@cantoo/pdf-lib
Version:
Create and modify PDF files with JavaScript
211 lines • 8.55 kB
JavaScript
"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.layoutSinglelineText = exports.layoutCombedText = exports.layoutMultilineText = void 0;
const errors_1 = require("../errors");
const alignment_1 = require("./alignment");
const utils_1 = require("../../utils");
const MIN_FONT_SIZE = 4;
const MAX_FONT_SIZE = 500;
const computeFontSize = (lines, font, bounds, multiline = false) => {
let fontSize = MIN_FONT_SIZE;
while (fontSize < MAX_FONT_SIZE) {
let linesUsed = 0;
for (let lineIdx = 0, lineLen = lines.length; lineIdx < lineLen; lineIdx++) {
linesUsed += 1;
const line = lines[lineIdx];
const words = line.split(' ');
// Layout the words using the current `fontSize`, line wrapping
// whenever we reach the end of the current line.
let spaceInLineRemaining = bounds.width;
for (let idx = 0, len = words.length; idx < len; idx++) {
const isLastWord = idx === len - 1;
const word = isLastWord ? words[idx] : words[idx] + ' ';
const widthOfWord = font.widthOfTextAtSize(word, fontSize);
spaceInLineRemaining -= widthOfWord;
if (spaceInLineRemaining <= 0) {
linesUsed += 1;
spaceInLineRemaining = bounds.width - widthOfWord;
}
}
}
// Return if we exceeded the allowed width
if (!multiline && linesUsed > lines.length)
return fontSize - 1;
const height = font.heightAtSize(fontSize);
const lineHeight = height + height * 0.2;
const totalHeight = lineHeight * linesUsed;
// Return if we exceeded the allowed height
if (totalHeight > Math.abs(bounds.height))
return fontSize - 1;
fontSize += 1;
}
return fontSize;
};
const computeCombedFontSize = (line, font, bounds, cellCount) => {
const cellWidth = bounds.width / cellCount;
const cellHeight = bounds.height;
let fontSize = MIN_FONT_SIZE;
const chars = (0, utils_1.charSplit)(line);
while (fontSize < MAX_FONT_SIZE) {
for (let idx = 0, len = chars.length; idx < len; idx++) {
const c = chars[idx];
const tooLong = font.widthOfTextAtSize(c, fontSize) > cellWidth * 0.75;
if (tooLong)
return fontSize - 1;
}
const height = font.heightAtSize(fontSize, { descender: false });
if (height > cellHeight)
return fontSize - 1;
fontSize += 1;
}
return fontSize;
};
const lastIndexOfWhitespace = (line) => {
for (let idx = line.length; idx > 0; idx--) {
if (/\s/.test(line[idx]))
return idx;
}
return undefined;
};
const splitOutLines = (input, maxWidth, font, fontSize) => {
var _a;
let lastWhitespaceIdx = input.length;
while (lastWhitespaceIdx > 0) {
const line = input.substring(0, lastWhitespaceIdx);
const encoded = font.encodeText(line);
const width = font.widthOfTextAtSize(line, fontSize);
if (width < maxWidth) {
const remainder = input.substring(lastWhitespaceIdx) || undefined;
return { line, encoded, width, remainder };
}
lastWhitespaceIdx = (_a = lastIndexOfWhitespace(line)) !== null && _a !== void 0 ? _a : 0;
}
// We were unable to split the input enough to get a chunk that would fit
// within the specified `maxWidth` so we'll just return everything
return {
line: input,
encoded: font.encodeText(input),
width: font.widthOfTextAtSize(input, fontSize),
remainder: undefined,
};
};
const layoutMultilineText = (text, { alignment, fontSize, font, bounds }) => {
const lines = (0, utils_1.lineSplit)((0, utils_1.cleanText)(text));
if (fontSize === undefined || fontSize === 0) {
fontSize = computeFontSize(lines, font, bounds, true);
}
const height = font.heightAtSize(fontSize);
const lineHeight = height + height * 0.2;
const textLines = [];
let minX = bounds.x;
let minY = bounds.y;
let maxX = bounds.x + bounds.width;
let maxY = bounds.y + bounds.height;
let y = bounds.y + bounds.height;
for (let idx = 0, len = lines.length; idx < len; idx++) {
let prevRemainder = lines[idx];
while (prevRemainder !== undefined) {
const { line, encoded, width, remainder } = splitOutLines(prevRemainder, bounds.width, font, fontSize);
// prettier-ignore
const x = (alignment === alignment_1.TextAlignment.Left ? bounds.x
: alignment === alignment_1.TextAlignment.Center ? bounds.x + (bounds.width / 2) - (width / 2)
: alignment === alignment_1.TextAlignment.Right ? bounds.x + bounds.width - width
: bounds.x);
y -= lineHeight;
if (x < minX)
minX = x;
if (y < minY)
minY = y;
if (x + width > maxX)
maxX = x + width;
if (y + height > maxY)
maxY = y + height;
textLines.push({ text: line, encoded, width, height, x, y });
// Only trim lines that we had to split ourselves. So we won't trim lines
// that the user provided themselves with whitespace.
prevRemainder = remainder === null || remainder === void 0 ? void 0 : remainder.trim();
}
}
return {
fontSize,
lineHeight,
lines: textLines,
bounds: {
x: minX,
y: minY,
width: maxX - minX,
height: maxY - minY,
},
};
};
exports.layoutMultilineText = layoutMultilineText;
const layoutCombedText = (text, { fontSize, font, bounds, cellCount }) => {
const line = (0, utils_1.mergeLines)((0, utils_1.cleanText)(text));
if (line.length > cellCount) {
throw new errors_1.CombedTextLayoutError(line.length, cellCount);
}
if (fontSize === undefined || fontSize === 0) {
fontSize = computeCombedFontSize(line, font, bounds, cellCount);
}
const cellWidth = bounds.width / cellCount;
const height = font.heightAtSize(fontSize, { descender: false });
const y = bounds.y + (bounds.height / 2 - height / 2);
const cells = [];
let minX = bounds.x;
let minY = bounds.y;
let maxX = bounds.x + bounds.width;
let maxY = bounds.y + bounds.height;
let cellOffset = 0;
let charOffset = 0;
while (cellOffset < cellCount) {
const [char, charLength] = (0, utils_1.charAtIndex)(line, charOffset);
const encoded = font.encodeText(char);
const width = font.widthOfTextAtSize(char, fontSize);
const cellCenter = bounds.x + (cellWidth * cellOffset + cellWidth / 2);
const x = cellCenter - width / 2;
if (x < minX)
minX = x;
if (y < minY)
minY = y;
if (x + width > maxX)
maxX = x + width;
if (y + height > maxY)
maxY = y + height;
cells.push({ text: line, encoded, width, height, x, y });
cellOffset += 1;
charOffset += charLength;
}
return {
fontSize,
cells,
bounds: {
x: minX,
y: minY,
width: maxX - minX,
height: maxY - minY,
},
};
};
exports.layoutCombedText = layoutCombedText;
const layoutSinglelineText = (text, { alignment, fontSize, font, bounds }) => {
const line = (0, utils_1.mergeLines)((0, utils_1.cleanText)(text));
if (fontSize === undefined || fontSize === 0) {
fontSize = computeFontSize([line], font, bounds);
}
const encoded = font.encodeText(line);
const width = font.widthOfTextAtSize(line, fontSize);
const height = font.heightAtSize(fontSize, { descender: false });
// prettier-ignore
const x = (alignment === alignment_1.TextAlignment.Left ? bounds.x
: alignment === alignment_1.TextAlignment.Center ? bounds.x + (bounds.width / 2) - (width / 2)
: alignment === alignment_1.TextAlignment.Right ? bounds.x + bounds.width - width
: bounds.x);
const y = bounds.y + (bounds.height / 2 - height / 2);
return {
fontSize,
line: { text: line, encoded, width, height, x, y },
bounds: { x, y, width, height },
};
};
exports.layoutSinglelineText = layoutSinglelineText;
//# sourceMappingURL=layout.js.map