html2canvas-pro/dist/types/render/canvas/text-renderer.d.ts

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/**
 * Text Renderer
 *
 * Handles rendering of text content including:
 * - Text with letter spacing
 * - Text decorations (underline, overline, line-through)
 * - Text shadows
 * - Webkit line clamp
 * - Text overflow ellipsis
 * - Paint order (fill/stroke)
 * - Font styles
 */
import { Context } from '../../core/context';
import { TextContainer } from '../../dom/text-container';
import { CSSParsedDeclaration } from '../../css';
import { Bounds } from '../../css/layout/bounds';
import { TextBounds } from '../../css/layout/text';
/**
 * Dependencies required for TextRenderer
 */
export interface TextRendererDependencies {
    ctx: CanvasRenderingContext2D;
    context: Context;
    options: {
        scale: number;
    };
}
export declare const hasCJKCharacters: (text: string) => boolean;
/**
 * Text Renderer
 *
 * Specialized renderer for text content.
 * Extracted from CanvasRenderer to improve code organization and maintainability.
 */
export declare class TextRenderer {
    private readonly ctx;
    private readonly options;
    constructor(deps: TextRendererDependencies);
    /**
     * Iterate grapheme clusters one-by-one, applying correct letter-spacing and
     * per-script baseline for each character.
     *
     * Issue #73: When letter-spacing is non-zero, text must be rendered character by
     * character. This helper centralises two fixes applied during that iteration:
     *   1. Add `letterSpacing` to each character's advance width (was previously
     *      omitted, causing characters to render without any spacing).
     *   2. Switch to the ideographic baseline for CJK glyphs so their vertical
     *      position matches how browsers lay them out in the DOM.
     *
     * The `renderFn` callback receives (letter, x, y) and performs the actual draw
     * call (fillText or strokeText), allowing fill and stroke paths to share one
     * implementation.
     */
    private iterateLettersWithLetterSpacing;
    /**
     * Render text with letter-spacing applied (fill pass).
     * When letterSpacing is 0 the whole string is drawn in one call; otherwise each
     * grapheme is drawn individually so spacing and CJK baseline are applied correctly.
     */
    renderTextWithLetterSpacing(text: TextBounds, letterSpacing: number, baseline: number): void;
    /**
     * Helper method to render text with paint order support
     * Reduces code duplication in line-clamp and normal rendering
     */
    private renderTextBoundWithPaintOrder;
    private renderTextDecoration;
    private drawDecorationLine;
    private truncateTextWithEllipsis;
    /**
     * Create font style array
     * Public method used by list rendering
     */
    createFontStyle(styles: CSSParsedDeclaration): string[];
    renderTextNode(text: TextContainer, styles: CSSParsedDeclaration, containerBounds?: Bounds): Promise<void>;
}