[ADF-1416] image viewer enhancements (#2895)

* image viewer enhancements

* code improvements

* fix scrolling of the zommed in content

* remove flip for now as it needs much efforts

* unit tests, thumbnail selector enhancements

lib/core/viewer/components/imgViewer.component.spec.ts

@@ -62,6 +62,176 @@ describe('Test Img viewer component ', () => {
         fixture.detectChanges();
     });
 
+    it('should display current scale as percent string', () => {
+        component.scaleX = 0.5;
+        expect(component.currentScaleText).toBe('50%');
+
+        component.scaleX = 1.0;
+        expect(component.currentScaleText).toBe('100%');
+    });
+
+    it('should generate transform settings', () => {
+        component.scaleX = 1.0;
+        component.scaleY = 2.0;
+        component.rotate = 10;
+        component.offsetX = 20;
+        component.offsetY = 30;
+
+        expect(component.transform).toBe('scale(1, 2) rotate(10deg) translate(20px, 30px)');
+    });
+
+    it('should start drag on mouse down', () => {
+        expect(component.isDragged).toBeFalsy();
+
+        component.onMouseDown(<any> new CustomEvent('mousedown'));
+
+        expect(component.isDragged).toBeTruthy();
+    });
+
+    it('should prevent default behaviour on mouse down', () => {
+        const event = jasmine.createSpyObj('mousedown', ['preventDefault']);
+
+        component.onMouseDown(event);
+
+        expect(event.preventDefault).toHaveBeenCalled();
+    });
+
+    it('should prevent default mouse move during drag', () => {
+        const event = jasmine.createSpyObj('mousemove', ['preventDefault']);
+
+        component.onMouseDown(<any> new CustomEvent('mousedown'));
+        component.onMouseMove(event);
+
+        expect(event.preventDefault).toHaveBeenCalled();
+    });
+
+    it('should not prevent default mouse move if not dragged', () => {
+        const event = jasmine.createSpyObj('mousemove', ['preventDefault']);
+
+        component.onMouseMove(event);
+
+        expect(component.isDragged).toBeFalsy();
+        expect(event.preventDefault).not.toHaveBeenCalled();
+    });
+
+    it('should prevent default mouse up during drag end', () => {
+        const event = jasmine.createSpyObj('mouseup', ['preventDefault']);
+
+        component.onMouseDown(<any> new CustomEvent('mousedown'));
+        expect(component.isDragged).toBeTruthy();
+
+        component.onMouseUp(event);
+        expect(event.preventDefault).toHaveBeenCalled();
+    });
+
+    it('should stop drag on mouse up', () => {
+        component.onMouseDown(<any> new CustomEvent('mousedown'));
+        expect(component.isDragged).toBeTruthy();
+
+        component.onMouseUp(<any> new CustomEvent('mouseup'));
+        expect(component.isDragged).toBeFalsy();
+    });
+
+    it('should stop drag on mouse leave', () => {
+        component.onMouseDown(<any> new CustomEvent('mousedown'));
+        expect(component.isDragged).toBeTruthy();
+
+        component.onMouseLeave(<any> new CustomEvent('mouseleave'));
+        expect(component.isDragged).toBeFalsy();
+    });
+
+    it('should stop drag on mouse out', () => {
+        component.onMouseDown(<any> new CustomEvent('mousedown'));
+        expect(component.isDragged).toBeTruthy();
+
+        component.onMouseOut(<any> new CustomEvent('mouseout'));
+        expect(component.isDragged).toBeFalsy();
+    });
+
+    it('should update scales on zoom in', () => {
+        component.scaleX = 1.0;
+
+        component.zoomIn();
+        expect(component.scaleX).toBe(1.2);
+        expect(component.scaleY).toBe(1.2);
+
+        component.zoomIn();
+        expect(component.scaleX).toBe(1.4);
+        expect(component.scaleY).toBe(1.4);
+    });
+
+    it('should update scales on zoom out', () => {
+        component.scaleX = 1.0;
+
+        component.zoomOut();
+        expect(component.scaleX).toBe(0.8);
+        expect(component.scaleY).toBe(0.8);
+
+        component.zoomOut();
+        expect(component.scaleX).toBe(0.6);
+        expect(component.scaleY).toBe(0.6);
+    });
+
+    it('should not zoom out past 20%', () => {
+        component.scaleX = 0.4;
+
+        component.zoomOut();
+        component.zoomOut();
+        component.zoomOut();
+
+        expect(component.scaleX).toBe(0.2);
+    });
+
+    it('should update angle by 90 degrees on rotate left', () => {
+        component.rotate = 0;
+
+        component.rotateLeft();
+        expect(component.rotate).toBe(-90);
+
+        component.rotateLeft();
+        expect(component.rotate).toBe(-180);
+    });
+
+    it('should reset to 0 degrees for full rotate left round', () => {
+        component.rotate = -270;
+
+        component.rotateLeft();
+        expect(component.rotate).toBe(0);
+    });
+
+    it('should update angle by 90 degrees on rotate right', () => {
+        component.rotate = 0;
+
+        component.rotateRight();
+        expect(component.rotate).toBe(90);
+
+        component.rotateRight();
+        expect(component.rotate).toBe(180);
+    });
+
+    it('should reset to 0 degrees for full rotate right round', () => {
+        component.rotate = 270;
+
+        component.rotateRight();
+        expect(component.rotate).toBe(0);
+    });
+
+    it('should reset all image modifications', () => {
+        component.rotate = 10;
+        component.scaleX = 20;
+        component.scaleY = 30;
+        component.offsetX = 40;
+        component.offsetY = 50;
+
+        component.reset();
+
+        expect(component.rotate).toBe(0);
+        expect(component.scaleX).toBe(1.0);
+        expect(component.scaleY).toBe(1.0);
+        expect(component.offsetX).toBe(0);
+        expect(component.offsetY).toBe(0);
+    });
+
     it('If no url or blob are passed should thrown an error', () => {
         let change = new SimpleChange(null, null, true);
         expect(() => {