NativeScript/nativescript-core/utils/layout-helper/layout-helper-common.ts

// cache the MeasureSpec constants here, to prevent extensive marshaling calls to and from Java
// TODO: While this boosts the performance it is error-prone in case Google changes these constants
export const MODE_SHIFT = 30;
export const MODE_MASK = 0x3 << MODE_SHIFT;

export const UNSPECIFIED = 0 << MODE_SHIFT;
export const EXACTLY = 1 << MODE_SHIFT;
export const AT_MOST = 2 << MODE_SHIFT;

export const MEASURED_HEIGHT_STATE_SHIFT = 0x00000010; /* 16 */
export const MEASURED_STATE_TOO_SMALL = 0x01000000;
export const MEASURED_STATE_MASK = 0xff000000;
export const MEASURED_SIZE_MASK = 0x00ffffff;

export function getMode(mode: number): string {
    switch (mode) {
        case EXACTLY:
            return "Exact";
        case AT_MOST:
            return "AtMost";
        default:
            return "Unspecified";
    }
}

export function getMeasureSpecMode(spec: number): number {
    return (spec & MODE_MASK);
}

export function getMeasureSpecSize(spec: number): number {
    return (spec & ~MODE_MASK);
}

export function measureSpecToString(measureSpec: number): string {
    const mode = getMeasureSpecMode(measureSpec);
    const size = getMeasureSpecSize(measureSpec);

    let text = "MeasureSpec: ";
    if (mode === UNSPECIFIED) {
        text += "UNSPECIFIED ";
    } else if (mode === EXACTLY) {
        text += "EXACTLY ";
    } else if (mode === AT_MOST) {
        text += "AT_MOST ";
    }

    text += size;

    return text;
}

export function round(value: number): number {
    const res = Math.floor(value + 0.5);
    if (res !== 0) {
        return res;
    } else if (value === 0) {
        return 0;
    } else if (value > 0) {
        return 1;
    }

    return -1;
}