feat(overlay): support rtl in overlays (#1593)

src/lib/core/overlay/overlay-directives.ts

@@ -5,6 +5,7 @@ import {
     EventEmitter,
     TemplateRef,
     ViewContainerRef,
+    Optional,
     Input,
     OnDestroy,
     Output,
@@ -18,6 +19,7 @@ import {ConnectionPositionPair} from './position/connected-position';
 import {PortalModule} from '../portal/portal-directives';
 import {ConnectedPositionStrategy} from './position/connected-position-strategy';
 import {Subscription} from 'rxjs/Subscription';
+import {Dir, LayoutDirection} from '../rtl/dir';
 
 /** Default set of positions for the overlay. Follows the behavior of a dropdown. */
 let defaultPositionList = [
@@ -103,14 +105,19 @@ export class ConnectedOverlayDirective implements OnDestroy {
   constructor(
       private _overlay: Overlay,
       templateRef: TemplateRef<any>,
-      viewContainerRef: ViewContainerRef) {
+      viewContainerRef: ViewContainerRef,
+      @Optional() private _dir: Dir) {
     this._templatePortal = new TemplatePortal(templateRef, viewContainerRef);
   }
 
   get overlayRef(): OverlayRef {
     return this._overlayRef;
   }
 
+  get dir(): LayoutDirection {
+    return this._dir ? this._dir.value : 'ltr';
+  }
+
   /** TODO: internal */
   ngOnDestroy() {
     this._destroyOverlay();
@@ -145,6 +152,8 @@ export class ConnectedOverlayDirective implements OnDestroy {
 
     overlayConfig.positionStrategy = this._getPosition();
 
+    overlayConfig.direction = this.dir;
+
     return overlayConfig;
   }
 
@@ -153,7 +162,8 @@ export class ConnectedOverlayDirective implements OnDestroy {
     return this._overlay.position().connectedTo(
       this.origin.elementRef,
       {originX: this.positions[0].overlayX, originY: this.positions[0].originY},
-      {overlayX: this.positions[0].overlayX, overlayY: this.positions[0].overlayY});
+      {overlayX: this.positions[0].overlayX, overlayY: this.positions[0].overlayY})
+      .setDirection(this.dir);
   }
 
   /** Attaches the overlay and subscribes to backdrop clicks if backdrop exists */

src/lib/core/overlay/overlay-ref.ts

@@ -24,6 +24,7 @@ export class OverlayRef implements PortalHost {
 
     let attachResult = this._portalHost.attach(portal);
     this.updateSize();
+    this.updateDirection();
     this.updatePosition();
 
     return attachResult;
@@ -59,6 +60,11 @@ export class OverlayRef implements PortalHost {
     }
   }
 
+  /** Updates the text direction of the overlay panel. **/
+  private updateDirection() {
+    this._pane.setAttribute('dir', this._state.direction);
+  }
+
   /** Updates the size of the overlay based on the overlay config. */
   updateSize() {
     if (this._state.width || this._state.width === 0) {

src/lib/core/overlay/overlay-state.ts

@@ -1,4 +1,5 @@
 import {PositionStrategy} from './position/position-strategy';
+import {LayoutDirection} from '../rtl/dir';
 
 
 /**
@@ -21,6 +22,9 @@ export class OverlayState {
   /** The height of the overlay panel. If a number is provided, pixel units are assumed. **/
   height: number | string;
 
+  /** The direction of the text in the overlay panel. */
+  direction: LayoutDirection = 'ltr';
+
   // TODO(jelbourn): configuration still to add
   // - focus trap
   // - disable pointer events

src/lib/core/overlay/overlay.spec.ts

@@ -82,6 +82,16 @@ describe('Overlay', () => {
     expect(overlayContainerElement.textContent).toBe('');
   });
 
+  it('should set the direction', () => {
+    const state = new OverlayState();
+    state.direction = 'rtl';
+
+    overlay.create(state).attach(componentPortal);
+
+    const pane = overlayContainerElement.children[0] as HTMLElement;
+    expect(pane.getAttribute('dir')).toEqual('rtl');
+  });
+
   describe('positioning', () => {
     let state: OverlayState;
 

src/lib/core/overlay/position/connected-position-strategy.spec.ts

@@ -206,6 +206,23 @@ describe('ConnectedPositionStrategy', () => {
       expect(overlayRect.top).toBe(originRect.bottom);
       expect(overlayRect.right).toBe(originRect.left);
     });
+
+    it('should position a panel properly when rtl', () => {
+      // must make the overlay longer than the origin to properly test attachment
+      overlayElement.style.width = `500px`;
+      originRect = originElement.getBoundingClientRect();
+      strategy = positionBuilder.connectedTo(
+        fakeElementRef,
+        {originX: 'start', originY: 'bottom'},
+        {overlayX: 'start', overlayY: 'top'})
+        .setDirection('rtl');
+
+      strategy.apply(overlayElement);
+
+      let overlayRect = overlayElement.getBoundingClientRect();
+      expect(overlayRect.top).toBe(originRect.bottom);
+      expect(overlayRect.right).toBe(originRect.right);
+    });
   });
 
 

src/lib/core/overlay/position/connected-position-strategy.ts

@@ -17,9 +17,12 @@ import {
  * of the overlay.
  */
 export class ConnectedPositionStrategy implements PositionStrategy {
-  // TODO(jelbourn): set RTL to the actual value from the app.
+  private _dir = 'ltr';
+
   /** Whether the we're dealing with an RTL context */
-  _isRtl: boolean = false;
+  get _isRtl() {
+    return this._dir === 'rtl';
+  }
 
   /** Ordered list of preferred positions, from most to least desirable. */
   _preferredPositions: ConnectionPositionPair[] = [];
@@ -85,6 +88,11 @@ export class ConnectedPositionStrategy implements PositionStrategy {
     return this;
   }
 
+  /** Sets the layout direction so the overlay's position can be adjusted to match. */
+  setDirection(dir: 'ltr' | 'rtl') {
+    this._dir = dir;
+    return this;
+  }
 
   /**
    * Gets the horizontal (x) "start" dimension based on whether the overlay is in an RTL context.
@@ -146,8 +154,10 @@ export class ConnectedPositionStrategy implements PositionStrategy {
     let overlayStartX: number;
     if (pos.overlayX == 'center') {
       overlayStartX = -overlayRect.width / 2;
+    } else if (pos.overlayX === 'start') {
+      overlayStartX = this._isRtl ? -overlayRect.width : 0;
     } else {
-      overlayStartX = pos.overlayX == 'start' ? 0 : -overlayRect.width;
+      overlayStartX = this._isRtl ? 0 : -overlayRect.width;
     }
 
     let overlayStartY: number;