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1// Copyright (C) 2019 The Android Open Source Project
2//
3// Licensed under the Apache License, Version 2.0 (the "License");
4// you may not use this file except in compliance with the License.
5// You may obtain a copy of the License at
6//
7//      http://www.apache.org/licenses/LICENSE-2.0
8//
9// Unless required by applicable law or agreed to in writing, software
10// distributed under the License is distributed on an "AS IS" BASIS,
11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12// See the License for the specific language governing permissions and
13// limitations under the License.
14
15import {TRACK_SHELL_WIDTH} from './css_constants';
16import {TimeScale} from './time_scale';
17
18export function drawVerticalLineAtTime(ctx: CanvasRenderingContext2D,
19                                       timeScale: TimeScale,
20                                       time: number,
21                                       height: number,
22                                       color: string,
23                                       lineWidth = 2) {
24    const xPos = TRACK_SHELL_WIDTH + Math.floor(timeScale.timeToPx(time));
25    drawVerticalLine(ctx, xPos, height, color, lineWidth);
26  }
27
28function drawVerticalLine(ctx: CanvasRenderingContext2D,
29                          xPos: number,
30                          height: number,
31                          color: string,
32                          lineWidth = 2) {
33    ctx.beginPath();
34    ctx.strokeStyle = color;
35    const prevLineWidth = ctx.lineWidth;
36    ctx.lineWidth = lineWidth;
37    ctx.moveTo(xPos, 0);
38    ctx.lineTo(xPos, height);
39    ctx.stroke();
40    ctx.closePath();
41    ctx.lineWidth = prevLineWidth;
42}
43
44// This draws two shaded rectangles outside of the area of interest. Effectivly
45// highlighting an area by colouring/darkening the outside areas.
46export function drawVerticalSelection(
47    ctx: CanvasRenderingContext2D,
48    timeScale: TimeScale,
49    timeStart: number,
50    timeEnd: number,
51    height: number,
52    color: string) {
53  const xStartPos =
54      TRACK_SHELL_WIDTH + Math.floor(timeScale.timeToPx(timeStart));
55  const xEndPos = TRACK_SHELL_WIDTH + Math.floor(timeScale.timeToPx(timeEnd));
56  const width = timeScale.endPx;
57  ctx.fillStyle = color;
58  ctx.fillRect(0, 0, xStartPos, height);
59  // In the worst case xEndPos may be far to the left of the canvas (and so be
60  // <0) in this case fill the whole screen.
61  ctx.fillRect(Math.max(xEndPos, 0), 0, width + TRACK_SHELL_WIDTH, height);
62  drawVerticalLine(ctx, xStartPos, height, `rgba(52,69,150)`);
63  drawVerticalLine(ctx, xEndPos, height, `rgba(52,69,150)`);
64}
65