Function applyDefaultTextStyle

libs/echarts/echarts.simple.js:17819–17863

* Give some default value to the input `textStyle` object, based on the current settings * in this `textStyle` object. * * The Scenario: * when text position is `inside` and `textFill` is not specified, we show * text border by default for better view. But it should be considered that text posi

(textStyle)

 * does, `rollbackDefaultTextStyle` is not needed to be called).
 */
function applyDefaultTextStyle(textStyle) {
    var textPosition = textStyle.textPosition;
    var opt = textStyle.insideRollbackOpt;
    var insideRollback;

    if (opt && textStyle.textFill == null) {
        var autoColor = opt.autoColor;
        var isRectText = opt.isRectText;
        var useInsideStyle = opt.useInsideStyle;

        var useInsideStyleCache = useInsideStyle !== false
            && (useInsideStyle === true
                || (isRectText
                    && textPosition
                    // textPosition can be [10, 30]
                    && typeof textPosition === 'string'
                    && textPosition.indexOf('inside') >= 0
                )
            );
        var useAutoColorCache = !useInsideStyleCache && autoColor != null;

        // All of the props declared in `CACHED_LABEL_STYLE_PROPERTIES` are to be cached.
        if (useInsideStyleCache || useAutoColorCache) {
            insideRollback = {
                textFill: textStyle.textFill,
                textStroke: textStyle.textStroke,
                textStrokeWidth: textStyle.textStrokeWidth
            };
        }
        if (useInsideStyleCache) {
            textStyle.textFill = '#fff';
            // Consider text with #fff overflow its container.
            if (textStyle.textStroke == null) {
                textStyle.textStroke = autoColor;
                textStyle.textStrokeWidth == null && (textStyle.textStrokeWidth = 2);
            }
        }
        if (useAutoColorCache) {
            textStyle.textFill = autoColor;
        }
    }

    // Always set `insideRollback`, so that the previous one can be cleared.
    textStyle.insideRollback = insideRollback;
}

/**
 * Consider the case: in a scatter,