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// Copyright (C) 2021 The Android Open Source Project
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
import {assertExists} from '../base/logging';
import {Actions} from '../common/actions';
import {cropText, drawIncompleteSlice} from '../common/canvas_utils';
import {colorCompare, colorToStr, GRAY_COLOR} from '../common/colorizer';
import {NUM, QueryResult} from '../common/query_result';
import {SelectionKind} from '../common/state';
import {fromNs, toNs} from '../common/time';
import {checkerboardExcept} from './checkerboard';
import {globals} from './globals';
import {Slice} from './slice';
import {DEFAULT_SLICE_LAYOUT, SliceLayout} from './slice_layout';
import {NewTrackArgs, SliceRect, Track} from './track';
// The common class that underpins all tracks drawing slices.
export const SLICE_FLAGS_INCOMPLETE = 1;
export const SLICE_FLAGS_INSTANT = 2;
// Slices smaller than this don't get any text:
const SLICE_MIN_WIDTH_FOR_TEXT_PX = 5;
// Slices smaller than this aren't rendered at all.
const SLICE_MIN_WIDTH_PX = 0.1;
const CHEVRON_WIDTH_PX = 10;
const DEFAULT_SLICE_COLOR = GRAY_COLOR;
// TODO(hjd): Implement caching.
// The minimal set of columns that any table/view must expose to render tracks.
// Note: this class assumes that, at the SQL level, slices are:
// - Not temporally overlapping (unless they are nested at inner depth).
// - Strictly stacked (i.e. a slice at depth N+1 cannot be larger than any
// slices at depth 0..N.
// If you need temporally overlapping slices, look at AsyncSliceTrack, which
// merges several tracks into one visual track.
export const BASE_SLICE_ROW = {
id: NUM, // The slice ID, for selection / lookups.
tsq: NUM, // Quantized |ts|. This class owns the quantization logic.
ts: NUM, // Start time in nanoseconds.
dur: NUM, // Duration in nanoseconds. -1 = incomplete, 0 = instant.
depth: NUM, // Vertical depth.
};
export type BaseSliceRow = typeof BASE_SLICE_ROW;
// These properties change @ 60FPS and shouldn't be touched by the subclass.
// since the Impl doesn't see every frame attempting to reason on them in a
// subclass will run in to issues.
interface SliceInternal {
x: number;
w: number;
}
// We use this to avoid exposing subclasses to the properties that live on
// SliceInternal. Within BaseSliceTrack the underlying storage and private
// methods use CastInternal<T['slice']> (i.e. whatever the subclass requests
// plus our implementation fields) but when we call 'virtual' methods that
// the subclass should implement we use just T['slice'] hiding x & w.
type CastInternal<S extends Slice> = S&SliceInternal;
// The meta-type which describes the types used to extend the BaseSliceTrack.
// Derived classes can extend this interface to override these types if needed.
export interface BaseSliceTrackTypes {
slice: Slice;
row: BaseSliceRow;
config: {};
}
export abstract class BaseSliceTrack<T extends BaseSliceTrackTypes =
BaseSliceTrackTypes> extends
Track<T['config']> {
// This is the slice cache.
private slices = new Array<CastInternal<T['slice']>>();
protected sliceLayout: SliceLayout = {...DEFAULT_SLICE_LAYOUT};
// These are the over-skirted cached bounds.
private slicesStartNs = -1;
private slicesEndNs = -1;
private slicesBucketNs = -1;
private readonly tableName: string;
private maxDurNs = 0;
private sqlState: 'UNINITIALIZED'|'INITIALIZING'|'QUERY_PENDING'|
'QUERY_DONE' = 'UNINITIALIZED';
private extraSqlColumns: string[];
private charWidth = -1;
private hoverPos?: {x: number, y: number};
protected hoveredSlice?: T['slice'];
private hoverTooltip: string[] = [];
private maxDataDepth = 0;
// Computed layout.
private computedTrackHeight = 0;
private computedSliceHeight = 0;
private computedRowSpacing = 0;
// True if this track (and any views tables it might have created) has been
// destroyed. This is unfortunately error prone (since we must manually check
// this between each query).
// TODO(hjd): Replace once we have cancellable query sequences.
private isDestroyed = false;
// TODO(hjd): Remove when updating selection.
// We shouldn't know here about CHROME_SLICE. Maybe should be set by
// whatever deals with that. Dunno the namespace of selection is weird. For
// most cases in non-ambiguous (because most things are a 'slice'). But some
// others (e.g. THREAD_SLICE) have their own ID namespace so we need this.
protected selectionKinds: SelectionKind[] = ['SLICE', 'CHROME_SLICE'];
// Extension points.
// Each extension point should take a dedicated argument type (e.g.,
// OnSliceOverArgs {slice?: T['slice']}) so it makes future extensions
// non-API-breaking (e.g. if we want to add the X position).
abstract initSqlTable(_tableName: string): Promise<void>;
getRowSpec(): T['row'] {
return BASE_SLICE_ROW;
}
onSliceOver(_args: OnSliceOverArgs<T['slice']>): void {}
onSliceOut(_args: OnSliceOutArgs<T['slice']>): void {}
onSliceClick(_args: OnSliceClickArgs<T['slice']>): void {}
prepareSlices(slices: Array<T['slice']>): void {
this.highlightHovererdAndSameTitle(slices);
}
// TODO(hjd): Remove.
drawSchedLatencyArrow(
_: CanvasRenderingContext2D, _selectedSlice?: T['slice']): void {}
constructor(args: NewTrackArgs) {
super(args);
this.frontendOnly = true; // Disable auto checkerboarding.
this.tableName = `track_${this.trackId}`.replace(/[^a-zA-Z0-9_]+/g, '_');
// Work out the extra columns.
// This is the union of the embedder-defined columns and the base columns
// we know about (ts, dur, ...).
const allCols = Object.keys(this.getRowSpec());
const baseCols = Object.keys(BASE_SLICE_ROW);
this.extraSqlColumns = allCols.filter(key => !baseCols.includes(key));
}
setSliceLayout(sliceLayout: SliceLayout) {
if (sliceLayout.minDepth > sliceLayout.maxDepth) {
const {maxDepth, minDepth} = sliceLayout;
throw new Error(`minDepth ${minDepth} must be <= maxDepth ${maxDepth}`);
}
this.sliceLayout = sliceLayout;
}
onFullRedraw(): void {
// TODO(hjd): Call this only when cache changes. See discussion:
// What we want to do here is give the Impl a chance to colour the slice,
// e.g. depending on the currently selected thread or process.
// Here's an interesting thought. We have two options here:
// A) We could pass only the vizSlices, but then we'd have to call this
// @ 60FPS (because vizSlices changes as we pan).
// B) We could call this only on full redraws (when the state changes),
// but then the track needs to process *all* cached slices, not just
// the visible ones. It's okay now (it's a 2x factor) but might get
// worse if we cache several layers of slices at various resolutions.
// But there's an escape, I think. I think the right thing to do is:
// - For now call it on the full slices, but only on full redraws.
// - When we get caching, call it every time we switch "cached quantization
// level", which is a way in the middle between 60FPS and full redraws..
// Overall the API contract of this prepareSlices() call is:
// - I am going to draw these slices in the near future.
// - I am not going to draw any slice that I haven't passed here first.
// - This is guaranteed to be called at least on every state change.
// - This is NOT guaranteed to be called on every frame. For instance you
// cannot use this to do some colour-based animation.
// Give a chance to the embedder to change colors and other stuff.
this.prepareSlices(this.slices);
}
renderCanvas(ctx: CanvasRenderingContext2D): void {
// TODO(hjd): fonts and colors should come from the CSS and not hardcoded
// here.
const {timeScale} = globals.frontendLocalState;
const vizTime = globals.frontendLocalState.visibleWindowTime;
// If the visible time range is outside the cached area, requests
// asynchronously new data from the SQL engine.
this.maybeRequestData();
// In any case, draw whatever we have (which might be stale/incomplete).
// If the cached trace slices don't fully cover the visible time range,
// show a gray rectangle with a "Loading..." label.
checkerboardExcept(
ctx,
this.getHeight(),
timeScale.timeToPx(vizTime.start),
timeScale.timeToPx(vizTime.end),
timeScale.timeToPx(fromNs(this.slicesStartNs)),
timeScale.timeToPx(fromNs(this.slicesEndNs)));
let charWidth = this.charWidth;
if (charWidth < 0) {
// TODO(hjd): Centralize font measurement/invalidation.
ctx.font = '12px Roboto Condensed';
charWidth = this.charWidth = ctx.measureText('dbpqaouk').width / 8;
}
// Filter only the visible slices. |this.slices| will have more slices than
// needed because maybeRequestData() over-fetches to handle small pan/zooms.
// We don't want to waste time drawing slices that are off screen.
const vizSlices = this.getVisibleSlicesInternal(vizTime.start, vizTime.end);
let selection = globals.state.currentSelection;
if (!selection || !this.selectionKinds.includes(selection.kind)) {
selection = null;
}
// Believe it or not, doing 4xO(N) passes is ~2x faster than trying to draw
// everything in one go. The key is that state changes operations on the
// canvas (e.g., color, fonts) dominate any number crunching we do in JS.
this.updateSliceAndTrackHeight();
const sliceHeight = this.computedSliceHeight;
const padding = this.sliceLayout.padding;
const rowSpacing = this.computedRowSpacing;
// First pass: compute geometry of slices.
let selSlice: CastInternal<T['slice']>|undefined;
// pxEnd is the last visible pixel in the visible viewport. Drawing
// anything < 0 or > pxEnd doesn't produce any visible effect as it goes
// beyond the visible portion of the canvas.
const pxEnd = Math.floor(timeScale.timeToPx(vizTime.end));
for (const slice of vizSlices) {
// Compute the basic geometry for any visible slice, even if only
// partially visible. This might end up with a negative x if the
// slice starts before the visible time or with a width that overflows
// pxEnd.
slice.x = timeScale.timeToPx(slice.startS);
slice.w = timeScale.deltaTimeToPx(slice.durationS);
if (slice.flags & SLICE_FLAGS_INSTANT) {
// In the case of an instant slice, set the slice geometry on the
// bounding box that will contain the chevron.
slice.x -= CHEVRON_WIDTH_PX / 2;
slice.w = CHEVRON_WIDTH_PX;
} else {
// If the slice is an actual slice, intersect the slice geometry with
// the visible viewport (this affects only the first and last slice).
// This is so that text is always centered even if we are zoomed in.
// Visually if we have
// [ visible viewport ]
// [ slice ]
// The resulting geometry will be:
// [slice]
// So that the slice title stays within the visible region.
const sliceVizLimit = Math.min(slice.x + slice.w, pxEnd);
slice.x = Math.max(slice.x, 0);
slice.w = sliceVizLimit - slice.x;
}
if (selection && (selection as {id: number}).id === slice.id) {
selSlice = slice;
}
}
// Second pass: fill slices by color.
// The .slice() turned out to be an unintended pun.
const vizSlicesByColor = vizSlices.slice();
vizSlicesByColor.sort((a, b) => colorCompare(a.color, b.color));
let lastColor = undefined;
for (const slice of vizSlicesByColor) {
if (slice.color !== lastColor) {
lastColor = slice.color;
ctx.fillStyle = colorToStr(slice.color);
}
const y = padding + slice.depth * (sliceHeight + rowSpacing);
if (slice.flags & SLICE_FLAGS_INSTANT) {
this.drawChevron(ctx, slice.x, y, sliceHeight);
} else if (slice.flags & SLICE_FLAGS_INCOMPLETE) {
const w = Math.max(slice.w - 2, 2);
drawIncompleteSlice(ctx, slice.x, y, w, sliceHeight);
} else if (slice.w > SLICE_MIN_WIDTH_PX) {
ctx.fillRect(slice.x, y, slice.w, sliceHeight);
}
}
// Third pass, draw the titles (e.g., process name for sched slices).
ctx.fillStyle = '#fff';
ctx.textAlign = 'center';
ctx.font = '12px Roboto Condensed';
ctx.textBaseline = 'middle';
for (const slice of vizSlices) {
if ((slice.flags & SLICE_FLAGS_INSTANT) || !slice.title ||
slice.w < SLICE_MIN_WIDTH_FOR_TEXT_PX) {
continue;
}
const title = cropText(slice.title, charWidth, slice.w);
const rectXCenter = slice.x + slice.w / 2;
const y = padding + slice.depth * (sliceHeight + rowSpacing);
const yDiv = slice.subTitle ? 3 : 2;
const yMidPoint = Math.floor(y + sliceHeight / yDiv) - 0.5;
ctx.fillText(title, rectXCenter, yMidPoint);
}
// Fourth pass, draw the subtitles (e.g., thread name for sched slices).
ctx.fillStyle = 'rgba(255, 255, 255, 0.6)';
ctx.font = '10px Roboto Condensed';
for (const slice of vizSlices) {
if (slice.w < SLICE_MIN_WIDTH_FOR_TEXT_PX || !slice.subTitle ||
(slice.flags & SLICE_FLAGS_INSTANT)) {
continue;
}
const rectXCenter = slice.x + slice.w / 2;
const subTitle = cropText(slice.subTitle, charWidth, slice.w);
const y = padding + slice.depth * (sliceHeight + rowSpacing);
const yMidPoint = Math.ceil(y + sliceHeight * 2 / 3) + 1.5;
ctx.fillText(subTitle, rectXCenter, yMidPoint);
}
// Draw a thicker border around the selected slice (or chevron).
if (selSlice !== undefined) {
const color = selSlice.color;
const y = padding + selSlice.depth * (sliceHeight + rowSpacing);
ctx.strokeStyle = `hsl(${color.h}, ${color.s}%, 30%)`;
ctx.beginPath();
const THICKNESS = 3;
ctx.lineWidth = THICKNESS;
ctx.strokeRect(
selSlice.x, y - THICKNESS / 2, selSlice.w, sliceHeight + THICKNESS);
ctx.closePath();
}
// TODO(hjd): Remove this.
// The only thing this does is drawing the sched latency arrow. We should
// have some abstraction for that arrow (ideally the same we'd use for
// flows).
this.drawSchedLatencyArrow(ctx, selSlice);
// If a slice is hovered, draw the tooltip.
const tooltip = this.hoverTooltip;
if (this.hoveredSlice !== undefined && tooltip.length > 0 &&
this.hoverPos !== undefined) {
if (tooltip.length === 1) {
this.drawTrackHoverTooltip(ctx, this.hoverPos, tooltip[0]);
} else {
this.drawTrackHoverTooltip(ctx, this.hoverPos, tooltip[0], tooltip[1]);
}
} // if (howSlice)
}
onDestroy() {
super.onDestroy();
this.isDestroyed = true;
this.engine.query(`DROP VIEW IF EXISTS ${this.tableName}`);
}
// This method figures out if the visible window is outside the bounds of
// the cached data and if so issues new queries (i.e. sorta subsumes the
// onBoundsChange).
async maybeRequestData() {
// Important: this method is async and is invoked on every frame. Care
// must be taken to avoid piling up queries on every frame, hence the FSM.
if (this.sqlState === 'UNINITIALIZED') {
this.sqlState = 'INITIALIZING';
if (this.isDestroyed) {
return;
}
await this.initSqlTable(this.tableName);
if (this.isDestroyed) {
return;
}
const queryRes = await this.engine.query(`select
ifnull(max(dur), 0) as maxDur, count(1) as rowCount
from ${this.tableName}`);
const row = queryRes.firstRow({maxDur: NUM, rowCount: NUM});
this.maxDurNs = row.maxDur;
this.sqlState = 'QUERY_DONE';
} else if (
this.sqlState === 'INITIALIZING' || this.sqlState === 'QUERY_PENDING') {
return;
}
const resolutionNs = toNs(globals.getCurResolution());
const vizTime = globals.frontendLocalState.visibleWindowTime;
const startNs = toNs(vizTime.start);
const endNs = toNs(vizTime.end);
// TODO(hjd): figure out / centralize the resolution steps.
// Will handle this at the same time as cacheing.
const bucketNs = resolutionNs;
if (startNs >= this.slicesStartNs && endNs <= this.slicesEndNs &&
bucketNs === this.slicesBucketNs) {
return; // We have the data already, no need to re-query
}
this.sqlState = 'QUERY_PENDING';
const queryTsq = `(ts + ${bucketNs / 2}) / ${bucketNs} * ${bucketNs}`;
const extraCols = this.extraSqlColumns.join(',');
let depthCol = 'depth';
let maybeGroupByDepth = 'depth, ';
const layout = this.sliceLayout;
const isFlat = (layout.maxDepth - layout.minDepth) <= 1;
// maxDepth === minDepth only makes sense if track is empty which on the
// one hand isn't very useful (and so maybe should be an error) on the
// other hand I can see it happening if someone does:
// minDepth = min(slices.depth); maxDepth = max(slices.depth);
// and slices is empty, so we treat that as flat.
if (isFlat) {
depthCol = `${this.sliceLayout.minDepth} as depth`;
maybeGroupByDepth = '';
}
// TODO(hjd): Re-reason and improve this query:
// - Materialize the unfinished slices one off.
// - Avoid the union if we know we don't have any -1 slices.
// - Maybe we don't need the union at all and can deal in TS?
if (this.isDestroyed) {
return;
}
const queryRes = await this.engine.query(`
with q1 as (
select
${queryTsq} as tsq,
ts,
max(dur) as dur,
id,
${depthCol}
${extraCols ? ',' + extraCols : ''}
from ${this.tableName}
where
ts >= ${startNs - this.maxDurNs /* - durNs */} and
ts <= ${endNs /* + durNs */}
group by ${maybeGroupByDepth} tsq
order by tsq),
q2 as (
select
${queryTsq} as tsq,
ts,
-1 as dur,
id,
${depthCol}
${extraCols ? ',' + extraCols : ''}
from ${this.tableName}
where dur = -1
group by ${maybeGroupByDepth} tsq
)
select min(dur) as _unused, * from
(select * from q1 union all select * from q2)
group by ${maybeGroupByDepth} tsq
order by tsq
`);
this.convertQueryResultToSlices(queryRes, startNs, endNs, bucketNs);
this.sqlState = 'QUERY_DONE';
globals.rafScheduler.scheduleRedraw();
}
// Here convert each row to a Slice. We do what we can do generically
// in the base class, and delegate the rest to the impl via that rowToSlice()
// abstract call.
convertQueryResultToSlices(
queryRes: QueryResult, startNs: number, endNs: number, bucketNs: number) {
const slices = new Array<CastInternal<T['slice']>>(queryRes.numRows());
const it = queryRes.iter(this.getRowSpec());
let maxDataDepth = this.maxDataDepth;
this.slicesStartNs = startNs;
this.slicesEndNs = endNs;
this.slicesBucketNs = bucketNs;
for (let i = 0; it.valid(); it.next(), ++i) {
maxDataDepth = Math.max(maxDataDepth, it.depth);
// Construct the base slice. The Impl will construct and return the full
// derived T["slice"] (e.g. CpuSlice) in the rowToSlice() method.
slices[i] = this.rowToSliceInternal(it);
}
this.maxDataDepth = maxDataDepth;
this.slices = slices;
}
private rowToSliceInternal(row: T['row']): CastInternal<T['slice']> {
const slice = this.rowToSlice(row) as CastInternal<T['slice']>;
slice.x = -1;
slice.w = -1;
return slice;
}
rowToSlice(row: T['row']): T['slice'] {
const startNsQ = row.tsq;
const startNs = row.ts;
let flags = 0;
let durNs: number;
if (row.dur === -1) {
durNs = toNs(globals.state.traceTime.endSec) - startNs;
flags |= SLICE_FLAGS_INCOMPLETE;
} else {
flags |= (row.dur === 0) ? SLICE_FLAGS_INSTANT : 0;
durNs = row.dur;
}
const endNs = startNs + durNs;
const bucketNs = this.slicesBucketNs;
let endNsQ = Math.floor((endNs + bucketNs / 2 - 1) / bucketNs) * bucketNs;
endNsQ = Math.max(endNsQ, startNsQ + bucketNs);
return {
id: row.id,
startS: fromNs(startNsQ),
durationS: fromNs(endNsQ - startNsQ),
flags,
depth: row.depth,
title: '',
subTitle: '',
// The derived class doesn't need to initialize these. They are
// rewritten on every renderCanvas() call. We just need to initialize
// them to something.
baseColor: DEFAULT_SLICE_COLOR,
color: DEFAULT_SLICE_COLOR,
};
}
private findSlice({x, y}: {x: number, y: number}): undefined|Slice {
const trackHeight = this.computedTrackHeight;
const sliceHeight = this.computedSliceHeight;
const padding = this.sliceLayout.padding;
const rowSpacing = this.computedRowSpacing;
// Need at least a draw pass to resolve the slice layout.
if (sliceHeight === 0) {
return undefined;
}
if (y >= padding && y <= trackHeight - padding) {
const depth = Math.floor((y - padding) / (sliceHeight + rowSpacing));
for (const slice of this.slices) {
if (slice.depth === depth && slice.x <= x && x <= slice.x + slice.w) {
return slice;
}
}
}
return undefined;
}
onMouseMove(position: {x: number, y: number}): void {
this.hoverPos = position;
this.updateHoveredSlice(this.findSlice(position));
}
onMouseOut(): void {
this.updateHoveredSlice(undefined);
}
private updateHoveredSlice(slice?: T['slice']): void {
const lastHoveredSlice = this.hoveredSlice;
this.hoveredSlice = slice;
// Only notify the Impl if the hovered slice changes:
if (slice === lastHoveredSlice) return;
if (this.hoveredSlice === undefined) {
globals.dispatch(Actions.setHighlightedSliceId({sliceId: -1}));
this.onSliceOut({slice: assertExists(lastHoveredSlice)});
this.hoverTooltip = [];
this.hoverPos = undefined;
} else {
const args: OnSliceOverArgs<T['slice']> = {slice: this.hoveredSlice};
globals.dispatch(
Actions.setHighlightedSliceId({sliceId: this.hoveredSlice.id}));
this.onSliceOver(args);
this.hoverTooltip = args.tooltip || [];
}
}
onMouseClick(position: {x: number, y: number}): boolean {
const slice = this.findSlice(position);
if (slice === undefined) {
return false;
}
const args: OnSliceClickArgs<T['slice']> = {slice};
this.onSliceClick(args);
return true;
}
private getVisibleSlicesInternal(startS: number, endS: number):
Array<CastInternal<T['slice']>> {
return this.getVisibleSlices(startS, endS);
}
getVisibleSlices(startS: number, endS: number):
Array<CastInternal<T['slice']>> {
let startIdx = -1;
let endIdx = -1;
let i = 0;
// TODO(hjd): binary search.
for (const slice of this.slices) {
if (startIdx < 0 && slice.startS + slice.durationS >= startS) {
startIdx = i;
}
if (slice.startS <= endS) {
endIdx = i + 1;
} else if (slice.startS > endS) {
endIdx = i;
break;
}
i++;
}
return this.slices.slice(startIdx, endIdx);
}
private updateSliceAndTrackHeight() {
const lay = this.sliceLayout;
const rows =
Math.min(Math.max(this.maxDataDepth + 1, lay.minDepth), lay.maxDepth);
// Compute the track height.
let trackHeight;
if (lay.heightMode === 'FIXED') {
trackHeight = lay.fixedHeight;
} else {
trackHeight = 2 * lay.padding + rows * (lay.sliceHeight + lay.rowSpacing);
}
// Compute the slice height.
let sliceHeight: number;
let rowSpacing: number = lay.rowSpacing;
if (lay.heightMode === 'FIXED') {
const rowHeight = (trackHeight - 2 * lay.padding) / rows;
sliceHeight = Math.floor(Math.max(rowHeight - lay.rowSpacing, 0.5));
rowSpacing = Math.max(lay.rowSpacing, rowHeight - sliceHeight);
rowSpacing = Math.floor(rowSpacing * 2) / 2;
} else {
sliceHeight = lay.sliceHeight;
}
this.computedSliceHeight = sliceHeight;
this.computedTrackHeight = trackHeight;
this.computedRowSpacing = rowSpacing;
}
private drawChevron(
ctx: CanvasRenderingContext2D, x: number, y: number, h: number) {
// Draw an upward facing chevrons, in order: A, B, C, D, and back to A.
// . (x, y)
// A
// ###
// ##C##
// ## ##
// D B
// . (x + CHEVRON_WIDTH_PX, y + h)
const HALF_CHEVRON_WIDTH_PX = CHEVRON_WIDTH_PX / 2;
const midX = x + HALF_CHEVRON_WIDTH_PX;
ctx.beginPath();
ctx.moveTo(midX, y); // A.
ctx.lineTo(x + CHEVRON_WIDTH_PX, y + h); // B.
ctx.lineTo(midX, y + h - HALF_CHEVRON_WIDTH_PX); // C.
ctx.lineTo(x, y + h); // D.
ctx.lineTo(midX, y); // Back to A.
ctx.closePath();
ctx.fill();
}
// This is a good default implemenation for highlighting slices. By default
// prepareSlices() calls this. However, if the XxxSliceTrack impl overrides
// prepareSlices() this gives them a chance to call the highlighting witout
// having to reimplement it.
protected highlightHovererdAndSameTitle(slices: Slice[]) {
for (const slice of slices) {
const isHovering = globals.state.highlightedSliceId === slice.id ||
(this.hoveredSlice && this.hoveredSlice.title === slice.title);
if (isHovering) {
slice.color = {
c: slice.baseColor.c,
h: slice.baseColor.h,
s: slice.baseColor.s,
l: 30
};
} else {
slice.color = slice.baseColor;
}
}
}
getHeight(): number {
this.updateSliceAndTrackHeight();
return this.computedTrackHeight;
}
getSliceRect(_tStart: number, _tEnd: number, _depth: number): SliceRect
|undefined {
// TODO(hjd): Implement this as part of updating flow events.
return undefined;
}
}
// This is the argument passed to onSliceOver(args).
// This is really a workaround for the fact that TypeScript doesn't allow
// inner types within a class (whether the class is templated or not).
export interface OnSliceOverArgs<S extends Slice> {
// Input args (BaseSliceTrack -> Impl):
slice: S; // The slice being hovered.
// Output args (Impl -> BaseSliceTrack):
tooltip?: string[]; // One entry per row, up to a max of 2.
}
export interface OnSliceOutArgs<S extends Slice> {
// Input args (BaseSliceTrack -> Impl):
slice: S; // The slice which is not hovered anymore.
}
export interface OnSliceClickArgs<S extends Slice> {
// Input args (BaseSliceTrack -> Impl):
slice: S; // The slice which is clicked.
}