--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/.cms/lib/codemirror/src/display/update_lines.js	Fri Oct 11 22:40:23 2024 +0000
@@ -0,0 +1,82 @@
+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 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)}
+}