test: BrowserWindow backgroundColor and transparency (#31017)

* test: BrowserWindow backgroundColor

* test: allow similar colors

* test: disable linux capturing

* refactor: split screen capture from reading pixel color
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Samuel Maddock 2022-03-01 14:14:11 -08:00 committed by GitHub
parent 283fa2b79d
commit 7cb62bfc22
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3 changed files with 172 additions and 0 deletions

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@ -12,6 +12,7 @@ import { app, BrowserWindow, BrowserView, dialog, ipcMain, OnBeforeSendHeadersLi
import { emittedOnce, emittedUntil, emittedNTimes } from './events-helpers';
import { ifit, ifdescribe, defer, delay } from './spec-helpers';
import { closeWindow, closeAllWindows } from './window-helpers';
import { areColorsSimilar, captureScreen, CHROMA_COLOR_HEX, getPixelColor } from './screen-helpers';
const features = process._linkedBinding('electron_common_features');
const fixtures = path.resolve(__dirname, '..', 'spec', 'fixtures');
@ -4872,5 +4873,69 @@ describe('BrowserWindow module', () => {
w.setBounds(newBounds);
expect(w.getBounds()).to.deep.equal(newBounds);
});
// Linux doesn't return any capture sources.
ifit(process.platform !== 'linux')('should not display a visible background', async () => {
const display = screen.getPrimaryDisplay();
const backgroundWindow = new BrowserWindow({
...display.bounds,
frame: false,
backgroundColor: CHROMA_COLOR_HEX,
hasShadow: false
});
await backgroundWindow.loadURL('about:blank');
const foregroundWindow = new BrowserWindow({
...display.bounds,
show: true,
transparent: true,
frame: false,
hasShadow: false
});
foregroundWindow.loadFile(path.join(__dirname, 'fixtures', 'pages', 'half-background-color.html'));
await emittedOnce(foregroundWindow, 'ready-to-show');
const screenCapture = await captureScreen();
const leftHalfColor = getPixelColor(screenCapture, {
x: display.size.width / 4,
y: display.size.height / 2
});
const rightHalfColor = getPixelColor(screenCapture, {
x: display.size.width - (display.size.width / 4),
y: display.size.height / 2
});
expect(areColorsSimilar(leftHalfColor, CHROMA_COLOR_HEX)).to.be.true();
expect(areColorsSimilar(rightHalfColor, '#ff0000')).to.be.true();
});
});
describe('"backgroundColor" option', () => {
afterEach(closeAllWindows);
// Linux doesn't return any capture sources.
ifit(process.platform !== 'linux')('should display the set color', async () => {
const display = screen.getPrimaryDisplay();
const w = new BrowserWindow({
...display.bounds,
show: true,
backgroundColor: CHROMA_COLOR_HEX
});
w.loadURL('about:blank');
await emittedOnce(w, 'ready-to-show');
const screenCapture = await captureScreen();
const centerColor = getPixelColor(screenCapture, {
x: display.size.width / 2,
y: display.size.height / 2
});
expect(areColorsSimilar(centerColor, CHROMA_COLOR_HEX)).to.be.true();
});
});
});

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@ -0,0 +1,20 @@
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width">
<style>
#main {
position: fixed;
left: 50%;
right: 0;
top: 0;
bottom: 0;
background-color: #ff0000;
}
</style>
</head>
<body>
<div id="main"></div>
</body>
</html>

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@ -0,0 +1,87 @@
import * as path from 'path';
import * as fs from 'fs';
import { screen, desktopCapturer, NativeImage } from 'electron';
const fixtures = path.resolve(__dirname, '..', 'spec', 'fixtures');
/** Chroma key green. */
export const CHROMA_COLOR_HEX = '#00b140';
/**
* Capture the screen at the given point.
*
* NOTE: Not yet supported on Linux in CI due to empty sources list.
*/
export const captureScreen = async (point: Electron.Point = { x: 0, y: 0 }): Promise<NativeImage> => {
const display = screen.getDisplayNearestPoint(point);
const sources = await desktopCapturer.getSources({ types: ['screen'], thumbnailSize: display.size });
// Toggle to save screen captures for debugging.
const DEBUG_CAPTURE = false;
if (DEBUG_CAPTURE) {
for (const source of sources) {
await fs.promises.writeFile(path.join(fixtures, `screenshot_${source.display_id}.png`), source.thumbnail.toPNG());
}
}
const screenCapture = sources.find(source => source.display_id === `${display.id}`);
// Fails when HDR is enabled on Windows.
// https://bugs.chromium.org/p/chromium/issues/detail?id=1247730
if (!screenCapture) {
const displayIds = sources.map(source => source.display_id);
throw new Error(`Unable to find screen capture for display '${display.id}'\n\tAvailable displays: ${displayIds.join(', ')}`);
}
return screenCapture.thumbnail;
};
const formatHexByte = (val: number): string => {
const str = val.toString(16);
return str.length === 2 ? str : `0${str}`;
};
/**
* Get the hex color at the given pixel coordinate in an image.
*/
export const getPixelColor = (image: Electron.NativeImage, point: Electron.Point): string => {
const pixel = image.crop({ ...point, width: 1, height: 1 });
// TODO(samuelmaddock): NativeImage.toBitmap() should return the raw pixel
// color, but it sometimes differs. Why is that?
const [b, g, r] = pixel.toBitmap();
return `#${formatHexByte(r)}${formatHexByte(g)}${formatHexByte(b)}`;
};
const hexToRgba = (hexColor: string) => {
const match = hexColor.match(/^#([0-9a-fA-F]{6,8})$/);
if (!match) return;
const colorStr = match[1];
return [
parseInt(colorStr.substring(0, 2), 16),
parseInt(colorStr.substring(2, 4), 16),
parseInt(colorStr.substring(4, 6), 16),
parseInt(colorStr.substring(6, 8), 16) || 0xFF
];
};
/** Calculate euclidian distance between colors. */
const colorDistance = (hexColorA: string, hexColorB: string) => {
const colorA = hexToRgba(hexColorA);
const colorB = hexToRgba(hexColorB);
if (!colorA || !colorB) return -1;
return Math.sqrt(
Math.pow(colorB[0] - colorA[0], 2) +
Math.pow(colorB[1] - colorA[1], 2) +
Math.pow(colorB[2] - colorA[2], 2)
);
};
/**
* Determine if colors are similar based on distance. This can be useful when
* comparing colors which may differ based on lossy compression.
*/
export const areColorsSimilar = (
hexColorA: string,
hexColorB: string,
distanceThreshold = 90
): boolean => {
const distance = colorDistance(hexColorA, hexColorB);
return distance <= distanceThreshold;
};