grafana/public/app/plugins/panel/barchart/bars.ts

596 lines
18 KiB
TypeScript

import uPlot, { Axis, AlignedData, Scale } from 'uplot';
import { intersects, pointWithin, Quadtree, Rect } from './quadtree';
import { distribute, SPACE_BETWEEN } from './distribute';
import { DataFrame, GrafanaTheme2 } from '@grafana/data';
import { measureText, PlotTooltipInterpolator } from '@grafana/ui';
import {
StackingMode,
VisibilityMode,
ScaleDirection,
ScaleOrientation,
VizTextDisplayOptions,
VizLegendOptions,
} from '@grafana/schema';
import { preparePlotData } from '../../../../../packages/grafana-ui/src/components/uPlot/utils';
import { alpha } from '@grafana/data/src/themes/colorManipulator';
import { formatTime } from '@grafana/ui/src/components/uPlot/config/UPlotAxisBuilder';
const groupDistr = SPACE_BETWEEN;
const barDistr = SPACE_BETWEEN;
// min.max font size for value label
const VALUE_MIN_FONT_SIZE = 8;
const VALUE_MAX_FONT_SIZE = 30;
// % of width/height of the bar that value should fit in when measuring size
const BAR_FONT_SIZE_RATIO = 0.65;
// distance between label and a bar in % of bar width
const LABEL_OFFSET_FACTOR_VT = 0.1;
const LABEL_OFFSET_FACTOR_HZ = 0.15;
// max distance
const LABEL_OFFSET_MAX_VT = 5;
const LABEL_OFFSET_MAX_HZ = 10;
// text baseline middle runs through the middle of lowercase letters
// since bar values are numbers and uppercase-like, we want the middle of uppercase
// this is a cheap fudge factor that skips expensive and inconsistent cross-browser measuring
const MIDDLE_BASELINE_SHIFT = 0.1;
/**
* @internal
*/
export interface BarsOptions {
xOri: ScaleOrientation;
xDir: ScaleDirection;
groupWidth: number;
barWidth: number;
barRadius: number;
showValue: VisibilityMode;
stacking: StackingMode;
rawValue: (seriesIdx: number, valueIdx: number) => number | null;
getColor?: (seriesIdx: number, valueIdx: number, value: any) => string | null;
fillOpacity?: number;
formatValue: (seriesIdx: number, value: any) => string;
text?: VizTextDisplayOptions;
onHover?: (seriesIdx: number, valueIdx: number) => void;
onLeave?: (seriesIdx: number, valueIdx: number) => void;
legend?: VizLegendOptions;
xSpacing?: number;
xTimeAuto?: boolean;
}
/**
* @internal
*/
interface ValueLabelTable {
[index: number]: ValueLabelArray;
}
/**
* @internal
*/
interface ValueLabelArray {
[index: number]: ValueLabel;
}
/**
* @internal
*/
interface ValueLabel {
text: string;
value: number | null;
hidden: boolean;
bbox?: Rect;
textMetrics?: TextMetrics;
x?: number;
y?: number;
}
/**
* @internal
*/
function calculateFontSizeWithMetrics(
text: string,
width: number,
height: number,
lineHeight: number,
maxSize?: number
) {
// calculate width in 14px
const textSize = measureText(text, 14);
// how much bigger than 14px can we make it while staying within our width constraints
const fontSizeBasedOnWidth = (width / (textSize.width + 2)) * 14;
const fontSizeBasedOnHeight = height / lineHeight;
// final fontSize
const optimalSize = Math.min(fontSizeBasedOnHeight, fontSizeBasedOnWidth);
return {
fontSize: Math.min(optimalSize, maxSize ?? optimalSize),
textMetrics: textSize,
};
}
/**
* @internal
*/
export function getConfig(opts: BarsOptions, theme: GrafanaTheme2) {
const { xOri, xDir: dir, rawValue, getColor, formatValue, fillOpacity = 1, showValue, xSpacing = 0 } = opts;
const isXHorizontal = xOri === ScaleOrientation.Horizontal;
const hasAutoValueSize = !Boolean(opts.text?.valueSize);
const isStacked = opts.stacking !== StackingMode.None;
const pctStacked = opts.stacking === StackingMode.Percent;
let { groupWidth, barWidth, barRadius = 0 } = opts;
if (isStacked) {
[groupWidth, barWidth] = [barWidth, groupWidth];
}
let qt: Quadtree;
let hRect: Rect | null;
const xSplits: Axis.Splits = (u: uPlot) => {
const dim = isXHorizontal ? u.bbox.width : u.bbox.height;
const _dir = dir * (isXHorizontal ? 1 : -1);
let dataLen = u.data[0].length;
let lastIdx = dataLen - 1;
let skipMod = 0;
if (xSpacing !== 0) {
let cssDim = dim / devicePixelRatio;
let maxTicks = Math.abs(Math.floor(cssDim / xSpacing));
skipMod = dataLen < maxTicks ? 0 : Math.ceil(dataLen / maxTicks);
}
let splits: number[] = [];
// for distr: 2 scales, the splits array should contain indices into data[0] rather than values
u.data[0].forEach((v, i) => {
let shouldSkip = skipMod !== 0 && (xSpacing > 0 ? i : lastIdx - i) % skipMod > 0;
if (!shouldSkip) {
splits.push(i);
}
});
return _dir === 1 ? splits : splits.reverse();
};
// the splits passed into here are data[0] values looked up by the indices returned from splits()
const xValues: Axis.Values = (u, splits, axisIdx, foundSpace, foundIncr) => {
if (opts.xTimeAuto) {
// bit of a hack:
// temporarily set x scale range to temporal (as expected by formatTime()) rather than ordinal
let xScale = u.scales.x;
let oMin = xScale.min;
let oMax = xScale.max;
xScale.min = u.data[0][0];
xScale.max = u.data[0][u.data[0].length - 1];
let vals = formatTime(u, splits, axisIdx, foundSpace, foundIncr);
// revert
xScale.min = oMin;
xScale.max = oMax;
return vals;
}
return splits.map((v) => formatValue(0, v));
};
// this expands the distr: 2 scale so that the indicies of each data[0] land at the proper justified positions
const xRange: Scale.Range = (u, min, max) => {
min = 0;
max = Math.max(1, u.data[0].length - 1);
let pctOffset = 0;
// how far in is the first tick in % of full dimension
distribute(u.data[0].length, groupWidth, groupDistr, 0, (di, lftPct, widPct) => {
pctOffset = lftPct + widPct / 2;
});
// expand scale range by equal amounts on both ends
let rn = max - min;
if (pctOffset === 0.5) {
min -= rn;
} else {
let upScale = 1 / (1 - pctOffset * 2);
let offset = (upScale * rn - rn) / 2;
min -= offset;
max += offset;
}
return [min, max];
};
let distrTwo = (groupCount: number, barCount: number) => {
let out = Array.from({ length: barCount }, () => ({
offs: Array(groupCount).fill(0),
size: Array(groupCount).fill(0),
}));
distribute(groupCount, groupWidth, groupDistr, null, (groupIdx, groupOffPct, groupDimPct) => {
distribute(barCount, barWidth, barDistr, null, (barIdx, barOffPct, barDimPct) => {
out[barIdx].offs[groupIdx] = groupOffPct + groupDimPct * barOffPct;
out[barIdx].size[groupIdx] = groupDimPct * barDimPct;
});
});
return out;
};
let distrOne = (groupCount: number, barCount: number) => {
let out = Array.from({ length: barCount }, () => ({
offs: Array(groupCount).fill(0),
size: Array(groupCount).fill(0),
}));
distribute(groupCount, groupWidth, groupDistr, null, (groupIdx, groupOffPct, groupDimPct) => {
distribute(barCount, barWidth, barDistr, null, (barIdx, barOffPct, barDimPct) => {
out[barIdx].offs[groupIdx] = groupOffPct;
out[barIdx].size[groupIdx] = groupDimPct;
});
});
return out;
};
const LABEL_OFFSET_FACTOR = isXHorizontal ? LABEL_OFFSET_FACTOR_VT : LABEL_OFFSET_FACTOR_HZ;
const LABEL_OFFSET_MAX = isXHorizontal ? LABEL_OFFSET_MAX_VT : LABEL_OFFSET_MAX_HZ;
let barsPctLayout: Array<null | { offs: number[]; size: number[] }> = [];
let barsColors: Array<null | { fill: Array<string | null>; stroke: Array<string | null> }> = [];
let scaleFactor = 1;
let labels: ValueLabelTable = {};
let fontSize = opts.text?.valueSize ?? VALUE_MAX_FONT_SIZE;
let labelOffset = LABEL_OFFSET_MAX;
// minimum available space for labels between bar end and plotting area bound (in canvas pixels)
let vSpace = Infinity;
let hSpace = Infinity;
let useMappedColors = getColor != null;
let mappedColorDisp = useMappedColors
? {
fill: {
unit: 3,
values: (u: uPlot, seriesIdx: number) => barsColors[seriesIdx]!.fill,
},
stroke: {
unit: 3,
values: (u: uPlot, seriesIdx: number) => barsColors[seriesIdx]!.stroke,
},
}
: {};
let barsBuilder = uPlot.paths.bars!({
radius: barRadius,
disp: {
x0: {
unit: 2,
values: (u, seriesIdx) => barsPctLayout[seriesIdx]!.offs,
},
size: {
unit: 2,
values: (u, seriesIdx) => barsPctLayout[seriesIdx]!.size,
},
...mappedColorDisp,
},
// collect rendered bar geometry
each: (u, seriesIdx, dataIdx, lft, top, wid, hgt) => {
// we get back raw canvas coords (included axes & padding)
// translate to the plotting area origin
lft -= u.bbox.left;
top -= u.bbox.top;
let val = u.data[seriesIdx][dataIdx]!;
// accum min space abvailable for labels
if (isXHorizontal) {
vSpace = Math.min(vSpace, val < 0 ? u.bbox.height - (top + hgt) : top);
hSpace = wid;
} else {
vSpace = hgt;
hSpace = Math.min(hSpace, val < 0 ? lft : u.bbox.width - (lft + wid));
}
let barRect = { x: lft, y: top, w: wid, h: hgt, sidx: seriesIdx, didx: dataIdx };
qt.add(barRect);
if (showValue !== VisibilityMode.Never) {
// Format Values and calculate label offsets
const text = formatValue(
seriesIdx,
rawValue(seriesIdx, dataIdx)! / (pctStacked ? alignedTotals![seriesIdx][dataIdx]! : 1)
);
labelOffset = Math.min(labelOffset, Math.round(LABEL_OFFSET_FACTOR * (isXHorizontal ? wid : hgt)));
if (labels[dataIdx] === undefined) {
labels[dataIdx] = {};
}
labels[dataIdx][seriesIdx] = { text: text, value: rawValue(seriesIdx, dataIdx), hidden: false };
// Calculate font size when it's set to be automatic
if (hasAutoValueSize) {
const { fontSize: calculatedSize, textMetrics } = calculateFontSizeWithMetrics(
labels[dataIdx][seriesIdx].text,
hSpace * (isXHorizontal ? BAR_FONT_SIZE_RATIO : 1) - (isXHorizontal ? 0 : labelOffset),
vSpace * (isXHorizontal ? 1 : BAR_FONT_SIZE_RATIO) - (isXHorizontal ? labelOffset : 0),
1
);
// Save text metrics
labels[dataIdx][seriesIdx].textMetrics = textMetrics;
// Retrieve the new font size and use it
let autoFontSize = Math.round(Math.min(fontSize, VALUE_MAX_FONT_SIZE, calculatedSize));
// Calculate the scaling factor for bouding boxes
// Take into account the fact that calculateFontSize
// uses 14px measurement so we need to adjust the scale factor
scaleFactor = (autoFontSize / fontSize) * (autoFontSize / 14);
// Update the end font-size
fontSize = autoFontSize;
} else {
labels[dataIdx][seriesIdx].textMetrics = measureText(labels[dataIdx][seriesIdx].text, fontSize);
}
let middleShift = isXHorizontal ? 0 : -Math.round(MIDDLE_BASELINE_SHIFT * fontSize);
let value = rawValue(seriesIdx, dataIdx);
if (value != null) {
// Calculate final co-ordinates for text position
const x =
u.bbox.left + (isXHorizontal ? lft + wid / 2 : value < 0 ? lft - labelOffset : lft + wid + labelOffset);
const y =
u.bbox.top +
(isXHorizontal ? (value < 0 ? top + hgt + labelOffset : top - labelOffset) : top + hgt / 2 - middleShift);
// Retrieve textMetrics with necessary default values
// These _shouldn't_ be undefined at this point
// but they _could_ be.
const {
textMetrics = {
width: 1,
actualBoundingBoxAscent: 1,
actualBoundingBoxDescent: 1,
},
} = labels[dataIdx][seriesIdx];
// Adjust bounding boxes based on text scale
// factor and orientation (which changes the baseline)
let xAdjust = 0,
yAdjust = 0;
if (isXHorizontal) {
// Adjust for baseline which is "top" in this case
xAdjust = (textMetrics.width * scaleFactor) / 2;
// yAdjust only matters when when the value isn't negative
yAdjust =
value > 0
? (textMetrics.actualBoundingBoxAscent + textMetrics.actualBoundingBoxDescent) * scaleFactor
: 0;
} else {
// Adjust from the baseline which is "middle" in this case
yAdjust = ((textMetrics.actualBoundingBoxAscent + textMetrics.actualBoundingBoxDescent) * scaleFactor) / 2;
// Adjust for baseline being "right" in the x direction
xAdjust = value < 0 ? textMetrics.width * scaleFactor : 0;
}
// Construct final bounding box for the label text
labels[dataIdx][seriesIdx].x = x;
labels[dataIdx][seriesIdx].y = y;
labels[dataIdx][seriesIdx].bbox = {
x: x - xAdjust,
y: y - yAdjust,
w: textMetrics.width * scaleFactor,
h: (textMetrics.actualBoundingBoxAscent + textMetrics.actualBoundingBoxDescent) * scaleFactor,
};
}
}
},
});
const init = (u: uPlot) => {
let over = u.over;
over.style.overflow = 'hidden';
u.root.querySelectorAll('.u-cursor-pt').forEach((el) => {
(el as HTMLElement).style.borderRadius = '0';
});
};
const cursor: uPlot.Cursor = {
x: false,
y: false,
drag: {
x: false,
y: false,
},
dataIdx: (u, seriesIdx) => {
if (seriesIdx === 1) {
hRect = null;
let cx = u.cursor.left! * devicePixelRatio;
let cy = u.cursor.top! * devicePixelRatio;
qt.get(cx, cy, 1, 1, (o) => {
if (pointWithin(cx, cy, o.x, o.y, o.x + o.w, o.y + o.h)) {
hRect = o;
}
});
}
return hRect && seriesIdx === hRect.sidx ? hRect.didx : null;
},
points: {
fill: 'rgba(255,255,255,0.4)',
bbox: (u, seriesIdx) => {
let isHovered = hRect && seriesIdx === hRect.sidx;
return {
left: isHovered ? hRect!.x / devicePixelRatio : -10,
top: isHovered ? hRect!.y / devicePixelRatio : -10,
width: isHovered ? hRect!.w / devicePixelRatio : 0,
height: isHovered ? hRect!.h / devicePixelRatio : 0,
};
},
},
};
// Build bars
const drawClear = (u: uPlot) => {
qt = qt || new Quadtree(0, 0, u.bbox.width, u.bbox.height);
qt.clear();
// clear the path cache to force drawBars() to rebuild new quadtree
u.series.forEach((s) => {
// @ts-ignore
s._paths = null;
});
if (isStacked) {
//barsPctLayout = [null as any].concat(distrOne(u.data.length - 1, u.data[0].length));
barsPctLayout = [null as any].concat(distrOne(u.data[0].length, u.data.length - 1));
} else {
barsPctLayout = [null as any].concat(distrTwo(u.data[0].length, u.data.length - 1));
}
if (useMappedColors) {
barsColors = [null];
// map per-bar colors
for (let i = 1; i < u.data.length; i++) {
let colors = u.data[i].map((value, valueIdx) => {
if (value != null) {
return getColor!(i, valueIdx, value);
}
return null;
});
barsColors.push({
fill: fillOpacity < 1 ? colors.map((c) => (c != null ? alpha(c, fillOpacity) : null)) : colors,
stroke: colors,
});
}
}
labels = {};
fontSize = opts.text?.valueSize ?? VALUE_MAX_FONT_SIZE;
labelOffset = LABEL_OFFSET_MAX;
vSpace = hSpace = Infinity;
};
// uPlot hook to draw the labels on the bar chart.
const draw = (u: uPlot) => {
if (showValue === VisibilityMode.Never || fontSize < VALUE_MIN_FONT_SIZE) {
return;
}
u.ctx.save();
u.ctx.fillStyle = theme.colors.text.primary;
u.ctx.font = `${fontSize}px ${theme.typography.fontFamily}`;
let curAlign: CanvasTextAlign | undefined = undefined,
curBaseline: CanvasTextBaseline | undefined = undefined;
for (const didx in labels) {
for (const sidx in labels[didx]) {
const { text, value, x = 0, y = 0, bbox = { x: 0, y: 0, w: 1, h: 1 } } = labels[didx][sidx];
let align: CanvasTextAlign = isXHorizontal ? 'center' : value !== null && value < 0 ? 'right' : 'left';
let baseline: CanvasTextBaseline = isXHorizontal
? value !== null && value < 0
? 'top'
: 'alphabetic'
: 'middle';
if (align !== curAlign) {
u.ctx.textAlign = curAlign = align;
}
if (baseline !== curBaseline) {
u.ctx.textBaseline = curBaseline = baseline;
}
if (showValue === VisibilityMode.Always) {
u.ctx.fillText(text, x, y);
} else if (showValue === VisibilityMode.Auto) {
let intersectsLabel = false;
// Test for any collisions
for (const subsidx in labels[didx]) {
const r = labels[didx][subsidx].bbox!;
if (!labels[didx][subsidx].hidden && sidx !== subsidx && intersects(bbox, r)) {
intersectsLabel = true;
labels[didx][sidx].hidden = true;
break;
}
}
!intersectsLabel && u.ctx.fillText(text, x, y);
}
}
}
u.ctx.restore();
};
// handle hover interaction with quadtree probing
const interpolateTooltip: PlotTooltipInterpolator = (
updateActiveSeriesIdx,
updateActiveDatapointIdx,
updateTooltipPosition,
u
) => {
if (hRect) {
updateActiveSeriesIdx(hRect.sidx);
updateActiveDatapointIdx(hRect.didx);
updateTooltipPosition();
} else {
updateTooltipPosition(true);
}
};
let alignedTotals: AlignedData | null = null;
function prepData(frames: DataFrame[]) {
alignedTotals = null;
return preparePlotData(
frames,
({ totals }) => {
alignedTotals = totals;
},
opts.legend
);
}
return {
cursor,
// scale & axis opts
xRange,
xValues,
xSplits,
barsBuilder,
// hooks
init,
drawClear,
draw,
interpolateTooltip,
prepData,
};
}