Method updateContentMargins

src/material/sidenav/drawer.ts:905–949

* Recalculates and updates the inline styles for the content. Note that this should be used * sparingly, because it causes a reflow.

()

   * sparingly, because it causes a reflow.
   */
  updateContentMargins() {
    // 1. For drawers in `over` mode, they don't affect the content.
    // 2. For drawers in `side` mode they should shrink the content. We do this by adding to the
    //    left margin (for left drawer) or right margin (for right the drawer).
    // 3. For drawers in `push` mode the should shift the content without resizing it. We do this by
    //    adding to the left or right margin and simultaneously subtracting the same amount of
    //    margin from the other side.
    let left = 0;
    let right = 0;

    if (this._left && this._left.opened) {
      if (this._left.mode == 'side') {
        left += this._left._getWidth();
      } else if (this._left.mode == 'push') {
        const width = this._left._getWidth();
        left += width;
        right -= width;
      }
    }

    if (this._right && this._right.opened) {
      if (this._right.mode == 'side') {
        right += this._right._getWidth();
      } else if (this._right.mode == 'push') {
        const width = this._right._getWidth();
        right += width;
        left -= width;
      }
    }

    // If either `right` or `left` is zero, don't set a style to the element. This
    // allows users to specify a custom size via CSS class in SSR scenarios where the
    // measured widths will always be zero. Note that we reset to `null` here, rather
    // than below, in order to ensure that the types in the `if` below are consistent.
    left = left || null!;
    right = right || null!;

    if (left !== this._contentMargins.left || right !== this._contentMargins.right) {
      this._contentMargins = {left, right};

      // Pull back into the NgZone since in some cases we could be outside. We need to be careful
      // to do it only when something changed, otherwise we can end up hitting the zone too often.
      this._ngZone.run(() => this._contentMarginChanges.next(this._contentMargins));
    }
  }

  ngDoCheck() {
    // If users opted into autosizing, do a check every change detection cycle.