merge: Address technical dept in topology view (#162)

This pull request aims to address some of the technical debt in the topology 
view of the OpenDC frontend.

* Add support for panning of the datacenter topology
* Isolate world coordinate space (world objects do not depend on camera scale or position)
* Split transpiled modules into a separate chunk to reduce deduplication
* Encode state in topology actions to reduce global state
* Restructure components per page
* Enable more ESLint rules through `eslint:recommended` ruleset
* Move page components in separate files.

1 files changed, 41 insertions, 0 deletions

diff --git a/opendc-web/opendc-web-ui/src/util/effect-ref.js b/opendc-web/opendc-web-ui/src/util/effect-ref.js
new file mode 100644
index 00000000..cda0324b
--- /dev/null
+++ b/opendc-web/opendc-web-ui/src/util/effect-ref.js
@@ -0,0 +1,41 @@
+/*
+ * Copyright (c) 2021 AtLarge Research
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+import { useCallback, useRef } from 'react'
+
+const noop = () => {}
+
+/**
+ * A hook that will invoke the specified callback when the reference returned by this function is initialized.
+ * The callback can return an optional clean up function.
+ */
+export function useEffectRef(callback) {
+    const disposeRef = useRef(noop)
+    return useCallback((element) => {
+        disposeRef.current()
+        disposeRef.current = noop
+
+        if (element) {
+            disposeRef.current = callback(element) || noop
+        }
+    }, []) // eslint-disable-line react-hooks/exhaustive-deps
+}