react-native-chart-kit/dist/v2/core/interaction/viewportTransform.js

Beautiful React Native charts for dashboards, reports, and data-rich mobile apps.

import { resolveChartViewportWindow } from "./viewport";
const minVisiblePoints = 2;
const clamp = (value, min, max) => {
    if (max < min) {
        return min;
    }
    return Math.min(Math.max(value, min), max);
};
const normalizePositiveInteger = (value, fallback, min = 1) => {
    if (typeof value !== "number" || !Number.isFinite(value)) {
        return fallback;
    }
    return Math.max(min, Math.floor(value));
};
export const resolveChartViewportWindowFromZoom = ({ anchorIndex, currentWindow, itemCount, maxVisibleCount, minVisibleCount, zoomFactor }) => {
    const safeItemCount = normalizePositiveInteger(itemCount, 0, 0);
    if (safeItemCount === 0) {
        return resolveChartViewportWindow({ itemCount: safeItemCount });
    }
    const normalizedCurrentWindow = resolveChartViewportWindow({
        itemCount: safeItemCount,
        startIndex: currentWindow.startIndex,
        endIndex: currentWindow.endIndex
    });
    const normalizedMinVisibleCount = clamp(normalizePositiveInteger(minVisibleCount, minVisiblePoints), minVisiblePoints, safeItemCount);
    const normalizedMaxVisibleCount = clamp(normalizePositiveInteger(maxVisibleCount, safeItemCount), normalizedMinVisibleCount, safeItemCount);
    const safeZoomFactor = typeof zoomFactor === "number" && Number.isFinite(zoomFactor)
        ? Math.max(0.01, zoomFactor)
        : 1;
    const nextVisibleCount = clamp(Math.round(normalizedCurrentWindow.visibleCount / safeZoomFactor), normalizedMinVisibleCount, normalizedMaxVisibleCount);
    if (nextVisibleCount >= safeItemCount) {
        return resolveChartViewportWindow({ itemCount: safeItemCount });
    }
    const currentSpan = Math.max(1, normalizedCurrentWindow.visibleCount - 1);
    const fallbackAnchor = normalizedCurrentWindow.startIndex +
        (normalizedCurrentWindow.visibleCount - 1) / 2;
    const resolvedAnchor = clamp(typeof anchorIndex === "number" && Number.isFinite(anchorIndex)
        ? anchorIndex
        : fallbackAnchor, normalizedCurrentWindow.startIndex, normalizedCurrentWindow.endIndex - 1);
    const anchorRatio = clamp((resolvedAnchor - normalizedCurrentWindow.startIndex) / currentSpan, 0, 1);
    const startIndex = clamp(Math.round(resolvedAnchor - (nextVisibleCount - 1) * anchorRatio), 0, safeItemCount - nextVisibleCount);
    return resolveChartViewportWindow({
        itemCount: safeItemCount,
        startIndex,
        endIndex: startIndex + nextVisibleCount
    });
};
export const resolveChartViewportWindowFromPanDelta = ({ currentWindow, deltaPoints, itemCount }) => {
    const safeItemCount = normalizePositiveInteger(itemCount, 0, 0);
    if (safeItemCount === 0) {
        return resolveChartViewportWindow({ itemCount: safeItemCount });
    }
    const normalizedCurrentWindow = resolveChartViewportWindow({
        itemCount: safeItemCount,
        startIndex: currentWindow.startIndex,
        endIndex: currentWindow.endIndex
    });
    if (normalizedCurrentWindow.visibleCount >= safeItemCount) {
        return normalizedCurrentWindow;
    }
    const delta = typeof deltaPoints === "number" && Number.isFinite(deltaPoints)
        ? Math.round(deltaPoints)
        : 0;
    const startIndex = clamp(normalizedCurrentWindow.startIndex + delta, 0, safeItemCount - normalizedCurrentWindow.visibleCount);
    return resolveChartViewportWindow({
        itemCount: safeItemCount,
        startIndex,
        endIndex: startIndex + normalizedCurrentWindow.visibleCount
    });
};