asciitorium/dist/core/layouts/VerticalLayoutStrategy.js

an ASCII ui framework for web + cli

export class VerticalLayoutStrategy {
    constructor(options) {
        this.fit = options?.fit ?? false;
    }
    layout(parent, children) {
        const borderPad = parent.border ? 1 : 0;
        const innerWidth = parent.width - 2 * borderPad;
        const innerHeight = parent.height - 2 * borderPad;
        const count = children.length;
        let currentY = borderPad;
        for (const child of children) {
            if (child.fixed) {
                continue; // Skip positioning if component is fixed
            }
            if (this.fit && count > 0) {
                child.height = Math.floor(innerHeight / count);
            }
            if (!child.width) {
                child.width = innerWidth;
            }
            const { x } = this.resolveAlignment(child.align, innerWidth, child.height, child.width, child.height);
            child.x = borderPad + x;
            child.y = currentY;
            currentY += child.height + child.gap;
        }
    }
    resolveAlignment(align, parentWidth, _parentHeight, childWidth, _childHeight) {
        let hAlign = 'left';
        if (typeof align === 'string') {
            // For vertical layout, alignment affects horizontal positioning
            switch (align) {
                case 'top-left':
                case 'left':
                case 'bottom-left':
                    hAlign = 'left';
                    break;
                case 'top':
                case 'center':
                case 'bottom':
                    hAlign = 'center';
                    break;
                case 'top-right':
                case 'right':
                case 'bottom-right':
                    hAlign = 'right';
                    break;
                default:
                    hAlign = 'left';
                    break;
            }
        }
        else if (typeof align === 'object' && align !== null) {
            hAlign = align.x ?? 'left';
        }
        const padX = parentWidth - childWidth;
        let x;
        if (typeof hAlign === 'number')
            x = hAlign;
        else if (hAlign === 'center')
            x = Math.floor(padX / 2);
        else if (hAlign === 'right')
            x = padX;
        else
            x = 0;
        return { x, y: 0 };
    }
}