2 files changed, 76 insertions, 0 deletions
diff --git a/opendc-web/opendc-web-ui/src/store/middlewares/dummy-middleware.js b/opendc-web/opendc-web-ui/src/store/middlewares/dummy-middleware.js
new file mode 100644
index 00000000..5ba35691
--- /dev/null
+++ b/opendc-web/opendc-web-ui/src/store/middlewares/dummy-middleware.js
@@ -0,0 +1,3 @@
+export const dummyMiddleware = (store) => (next) => (action) => {
+    next(action)
+}
diff --git a/opendc-web/opendc-web-ui/src/store/middlewares/viewport-adjustment.js b/opendc-web/opendc-web-ui/src/store/middlewares/viewport-adjustment.js
new file mode 100644
index 00000000..b4472c54
--- /dev/null
+++ b/opendc-web/opendc-web-ui/src/store/middlewares/viewport-adjustment.js
@@ -0,0 +1,73 @@
+import { SET_MAP_DIMENSIONS, setMapPosition, setMapScale } from '../../actions/map'
+import { SET_CURRENT_TOPOLOGY } from '../../actions/topology/building'
+import {
+    MAP_MAX_SCALE,
+    MAP_MIN_SCALE,
+    SIDEBAR_WIDTH,
+    TILE_SIZE_IN_PIXELS,
+    VIEWPORT_PADDING,
+} from '../../components/app/map/MapConstants'
+import { calculateRoomListBounds } from '../../util/tile-calculations'
+
+export const viewportAdjustmentMiddleware = (store) => (next) => (action) => {
+    const state = store.getState()
+
+    let topologyId = '-1'
+    let mapDimensions = {}
+    if (action.type === SET_CURRENT_TOPOLOGY && action.topologyId !== '-1') {
+        topologyId = action.topologyId
+        mapDimensions = state.map.dimensions
+    } else if (action.type === SET_MAP_DIMENSIONS && state.currentTopologyId !== '-1') {
+        topologyId = state.currentTopologyId
+        mapDimensions = { width: action.width, height: action.height }
+    }
+
+    if (topologyId !== '-1') {
+        const roomIds = state.objects.topology[topologyId].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])))
+
+        let hasNoTiles = true
+        for (let i in rooms) {
+            if (rooms[i].tiles.length > 0) {
+                hasNoTiles = false
+                break
+            }
+        }
+
+        if (!hasNoTiles) {
+            const viewportParams = calculateParametersToZoomInOnRooms(rooms, mapDimensions.width, mapDimensions.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)
+}