/*  DokuWiki MoaiEditor Scroll_tools.js file
    Version : 0.5 (May 5, 2026)
    Author  : MoaiTools <info@moaitools.org>
    License : GPL 3 (http://www.gnu.org/licenses/gpl.html) */

MoaiEditor.ScrollTools = class {


    getMaxScrollY(element) {
        const extraHeight = this.calcExtraHeight(element);
        const bounds = element.getBoundingClientRect();  
        const height = bounds.height - extraHeight.border;
        const maxScroll = Math.round(element.scrollHeight - height);
        return maxScroll;
    } 
    // ──────────────────────────────────── 
    getMaxScrollX(element) {
        const extraWidth = this.calcExtraWidth(element);  
        const bounds = element.getBoundingClientRect();  
        const width = bounds.width - extraWidth.total;
        const maxScroll = Math.round(element.scrollWidth - width);
        return maxScroll;
    } 
    // ──────────────────────────────────── 
    calcExtraHeight(element) {
        const styles = window.getComputedStyle(element);
        const parseValue = (v) => v.endsWith('px') ? parseInt(v.slice(0, -2), 10) : 0;
        const paddingTop        = parseValue(styles.paddingTop);
        const paddingBottom     = parseValue(styles.paddingBottom);
        const borderTopWidth    = parseValue(styles.borderTopWidth);
        const borderBottomWidth = parseValue(styles.borderBottomWidth);
        return {
            top     : paddingTop + borderTopWidth,
            bottom  : paddingBottom + borderBottomWidth,
            total   : paddingTop + paddingBottom + borderTopWidth + borderBottomWidth,
            border  : borderTopWidth + borderBottomWidth
        }    
    }
    // ──────────────────────────────────── 
    calcExtraWidth(element) {
        const styles = window.getComputedStyle(element);
        const parseValue = (v) => v.endsWith('px') ? parseInt(v.slice(0, -2), 10) : 0;
        const paddingLeft       = parseValue(styles.paddingLeft);
        const paddingRight      = parseValue(styles.paddingRight);
        const borderLeftWidth   = parseValue(styles.borderLeftWidth);
        const borderRightWidth  = parseValue(styles.borderRightWidth);
        return {
            left  : paddingLeft + borderLeftWidth,
            right : paddingRight + borderRightWidth,
            total : paddingLeft + paddingRight + borderLeftWidth + borderRightWidth
        }    
    }
    // ──────────────────────────────────── 
    getRectRelativeToParent(element) {
        const parent = element.parentElement;
        const parentRect = parent.getBoundingClientRect();
        const elementRect = element.getBoundingClientRect();
        return {
            top    : elementRect.top - parentRect.top + parent.scrollTop,
            bottom : elementRect.bottom - parentRect.top + parent.scrollTop,
            left   : elementRect.left - parentRect.left,
            right  : elementRect.right - parentRect.left,
            height : elementRect.bottom - elementRect.top,
            width  : elementRect.right - elementRect.left,
        };
    }
}; // End Class