile)) d.scroller.draggable = true
+
+  if (place) {
+    if (place.appendChild) place.appendChild(d.wrapper)
+    else place(d.wrapper)
+  }
+
+  // Current rendered range (may be bigger than the view window).
+  d.viewFrom = d.viewTo = doc.first
+  d.reportedViewFrom = d.reportedViewTo = doc.first
+  // Information about the rendered lines.
+  d.view = []
+  d.renderedView = null
+  // Holds info about a single rendered line when it was rendered
+  // for measurement, while not in view.
+  d.externalMeasured = null
+  // Empty space (in pixels) above the view
+  d.viewOffset = 0
+  d.lastWrapHeight = d.lastWrapWidth = 0
+  d.updateLineNumbers = null
+
+  d.nativeBarWidth = d.barHeight = d.barWidth = 0
+  d.scrollbarsClipped = false
+
+  // Used to only resize the line number gutter when necessary (when
+  // the amount of lines crosses a boundary that makes its width change)
+  d.lineNumWidth = d.lineNumInnerWidth = d.lineNumChars = null
+  // Set to true when a non-horizontal-scrolling line widget is
+  // added. As an optimization, line widget aligning is skipped when
+  // this is false.
+  d.alignWidgets = false
+
+  d.cachedCharWidth = d.cachedTextHeight = d.cachedPaddingH = null
+
+  // Tracks the maximum line length so that the horizontal scrollbar
+  // can be kept static when scrolling.
+  d.maxLine = null
+  d.maxLineLength = 0
+  d.maxLineChanged = false
+
+  // Used for measuring wheel scrolling granularity
+  d.wheelDX = d.wheelDY = d.wheelStartX = d.wheelStartY = null
+
+  // True when shift is held down.
+  d.shift = false
+
+  // Used to track whether anything happened since the context menu
+  // was opened.
+  d.selForContextMenu = null
+
+  d.activeTouch = null
+
+  d.gutterSpecs = getGutters(options.gutters, options.lineNumbers)
+  renderGutters(d)
+
+  input.init(d)
+}

static/filemanager/src/display/focus.js

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+import { restartBlink } from "./selection.js"
+import { webkit } from "../util/browser.js"
+import { addClass, rmClass } from "../util/dom.js"
+import { signal } from "../util/event.js"
+
+export function ensureFocus(cm) {
+  if (!cm.state.focused) { cm.display.input.focus(); onFocus(cm) }
+}
+
+export function delayBlurEvent(cm) {
+  cm.state.delayingBlurEvent = true
+  setTimeout(() => { if (cm.state.delayingBlurEvent) {
+    cm.state.delayingBlurEvent = false
+    onBlur(cm)
+  } }, 100)
+}
+
+export function onFocus(cm, e) {
+  if (cm.state.delayingBlurEvent) cm.state.delayingBlurEvent = false
+
+  if (cm.options.readOnly == "nocursor") return
+  if (!cm.state.focused) {
+    signal(cm, "focus", cm, e)
+    cm.state.focused = true
+    addClass(cm.display.wrapper, "CodeMirror-focused")
+    // This test prevents this from firing when a context
+    // menu is closed (since the input reset would kill the
+    // select-all detection hack)
+    if (!cm.curOp && cm.display.selForContextMenu != cm.doc.sel) {
+      cm.display.input.reset()
+      if (webkit) setTimeout(() => cm.display.input.reset(true), 20) // Issue #1730
+    }
+    cm.display.input.receivedFocus()
+  }
+  restartBlink(cm)
+}
+export function onBlur(cm, e) {
+  if (cm.state.delayingBlurEvent) return
+
+  if (cm.state.focused) {
+    signal(cm, "blur", cm, e)
+    cm.state.focused = false
+    rmClass(cm.display.wrapper, "CodeMirror-focused")
+  }
+  clearInterval(cm.display.blinker)
+  setTimeout(() => { if (!cm.state.focused) cm.display.shift = false }, 150)
+}

static/filemanager/src/display/gutters.js

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+import { elt, removeChildren } from "../util/dom.js"
+import { regChange } from "./view_tracking.js"
+import { alignHorizontally } from "./line_numbers.js"
+import { updateGutterSpace } from "./update_display.js"
+
+export function getGutters(gutters, lineNumbers) {
+  let result = [], sawLineNumbers = false
+  for (let i = 0; i < gutters.length; i++) {
+    let name = gutters[i], style = null
+    if (typeof name != "string") { style = name.style; name = name.className }
+    if (name == "CodeMirror-linenumbers") {
+      if (!lineNumbers) continue
+      else sawLineNumbers = true
+    }
+    result.push({className: name, style})
+  }
+  if (lineNumbers && !sawLineNumbers) result.push({className: "CodeMirror-linenumbers", style: null})
+  return result
+}
+
+// Rebuild the gutter elements, ensure the margin to the left of the
+// code matches their width.
+export function renderGutters(display) {
+  let gutters = display.gutters, specs = display.gutterSpecs
+  removeChildren(gutters)
+  display.lineGutter = null
+  for (let i = 0; i < specs.length; ++i) {
+    let {className, style} = specs[i]
+    let gElt = gutters.appendChild(elt("div", null, "CodeMirror-gutter " + className))
+    if (style) gElt.style.cssText = style
+    if (className == "CodeMirror-linenumbers") {
+      display.lineGutter = gElt
+      gElt.style.width = (display.lineNumWidth || 1) + "px"
+    }
+  }
+  gutters.style.display = specs.length ? "" : "none"
+  updateGutterSpace(display)
+}
+
+export function updateGutters(cm) {
+  renderGutters(cm.display)
+  regChange(cm)
+  alignHorizontally(cm)
+}

static/filemanager/src/display/highlight_worker.js

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+import { getContextBefore, highlightLine, processLine } from "../line/highlight.js"
+import { copyState } from "../modes.js"
+import { bind } from "../util/misc.js"
+
+import { runInOp } from "./operations.js"
+import { regLineChange } from "./view_tracking.js"
+
+// HIGHLIGHT WORKER
+
+export function startWorker(cm, time) {
+  if (cm.doc.highlightFrontier < cm.display.viewTo)
+    cm.state.highlight.set(time, bind(highlightWorker, cm))
+}
+
+function highlightWorker(cm) {
+  let doc = cm.doc
+  if (doc.highlightFrontier >= cm.display.viewTo) return
+  let end = +new Date + cm.options.workTime
+  let context = getContextBefore(cm, doc.highlightFrontier)
+  let changedLines = []
+
+  doc.iter(context.line, Math.min(doc.first + doc.size, cm.display.viewTo + 500), line => {
+    if (context.line >= cm.display.viewFrom) { // Visible
+      let oldStyles = line.styles
+      let resetState = line.text.length > cm.options.maxHighlightLength ? copyState(doc.mode, context.state) : null
+      let highlighted = highlightLine(cm, line, context, true)
+      if (resetState) context.state = resetState
+      line.styles = highlighted.styles
+      let oldCls = line.styleClasses, newCls = highlighted.classes
+      if (newCls) line.styleClasses = newCls
+      else if (oldCls) line.styleClasses = null
+      let ischange = !oldStyles || oldStyles.length != line.styles.length ||
+        oldCls != newCls && (!oldCls || !newCls || oldCls.bgClass != newCls.bgClass || oldCls.textClass != newCls.textClass)
+      for (let i = 0; !ischange && i < oldStyles.length; ++i) ischange = oldStyles[i] != line.styles[i]
+      if (ischange) changedLines.push(context.line)
+      line.stateAfter = context.save()
+      context.nextLine()
+    } else {
+      if (line.text.length <= cm.options.maxHighlightLength)
+        processLine(cm, line.text, context)
+      line.stateAfter = context.line % 5 == 0 ? context.save() : null
+      context.nextLine()
+    }
+    if (+new Date > end) {
+      startWorker(cm, cm.options.workDelay)
+      return true
+    }
+  })
+  doc.highlightFrontier = context.line
+  doc.modeFrontier = Math.max(doc.modeFrontier, context.line)
+  if (changedLines.length) runInOp(cm, () => {
+    for (let i = 0; i < changedLines.length; i++)
+      regLineChange(cm, changedLines[i], "text")
+  })
+}

static/filemanager/src/display/line_numbers.js

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+import { lineNumberFor } from "../line/utils_line.js"
+import { compensateForHScroll } from "../measurement/position_measurement.js"
+import { elt } from "../util/dom.js"
+
+import { updateGutterSpace } from "./update_display.js"
+
+// Re-align line numbers and gutter marks to compensate for
+// horizontal scrolling.
+export function alignHorizontally(cm) {
+  let display = cm.display, view = display.view
+  if (!display.alignWidgets && (!display.gutters.firstChild || !cm.options.fixedGutter)) return
+  let comp = compensateForHScroll(display) - display.scroller.scrollLeft + cm.doc.scrollLeft
+  let gutterW = display.gutters.offsetWidth, left = comp + "px"
+  for (let i = 0; i < view.length; i++) if (!view[i].hidden) {
+    if (cm.options.fixedGutter) {
+      if (view[i].gutter)
+        view[i].gutter.style.left = left
+      if (view[i].gutterBackground)
+        view[i].gutterBackground.style.left = left
+    }
+    let align = view[i].alignable
+    if (align) for (let j = 0; j < align.length; j++)
+      align[j].style.left = left
+  }
+  if (cm.options.fixedGutter)
+    display.gutters.style.left = (comp + gutterW) + "px"
+}
+
+// Used to ensure that the line number gutter is still the right
+// size for the current document size. Returns true when an update
+// is needed.
+export function maybeUpdateLineNumberWidth(cm) {
+  if (!cm.options.lineNumbers) return false
+  let doc = cm.doc, last = lineNumberFor(cm.options, doc.first + doc.size - 1), display = cm.display
+  if (last.length != display.lineNumChars) {
+    let test = display.measure.appendChild(elt("div", [elt("div", last)],
+                                               "CodeMirror-linenumber CodeMirror-gutter-elt"))
+    let innerW = test.firstChild.offsetWidth, padding = test.offsetWidth - innerW
+    display.lineGutter.style.width = ""
+    display.lineNumInnerWidth = Math.max(innerW, display.lineGutter.offsetWidth - padding) + 1
+    display.lineNumWidth = display.lineNumInnerWidth + padding
+    display.lineNumChars = display.lineNumInnerWidth ? last.length : -1
+    display.lineGutter.style.width = display.lineNumWidth + "px"
+    updateGutterSpace(cm.display)
+    return true
+  }
+  return false
+}

static/filemanager/src/display/mode_state.js

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+import { getMode } from "../modes.js"
+
+import { startWorker } from "./highlight_worker.js"
+import { regChange } from "./view_tracking.js"
+
+// Used to get the editor into a consistent state again when options change.
+
+export function loadMode(cm) {
+  cm.doc.mode = getMode(cm.options, cm.doc.modeOption)
+  resetModeState(cm)
+}
+
+export function resetModeState(cm) {
+  cm.doc.iter(line => {
+    if (line.stateAfter) line.stateAfter = null
+    if (line.styles) line.styles = null
+  })
+  cm.doc.modeFrontier = cm.doc.highlightFrontier = cm.doc.first
+  startWorker(cm, 100)
+  cm.state.modeGen++
+  if (cm.curOp) regChange(cm)
+}

static/filemanager/src/display/operations.js

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+import { clipPos } from "../line/pos.js"
+import { findMaxLine } from "../line/spans.js"
+import { displayWidth, measureChar, scrollGap } from "../measurement/position_measurement.js"
+import { signal } from "../util/event.js"
+import { activeElt } from "../util/dom.js"
+import { finishOperation, pushOperation } from "../util/operation_group.js"
+
+import { ensureFocus } from "./focus.js"
+import { measureForScrollbars, updateScrollbars } from "./scrollbars.js"
+import { restartBlink } from "./selection.js"
+import { maybeScrollWindow, scrollPosIntoView, setScrollLeft, setScrollTop } from "./scrolling.js"
+import { DisplayUpdate, maybeClipScrollbars, postUpdateDisplay, setDocumentHeight, updateDisplayIfNeeded } from "./update_display.js"
+import { updateHeightsInViewport } from "./update_lines.js"
+
+// Operations are used to wrap a series of changes to the editor
+// state in such a way that each change won't have to update the
+// cursor and display (which would be awkward, slow, and
+// error-prone). Instead, display updates are batched and then all
+// combined and executed at once.
+
+let nextOpId = 0
+// Start a new operation.
+export function startOperation(cm) {
+  cm.curOp = {
+    cm: cm,
+    viewChanged: false,      // Flag that indicates that lines might need to be redrawn
+    startHeight: cm.doc.height, // Used to detect need to update scrollbar
+    forceUpdate: false,      // Used to force a redraw
+    updateInput: 0,       // Whether to reset the input textarea
+    typing: false,           // Whether this reset should be careful to leave existing text (for compositing)
+    changeObjs: null,        // Accumulated changes, for firing change events
+    cursorActivityHandlers: null, // Set of handlers to fire cursorActivity on
+    cursorActivityCalled: 0, // Tracks which cursorActivity handlers have been called already
+    selectionChanged: false, // Whether the selection needs to be redrawn
+    updateMaxLine: false,    // Set when the widest line needs to be determined anew
+    scrollLeft: null, scrollTop: null, // Intermediate scroll position, not pushed to DOM yet
+    scrollToPos: null,       // Used to scroll to a specific position
+    focus: false,
+    id: ++nextOpId           // Unique ID
+  }
+  pushOperation(cm.curOp)
+}
+
+// Finish an operation, updating the display and signalling delayed events
+export function endOperation(cm) {
+  let op = cm.curOp
+  if (op) finishOperation(op, group => {
+    for (let i = 0; i < group.ops.length; i++)
+      group.ops[i].cm.curOp = null
+    endOperations(group)
+  })
+}
+
+// The DOM updates done when an operation finishes are batched so
+// that the minimum number of relayouts are required.
+function endOperations(group) {
+  let ops = group.ops
+  for (let i = 0; i < ops.length; i++) // Read DOM
+    endOperation_R1(ops[i])
+  for (let i = 0; i < ops.length; i++) // Write DOM (maybe)
+    endOperation_W1(ops[i])
+  for (let i = 0; i < ops.length; i++) // Read DOM
+    endOperation_R2(ops[i])
+  for (let i = 0; i < ops.length; i++) // Write DOM (maybe)
+    endOperation_W2(ops[i])
+  for (let i = 0; i < ops.length; i++) // Read DOM
+    endOperation_finish(ops[i])
+}
+
+function endOperation_R1(op) {
+  let cm = op.cm, display = cm.display
+  maybeClipScrollbars(cm)
+  if (op.updateMaxLine) findMaxLine(cm)
+
+  op.mustUpdate = op.viewChanged || op.forceUpdate || op.scrollTop != null ||
+    op.scrollToPos && (op.scrollToPos.from.line < display.viewFrom ||
+                       op.scrollToPos.to.line >= display.viewTo) ||
+    display.maxLineChanged && cm.options.lineWrapping
+  op.update = op.mustUpdate &&
+    new DisplayUpdate(cm, op.mustUpdate && {top: op.scrollTop, ensure: op.scrollToPos}, op.forceUpdate)
+}
+
+function endOperation_W1(op) {
+  op.updatedDisplay = op.mustUpdate && updateDisplayIfNeeded(op.cm, op.update)
+}
+
+function endOperation_R2(op) {
+  let cm = op.cm, display = cm.display
+  if (op.updatedDisplay) updateHeightsInViewport(cm)
+
+  op.barMeasure = measureForScrollbars(cm)
+
+  // If the max line changed since it was last measured, measure it,
+  // and ensure the document's width matches it.
+  // updateDisplay_W2 will use these properties to do the actual resizing
+  if (display.maxLineChanged && !cm.options.lineWrapping) {
+    op.adjustWidthTo = measureChar(cm, display.maxLine, display.maxLine.text.length).left + 3
+    cm.display.sizerWidth = op.adjustWidthTo
+    op.barMeasure.scrollWidth =
+      Math.max(display.scroller.clientWidth, display.sizer.offsetLeft + op.adjustWidthTo + scrollGap(cm) + cm.display.barWidth)
+    op.maxScrollLeft = Math.max(0, display.sizer.offsetLeft + op.adjustWidthTo - displayWidth(cm))
+  }
+
+  if (op.updatedDisplay || op.selectionChanged)
+    op.preparedSelection = display.input.prepareSelection()
+}
+
+function endOperation_W2(op) {
+  let cm = op.cm
+
+  if (op.adjustWidthTo != null) {
+    cm.display.sizer.style.minWidth = op.adjustWidthTo + "px"
+    if (op.maxScrollLeft < cm.doc.scrollLeft)
+      setScrollLeft(cm, Math.min(cm.display.scroller.scrollLeft, op.maxScrollLeft), true)
+    cm.display.maxLineChanged = false
+  }
+
+  let takeFocus = op.focus && op.focus == activeElt()
+  if (op.preparedSelection)
+    cm.display.input.showSelection(op.preparedSelection, takeFocus)
+  if (op.updatedDisplay || op.startHeight != cm.doc.height)
+    updateScrollbars(cm, op.barMeasure)
+  if (op.updatedDisplay)
+    setDocumentHeight(cm, op.barMeasure)
+
+  if (op.selectionChanged) restartBlink(cm)
+
+  if (cm.state.focused && op.updateInput)
+    cm.display.input.reset(op.typing)
+  if (takeFocus) ensureFocus(op.cm)
+}
+
+function endOperation_finish(op) {
+  let cm = op.cm, display = cm.display, doc = cm.doc
+
+  if (op.updatedDisplay) postUpdateDisplay(cm, op.update)
+
+  // Abort mouse wheel delta measurement, when scrolling explicitly
+  if (display.wheelStartX != null && (op.scrollTop != null || op.scrollLeft != null || op.scrollToPos))
+    display.wheelStartX = display.wheelStartY = null
+
+  // Propagate the scroll position to the actual DOM scroller
+  if (op.scrollTop != null) setScrollTop(cm, op.scrollTop, op.forceScroll)
+
+  if (op.scrollLeft != null) setScrollLeft(cm, op.scrollLeft, true, true)
+  // If we need to scroll a specific position into view, do so.
+  if (op.scrollToPos) {
+    let rect = scrollPosIntoView(cm, clipPos(doc, op.scrollToPos.from),
+                                 clipPos(doc, op.scrollToPos.to), op.scrollToPos.margin)
+    maybeScrollWindow(cm, rect)
+  }
+
+  // Fire events for markers that are hidden/unidden by editing or
+  // undoing
+  let hidden = op.maybeHiddenMarkers, unhidden = op.maybeUnhiddenMarkers
+  if (hidden) for (let i = 0; i < hidden.length; ++i)
+    if (!hidden[i].lines.length) signal(hidden[i], "hide")
+  if (unhidden) for (let i = 0; i < unhidden.length; ++i)
+    if (unhidden[i].lines.length) signal(unhidden[i], "unhide")
+
+  if (display.wrapper.offsetHeight)
+    doc.scrollTop = cm.display.scroller.scrollTop
+
+  // Fire change events, and delayed event handlers
+  if (op.changeObjs)
+    signal(cm, "changes", cm, op.changeObjs)
+  if (op.update)
+    op.update.finish()
+}
+
+// Run the given function in an operation
+export function runInOp(cm, f) {
+  if (cm.curOp) return f()
+  startOperation(cm)
+  try { return f() }
+  finally { endOperation(cm) }
+}
+// Wraps a function in an operation. Returns the wrapped function.
+export function operation(cm, f) {
+  return function() {
+    if (cm.curOp) return f.apply(cm, arguments)
+    startOperation(cm)
+    try { return f.apply(cm, arguments) }
+    finally { endOperation(cm) }
+  }
+}
+// Used to add methods to editor and doc instances, wrapping them in
+// operations.
+export function methodOp(f) {
+  return function() {
+    if (this.curOp) return f.apply(this, arguments)
+    startOperation(this)
+    try { return f.apply(this, arguments) }
+    finally { endOperation(this) }
+  }
+}
+export function docMethodOp(f) {
+  return function() {
+    let cm = this.cm
+    if (!cm || cm.curOp) return f.apply(this, arguments)
+    startOperation(cm)
+    try { return f.apply(this, arguments) }
+    finally { endOperation(cm) }
+  }
+}

static/filemanager/src/display/scroll_events.js

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+import { chrome, gecko, ie, mac, presto, safari, webkit } from "../util/browser.js"
+import { e_preventDefault } from "../util/event.js"
+
+import { updateDisplaySimple } from "./update_display.js"
+import { setScrollLeft, updateScrollTop } from "./scrolling.js"
+
+// Since the delta values reported on mouse wheel events are
+// unstandardized between browsers and even browser versions, and
+// generally horribly unpredictable, this code starts by measuring
+// the scroll effect that the first few mouse wheel events have,
+// and, from that, detects the way it can convert deltas to pixel
+// offsets afterwards.
+//
+// The reason we want to know the amount a wheel event will scroll
+// is that it gives us a chance to update the display before the
+// actual scrolling happens, reducing flickering.
+
+let wheelSamples = 0, wheelPixelsPerUnit = null
+// Fill in a browser-detected starting value on browsers where we
+// know one. These don't have to be accurate -- the result of them
+// being wrong would just be a slight flicker on the first wheel
+// scroll (if it is large enough).
+if (ie) wheelPixelsPerUnit = -.53
+else if (gecko) wheelPixelsPerUnit = 15
+else if (chrome) wheelPixelsPerUnit = -.7
+else if (safari) wheelPixelsPerUnit = -1/3
+
+function wheelEventDelta(e) {
+  let dx = e.wheelDeltaX, dy = e.wheelDeltaY
+  if (dx == null && e.detail && e.axis == e.HORIZONTAL_AXIS) dx = e.detail
+  if (dy == null && e.detail && e.axis == e.VERTICAL_AXIS) dy = e.detail
+  else if (dy == null) dy = e.wheelDelta
+  return {x: dx, y: dy}
+}
+export function wheelEventPixels(e) {
+  let delta = wheelEventDelta(e)
+  delta.x *= wheelPixelsPerUnit
+  delta.y *= wheelPixelsPerUnit
+  return delta
+}
+
+export function onScrollWheel(cm, e) {
+  let delta = wheelEventDelta(e), dx = delta.x, dy = delta.y
+
+  let display = cm.display, scroll = display.scroller
+  // Quit if there's nothing to scroll here
+  let canScrollX = scroll.scrollWidth > scroll.clientWidth
+  let canScrollY = scroll.scrollHeight > scroll.clientHeight
+  if (!(dx && canScrollX || dy && canScrollY)) return
+
+  // Webkit browsers on OS X abort momentum scrolls when the target
+  // of the scroll event is removed from the scrollable element.
+  // This hack (see related code in patchDisplay) makes sure the
+  // element is kept around.
+  if (dy && mac && webkit) {
+    outer: for (let cur = e.target, view = display.view; cur != scroll; cur = cur.parentNode) {
+      for (let i = 0; i < view.length; i++) {
+        if (view[i].node == cur) {
+          cm.display.currentWheelTarget = cur
+          break outer
+        }
+      }
+    }
+  }
+
+  // On some browsers, horizontal scrolling will cause redraws to
+  // happen before the gutter has been realigned, causing it to
+  // wriggle around in a most unseemly way. When we have an
+  // estimated pixels/delta value, we just handle horizontal
+  // scrolling entirely here. It'll be slightly off from native, but
+  // better than glitching out.
+  if (dx && !gecko && !presto && wheelPixelsPerUnit != null) {
+    if (dy && canScrollY)
+      updateScrollTop(cm, Math.max(0, scroll.scrollTop + dy * wheelPixelsPerUnit))
+    setScrollLeft(cm, Math.max(0, scroll.scrollLeft + dx * wheelPixelsPerUnit))
+    // Only prevent default scrolling if vertical scrolling is
+    // actually possible. Otherwise, it causes vertical scroll
+    // jitter on OSX trackpads when deltaX is small and deltaY
+    // is large (issue #3579)
+    if (!dy || (dy && canScrollY))
+      e_preventDefault(e)
+    display.wheelStartX = null // Abort measurement, if in progress
+    return
+  }
+
+  // 'Project' the visible viewport to cover the area that is being
+  // scrolled into view (if we know enough to estimate it).
+  if (dy && wheelPixelsPerUnit != null) {
+    let pixels = dy * wheelPixelsPerUnit
+    let top = cm.doc.scrollTop, bot = top + display.wrapper.clientHeight
+    if (pixels < 0) top = Math.max(0, top + pixels - 50)
+    else bot = Math.min(cm.doc.height, bot + pixels + 50)
+    updateDisplaySimple(cm, {top: top, bottom: bot})
+  }
+
+  if (wheelSamples < 20) {
+    if (display.wheelStartX == null) {
+      display.wheelStartX = scroll.scrollLeft; display.wheelStartY = scroll.scrollTop
+      display.wheelDX = dx; display.wheelDY = dy
+      setTimeout(() => {
+        if (display.wheelStartX == null) return
+        let movedX = scroll.scrollLeft - display.wheelStartX
+        let movedY = scroll.scrollTop - display.wheelStartY
+        let sample = (movedY && display.wheelDY && movedY / display.wheelDY) ||
+          (movedX && display.wheelDX && movedX / display.wheelDX)
+        display.wheelStartX = display.wheelStartY = null
+        if (!sample) return
+        wheelPixelsPerUnit = (wheelPixelsPerUnit * wheelSamples + sample) / (wheelSamples + 1)
+        ++wheelSamples
+      }, 200)
+    } else {
+      display.wheelDX += dx; display.wheelDY += dy
+    }
+  }
+}

static/filemanager/src/display/scrollbars.js

@@ -0,0 +1,193 @@
+import { addClass, elt, rmClass } from "../util/dom.js"
+import { on } from "../util/event.js"
+import { scrollGap, paddingVert } from "../measurement/position_measurement.js"
+import { ie, ie_version, mac, mac_geMountainLion } from "../util/browser.js"
+import { updateHeightsInViewport } from "./update_lines.js"
+import { Delayed } from "../util/misc.js"
+
+import { setScrollLeft, updateScrollTop } from "./scrolling.js"
+
+// SCROLLBARS
+
+// Prepare DOM reads needed to update the scrollbars. Done in one
+// shot to minimize update/measure roundtrips.
+export function measureForScrollbars(cm) {
+  let d = cm.display, gutterW = d.gutters.offsetWidth
+  let docH = Math.round(cm.doc.height + paddingVert(cm.display))
+  return {
+    clientHeight: d.scroller.clientHeight,
+    viewHeight: d.wrapper.clientHeight,
+    scrollWidth: d.scroller.scrollWidth, clientWidth: d.scroller.clientWidth,
+    viewWidth: d.wrapper.clientWidth,
+    barLeft: cm.options.fixedGutter ? gutterW : 0,
+    docHeight: docH,
+    scrollHeight: docH + scrollGap(cm) + d.barHeight,
+    nativeBarWidth: d.nativeBarWidth,
+    gutterWidth: gutterW
+  }
+}
+
+class NativeScrollbars {
+  constructor(place, scroll, cm) {
+    this.cm = cm
+    let vert = this.vert = elt("div", [elt("div", null, null, "min-width: 1px")], "CodeMirror-vscrollbar")
+    let horiz = this.horiz = elt("div", [elt("div", null, null, "height: 100%; min-height: 1px")], "CodeMirror-hscrollbar")
+    vert.tabIndex = horiz.tabIndex = -1
+    place(vert); place(horiz)
+
+    on(vert, "scroll", () => {
+      if (vert.clientHeight) scroll(vert.scrollTop, "vertical")
+    })
+    on(horiz, "scroll", () => {
+      if (horiz.clientWidth) scroll(horiz.scrollLeft, "horizontal")
+    })
+
+    this.checkedZeroWidth = false
+    // Need to set a minimum width to see the scrollbar on IE7 (but must not set it on IE8).
+    if (ie && ie_version < 8) this.horiz.style.minHeight = this.vert.style.minWidth = "18px"
+  }
+
+  update(measure) {
+    let needsH = measure.scrollWidth > measure.clientWidth + 1
+    let needsV = measure.scrollHeight > measure.clientHeight + 1
+    let sWidth = measure.nativeBarWidth
+
+    if (needsV) {
+      this.vert.style.display = "block"
+      this.vert.style.bottom = needsH ? sWidth + "px" : "0"
+      let totalHeight = measure.viewHeight - (needsH ? sWidth : 0)
+      // A bug in IE8 can cause this value to be negative, so guard it.
+      this.vert.firstChild.style.height =
+        Math.max(0, measure.scrollHeight - measure.clientHeight + totalHeight) + "px"
+    } else {
+      this.vert.style.display = ""
+      this.vert.firstChild.style.height = "0"
+    }
+
+    if (needsH) {
+      this.horiz.style.display = "block"
+      this.horiz.style.right = needsV ? sWidth + "px" : "0"
+      this.horiz.style.left = measure.barLeft + "px"
+      let totalWidth = measure.viewWidth - measure.barLeft - (needsV ? sWidth : 0)
+      this.horiz.firstChild.style.width =
+        Math.max(0, measure.scrollWidth - measure.clientWidth + totalWidth) + "px"
+    } else {
+      this.horiz.style.display = ""
+      this.horiz.firstChild.style.width = "0"
+    }
+
+    if (!this.checkedZeroWidth && measure.clientHeight > 0) {
+      if (sWidth == 0) this.zeroWidthHack()
+      this.checkedZeroWidth = true
+    }
+
+    return {right: needsV ? sWidth : 0, bottom: needsH ? sWidth : 0}
+  }
+
+  setScrollLeft(pos) {
+    if (this.horiz.scrollLeft != pos) this.horiz.scrollLeft = pos
+    if (this.disableHoriz) this.enableZeroWidthBar(this.horiz, this.disableHoriz, "horiz")
+  }
+
+  setScrollTop(pos) {
+    if (this.vert.scrollTop != pos) this.vert.scrollTop = pos
+    if (this.disableVert) this.enableZeroWidthBar(this.vert, this.disableVert, "vert")
+  }
+
+  zeroWidthHack() {
+    let w = mac && !mac_geMountainLion ? "12px" : "18px"
+    this.horiz.style.height = this.vert.style.width = w
+    this.horiz.style.pointerEvents = this.vert.style.pointerEvents = "none"
+    this.disableHoriz = new Delayed
+    this.disableVert = new Delayed
+  }
+
+  enableZeroWidthBar(bar, delay, type) {
+    bar.style.pointerEvents = "auto"
+    function maybeDisable() {
+      // To find out whether the scrollbar is still visible, we
+      // check whether the element under the pixel in the bottom
+      // right corner of the scrollbar box is the scrollbar box
+      // itself (when the bar is still visible) or its filler child
+      // (when the bar is hidden). If it is still visible, we keep
+      // it enabled, if it's hidden, we disable pointer events.
+      let box = bar.getBoundingClientRect()
+      let elt = type == "vert" ? document.elementFromPoint(box.right - 1, (box.top + box.bottom) / 2)
+          : document.elementFromPoint((box.right + box.left) / 2, box.bottom - 1)
+      if (elt != bar) bar.style.pointerEvents = "none"
+      else delay.set(1000, maybeDisable)
+    }
+    delay.set(1000, maybeDisable)
+  }
+
+  clear() {
+    let parent = this.horiz.parentNode
+    parent.removeChild(this.horiz)
+    parent.removeChild(this.vert)
+  }
+}
+
+class NullScrollbars {
+  update() { return {bottom: 0, right: 0} }
+  setScrollLeft() {}
+  setScrollTop() {}
+  clear() {}
+}
+
+export function updateScrollbars(cm, measure) {
+  if (!measure) measure = measureForScrollbars(cm)
+  let startWidth = cm.display.barWidth, startHeight = cm.display.barHeight
+  updateScrollbarsInner(cm, measure)
+  for (let i = 0; i < 4 && startWidth != cm.display.barWidth || startHeight != cm.display.barHeight; i++) {
+    if (startWidth != cm.display.barWidth && cm.options.lineWrapping)
+      updateHeightsInViewport(cm)
+    updateScrollbarsInner(cm, measureForScrollbars(cm))
+    startWidth = cm.display.barWidth; startHeight = cm.display.barHeight
+  }
+}
+
+// Re-synchronize the fake scrollbars with the actual size of the
+// content.
+function updateScrollbarsInner(cm, measure) {
+  let d = cm.display
+  let sizes = d.scrollbars.update(measure)
+
+  d.sizer.style.paddingRight = (d.barWidth = sizes.right) + "px"
+  d.sizer.style.paddingBottom = (d.barHeight = sizes.bottom) + "px"
+  d.heightForcer.style.borderBottom = sizes.bottom + "px solid transparent"
+
+  if (sizes.right && sizes.bottom) {
+    d.scrollbarFiller.style.display = "block"
+    d.scrollbarFiller.style.height = sizes.bottom + "px"
+    d.scrollbarFiller.style.width = sizes.right + "px"
+  } else d.scrollbarFiller.style.display = ""
+  if (sizes.bottom && cm.options.coverGutterNextToScrollbar && cm.options.fixedGutter) {
+    d.gutterFiller.style.display = "block"
+    d.gutterFiller.style.height = sizes.bottom + "px"
+    d.gutterFiller.style.width = measure.gutterWidth + "px"
+  } else d.gutterFiller.style.display = ""
+}
+
+export let scrollbarModel = {"native": NativeScrollbars, "null": NullScrollbars}
+
+export function initScrollbars(cm) {
+  if (cm.display.scrollbars) {
+    cm.display.scrollbars.clear()
+    if (cm.display.scrollbars.addClass)
+      rmClass(cm.display.wrapper, cm.display.scrollbars.addClass)
+  }
+
+  cm.display.scrollbars = new scrollbarModel[cm.options.scrollbarStyle](node => {
+    cm.display.wrapper.insertBefore(node, cm.display.scrollbarFiller)
+    // Prevent clicks in the scrollbars from killing focus
+    on(node, "mousedown", () => {
+      if (cm.state.focused) setTimeout(() => cm.display.input.focus(), 0)
+    })
+    node.setAttribute("cm-not-content", "true")
+  }, (pos, axis) => {
+    if (axis == "horizontal") setScrollLeft(cm, pos)
+    else updateScrollTop(cm, pos)
+  }, cm)
+  if (cm.display.scrollbars.addClass)
+    addClass(cm.display.wrapper, cm.display.scrollbars.addClass)
+}

static/filemanager/src/display/scrolling.js

@@ -0,0 +1,185 @@
+import { Pos } from "../line/pos.js"
+import { cursorCoords, displayHeight, displayWidth, estimateCoords, paddingTop, paddingVert, scrollGap, textHeight } from "../measurement/position_measurement.js"
+import { gecko, phantom } from "../util/browser.js"
+import { elt } from "../util/dom.js"
+import { signalDOMEvent } from "../util/event.js"
+
+import { startWorker } from "./highlight_worker.js"
+import { alignHorizontally } from "./line_numbers.js"
+import { updateDisplaySimple } from "./update_display.js"
+
+// SCROLLING THINGS INTO VIEW
+
+// If an editor sits on the top or bottom of the window, partially
+// scrolled out of view, this ensures that the cursor is visible.
+export function maybeScrollWindow(cm, rect) {
+  if (signalDOMEvent(cm, "scrollCursorIntoView")) return
+
+  let display = cm.display, box = display.sizer.getBoundingClientRect(), doScroll = null
+  if (rect.top + box.top < 0) doScroll = true
+  else if (rect.bottom + box.top > (window.innerHeight || document.documentElement.clientHeight)) doScroll = false
+  if (doScroll != null && !phantom) {
+    let scrollNode = elt("div", "\u200b", null, `position: absolute;
+                         top: ${rect.top - display.viewOffset - paddingTop(cm.display)}px;
+                         height: ${rect.bottom - rect.top + scrollGap(cm) + display.barHeight}px;
+                         left: ${rect.left}px; width: ${Math.max(2, rect.right - rect.left)}px;`)
+    cm.display.lineSpace.appendChild(scrollNode)
+    scrollNode.scrollIntoView(doScroll)
+    cm.display.lineSpace.removeChild(scrollNode)
+  }
+}
+
+// Scroll a given position into view (immediately), verifying that
+// it actually became visible (as line heights are accurately
+// measured, the position of something may 'drift' during drawing).
+export function scrollPosIntoView(cm, pos, end, margin) {
+  if (margin == null) margin = 0
+  let rect
+  if (!cm.options.lineWrapping && pos == end) {
+    // Set pos and end to the cursor positions around the character pos sticks to
+    // If pos.sticky == "before", that is around pos.ch - 1, otherwise around pos.ch
+    // If pos == Pos(_, 0, "before"), pos and end are unchanged
+    pos = pos.ch ? Pos(pos.line, pos.sticky == "before" ? pos.ch - 1 : pos.ch, "after") : pos
+    end = pos.sticky == "before" ? Pos(pos.line, pos.ch + 1, "before") : pos
+  }
+  for (let limit = 0; limit < 5; limit++) {
+    let changed = false
+    let coords = cursorCoords(cm, pos)
+    let endCoords = !end || end == pos ? coords : cursorCoords(cm, end)
+    rect = {left: Math.min(coords.left, endCoords.left),
+            top: Math.min(coords.top, endCoords.top) - margin,
+            right: Math.max(coords.left, endCoords.left),
+            bottom: Math.max(coords.bottom, endCoords.bottom) + margin}
+    let scrollPos = calculateScrollPos(cm, rect)
+    let startTop = cm.doc.scrollTop, startLeft = cm.doc.scrollLeft
+    if (scrollPos.scrollTop != null) {
+      updateScrollTop(cm, scrollPos.scrollTop)
+      if (Math.abs(cm.doc.scrollTop - startTop) > 1) changed = true
+    }
+    if (scrollPos.scrollLeft != null) {
+      setScrollLeft(cm, scrollPos.scrollLeft)
+      if (Math.abs(cm.doc.scrollLeft - startLeft) > 1) changed = true
+    }
+    if (!changed) break
+  }
+  return rect
+}
+
+// Scroll a given set of coordinates into view (immediately).
+export function scrollIntoView(cm, rect) {
+  let scrollPos = calculateScrollPos(cm, rect)
+  if (scrollPos.scrollTop != null) updateScrollTop(cm, scrollPos.scrollTop)
+  if (scrollPos.scrollLeft != null) setScrollLeft(cm, scrollPos.scrollLeft)
+}
+
+// Calculate a new scroll position needed to scroll the given
+// rectangle into view. Returns an object with scrollTop and
+// scrollLeft properties. When these are undefined, the
+// vertical/horizontal position does not need to be adjusted.
+function calculateScrollPos(cm, rect) {
+  let display = cm.display, snapMargin = textHeight(cm.display)
+  if (rect.top < 0) rect.top = 0
+  let screentop = cm.curOp && cm.curOp.scrollTop != null ? cm.curOp.scrollTop : display.scroller.scrollTop
+  let screen = displayHeight(cm), result = {}
+  if (rect.bottom - rect.top > screen) rect.bottom = rect.top + screen
+  let docBottom = cm.doc.height + paddingVert(display)
+  let atTop = rect.top < snapMargin, atBottom = rect.bottom > docBottom - snapMargin
+  if (rect.top < screentop) {
+    result.scrollTop = atTop ? 0 : rect.top
+  } else if (rect.bottom > screentop + screen) {
+    let newTop = Math.min(rect.top, (atBottom ? docBottom : rect.bottom) - screen)
+    if (newTop != screentop) result.scrollTop = newTop
+  }
+
+  let gutterSpace = cm.options.fixedGutter ? 0 : display.gutters.offsetWidth
+  let screenleft = cm.curOp && cm.curOp.scrollLeft != null ? cm.curOp.scrollLeft : display.scroller.scrollLeft - gutterSpace
+  let screenw = displayWidth(cm) - display.gutters.offsetWidth
+  let tooWide = rect.right - rect.left > screenw
+  if (tooWide) rect.right = rect.left + screenw
+  if (rect.left < 10)
+    result.scrollLeft = 0
+  else if (rect.left < screenleft)
+    result.scrollLeft = Math.max(0, rect.left + gutterSpace - (tooWide ? 0 : 10))
+  else if (rect.right > screenw + screenleft - 3)
+    result.scrollLeft = rect.right + (tooWide ? 0 : 10) - screenw
+  return result
+}
+
+// Store a relative adjustment to the scroll position in the current
+// operation (to be applied when the operation finishes).
+export function addToScrollTop(cm, top) {
+  if (top == null) return
+  resolveScrollToPos(cm)
+  cm.curOp.scrollTop = (cm.curOp.scrollTop == null ? cm.doc.scrollTop : cm.curOp.scrollTop) + top
+}
+
+// Make sure that at the end of the operation the current cursor is
+// shown.
+export function ensureCursorVisible(cm) {
+  resolveScrollToPos(cm)
+  let cur = cm.getCursor()
+  cm.curOp.scrollToPos = {from: cur, to: cur, margin: cm.options.cursorScrollMargin}
+}
+
+export function scrollToCoords(cm, x, y) {
+  if (x != null || y != null) resolveScrollToPos(cm)
+  if (x != null) cm.curOp.scrollLeft = x
+  if (y != null) cm.curOp.scrollTop = y
+}
+
+export function scrollToRange(cm, range) {
+  resolveScrollToPos(cm)
+  cm.curOp.scrollToPos = range
+}
+
+// When an operation has its scrollToPos property set, and another
+// scroll action is applied before the end of the operation, this
+// 'simulates' scrolling that position into view in a cheap way, so
+// that the effect of intermediate scroll commands is not ignored.
+function resolveScrollToPos(cm) {
+  let range = cm.curOp.scrollToPos
+  if (range) {
+    cm.curOp.scrollToPos = null
+    let from = estimateCoords(cm, range.from), to = estimateCoords(cm, range.to)
+    scrollToCoordsRange(cm, from, to, range.margin)
+  }
+}
+
+export function scrollToCoordsRange(cm, from, to, margin) {
+  let sPos = calculateScrollPos(cm, {
+    left: Math.min(from.left, to.left),
+    top: Math.min(from.top, to.top) - margin,
+    right: Math.max(from.right, to.right),
+    bottom: Math.max(from.bottom, to.bottom) + margin
+  })
+  scrollToCoords(cm, sPos.scrollLeft, sPos.scrollTop)
+}
+
+// Sync the scrollable area and scrollbars, ensure the viewport
+// covers the visible area.
+export function updateScrollTop(cm, val) {
+  if (Math.abs(cm.doc.scrollTop - val) < 2) return
+  if (!gecko) updateDisplaySimple(cm, {top: val})
+  setScrollTop(cm, val, true)
+  if (gecko) updateDisplaySimple(cm)
+  startWorker(cm, 100)
+}
+
+export function setScrollTop(cm, val, forceScroll) {
+  val = Math.max(0, Math.min(cm.display.scroller.scrollHeight - cm.display.scroller.clientHeight, val))
+  if (cm.display.scroller.scrollTop == val && !forceScroll) return
+  cm.doc.scrollTop = val
+  cm.display.scrollbars.setScrollTop(val)
+  if (cm.display.scroller.scrollTop != val) cm.display.scroller.scrollTop = val
+}
+
+// Sync scroller and scrollbar, ensure the gutter elements are
+// aligned.
+export function setScrollLeft(cm, val, isScroller, forceScroll) {
+  val = Math.max(0, Math.min(val, cm.display.scroller.scrollWidth - cm.display.scroller.clientWidth))
+  if ((isScroller ? val == cm.doc.scrollLeft : Math.abs(cm.doc.scrollLeft - val) < 2) && !forceScroll) return
+  cm.doc.scrollLeft = val
+  alignHorizontally(cm)
+  if (cm.display.scroller.scrollLeft != val) cm.display.scroller.scrollLeft = val
+  cm.display.scrollbars.setScrollLeft(val)
+}

static/filemanager/src/display/selection.js

@@ -0,0 +1,161 @@
+import { Pos } from "../line/pos.js"
+import { visualLine } from "../line/spans.js"
+import { getLine } from "../line/utils_line.js"
+import { charCoords, cursorCoords, displayWidth, paddingH, wrappedLineExtentChar } from "../measurement/position_measurement.js"
+import { getOrder, iterateBidiSections } from "../util/bidi.js"
+import { elt } from "../util/dom.js"
+import { onBlur } from "./focus.js"
+
+export function updateSelection(cm) {
+  cm.display.input.showSelection(cm.display.input.prepareSelection())
+}
+
+export function prepareSelection(cm, primary = true) {
+  let doc = cm.doc, result = {}
+  let curFragment = result.cursors = document.createDocumentFragment()
+  let selFragment = result.selection = document.createDocumentFragment()
+
+  for (let i = 0; i < doc.sel.ranges.length; i++) {
+    if (!primary && i == doc.sel.primIndex) continue
+    let range = doc.sel.ranges[i]
+    if (range.from().line >= cm.display.viewTo || range.to().line < cm.display.viewFrom) continue
+    let collapsed = range.empty()
+    if (collapsed || cm.options.showCursorWhenSelecting)
+      drawSelectionCursor(cm, range.head, curFragment)
+    if (!collapsed)
+      drawSelectionRange(cm, range, selFragment)
+  }
+  return result
+}
+
+// Draws a cursor for the given range
+export function drawSelectionCursor(cm, head, output) {
+  let pos = cursorCoords(cm, head, "div", null, null, !cm.options.singleCursorHeightPerLine)
+
+  let cursor = output.appendChild(elt("div", "\u00a0", "CodeMirror-cursor"))
+  cursor.style.left = pos.left + "px"
+  cursor.style.top = pos.top + "px"
+  cursor.style.height = Math.max(0, pos.bottom - pos.top) * cm.options.cursorHeight + "px"
+
+  if (pos.other) {
+    // Secondary cursor, shown when on a 'jump' in bi-directional text
+    let otherCursor = output.appendChild(elt("div", "\u00a0", "CodeMirror-cursor CodeMirror-secondarycursor"))
+    otherCursor.style.display = ""
+    otherCursor.style.left = pos.other.left + "px"
+    otherCursor.style.top = pos.other.top + "px"
+    otherCursor.style.height = (pos.other.bottom - pos.other.top) * .85 + "px"
+  }
+}
+
+function cmpCoords(a, b) { return a.top - b.top || a.left - b.left }
+
+// Draws the given range as a highlighted selection
+function drawSelectionRange(cm, range, output) {
+  let display = cm.display, doc = cm.doc
+  let fragment = document.createDocumentFragment()
+  let padding = paddingH(cm.display), leftSide = padding.left
+  let rightSide = Math.max(display.sizerWidth, displayWidth(cm) - display.sizer.offsetLeft) - padding.right
+  let docLTR = doc.direction == "ltr"
+
+  function add(left, top, width, bottom) {
+    if (top < 0) top = 0
+    top = Math.round(top)
+    bottom = Math.round(bottom)
+    fragment.appendChild(elt("div", null, "CodeMirror-selected", `position: absolute; left: ${left}px;
+                             top: ${top}px; width: ${width == null ? rightSide - left : width}px;
+                             height: ${bottom - top}px`))
+  }
+
+  function drawForLine(line, fromArg, toArg) {
+    let lineObj = getLine(doc, line)
+    let lineLen = lineObj.text.length
+    let start, end
+    function coords(ch, bias) {
+      return charCoords(cm, Pos(line, ch), "div", lineObj, bias)
+    }
+
+    function wrapX(pos, dir, side) {
+      let extent = wrappedLineExtentChar(cm, lineObj, null, pos)
+      let prop = (dir == "ltr") == (side == "after") ? "left" : "right"
+      let ch = side == "after" ? extent.begin : extent.end - (/\s/.test(lineObj.text.charAt(extent.end - 1)) ? 2 : 1)
+      return coords(ch, prop)[prop]
+    }
+
+    let order = getOrder(lineObj, doc.direction)
+    iterateBidiSections(order, fromArg || 0, toArg == null ? lineLen : toArg, (from, to, dir, i) => {
+      let ltr = dir == "ltr"
+      let fromPos = coords(from, ltr ? "left" : "right")
+      let toPos = coords(to - 1, ltr ? "right" : "left")
+
+      let openStart = fromArg == null && from == 0, openEnd = toArg == null && to == lineLen
+      let first = i == 0, last = !order || i == order.length - 1
+      if (toPos.top - fromPos.top <= 3) { // Single line
+        let openLeft = (docLTR ? openStart : openEnd) && first
+        let openRight = (docLTR ? openEnd : openStart) && last
+        let left = openLeft ? leftSide : (ltr ? fromPos : toPos).left
+        let right = openRight ? rightSide : (ltr ? toPos : fromPos).right
+        add(left, fromPos.top, right - left, fromPos.bottom)
+      } else { // Multiple lines
+        let topLeft, topRight, botLeft, botRight
+        if (ltr) {
+          topLeft = docLTR && openStart && first ? leftSide : fromPos.left
+          topRight = docLTR ? rightSide : wrapX(from, dir, "before")
+          botLeft = docLTR ? leftSide : wrapX(to, dir, "after")
+          botRight = docLTR && openEnd && last ? rightSide : toPos.right
+        } else {
+          topLeft = !docLTR ? leftSide : wrapX(from, dir, "before")
+          topRight = !docLTR && openStart && first ? rightSide : fromPos.right
+          botLeft = !docLTR && openEnd && last ? leftSide : toPos.left
+          botRight = !docLTR ? rightSide : wrapX(to, dir, "after")
+        }
+        add(topLeft, fromPos.top, topRight - topLeft, fromPos.bottom)
+        if (fromPos.bottom < toPos.top) add(leftSide, fromPos.bottom, null, toPos.top)
+        add(botLeft, toPos.top, botRight - botLeft, toPos.bottom)
+      }
+
+      if (!start || cmpCoords(fromPos, start) < 0) start = fromPos
+      if (cmpCoords(toPos, start) < 0) start = toPos
+      if (!end || cmpCoords(fromPos, end) < 0) end = fromPos
+      if (cmpCoords(toPos, end) < 0) end = toPos
+    })
+    return {start: start, end: end}
+  }
+
+  let sFrom = range.from(), sTo = range.to()
+  if (sFrom.line == sTo.line) {
+    drawForLine(sFrom.line, sFrom.ch, sTo.ch)
+  } else {
+    let fromLine = getLine(doc, sFrom.line), toLine = getLine(doc, sTo.line)
+    let singleVLine = visualLine(fromLine) == visualLine(toLine)
+    let leftEnd = drawForLine(sFrom.line, sFrom.ch, singleVLine ? fromLine.text.length + 1 : null).end
+    let rightStart = drawForLine(sTo.line, singleVLine ? 0 : null, sTo.ch).start
+    if (singleVLine) {
+      if (leftEnd.top < rightStart.top - 2) {
+        add(leftEnd.right, leftEnd.top, null, leftEnd.bottom)
+        add(leftSide, rightStart.top, rightStart.left, rightStart.bottom)
+      } else {
+        add(leftEnd.right, leftEnd.top, rightStart.left - leftEnd.right, leftEnd.bottom)
+      }
+    }
+    if (leftEnd.bottom < rightStart.top)
+      add(leftSide, leftEnd.bottom, null, rightStart.top)
+  }
+
+  output.appendChild(fragment)
+}
+
+// Cursor-blinking
+export function restartBlink(cm) {
+  if (!cm.state.focused) return
+  let display = cm.display
+  clearInterval(display.blinker)
+  let on = true
+  display.cursorDiv.style.visibility = ""
+  if (cm.options.cursorBlinkRate > 0)
+    display.blinker = setInterval(() => {
+      if (!cm.hasFocus()) onBlur(cm)
+      display.cursorDiv.style.visibility = (on = !on) ? "" : "hidden"
+    }, cm.options.cursorBlinkRate)
+  else if (cm.options.cursorBlinkRate < 0)
+    display.cursorDiv.style.visibility = "hidden"
+}

static/filemanager/src/display/update_display.js

@@ -0,0 +1,263 @@
+import { sawCollapsedSpans } from "../line/saw_special_spans.js"
+import { heightAtLine, visualLineEndNo, visualLineNo } from "../line/spans.js"
+import { getLine, lineNumberFor } from "../line/utils_line.js"
+import { displayHeight, displayWidth, getDimensions, paddingVert, scrollGap } from "../measurement/position_measurement.js"
+import { mac, webkit } from "../util/browser.js"
+import { activeElt, removeChildren, contains } from "../util/dom.js"
+import { hasHandler, signal } from "../util/event.js"
+import { indexOf } from "../util/misc.js"
+
+import { buildLineElement, updateLineForChanges } from "./update_line.js"
+import { startWorker } from "./highlight_worker.js"
+import { maybeUpdateLineNumberWidth } from "./line_numbers.js"
+import { measureForScrollbars, updateScrollbars } from "./scrollbars.js"
+import { updateSelection } from "./selection.js"
+import { updateHeightsInViewport, visibleLines } from "./update_lines.js"
+import { adjustView, countDirtyView, resetView } from "./view_tracking.js"
+
+// DISPLAY DRAWING
+
+export class DisplayUpdate {
+  constructor(cm, viewport, force) {
+    let display = cm.display
+
+    this.viewport = viewport
+    // Store some values that we'll need later (but don't want to force a relayout for)
+    this.visible = visibleLines(display, cm.doc, viewport)
+    this.editorIsHidden = !display.wrapper.offsetWidth
+    this.wrapperHeight = display.wrapper.clientHeight
+    this.wrapperWidth = display.wrapper.clientWidth
+    this.oldDisplayWidth = displayWidth(cm)
+    this.force = force
+    this.dims = getDimensions(cm)
+    this.events = []
+  }
+
+  signal(emitter, type) {
+    if (hasHandler(emitter, type))
+      this.events.push(arguments)
+  }
+  finish() {
+    for (let i = 0; i < this.events.length; i++)
+      signal.apply(null, this.events[i])
+  }
+}
+
+export function maybeClipScrollbars(cm) {
+  let display = cm.display
+  if (!display.scrollbarsClipped && display.scroller.offsetWidth) {
+    display.nativeBarWidth = display.scroller.offsetWidth - display.scroller.clientWidth
+    display.heightForcer.style.height = scrollGap(cm) + "px"
+    display.sizer.style.marginBottom = -display.nativeBarWidth + "px"
+    display.sizer.style.borderRightWidth = scrollGap(cm) + "px"
+    display.scrollbarsClipped = true
+  }
+}
+
+function selectionSnapshot(cm) {
+  if (cm.hasFocus()) return null
+  let active = activeElt()
+  if (!active || !contains(cm.display.lineDiv, active)) return null
+  let result = {activeElt: active}
+  if (window.getSelection) {
+    let sel = window.getSelection()
+    if (sel.anchorNode && sel.extend && contains(cm.display.lineDiv, sel.anchorNode)) {
+      result.anchorNode = sel.anchorNode
+      result.anchorOffset = sel.anchorOffset
+      result.focusNode = sel.focusNode
+      result.focusOffset = sel.focusOffset
+    }
+  }
+  return result
+}
+
+function restoreSelection(snapshot) {
+  if (!snapshot || !snapshot.activeElt || snapshot.activeElt == activeElt()) return
+  snapshot.activeElt.focus()
+  if (!/^(INPUT|TEXTAREA)$/.test(snapshot.activeElt.nodeName) &&
+      snapshot.anchorNode && contains(document.body, snapshot.anchorNode) && contains(document.body, snapshot.focusNode)) {
+    let sel = window.getSelection(), range = document.createRange()
+    range.setEnd(snapshot.anchorNode, snapshot.anchorOffset)
+    range.collapse(false)
+    sel.removeAllRanges()
+    sel.addRange(range)
+    sel.extend(snapshot.focusNode, snapshot.focusOffset)
+  }
+}
+
+// Does the actual updating of the line display. Bails out
+// (returning false) when there is nothing to be done and forced is
+// false.
+export function updateDisplayIfNeeded(cm, update) {
+  let display = cm.display, doc = cm.doc
+
+  if (update.editorIsHidden) {
+    resetView(cm)
+    return false
+  }
+
+  // Bail out if the visible area is already rendered and nothing changed.
+  if (!update.force &&
+      update.visible.from >= display.viewFrom && update.visible.to <= display.viewTo &&
+      (display.updateLineNumbers == null || display.updateLineNumbers >= display.viewTo) &&
+      display.renderedView == display.view && countDirtyView(cm) == 0)
+    return false
+
+  if (maybeUpdateLineNumberWidth(cm)) {
+    resetView(cm)
+    update.dims = getDimensions(cm)
+  }
+
+  // Compute a suitable new viewport (from & to)
+  let end = doc.first + doc.size
+  let from = Math.max(update.visible.from - cm.options.viewportMargin, doc.first)
+  let to = Math.min(end, update.visible.to + cm.options.viewportMargin)
+  if (display.viewFrom < from && from - display.viewFrom < 20) from = Math.max(doc.first, display.viewFrom)
+  if (display.viewTo > to && display.viewTo - to < 20) to = Math.min(end, display.viewTo)
+  if (sawCollapsedSpans) {
+    from = visualLineNo(cm.doc, from)
+    to = visualLineEndNo(cm.doc, to)
+  }
+
+  let different = from != display.viewFrom || to != display.viewTo ||
+    display.lastWrapHeight != update.wrapperHeight || display.lastWrapWidth != update.wrapperWidth
+  adjustView(cm, from, to)
+
+  display.viewOffset = heightAtLine(getLine(cm.doc, display.viewFrom))
+  // Position the mover div to align with the current scroll position
+  cm.display.mover.style.top = display.viewOffset + "px"
+
+  let toUpdate = countDirtyView(cm)
+  if (!different && toUpdate == 0 && !update.force && display.renderedView == display.view &&
+      (display.updateLineNumbers == null || display.updateLineNumbers >= display.viewTo))
+    return false
+
+  // For big changes, we hide the enclosing element during the
+  // update, since that speeds up the operations on most browsers.
+  let selSnapshot = selectionSnapshot(cm)
+  if (toUpdate > 4) display.lineDiv.style.display = "none"
+  patchDisplay(cm, display.updateLineNumbers, update.dims)
+  if (toUpdate > 4) display.lineDiv.style.display = ""
+  display.renderedView = display.view
+  // There might have been a widget with a focused element that got
+  // hidden or updated, if so re-focus it.
+  restoreSelection(selSnapshot)
+
+  // Prevent selection and cursors from interfering with the scroll
+  // width and height.
+  removeChildren(display.cursorDiv)
+  removeChildren(display.selectionDiv)
+  display.gutters.style.height = display.sizer.style.minHeight = 0
+
+  if (different) {
+    display.lastWrapHeight = update.wrapperHeight
+    display.lastWrapWidth = update.wrapperWidth
+    startWorker(cm, 400)
+  }
+
+  display.updateLineNumbers = null
+
+  return true
+}
+
+export function postUpdateDisplay(cm, update) {
+  let viewport = update.viewport
+
+  for (let first = true;; first = false) {
+    if (!first || !cm.options.lineWrapping || update.oldDisplayWidth == displayWidth(cm)) {
+      // Clip forced viewport to actual scrollable area.
+      if (viewport && viewport.top != null)
+        viewport = {top: Math.min(cm.doc.height + paddingVert(cm.display) - displayHeight(cm), viewport.top)}
+      // Updated line heights might result in the drawn area not
+      // actually covering the viewport. Keep looping until it does.
+      update.visible = visibleLines(cm.display, cm.doc, viewport)
+      if (update.visible.from >= cm.display.viewFrom && update.visible.to <= cm.display.viewTo)
+        break
+    } else if (first) {
+      update.visible = visibleLines(cm.display, cm.doc, viewport)
+    }
+    if (!updateDisplayIfNeeded(cm, update)) break
+    updateHeightsInViewport(cm)
+    let barMeasure = measureForScrollbars(cm)
+    updateSelection(cm)
+    updateScrollbars(cm, barMeasure)
+    setDocumentHeight(cm, barMeasure)
+    update.force = false
+  }
+
+  update.signal(cm, "update", cm)
+  if (cm.display.viewFrom != cm.display.reportedViewFrom || cm.display.viewTo != cm.display.reportedViewTo) {
+    update.signal(cm, "viewportChange", cm, cm.display.viewFrom, cm.display.viewTo)
+    cm.display.reportedViewFrom = cm.display.viewFrom; cm.display.reportedViewTo = cm.display.viewTo
+  }
+}
+
+export function updateDisplaySimple(cm, viewport) {
+  let update = new DisplayUpdate(cm, viewport)
+  if (updateDisplayIfNeeded(cm, update)) {
+    updateHeightsInViewport(cm)
+    postUpdateDisplay(cm, update)
+    let barMeasure = measureForScrollbars(cm)
+    updateSelection(cm)
+    updateScrollbars(cm, barMeasure)
+    setDocumentHeight(cm, barMeasure)
+    update.finish()
+  }
+}
+
+// Sync the actual display DOM structure with display.view, removing
+// nodes for lines that are no longer in view, and creating the ones
+// that are not there yet, and updating the ones that are out of
+// date.
+function patchDisplay(cm, updateNumbersFrom, dims) {
+  let display = cm.display, lineNumbers = cm.options.lineNumbers
+  let container = display.lineDiv, cur = container.firstChild
+
+  function rm(node) {
+    let next = node.nextSibling
+    // Works around a throw-scroll bug in OS X Webkit
+    if (webkit && mac && cm.display.currentWheelTarget == node)
+      node.style.display = "none"
+    else
+      node.parentNode.removeChild(node)
+    return next
+  }
+
+  let view = display.view, lineN = display.viewFrom
+  // Loop over the elements in the view, syncing cur (the DOM nodes
+  // in display.lineDiv) with the view as we go.
+  for (let i = 0; i < view.length; i++) {
+    let lineView = view[i]
+    if (lineView.hidden) {
+    } else if (!lineView.node || lineView.node.parentNode != container) { // Not drawn yet
+      let node = buildLineElement(cm, lineView, lineN, dims)
+      container.insertBefore(node, cur)
+    } else { // Already drawn
+      while (cur != lineView.node) cur = rm(cur)
+      let updateNumber = lineNumbers && updateNumbersFrom != null &&
+        updateNumbersFrom <= lineN && lineView.lineNumber
+      if (lineView.changes) {
+        if (indexOf(lineView.changes, "gutter") > -1) updateNumber = false
+        updateLineForChanges(cm, lineView, lineN, dims)
+      }
+      if (updateNumber) {
+        removeChildren(lineView.lineNumber)
+        lineView.lineNumber.appendChild(document.createTextNode(lineNumberFor(cm.options, lineN)))
+      }
+      cur = lineView.node.nextSibling
+    }
+    lineN += lineView.size
+  }
+  while (cur) cur = rm(cur)
+}
+
+export function updateGutterSpace(display) {
+  let width = display.gutters.offsetWidth
+  display.sizer.style.marginLeft = width + "px"
+}
+
+export function setDocumentHeight(cm, measure) {
+  cm.display.sizer.style.minHeight = measure.docHeight + "px"
+  cm.display.heightForcer.style.top = measure.docHeight + "px"
+  cm.display.gutters.style.height = (measure.docHeight + cm.display.barHeight + scrollGap(cm)) + "px"
+}

static/filemanager/src/display/update_line.js

@@ -0,0 +1,188 @@
+import { buildLineContent } from "../line/line_data.js"
+import { lineNumberFor } from "../line/utils_line.js"
+import { ie, ie_version } from "../util/browser.js"
+import { elt, classTest } from "../util/dom.js"
+import { signalLater } from "../util/operation_group.js"
+
+// When an aspect of a line changes, a string is added to
+// lineView.changes. This updates the relevant part of the line's
+// DOM structure.
+export function updateLineForChanges(cm, lineView, lineN, dims) {
+  for (let j = 0; j < lineView.changes.length; j++) {
+    let type = lineView.changes[j]
+    if (type == "text") updateLineText(cm, lineView)
+    else if (type == "gutter") updateLineGutter(cm, lineView, lineN, dims)
+    else if (type == "class") updateLineClasses(cm, lineView)
+    else if (type == "widget") updateLineWidgets(cm, lineView, dims)
+  }
+  lineView.changes = null
+}
+
+// Lines with gutter elements, widgets or a background class need to
+// be wrapped, and have the extra elements added to the wrapper div
+function ensureLineWrapped(lineView) {
+  if (lineView.node == lineView.text) {
+    lineView.node = elt("div", null, null, "position: relative")
+    if (lineView.text.parentNode)
+      lineView.text.parentNode.replaceChild(lineView.node, lineView.text)
+    lineView.node.appendChild(lineView.text)
+    if (ie && ie_version < 8) lineView.node.style.zIndex = 2
+  }
+  return lineView.node
+}
+
+function updateLineBackground(cm, lineView) {
+  let cls = lineView.bgClass ? lineView.bgClass + " " + (lineView.line.bgClass || "") : lineView.line.bgClass
+  if (cls) cls += " CodeMirror-linebackground"
+  if (lineView.background) {
+    if (cls) lineView.background.className = cls
+    else { lineView.background.parentNode.removeChild(lineView.background); lineView.background = null }
+  } else if (cls) {
+    let wrap = ensureLineWrapped(lineView)
+    lineView.background = wrap.insertBefore(elt("div", null, cls), wrap.firstChild)
+    cm.display.input.setUneditable(lineView.background)
+  }
+}
+
+// Wrapper around buildLineContent which will reuse the structure
+// in display.externalMeasured when possible.
+function getLineContent(cm, lineView) {
+  let ext = cm.display.externalMeasured
+  if (ext && ext.line == lineView.line) {
+    cm.display.externalMeasured = null
+    lineView.measure = ext.measure
+    return ext.built
+  }
+  return buildLineContent(cm, lineView)
+}
+
+// Redraw the line's text. Interacts with the background and text
+// classes because the mode may output tokens that influence these
+// classes.
+function updateLineText(cm, lineView) {
+  let cls = lineView.text.className
+  let built = getLineContent(cm, lineView)
+  if (lineView.text == lineView.node) lineView.node = built.pre
+  lineView.text.parentNode.replaceChild(built.pre, lineView.text)
+  lineView.text = built.pre
+  if (built.bgClass != lineView.bgClass || built.textClass != lineView.textClass) {
+    lineView.bgClass = built.bgClass
+    lineView.textClass = built.textClass
+    updateLineClasses(cm, lineView)
+  } else if (cls) {
+    lineView.text.className = cls
+  }
+}
+
+function updateLineClasses(cm, lineView) {
+  updateLineBackground(cm, lineView)
+  if (lineView.line.wrapClass)
+    ensureLineWrapped(lineView).className = lineView.line.wrapClass
+  else if (lineView.node != lineView.text)
+    lineView.node.className = ""
+  let textClass = lineView.textClass ? lineView.textClass + " " + (lineView.line.textClass || "") : lineView.line.textClass
+  lineView.text.className = textClass || ""
+}
+
+function updateLineGutter(cm, lineView, lineN, dims) {
+  if (lineView.gutter) {
+    lineView.node.removeChild(lineView.gutter)
+    lineView.gutter = null
+  }
+  if (lineView.gutterBackground) {
+    lineView.node.removeChild(lineView.gutterBackground)
+    lineView.gutterBackground = null
+  }
+  if (lineView.line.gutterClass) {
+    let wrap = ensureLineWrapped(lineView)
+    lineView.gutterBackground = elt("div", null, "CodeMirror-gutter-background " + lineView.line.gutterClass,
+                                    `left: ${cm.options.fixedGutter ? dims.fixedPos : -dims.gutterTotalWidth}px; width: ${dims.gutterTotalWidth}px`)
+    cm.display.input.setUneditable(lineView.gutterBackground)
+    wrap.insertBefore(lineView.gutterBackground, lineView.text)
+  }
+  let markers = lineView.line.gutterMarkers
+  if (cm.options.lineNumbers || markers) {
+    let wrap = ensureLineWrapped(lineView)
+    let gutterWrap = lineView.gutter = elt("div", null, "CodeMirror-gutter-wrapper", `left: ${cm.options.fixedGutter ? dims.fixedPos : -dims.gutterTotalWidth}px`)
+    cm.display.input.setUneditable(gutterWrap)
+    wrap.insertBefore(gutterWrap, lineView.text)
+    if (lineView.line.gutterClass)
+      gutterWrap.className += " " + lineView.line.gutterClass
+    if (cm.options.lineNumbers && (!markers || !markers["CodeMirror-linenumbers"]))
+      lineView.lineNumber = gutterWrap.appendChild(
+        elt("div", lineNumberFor(cm.options, lineN),
+            "CodeMirror-linenumber CodeMirror-gutter-elt",
+            `left: ${dims.gutterLeft["CodeMirror-linenumbers"]}px; width: ${cm.display.lineNumInnerWidth}px`))
+    if (markers) for (let k = 0; k < cm.display.gutterSpecs.length; ++k) {
+      let id = cm.display.gutterSpecs[k].className, found = markers.hasOwnProperty(id) && markers[id]
+      if (found)
+        gutterWrap.appendChild(elt("div", [found], "CodeMirror-gutter-elt",
+                                   `left: ${dims.gutterLeft[id]}px; width: ${dims.gutterWidth[id]}px`))
+    }
+  }
+}
+
+function updateLineWidgets(cm, lineView, dims) {
+  if (lineView.alignable) lineView.alignable = null
+  let isWidget = classTest("CodeMirror-linewidget")
+  for (let node = lineView.node.firstChild, next; node; node = next) {
+    next = node.nextSibling
+    if (isWidget.test(node.className)) lineView.node.removeChild(node)
+  }
+  insertLineWidgets(cm, lineView, dims)
+}
+
+// Build a line's DOM representation from scratch
+export function buildLineElement(cm, lineView, lineN, dims) {
+  let built = getLineContent(cm, lineView)
+  lineView.text = lineView.node = built.pre
+  if (built.bgClass) lineView.bgClass = built.bgClass
+  if (built.textClass) lineView.textClass = built.textClass
+
+  updateLineClasses(cm, lineView)
+  updateLineGutter(cm, lineView, lineN, dims)
+  insertLineWidgets(cm, lineView, dims)
+  return lineView.node
+}
+
+// A lineView may contain multiple logical lines (when merged by
+// collapsed spans). The widgets for all of them need to be drawn.
+function insertLineWidgets(cm, lineView, dims) {
+  insertLineWidgetsFor(cm, lineView.line, lineView, dims, true)
+  if (lineView.rest) for (let i = 0; i < lineView.rest.length; i++)
+    insertLineWidgetsFor(cm, lineView.rest[i], lineView, dims, false)
+}
+
+function insertLineWidgetsFor(cm, line, lineView, dims, allowAbove) {
+  if (!line.widgets) return
+  let wrap = ensureLineWrapped(lineView)
+  for (let i = 0, ws = line.widgets; i < ws.length; ++i) {
+    let widget = ws[i], node = elt("div", [widget.node], "CodeMirror-linewidget" + (widget.className ? " " + widget.className : ""))
+    if (!widget.handleMouseEvents) node.setAttribute("cm-ignore-events", "true")
+    positionLineWidget(widget, node, lineView, dims)
+    cm.display.input.setUneditable(node)
+    if (allowAbove && widget.above)
+      wrap.insertBefore(node, lineView.gutter || lineView.text)
+    else
+      wrap.appendChild(node)
+    signalLater(widget, "redraw")
+  }
+}
+
+function positionLineWidget(widget, node, lineView, dims) {
+  if (widget.noHScroll) {
+    ;(lineView.alignable || (lineView.alignable = [])).push(node)
+    let width = dims.wrapperWidth
+    node.style.left = dims.fixedPos + "px"
+    if (!widget.coverGutter) {
+      width -= dims.gutterTotalWidth
+      node.style.paddingLeft = dims.gutterTotalWidth + "px"
+    }
+    node.style.width = width + "px"
+  }
+  if (widget.coverGutter) {
+    node.style.zIndex = 5
+    node.style.position = "relative"
+    if (!widget.noHScroll) node.style.marginLeft = -dims.gutterTotalWidth + "px"
+  }
+}

static/filemanager/src/display/update_lines.js

@@ -0,0 +1,76 @@
+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
+  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
+    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) {
+      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
+      }
+    }
+  }
+}
+
+// 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)}
+}

static/filemanager/src/display/view_tracking.js

@@ -0,0 +1,153 @@
+import { buildViewArray } from "../line/line_data.js"
+import { sawCollapsedSpans } from "../line/saw_special_spans.js"
+import { visualLineEndNo, visualLineNo } from "../line/spans.js"
+import { findViewIndex } from "../measurement/position_measurement.js"
+import { indexOf } from "../util/misc.js"
+
+// Updates the display.view data structure for a given change to the
+// document. From and to are in pre-change coordinates. Lendiff is
+// the amount of lines added or subtracted by the change. This is
+// used for changes that span multiple lines, or change the way
+// lines are divided into visual lines. regLineChange (below)
+// registers single-line changes.
+export function regChange(cm, from, to, lendiff) {
+  if (from == null) from = cm.doc.first
+  if (to == null) to = cm.doc.first + cm.doc.size
+  if (!lendiff) lendiff = 0
+
+  let display = cm.display
+  if (lendiff && to < display.viewTo &&
+      (display.updateLineNumbers == null || display.updateLineNumbers > from))
+    display.updateLineNumbers = from
+
+  cm.curOp.viewChanged = true
+
+  if (from >= display.viewTo) { // Change after
+    if (sawCollapsedSpans && visualLineNo(cm.doc, from) < display.viewTo)
+      resetView(cm)
+  } else if (to <= display.viewFrom) { // Change before
+    if (sawCollapsedSpans && visualLineEndNo(cm.doc, to + lendiff) > display.viewFrom) {
+      resetView(cm)
+    } else {
+      display.viewFrom += lendiff
+      display.viewTo += lendiff
+    }
+  } else if (from <= display.viewFrom && to >= display.viewTo) { // Full overlap
+    resetView(cm)
+  } else if (from <= display.viewFrom) { // Top overlap
+    let cut = viewCuttingPoint(cm, to, to + lendiff, 1)
+    if (cut) {
+      display.view = display.view.slice(cut.index)
+      display.viewFrom = cut.lineN
+      display.viewTo += lendiff
+    } else {
+      resetView(cm)
+    }
+  } else if (to >= display.viewTo) { // Bottom overlap
+    let cut = viewCuttingPoint(cm, from, from, -1)
+    if (cut) {
+      display.view = display.view.slice(0, cut.index)
+      display.viewTo = cut.lineN
+    } else {
+      resetView(cm)
+    }
+  } else { // Gap in the middle
+    let cutTop = viewCuttingPoint(cm, from, from, -1)
+    let cutBot = viewCuttingPoint(cm, to, to + lendiff, 1)
+    if (cutTop && cutBot) {
+      display.view = display.view.slice(0, cutTop.index)
+        .concat(buildViewArray(cm, cutTop.lineN, cutBot.lineN))
+        .concat(display.view.slice(cutBot.index))
+      display.viewTo += lendiff
+    } else {
+      resetView(cm)
+    }
+  }
+
+  let ext = display.externalMeasured
+  if (ext) {
+    if (to < ext.lineN)
+      ext.lineN += lendiff
+    else if (from < ext.lineN + ext.size)
+      display.externalMeasured = null
+  }
+}
+
+// Register a change to a single line. Type must be one of "text",
+// "gutter", "class", "widget"
+export function regLineChange(cm, line, type) {
+  cm.curOp.viewChanged = true
+  let display = cm.display, ext = cm.display.externalMeasured
+  if (ext && line >= ext.lineN && line < ext.lineN + ext.size)
+    display.externalMeasured = null
+
+  if (line < display.viewFrom || line >= display.viewTo) return
+  let lineView = display.view[findViewIndex(cm, line)]
+  if (lineView.node == null) return
+  let arr = lineView.changes || (lineView.changes = [])
+  if (indexOf(arr, type) == -1) arr.push(type)
+}
+
+// Clear the view.
+export function resetView(cm) {
+  cm.display.viewFrom = cm.display.viewTo = cm.doc.first
+  cm.display.view = []
+  cm.display.viewOffset = 0
+}
+
+function viewCuttingPoint(cm, oldN, newN, dir) {
+  let index = findViewIndex(cm, oldN), diff, view = cm.display.view
+  if (!sawCollapsedSpans || newN == cm.doc.first + cm.doc.size)
+    return {index: index, lineN: newN}
+  let n = cm.display.viewFrom
+  for (let i = 0; i < index; i++)
+    n += view[i].size
+  if (n != oldN) {
+    if (dir > 0) {
+      if (index == view.length - 1) return null
+      diff = (n + view[index].size) - oldN
+      index++
+    } else {
+      diff = n - oldN
+    }
+    oldN += diff; newN += diff
+  }
+  while (visualLineNo(cm.doc, newN) != newN) {
+    if (index == (dir < 0 ? 0 : view.length - 1)) return null
+    newN += dir * view[index - (dir < 0 ? 1 : 0)].size
+    index += dir
+  }
+  return {index: index, lineN: newN}
+}
+
+// Force the view to cover a given range, adding empty view element
+// or clipping off existing ones as needed.
+export function adjustView(cm, from, to) {
+  let display = cm.display, view = display.view
+  if (view.length == 0 || from >= display.viewTo || to <= display.viewFrom) {
+    display.view = buildViewArray(cm, from, to)
+    display.viewFrom = from
+  } else {
+    if (display.viewFrom > from)
+      display.view = buildViewArray(cm, from, display.viewFrom).concat(display.view)
+    else if (display.viewFrom < from)
+      display.view = display.view.slice(findViewIndex(cm, from))
+    display.viewFrom = from
+    if (display.viewTo < to)
+      display.view = display.view.concat(buildViewArray(cm, display.viewTo, to))
+    else if (display.viewTo > to)
+      display.view = display.view.slice(0, findViewIndex(cm, to))
+  }
+  display.viewTo = to
+}
+
+// Count the number of lines in the view whose DOM representation is
+// out of date (or nonexistent).
+export function countDirtyView(cm) {
+  let view = cm.display.view, dirty = 0
+  for (let i = 0; i < view.length; i++) {
+    let lineView = view[i]
+    if (!lineView.hidden && (!lineView.node || lineView.changes)) ++dirty
+  }
+  return dirty
+}