Center datacenter on site load

2 files changed, 53 insertions, 0 deletions

diff --git a/src/store/configureStore.js b/src/store/configure-store.js
index 5bbaf811..a7f3ec31 100644
--- a/src/store/configureStore.js
+++ b/src/store/configure-store.js
@@ -6,6 +6,7 @@ import thunk from "redux-thunk";
 import {authRedirectMiddleware} from "../auth/index";
 import rootReducer from "../reducers/index";
 import rootSaga from "../sagas/index";
+import {viewportAdjustmentMiddleware} from "./middlewares/viewport-adjustment";
 
 const sagaMiddleware = createSagaMiddleware();
 const logger = createLogger();
@@ -20,6 +21,7 @@ export default function configureStore() {
                 thunk,
                 sagaMiddleware,
                 authRedirectMiddleware,
+                viewportAdjustmentMiddleware,
             )
         )
     );
diff --git a/src/store/middlewares/viewport-adjustment.js b/src/store/middlewares/viewport-adjustment.js
new file mode 100644
index 00000000..75ad6a2f
--- /dev/null
+++ b/src/store/middlewares/viewport-adjustment.js
@@ -0,0 +1,51 @@
+import {SET_MAP_DIMENSIONS, setMapPosition, setMapScale} from "../../actions/map";
+import {
+    MAP_MAX_SCALE,
+    MAP_MIN_SCALE,
+    SIDEBAR_WIDTH,
+    TILE_SIZE_IN_PIXELS,
+    VIEWPORT_PADDING
+} from "../../components/map/MapConstants";
+import {calculateRoomListBounds} from "../../util/tile-calculations";
+
+export const viewportAdjustmentMiddleware = store => next => action => {
+    const state = store.getState();
+    if (action.type === SET_MAP_DIMENSIONS && state.currentDatacenterId !== -1) {
+        const roomIds = state.objects.datacenter[state.currentDatacenterId].roomIds;
+        const rooms = roomIds.map(id => Object.assign({}, state.objects.room[id]));
+        rooms.forEach(room => room.tiles = room.tileIds.map(tileId => state.objects.tile[tileId]));
+
+        const viewportParams = calculateParametersToZoomInOnRooms(rooms, action.width, action.height);
+        store.dispatch(setMapPosition(viewportParams.newX, viewportParams.newY));
+        store.dispatch(setMapScale(viewportParams.newScale));
+    }
+
+    next(action);
+};
+
+function calculateParametersToZoomInOnRooms(rooms, mapWidth, mapHeight) {
+    const bounds = calculateRoomListBounds(rooms);
+    const newScale = calculateNewScale(bounds, mapWidth, mapHeight);
+
+    // Coordinates of the center of the room, relative to the global origin of the map
+    const roomCenterCoordinates = {
+        x: bounds.center.x * TILE_SIZE_IN_PIXELS * newScale,
+        y: bounds.center.y * TILE_SIZE_IN_PIXELS * newScale
+    };
+
+    const newX = -roomCenterCoordinates.x + mapWidth / 2;
+    const newY = -roomCenterCoordinates.y + mapHeight / 2;
+
+    return {newScale, newX, newY};
+}
+
+function calculateNewScale(bounds, mapWidth, mapHeight) {
+    const width = bounds.max.x - bounds.min.x;
+    const height = bounds.max.y - bounds.min.y;
+
+    const scaleX = (mapWidth - 2 * SIDEBAR_WIDTH) / (width * TILE_SIZE_IN_PIXELS + 2 * VIEWPORT_PADDING);
+    const scaleY = mapHeight / (height * TILE_SIZE_IN_PIXELS + 2 * VIEWPORT_PADDING);
+    const newScale = Math.min(scaleX, scaleY);
+
+    return Math.min(Math.max(MAP_MIN_SCALE, newScale), MAP_MAX_SCALE);
+}