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pdf.js/test/integration/text_layer_spec.mjs
Nicolò Ribaudo da5b681b16
[chrome] Fix text selection with .markedContent
The current text layer approach based on absolutely positioned
`<span>` elements by default causes flickering with text selection,
and we have browser-specific workarounds to solve that.

In Chrome, the workaround involves moving the `.endOfContent` element to
right after the last element that contains some selected content. This
works well in simple PDFs, but breaks when we have `span.markedContent`
elements. Given a text layer structure like the following, rendered
as four consecutive lines:
```html
<span class="markedContent">
  <br>
  <span>development enter the construction phase (estimated at around</span>
</span>
<span class="markedContent">
  <br>
  <span>300 MEUR).</span>
</span>
<span class="markedContent">
  <br>
  <span>Kreate's EBITA increased to 2.8 MEUR (Q4'23: 2.7 MEUR) and the</span>
</span>
<span class="markedContent">
  <br>
  <span>margin rose to 3.7% (Q4'23: 3.4%). However, profitability was</span>
</span>
```
when starting to select from inside the first line and dragging down
to the empty space after the second line, Chrome will anchor the
selection at the beginning of either the `<br>` or the `<span>` inside
the last `.markedContent`, depending on whether the selection is in
"per-character mode" (i.e. click and drag) or "per-word mode" (i.e.
double click and drag). This causes us to insert the `.endOfContent`
element in the wrong place (one element too far), which causes one
more line to be selected, which triggers another `"selecctionchange"`
event, which causes us to move `.endOfContent` again, and so on, looping
until when the whole page is selected.

This commit fixes the issue by making sure that when the end of the
selection range points to the _begining_ of an element, we walk back
the dom finding the first non-empty element, and attatch `.endOfContent`
to the end of that.
2025-04-07 17:36:40 +02:00

583 lines
20 KiB
JavaScript

/* Copyright 2024 Mozilla Foundation
*
* 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 {
closePages,
closeSinglePage,
getSpanRectFromText,
loadAndWait,
waitForEvent,
} from "./test_utils.mjs";
import { startBrowser } from "../test.mjs";
describe("Text layer", () => {
describe("Text selection", () => {
// page.mouse.move(x, y, { steps: ... }) doesn't work in Firefox, because
// puppeteer will send fractional intermediate positions and Firefox doesn't
// support them. Use this function to round each intermediate position to an
// integer.
async function moveInSteps(page, from, to, steps) {
const deltaX = to.x - from.x;
const deltaY = to.y - from.y;
for (let i = 0; i <= steps; i++) {
const x = Math.round(from.x + (deltaX * i) / steps);
const y = Math.round(from.y + (deltaY * i) / steps);
await page.mouse.move(x, y);
}
}
function middlePosition(rect) {
return {
x: Math.round(rect.x + rect.width / 2),
y: Math.round(rect.y + rect.height / 2),
};
}
function middleLeftPosition(rect) {
return {
x: Math.round(rect.x + 1),
y: Math.round(rect.y + rect.height / 2),
};
}
function belowEndPosition(rect) {
return {
x: Math.round(rect.x + rect.width),
y: Math.round(rect.y + rect.height * 1.5),
};
}
beforeAll(() => {
jasmine.addAsyncMatchers({
// Check that a page has a selection containing the given text, with
// some tolerance for extra characters before/after.
toHaveRoughlySelected({ pp }) {
return {
async compare(page, expected) {
const TOLERANCE = 10;
const actual = await page.evaluate(() =>
// We need to normalize EOL for Windows
window.getSelection().toString().replaceAll("\r\n", "\n")
);
let start, end;
if (expected instanceof RegExp) {
const match = expected.exec(actual);
start = -1;
if (match) {
start = match.index;
end = start + match[0].length;
}
} else {
start = actual.indexOf(expected);
if (start !== -1) {
end = start + expected.length;
}
}
const pass =
start !== -1 &&
start < TOLERANCE &&
end > actual.length - TOLERANCE;
return {
pass,
message: `Expected ${pp(
actual.length > 200
? actual.slice(0, 100) + "[...]" + actual.slice(-100)
: actual
)} to ${pass ? "not " : ""}roughly match ${pp(expected)}.`,
};
},
};
},
});
});
describe("using mouse", () => {
describe("doesn't jump when hovering on an empty area", () => {
let pages;
beforeAll(async () => {
pages = await loadAndWait(
"tracemonkey.pdf",
`.page[data-page-number = "1"] .endOfContent`
);
});
afterAll(async () => {
await closePages(pages);
});
it("in a single page", async () => {
await Promise.all(
pages.map(async ([browserName, page]) => {
const [positionStart, positionEnd] = await Promise.all([
getSpanRectFromText(
page,
1,
"(frequently executed) bytecode sequences, records"
).then(middlePosition),
getSpanRectFromText(
page,
1,
"them, and compiles them to fast native code. We call such a se-"
).then(belowEndPosition),
]);
await page.mouse.move(positionStart.x, positionStart.y);
await page.mouse.down();
await moveInSteps(page, positionStart, positionEnd, 20);
await page.mouse.up();
await expectAsync(page)
.withContext(`In ${browserName}`)
.toHaveRoughlySelected(
"code sequences, records\n" +
"them, and compiles them to fast native code. We call suc"
);
})
);
});
it("across multiple pages", async () => {
await Promise.all(
pages.map(async ([browserName, page]) => {
const scrollTarget = await getSpanRectFromText(
page,
1,
"Unlike method-based dynamic compilers, our dynamic com-"
);
await page.evaluate(top => {
document.getElementById("viewerContainer").scrollTop = top;
}, scrollTarget.y - 50);
const [
positionStartPage1,
positionEndPage1,
positionStartPage2,
positionEndPage2,
] = await Promise.all([
getSpanRectFromText(
page,
1,
"Each compiled trace covers one path through the program with"
).then(middlePosition),
getSpanRectFromText(
page,
1,
"or that the same types will occur in subsequent loop iterations."
).then(middlePosition),
getSpanRectFromText(
page,
2,
"Hence, recording and compiling a trace"
).then(middlePosition),
getSpanRectFromText(
page,
2,
"cache. Alternatively, the VM could simply stop tracing, and give up"
).then(belowEndPosition),
]);
await page.mouse.move(positionStartPage1.x, positionStartPage1.y);
await page.mouse.down();
await moveInSteps(page, positionStartPage1, positionEndPage1, 20);
await moveInSteps(page, positionEndPage1, positionStartPage2, 20);
await expectAsync(page)
.withContext(`In ${browserName}, first selection`)
.toHaveRoughlySelected(
/path through the program .*Hence, recording a/s
);
await moveInSteps(page, positionStartPage2, positionEndPage2, 20);
await page.mouse.up();
await expectAsync(page)
.withContext(`In ${browserName}, second selection`)
.toHaveRoughlySelected(
/path through.*Hence, recording and .* tracing, and give/s
);
})
);
});
});
describe("doesn't jump when hovering on an empty area, with .markedContent", () => {
let pages;
beforeAll(async () => {
pages = await loadAndWait(
"chrome-text-selection-markedContent.pdf",
`.page[data-page-number = "1"] .endOfContent`
);
});
afterAll(async () => {
await closePages(pages);
});
it("in per-character selection mode", async () => {
await Promise.all(
pages.map(async ([browserName, page]) => {
const [positionStart, positionEnd] = await Promise.all([
getSpanRectFromText(
page,
1,
"strengthen in the coming quarters as the railway projects under"
).then(middlePosition),
getSpanRectFromText(
page,
1,
"development enter the construction phase (estimated at around"
).then(belowEndPosition),
]);
await page.mouse.move(positionStart.x, positionStart.y);
await page.mouse.down();
await moveInSteps(page, positionStart, positionEnd, 20);
await page.mouse.up();
await expectAsync(page)
.withContext(`In ${browserName}`)
.toHaveRoughlySelected(
"rs as the railway projects under\n" +
"development enter the construction phase (estimated at "
);
})
);
});
it("in per-word selection mode", async () => {
await Promise.all(
pages.map(async ([browserName, page]) => {
const [positionStart, positionEnd] = await Promise.all([
getSpanRectFromText(
page,
1,
"strengthen in the coming quarters as the railway projects under"
).then(middlePosition),
getSpanRectFromText(
page,
1,
"development enter the construction phase (estimated at around"
).then(belowEndPosition),
]);
if (browserName !== "firefox") {
await page.mouse.move(positionStart.x, positionStart.y);
await page.mouse.down({ clickCount: 1 });
await page.mouse.up({ clickCount: 1 });
await page.mouse.down({ clickCount: 2 });
} else {
// When running tests with Firefox we use WebDriver BiDi, for
// which puppeteer doesn't support emulating "double click and
// hold". We need to manually dispatch an action through the
// protocol.
// See https://github.com/puppeteer/puppeteer/issues/13745.
await page.mainFrame().browsingContext.performActions([
{
type: "pointer",
id: "__puppeteer_mouse",
actions: [
{ type: "pointerMove", ...positionStart },
{ type: "pointerDown", button: 0 },
{ type: "pointerUp", button: 0 },
{ type: "pointerDown", button: 0 },
],
},
]);
}
await moveInSteps(page, positionStart, positionEnd, 20);
await page.mouse.up();
await expectAsync(page)
.withContext(`In ${browserName}`)
.toHaveRoughlySelected(
"quarters as the railway projects under\n" +
"development enter the construction phase (estimated at around"
);
})
);
});
});
describe("when selecting over a link", () => {
let pages;
beforeAll(async () => {
pages = await loadAndWait(
"annotation-link-text-popup.pdf",
`.page[data-page-number = "1"] .endOfContent`
);
});
afterAll(async () => {
await closePages(pages);
});
afterEach(() =>
Promise.all(
pages.map(([_, page]) =>
page.evaluate(() => window.getSelection().removeAllRanges())
)
)
);
it("allows selecting within the link", async () => {
await Promise.all(
pages.map(async ([browserName, page]) => {
const [positionStart, positionEnd] = await Promise.all([
getSpanRectFromText(page, 1, "Link").then(middleLeftPosition),
getSpanRectFromText(page, 1, "mozilla.org").then(
middlePosition
),
]);
await page.mouse.move(positionStart.x, positionStart.y);
await page.mouse.down();
await moveInSteps(page, positionStart, positionEnd, 20);
await page.mouse.up();
await expectAsync(page)
.withContext(`In ${browserName}`)
.toHaveRoughlySelected("Link\nmozil");
})
);
});
it("allows selecting within the link when going backwards", async () => {
await Promise.all(
pages.map(async ([browserName, page]) => {
const [positionStart, positionEnd] = await Promise.all([
getSpanRectFromText(page, 1, "Text").then(middlePosition),
getSpanRectFromText(page, 1, "mozilla.org").then(
middlePosition
),
]);
await page.mouse.move(positionStart.x, positionStart.y);
await page.mouse.down();
await moveInSteps(page, positionStart, positionEnd, 20);
await page.mouse.up();
await expectAsync(page)
.withContext(`In ${browserName}`)
.toHaveRoughlySelected("a.org\nTe");
})
);
});
it("allows clicking the link after selecting", async () => {
await Promise.all(
pages.map(async ([browserName, page]) => {
const [positionStart, positionEnd] = await Promise.all([
getSpanRectFromText(page, 1, "Link").then(middleLeftPosition),
getSpanRectFromText(page, 1, "mozilla.org").then(
middlePosition
),
]);
await page.mouse.move(positionStart.x, positionStart.y);
await page.mouse.down();
await moveInSteps(page, positionStart, positionEnd, 20);
await page.mouse.up();
await waitForEvent({
page,
eventName: "click",
action: () => page.mouse.click(positionEnd.x, positionEnd.y),
selector: "#pdfjs_internal_id_8R",
validator: e => {
// Don't navigate to the link destination: the `click` event
// firing is enough validation that the link can be clicked.
e.preventDefault();
return true;
},
});
})
);
});
it("allows clicking the link after changing selection with the keyboard", async () => {
await Promise.all(
pages.map(async ([browserName, page]) => {
const [positionStart, positionEnd] = await Promise.all([
getSpanRectFromText(page, 1, "Link").then(middleLeftPosition),
getSpanRectFromText(page, 1, "mozilla.org").then(
middlePosition
),
]);
await page.mouse.move(positionStart.x, positionStart.y);
await page.mouse.down();
await moveInSteps(page, positionStart, positionEnd, 20);
await page.mouse.up();
await page.keyboard.down("Shift");
await page.keyboard.press("ArrowRight");
await page.keyboard.up("Shift");
await waitForEvent({
page,
eventName: "click",
action: () => page.mouse.click(positionEnd.x, positionEnd.y),
selector: "#pdfjs_internal_id_8R",
validator: e => {
// Don't navigate to the link destination: the `click` event
// firing is enough validation that the link can be clicked.
e.preventDefault();
return true;
},
});
})
);
});
});
});
describe("using selection carets", () => {
let browser;
let page;
beforeAll(async () => {
// Chrome does not support simulating caret-based selection, so this
// test only runs in Firefox.
browser = await startBrowser({
browserName: "firefox",
startUrl: "",
extraPrefsFirefox: {
"layout.accessiblecaret.enabled": true,
"layout.accessiblecaret.hide_carets_for_mouse_input": false,
},
});
page = await browser.newPage();
await page.goto(
`${global.integrationBaseUrl}?file=/test/pdfs/tracemonkey.pdf#zoom=page-fit`
);
await page.bringToFront();
await page.waitForSelector(
`.page[data-page-number = "1"] .endOfContent`,
{ timeout: 0 }
);
});
afterAll(async () => {
await closeSinglePage(page);
await browser.close();
});
it("doesn't jump when moving selection", async () => {
const [initialStart, initialEnd, finalEnd] = await Promise.all([
getSpanRectFromText(
page,
1,
"(frequently executed) bytecode sequences, records"
).then(middleLeftPosition),
getSpanRectFromText(
page,
1,
"(frequently executed) bytecode sequences, records"
).then(middlePosition),
getSpanRectFromText(
page,
1,
"them, and compiles them to fast native code. We call such a se-"
).then(belowEndPosition),
]);
await page.mouse.move(initialStart.x, initialStart.y);
await page.mouse.down();
await moveInSteps(page, initialStart, initialEnd, 20);
await page.mouse.up();
await expectAsync(page)
.withContext(`first selection`)
.toHaveRoughlySelected("frequently executed) byt");
const initialCaretPos = {
x: initialEnd.x,
y: initialEnd.y + 10,
};
const intermediateCaretPos = {
x: finalEnd.x,
y: finalEnd.y + 5,
};
const finalCaretPos = {
x: finalEnd.x + 20,
y: finalEnd.y + 5,
};
await page.mouse.move(initialCaretPos.x, initialCaretPos.y);
await page.mouse.down();
await moveInSteps(page, initialCaretPos, intermediateCaretPos, 20);
await page.mouse.up();
await expectAsync(page)
.withContext(`second selection`)
.toHaveRoughlySelected(/frequently .* We call such a se/s);
await page.mouse.down();
await moveInSteps(page, intermediateCaretPos, finalCaretPos, 20);
await page.mouse.up();
await expectAsync(page)
.withContext(`third selection`)
.toHaveRoughlySelected(/frequently .* We call such a se/s);
});
});
});
describe("when the browser enforces a minimum font size", () => {
let browser;
let page;
beforeAll(async () => {
// Only testing in Firefox because, while Chrome has a setting similar to
// font.minimum-size.x-western, it is not exposed through its API.
browser = await startBrowser({
browserName: "firefox",
startUrl: "",
extraPrefsFirefox: { "font.minimum-size.x-western": 40 },
});
page = await browser.newPage();
await page.goto(
`${global.integrationBaseUrl}?file=/test/pdfs/tracemonkey.pdf#zoom=100`
);
await page.bringToFront();
await page.waitForSelector(
`.page[data-page-number = "1"] .endOfContent`,
{ timeout: 0 }
);
});
afterAll(async () => {
await closeSinglePage(page);
await browser.close();
});
it("renders spans with the right size", async () => {
const rect = await getSpanRectFromText(
page,
1,
"Dynamic languages such as JavaScript are more difficult to com-"
);
// The difference between `a` and `b`, as a percentage of the lower one
const getPercentDiff = (a, b) => Math.max(a, b) / Math.min(a, b) - 1;
expect(getPercentDiff(rect.width, 315)).toBeLessThan(0.03);
expect(getPercentDiff(rect.height, 12)).toBeLessThan(0.03);
});
});
});