ui/src/frontend/vertical_line_helper.ts

// Copyright (C) 2019 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 {time} from '../base/time';
import {TimeScale} from '../base/time_scale';

export function drawVerticalLineAtTime(
  ctx: CanvasRenderingContext2D,
  timeScale: TimeScale,
  time: time,
  height: number,
  color: string,
  lineWidth = 2,
) {
  const xPos = Math.floor(timeScale.timeToPx(time));
  drawVerticalLine(ctx, xPos, height, color, lineWidth);
}

function drawVerticalLine(
  ctx: CanvasRenderingContext2D,
  xPos: number,
  height: number,
  color: string,
  lineWidth = 2,
) {
  ctx.beginPath();
  ctx.strokeStyle = color;
  const prevLineWidth = ctx.lineWidth;
  ctx.lineWidth = lineWidth;
  ctx.moveTo(xPos, 0);
  ctx.lineTo(xPos, height);
  ctx.stroke();
  ctx.closePath();
  ctx.lineWidth = prevLineWidth;
}