Method position

src/js/tether.js:367–567

(flushChanges = true)

  }

  position(flushChanges = true) {
    // flushChanges commits the changes immediately, leave true unless you are positioning multiple
    // tethers (in which case call Tether.Utils.flush yourself when you're done)

    if (!this.enabled) {
      return;
    }

    this.clearCache();

    // Turn 'auto' attachments into the appropriate corner or edge
    const targetAttachment = autoToFixedAttachment(
      this.targetAttachment,
      this.attachment
    );

    this.updateAttachClasses(this.attachment, targetAttachment);

    const elementPos = this.cache('element-bounds', () => {
      return getBounds(this.bodyElement, this.element);
    });

    let { width, height } = elementPos;

    if (width === 0 && height === 0 && !isUndefined(this.lastSize)) {
      // We cache the height and width to make it possible to position elements that are
      // getting hidden.
      ({ width, height } = this.lastSize);
    } else {
      this.lastSize = { width, height };
    }

    const targetPos = this.cache('target-bounds', () => {
      return this.getTargetBounds();
    });
    const targetSize = targetPos;

    // Get an actual px offset from the attachment
    let offset = offsetToPx(attachmentToOffset(this.attachment), {
      width,
      height
    });
    let targetOffset = offsetToPx(
      attachmentToOffset(targetAttachment),
      targetSize
    );

    const manualOffset = offsetToPx(this.offset, { width, height });
    const manualTargetOffset = offsetToPx(this.targetOffset, targetSize);

    // Add the manually provided offset
    offset = addOffset(offset, manualOffset);
    targetOffset = addOffset(targetOffset, manualTargetOffset);

    // It's now our goal to make (element position + offset) == (target position + target offset)
    let left = targetPos.left + targetOffset.left - offset.left;
    let top = targetPos.top + targetOffset.top - offset.top;