refactor(sidenav): expose api to update content margins

Exposes an API so that consumers can trigger an update of the content margins manually. This allows the sidenav to handle some cases that might not have accounted for.

Fixes #15777.

Author: crisbeto

src/material/sidenav/drawer.ts

@@ -541,15 +541,15 @@ export class MatDrawerContainer implements AfterContentInit, DoCheck, OnDestroy
     if (_dir) {
       _dir.change.pipe(takeUntil(this._destroyed)).subscribe(() => {
         this._validateDrawers();
-        this._updateContentMargins();
+        this.updateContentMargins();
       });
     }
 
     // Since the minimum width of the sidenav depends on the viewport width,
     // we need to recompute the margins if the viewport changes.
     viewportRuler.change()
       .pipe(takeUntil(this._destroyed))
-      .subscribe(() => this._updateContentMargins());
+      .subscribe(() => this.updateContentMargins());
 
     this._autosize = defaultAutosize;
   }
@@ -567,7 +567,7 @@ export class MatDrawerContainer implements AfterContentInit, DoCheck, OnDestroy
       if (!this._drawers.length ||
           this._isDrawerOpen(this._start) ||
           this._isDrawerOpen(this._end)) {
-        this._updateContentMargins();
+        this.updateContentMargins();
       }
 
       this._changeDetectorRef.markForCheck();
@@ -576,7 +576,7 @@ export class MatDrawerContainer implements AfterContentInit, DoCheck, OnDestroy
     this._doCheckSubject.pipe(
       debounceTime(10), // Arbitrary debounce time, less than a frame at 60fps
       takeUntil(this._destroyed)
-    ).subscribe(() => this._updateContentMargins());
+    ).subscribe(() => this.updateContentMargins());
   }
 
   ngOnDestroy() {
@@ -596,6 +596,56 @@ export class MatDrawerContainer implements AfterContentInit, DoCheck, OnDestroy
     this._drawers.forEach(drawer => drawer.close());
   }
 
+  /**
+   * Recalculates and updates the inline styles for the content. Note that this should be used
+   * 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._width;
+      } else if (this._left.mode == 'push') {
+        const width = this._left._width;
+        left += width;
+        right -= width;
+      }
+    }
+
+    if (this._right && this._right.opened) {
+      if (this._right.mode == 'side') {
+        right += this._right._width;
+      } else if (this._right.mode == 'push') {
+        const width = this._right._width;
+        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.
     if (this._autosize && this._isPushed()) {
@@ -621,7 +671,7 @@ export class MatDrawerContainer implements AfterContentInit, DoCheck, OnDestroy
         this._element.nativeElement.classList.add('mat-drawer-transition');
       }
 
-      this._updateContentMargins();
+      this.updateContentMargins();
       this._changeDetectorRef.markForCheck();
     });
 
@@ -653,7 +703,7 @@ export class MatDrawerContainer implements AfterContentInit, DoCheck, OnDestroy
     if (drawer) {
       drawer._modeChanged.pipe(takeUntil(merge(this._drawers.changes, this._destroyed)))
         .subscribe(() => {
-          this._updateContentMargins();
+          this.updateContentMargins();
           this._changeDetectorRef.markForCheck();
         });
     }
@@ -730,55 +780,4 @@ export class MatDrawerContainer implements AfterContentInit, DoCheck, OnDestroy
     return drawer != null && drawer.opened;
   }
 
-  /**
-   * Recalculates and updates the inline styles for the content. Note that this should be used
-   * sparingly, because it causes a reflow.
-   */
-  private _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._width;
-      } else if (this._left.mode == 'push') {
-        let width = this._left._width;
-        left += width;
-        right -= width;
-      }
-    }
-
-    if (this._right && this._right.opened) {
-      if (this._right.mode == 'side') {
-        right += this._right._width;
-      } else if (this._right.mode == 'push') {
-        let width = this._right._width;
-        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));
-    }
-
-  }
 }

tools/public_api_guard/material/sidenav.d.ts

@@ -63,6 +63,7 @@ export declare class MatDrawerContainer implements AfterContentInit, DoCheck, On
     ngDoCheck(): void;
     ngOnDestroy(): void;
     open(): void;
+    updateContentMargins(): void;
 }
 
 export declare class MatDrawerContent extends CdkScrollable implements AfterContentInit {