Bar graph added.

node_modules/vega-scenegraph/src/util/text.js

@@ -0,0 +1,149 @@
+import {context} from './canvas/context';
+import {isArray, lruCache} from 'vega-util';
+
+// memoize text width measurement
+const widthCache = lruCache();
+
+export var textMetrics = {
+  height: fontSize,
+  measureWidth: measureWidth,
+  estimateWidth: estimateWidth,
+  width: estimateWidth,
+  canvas: useCanvas
+};
+
+useCanvas(true);
+
+function useCanvas(use) {
+  textMetrics.width = (use && context) ? measureWidth : estimateWidth;
+}
+
+// make dumb, simple estimate if no canvas is available
+function estimateWidth(item, text) {
+  return _estimateWidth(textValue(item, text), fontSize(item));
+}
+
+function _estimateWidth(text, currentFontHeight) {
+  return ~~(0.8 * text.length * currentFontHeight);
+}
+
+// measure text width if canvas is available
+function measureWidth(item, text) {
+  return fontSize(item) <= 0 || !(text = textValue(item, text)) ? 0
+    : _measureWidth(text, font(item));
+}
+
+function _measureWidth(text, currentFont) {
+  const key = `(${currentFont}) ${text}`;
+  let width = widthCache.get(key);
+  if (width === undefined) {
+    context.font = currentFont;
+    width = context.measureText(text).width;
+    widthCache.set(key, width);
+  }
+  return width;
+}
+
+export function fontSize(item) {
+  return item.fontSize != null ? (+item.fontSize || 0) : 11;
+}
+
+export function lineHeight(item) {
+  return item.lineHeight != null ? item.lineHeight : (fontSize(item) + 2);
+}
+
+function lineArray(_) {
+  return isArray(_) ? _.length > 1 ? _ : _[0] : _;
+}
+
+export function textLines(item) {
+  return lineArray(
+    item.lineBreak && item.text && !isArray(item.text)
+      ? item.text.split(item.lineBreak)
+      : item.text
+  );
+}
+
+export function multiLineOffset(item) {
+  const tl = textLines(item);
+  return (isArray(tl) ? (tl.length - 1) : 0) * lineHeight(item);
+}
+
+export function textValue(item, line) {
+  const text = line == null ? '' : (line + '').trim();
+  return item.limit > 0 && text.length ? truncate(item, text) : text;
+}
+
+function widthGetter(item) {
+  if (textMetrics.width === measureWidth) {
+    // we are using canvas
+    const currentFont = font(item);
+    return text => _measureWidth(text, currentFont);
+  } else {
+    // we are relying on estimates
+    const currentFontHeight = fontSize(item);
+    return text => _estimateWidth(text, currentFontHeight);
+  }
+}
+
+function truncate(item, text) {
+  var limit = +item.limit,
+      width = widthGetter(item);
+
+  if (width(text) < limit) return text;
+
+  var ellipsis = item.ellipsis || '\u2026',
+      rtl = item.dir === 'rtl',
+      lo = 0,
+      hi = text.length, mid;
+
+  limit -= width(ellipsis);
+
+  if (rtl) {
+    while (lo < hi) {
+      mid = (lo + hi >>> 1);
+      if (width(text.slice(mid)) > limit) lo = mid + 1;
+      else hi = mid;
+    }
+    return ellipsis + text.slice(lo);
+  } else {
+    while (lo < hi) {
+      mid = 1 + (lo + hi >>> 1);
+      if (width(text.slice(0, mid)) < limit) lo = mid;
+      else hi = mid - 1;
+    }
+    return text.slice(0, lo) + ellipsis;
+  }
+}
+
+export function fontFamily(item, quote) {
+  var font = item.font;
+  return (quote && font
+    ? String(font).replace(/"/g, '\'')
+    : font) || 'sans-serif';
+}
+
+export function font(item, quote) {
+  return '' +
+    (item.fontStyle ? item.fontStyle + ' ' : '') +
+    (item.fontVariant ? item.fontVariant + ' ' : '') +
+    (item.fontWeight ? item.fontWeight + ' ' : '') +
+    fontSize(item) + 'px ' +
+    fontFamily(item, quote);
+}
+
+export function offset(item) {
+  // perform our own font baseline calculation
+  // why? not all browsers support SVG 1.1 'alignment-baseline' :(
+  // this also ensures consistent layout across renderers
+  var baseline = item.baseline,
+      h = fontSize(item);
+
+  return Math.round(
+    baseline === 'top'         ?  0.79 * h :
+    baseline === 'middle'      ?  0.30 * h :
+    baseline === 'bottom'      ? -0.21 * h :
+    baseline === 'line-top'    ?  0.29 * h + 0.5 * lineHeight(item) :
+    baseline === 'line-bottom' ?  0.29 * h - 0.5 * lineHeight(item) : 0
+  );
+}