fix(module:drawer): provide custom scroll strategy (#2095)

close #2070

components/core/overlay/scroll/nz-block-scroll-strategy.ts

@@ -0,0 +1,19 @@
+import { ScrollStrategy } from '@angular/cdk/overlay';
+import { Renderer2 } from '@angular/core';
+
+export class NzBlockScrollStrategy implements ScrollStrategy {
+
+  constructor(private document: Document, private renderer: Renderer2) {
+  }
+
+  attach(): void {}
+
+  enable(): void {
+    this.renderer.setStyle(document.body, 'overflow', 'hidden');
+  }
+
+  disable(): void {
+    this.renderer.removeStyle(document.body, 'overflow');
+  }
+
+}

components/core/overlay/scroll/nz-scroll-strategy-options.ts

@@ -0,0 +1,19 @@
+import { DOCUMENT } from '@angular/common';
+import { Inject, Injectable, Renderer2, RendererFactory2 } from '@angular/core';
+import { NzBlockScrollStrategy } from './nz-block-scroll-strategy';
+
+@Injectable({providedIn: 'root'})
+export class NzScrollStrategyOptions {
+  private document: Document;
+  private renderer: Renderer2;
+  constructor(
+    rendererFactory: RendererFactory2,
+    // tslint:disable-next-line:no-any
+    @Inject(DOCUMENT) document: any
+  ) {
+    this.document = document;
+    this.renderer = rendererFactory.createRenderer(null, null);
+  }
+
+  block = () => new NzBlockScrollStrategy(this.document, this.renderer);
+}

components/drawer/nz-drawer.component.ts

@@ -14,6 +14,7 @@ import {
 
 import { CdkOverlayOrigin, Overlay, OverlayConfig, OverlayRef } from '@angular/cdk/overlay';
 import { TemplatePortal } from '@angular/cdk/portal';
+import { NzScrollStrategyOptions } from '../core/overlay/scroll/nz-scroll-strategy-options';
 
 import { InputBoolean } from '../core/util/convert';
 
@@ -77,6 +78,7 @@ export class NzDrawerComponent implements OnInit, OnDestroy {
     private renderer: Renderer2,
     private overlay: Overlay,
     private elementRef: ElementRef,
+    private nzScrollStrategyOptions: NzScrollStrategyOptions,
     private viewContainerRef: ViewContainerRef) {
 
   }
@@ -109,13 +111,18 @@ export class NzDrawerComponent implements OnInit, OnDestroy {
 
   getOverlayConfig(): OverlayConfig {
     return new OverlayConfig({
-      scrollStrategy: this.overlay.scrollStrategies.block()
+      scrollStrategy: this.nzScrollStrategyOptions.block()
     });
   }
 
   updateOverlayStyle(): void {
     if (this.overlayRef && this.overlayRef.overlayElement) {
       this.renderer.setStyle(this.overlayRef.overlayElement, 'pointer-events', this.isOpen ? 'auto' : 'none');
+      if (this.isOpen) {
+        this.overlayRef.getConfig().scrollStrategy.enable();
+      } else {
+        this.overlayRef.getConfig().scrollStrategy.disable();
+      }
     }
   }
 

components/drawer/nz-drawer.spec.ts

@@ -61,6 +61,15 @@ describe('NzDrawerComponent', () => {
     expect(component.drawerComponent.nzVisible).toBe(false);
   });
 
+  it('should set body overflow', () => {
+    component.open();
+    fixture.detectChanges();
+    expect(document.body.style.overflow).toBe('hidden');
+    component.close();
+    fixture.detectChanges();
+    expect(document.body.style.overflow).toBe('');
+  });
+
   it('should hied close button', () => {
     component.closable = false;
     component.open();