Reset the viewer state for a window when a canvas or viewertype changes

__tests__/src/reducers/viewers.test.js

@@ -42,6 +42,42 @@ describe('viewers reducer', () => {
       },
     });
   });
+  it('should handle SET_WINDOW_VIEW_TYPE', () => {
+    expect(viewersReducer({
+      abc123: {
+        foo: 'bar',
+      },
+      def456: {
+        foo: 'bar',
+      },
+    }, {
+      type: ActionTypes.SET_WINDOW_VIEW_TYPE,
+      windowId: 'abc123',
+    })).toEqual({
+      abc123: null,
+      def456: {
+        foo: 'bar',
+      },
+    });
+  });
+  it('should handle SET_CANVAS', () => {
+    expect(viewersReducer({
+      abc123: {
+        foo: 'bar',
+      },
+      def456: {
+        foo: 'bar',
+      },
+    }, {
+      type: ActionTypes.SET_CANVAS,
+      windowId: 'abc123',
+    })).toEqual({
+      abc123: null,
+      def456: {
+        foo: 'bar',
+      },
+    });
+  });
   it('should handle IMPORT_MIRADOR_STATE', () => {
     expect(viewersReducer({}, {
       state: { viewers: { new: 'stuff' } },

src/state/reducers/viewers.js

+import { setIn } from 'immutable';
 import ActionTypes from '../actions/action-types';
 
 /**
@@ -19,6 +20,10 @@ export const viewersReducer = (state = {}, action) => {
         }
         return object;
       }, {});
+    case ActionTypes.SET_WINDOW_VIEW_TYPE:
+      return setIn(state, [action.windowId], null);
+    case ActionTypes.SET_CANVAS:
+      return setIn(state, [action.windowId], null);
     case ActionTypes.IMPORT_MIRADOR_STATE:
       return action.state.viewers;
     default: