fix(ScrollCollapse): factor in element offsetTop when calculating min…

…imise mode Minimise mode did not factor in offsetTop, it now does and both affix mode and minimise mode were being triggered 1px too late
thisissoon · Feb 19, 2018 · 303b819 · 303b819
1 parent 8dfbacc
commit 303b819
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Showing 2 changed files with 15 additions and 2 deletions.
diff --git a/src/app/scroll-collapse/scroll-collapse.directive.spec.ts b/src/app/scroll-collapse/scroll-collapse.directive.spec.ts
@@ -100,6 +100,19 @@ describe('ScrollCollapseDirective', () => {
       directive.calculateMinimiseMode({ scrollX: 0, scrollY: 99, width: 1366, height: 768 });
       expect(directive.minimiseMode).toBeFalsy();
     });
+
+    it('should factor in element offsetTop when calculating minimise mode', () => {
+      directive.originalHeight = 100;
+      directive.originalTop = 100;
+      directive.calculateMinimiseMode({ scrollX: 0, scrollY: 0, width: 1366, height: 768 });
+      expect(directive.minimiseMode).toBeFalsy();
+
+      directive.calculateMinimiseMode({ scrollX: 0, scrollY: 200, width: 1366, height: 768 });
+      expect(directive.minimiseMode).toBeTruthy();
+
+      directive.calculateMinimiseMode({ scrollX: 0, scrollY: 199, width: 1366, height: 768 });
+      expect(directive.minimiseMode).toBeFalsy();
+    });
   });
 
   describe('affix mode', () => {

diff --git a/src/app/scroll-collapse/scroll-collapse.directive.ts b/src/app/scroll-collapse/scroll-collapse.directive.ts
@@ -185,7 +185,7 @@ export class ScrollCollapseDirective implements AfterViewInit, OnDestroy {
    * @memberof ScrollCollapseDirective
    */
   public calculateMinimiseMode(viewport: Viewport): void {
-    this.minimiseMode = viewport.scrollY > this.originalHeight;
+    this.minimiseMode = viewport.scrollY >= (this.originalHeight + this.originalTop);
   }
   /**
    * Calculate if the user has scrolled pass the origin height of
@@ -194,7 +194,7 @@ export class ScrollCollapseDirective implements AfterViewInit, OnDestroy {
    * @memberof ScrollCollapseDirective
    */
   public calculateAffixMode(viewport: Viewport): void {
-    this.affixMode = viewport.scrollY > this.originalTop;
+    this.affixMode = viewport.scrollY >= this.originalTop;
   }
   /**
    * Return current viewport values