1/*  DokuWiki MoaiEditor Scroll_tools.js file
2    Version : 0.5 (May 5, 2026)
3    Author  : MoaiTools <info@moaitools.org>
4    License : GPL 3 (http://www.gnu.org/licenses/gpl.html) */
5
6MoaiEditor.ScrollTools = class {
7
8
9    getMaxScrollY(element) {
10        const extraHeight = this.calcExtraHeight(element);
11        const bounds = element.getBoundingClientRect();
12        const height = bounds.height - extraHeight.border;
13        const maxScroll = Math.round(element.scrollHeight - height);
14        return maxScroll;
15    }
16    // ────────────────────────────────────
17    getMaxScrollX(element) {
18        const extraWidth = this.calcExtraWidth(element);
19        const bounds = element.getBoundingClientRect();
20        const width = bounds.width - extraWidth.total;
21        const maxScroll = Math.round(element.scrollWidth - width);
22        return maxScroll;
23    }
24    // ────────────────────────────────────
25    calcExtraHeight(element) {
26        const styles = window.getComputedStyle(element);
27        const parseValue = (v) => v.endsWith('px') ? parseInt(v.slice(0, -2), 10) : 0;
28        const paddingTop        = parseValue(styles.paddingTop);
29        const paddingBottom     = parseValue(styles.paddingBottom);
30        const borderTopWidth    = parseValue(styles.borderTopWidth);
31        const borderBottomWidth = parseValue(styles.borderBottomWidth);
32        return {
33            top     : paddingTop + borderTopWidth,
34            bottom  : paddingBottom + borderBottomWidth,
35            total   : paddingTop + paddingBottom + borderTopWidth + borderBottomWidth,
36            border  : borderTopWidth + borderBottomWidth
37        }
38    }
39    // ────────────────────────────────────
40    calcExtraWidth(element) {
41        const styles = window.getComputedStyle(element);
42        const parseValue = (v) => v.endsWith('px') ? parseInt(v.slice(0, -2), 10) : 0;
43        const paddingLeft       = parseValue(styles.paddingLeft);
44        const paddingRight      = parseValue(styles.paddingRight);
45        const borderLeftWidth   = parseValue(styles.borderLeftWidth);
46        const borderRightWidth  = parseValue(styles.borderRightWidth);
47        return {
48            left  : paddingLeft + borderLeftWidth,
49            right : paddingRight + borderRightWidth,
50            total : paddingLeft + paddingRight + borderLeftWidth + borderRightWidth
51        }
52    }
53    // ────────────────────────────────────
54    getRectRelativeToParent(element) {
55        const parent = element.parentElement;
56        const parentRect = parent.getBoundingClientRect();
57        const elementRect = element.getBoundingClientRect();
58        return {
59            top    : elementRect.top - parentRect.top + parent.scrollTop,
60            bottom : elementRect.bottom - parentRect.top + parent.scrollTop,
61            left   : elementRect.left - parentRect.left,
62            right  : elementRect.right - parentRect.left,
63            height : elementRect.bottom - elementRect.top,
64            width  : elementRect.right - elementRect.left,
65        };
66    }
67}; // End Class
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