less-pager-mini/dist/features/moving.js

A scrollable terminal pager for Node.js CLI apps (terminal only)

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.lineForward = lineForward;
exports.lineBackward = lineBackward;
exports.windowForward = windowForward;
exports.windowBackward = windowBackward;
exports.setWindowForward = setWindowForward;
exports.setWindowBackward = setWindowBackward;
exports.setHalfWindowForward = setHalfWindowForward;
exports.setHalfWindowBackward = setHalfWindowBackward;
exports.setHalfScreenRight = setHalfScreenRight;
exports.setHalfScreenLeft = setHalfScreenLeft;
const helpers_1 = require("../helpers");
const config_1 = require("../config");
/**
 * Moves forward by a given offset through content lines or subrows.
 *
 * @param content - Full content lines.
 * @param offset - Number of lines/subrows to move forward.
 * @param ignoreEOF - If true, ignores EOF clamp (optional).
 */
function lineForward(content, offset, ignoreEOF = false) {
    let currSubRowMax = (0, helpers_1.maxSubRow)(content[config_1.config.row]);
    if (isEndPosition(ignoreEOF, content.length, currSubRowMax)) {
        (0, helpers_1.ringBell)();
        return;
    }
    if (config_1.config.chopLongLines || config_1.config.col) {
        const maxRow = ignoreEOF
            ? content.length - 1
            : Math.max(content.length - config_1.config.window + 1, 0);
        config_1.config.row = Math.min(config_1.config.row + offset, maxRow);
        return;
    }
    const rowEnd = ignoreEOF ? null : getEndPosition(content);
    const maxRow = rowEnd ? rowEnd.maxRow : content.length - 1;
    while (offset > 0 && config_1.config.row <= maxRow) {
        currSubRowMax = (0, helpers_1.maxSubRow)(content[config_1.config.row]);
        if (config_1.config.row === maxRow && rowEnd)
            currSubRowMax = rowEnd.subRow;
        if (config_1.config.subRow + offset <= currSubRowMax) {
            config_1.config.subRow += offset;
            return;
        }
        offset -= currSubRowMax - config_1.config.subRow + 1;
        config_1.config.row++;
        config_1.config.subRow = 0;
    }
    if (rowEnd && config_1.config.row > rowEnd.maxRow) {
        config_1.config.row = rowEnd.maxRow;
        config_1.config.subRow = rowEnd.subRow;
    }
    else if (config_1.config.row === content.length) {
        config_1.config.row = content.length - 1;
        config_1.config.subRow = currSubRowMax;
    }
}
/**
 * Scroll backward by the given offset.
 *
 * - Stops and rings bell at BOF, also disables `mode.INIT`.
 * - In chopped mode, moves by whole lines.
 * - In wrapped mode, moves by sub-rows within a line.
 *
 * @param content - Full content lines.
 * @param offset - Lines or sub-rows to scroll backward.
 */
function lineBackward(content, offset) {
    if (!config_1.config.row && !config_1.config.subRow) {
        if (config_1.mode.INIT)
            config_1.mode.INIT = false;
        (0, helpers_1.ringBell)();
        return;
    }
    if (config_1.config.chopLongLines || config_1.config.col) {
        config_1.config.row = Math.max(config_1.config.row - offset, 0);
        return;
    }
    while (offset > 0 && config_1.config.row >= 0) {
        if (config_1.config.subRow >= offset) {
            config_1.config.subRow -= offset;
            return;
        }
        if (config_1.config.row === 0) {
            config_1.config.subRow = 0;
            return;
        }
        offset -= config_1.config.subRow + 1;
        config_1.config.row--;
        config_1.config.subRow = (0, helpers_1.maxSubRow)(content[config_1.config.row]);
    }
}
/**
 * Scrolls the view forward by a window size.
 *
 * - If `buffer` is a valid number, it overrides the default window size.
 * - Falls back to `config.setWindow` or `config.window - 1` if `buffer` is
 *   invalid.
 * - If `ignoreEOF` is `true`, allows scrolling beyond (END) without clamping.
 *
 * @param content - The full content to paginate.
 * @param buffer - A string array that represents the number of lines to scroll.
 * @param ignoreEOF - Whether to bypass EOF constraints during scrolling.
 */
function windowForward(content, buffer, ignoreEOF = false) {
    lineForward(content, (0, helpers_1.bufferToNum)(buffer) || config_1.config.setWindow || config_1.config.window - 1, ignoreEOF);
}
/**
 * Moves the view backward by one window.
 *
 * - If `buffer` is a valid number, uses it as the offset.
 * - Otherwise, uses `config.setWindow` if set, or defaults to
 *   `config.window - 1`.
 *
 * @param content - The full content as an array of lines.
 * @param buffer - A string array that represents the number of lines to scroll.
 */
function windowBackward(content, buffer) {
    lineBackward(content, (0, helpers_1.bufferToNum)(buffer) || config_1.config.setWindow || config_1.config.window - 1);
}
/**
 * Sets a custom window size using the given `buffer`, and scrolls forward.
 *
 * - If `buffer` is a valid number, updates `config.setWindow` with it.
 * - Then scrolls forward by `config.setWindow` or falls back to
 *   `config.window - 1`.
 *
 * @param content - The full content as an array of lines.
 * @param buffer - A string array that represents the number of lines to scroll.
 */
function setWindowForward(content, buffer) {
    config_1.config.setWindow = (0, helpers_1.bufferToNum)(buffer) || config_1.config.setWindow;
    lineForward(content, config_1.config.setWindow || config_1.config.window - 1);
}
/**
 * Sets a custom window size using the given `buffer`, and scrolls backward.
 *
 * - If `buffer` is a valid number, updates `config.setWindow` with it.
 * - Then scrolls backward by `config.setWindow` or falls back to
 *   `config.window - 1`.
 *
 * @param content - The full content as an array of lines.
 * @param buffer - A string array that represents the number of lines to scroll.
 */
function setWindowBackward(content, buffer) {
    config_1.config.setWindow = (0, helpers_1.bufferToNum)(buffer) || config_1.config.setWindow;
    lineBackward(content, config_1.config.setWindow || config_1.config.window - 1);
}
/**
 * Sets a custom half-window size using the given `buffer`, and scrolls forward.
 *
 * - If `buffer` is a valid number, updates `config.setHalfWindow` with it.
 * - Then scrolls forward by `config.setHalfWindow` or falls back to
 *   `config.halfWindow`.
 *
 * @param content - The full content as an array of lines.
 * @param buffer - A string array that represents the number of lines to scroll.
 */
function setHalfWindowForward(content, buffer) {
    config_1.config.setHalfWindow = (0, helpers_1.bufferToNum)(buffer) || config_1.config.setHalfWindow;
    lineForward(content, config_1.config.setHalfWindow || config_1.config.halfWindow);
}
/**
 * Sets a custom half-window size using the given `buffer`, and scrolls
 * backward.
 *
 * - If `buffer` is a valid number, updates `config.setHalfWindow` with it.
 * - Then scrolls backward by `config.setHalfWindow` or falls back to
 *   `config.halfWindow`.
 *
 * @param content - The full content as an array of lines.
 * @param buffer - A string array that represents the number of lines to scroll.
 */
function setHalfWindowBackward(content, buffer) {
    config_1.config.setHalfWindow = (0, helpers_1.bufferToNum)(buffer) || config_1.config.setHalfWindow;
    lineBackward(content, config_1.config.setHalfWindow || config_1.config.halfWindow);
}
/**
 * Scrolls right by buffer value or half screen width.
 *
 * @param buffer - Buffer containing scroll offset.
 */
function setHalfScreenRight(buffer) {
    if (config_1.mode.INIT)
        config_1.mode.INIT = false;
    config_1.config.setCol = (0, helpers_1.bufferToNum)(buffer) || config_1.config.setCol;
    config_1.config.col += config_1.config.setCol || config_1.config.halfScreenWidth;
}
/**
 * Scrolls left by buffer value or half screen width.
 *
 * @param buffer - Buffer containing scroll offset.
 */
function setHalfScreenLeft(buffer) {
    if (config_1.mode.INIT)
        config_1.mode.INIT = false;
    config_1.config.setCol = (0, helpers_1.bufferToNum)(buffer) || config_1.config.setCol;
    config_1.config.col -= config_1.config.setCol || config_1.config.halfScreenWidth;
    if (config_1.config.col < 0)
        config_1.config.col = 0;
}
/**
 * Determines whether the current viewport position is at the end of the
 * content.
 *
 * This check accounts for both EOF mode and the final row/subRow position
 * based on whether EOF should be ignored.
 *
 * @param ignoreEOF - If `true`, skips EOF check and only uses position
 *                    comparison.
 * @param contentLength - Total number of content rows.
 * @param currSubRowMax - The final sub-row index to compare against.
 * @returns `true` if the current position is at the end; otherwise, `false`.
 */
function isEndPosition(ignoreEOF, contentLength, currSubRowMax) {
    return ((!ignoreEOF && config_1.mode.EOF) ||
        (config_1.config.row === contentLength - 1 && config_1.config.subRow === currSubRowMax));
}
/**
 * Calculates the last visible row and subrow for window clamping.
 *
 * @param content - Full content lines.
 * @returns Object with `maxRow` and `subRow` for the end position.
 */
function getEndPosition(content) {
    let maxRow = content.length - 1;
    let subRow = 0;
    let rowCount = 0;
    while (maxRow >= 0) {
        const subRows = (0, helpers_1.maxSubRow)(content[maxRow]) + 1;
        const rowSum = rowCount + subRows;
        if (rowSum >= config_1.config.window - 1) {
            subRow = rowSum - config_1.config.window + 1;
            break;
        }
        rowCount = rowSum;
        maxRow--;
    }
    if (maxRow < 0) {
        maxRow = 0;
        subRow = 0;
    }
    return { maxRow, subRow };
}