cncjs

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class ResizeObserver {
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    callback = null;
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    observer = null;
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    constructor(callback) {
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      if (typeof callback === 'function') {
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        this.callback = callback;
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      }
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      return this;
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    }
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    observe(target) {
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      if (this.observer) {
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        this.observer.disconnect();
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        this.observer = null;
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      }
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      this.callback && this.callback();
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      this.observer = new MutationObserver(mutations => {
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        this.callback && this.callback();
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      });
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      this.observer.observe(target, {
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        attributes: true,
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        attributeOldValue: false,
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        characterData: true,
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        characterDataOldValue: false,
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        childList: true,
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        subtree: true
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      });
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    }
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    disconnect() {
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      if (this.observer) {
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        this.observer.disconnect();
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        this.observer = null;
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      }
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    }
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}
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export default ResizeObserver;
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