Adds generic popover component to ui-component

scm-ui/ui-components/src/popover/usePopover.ts

@@ -0,0 +1,137 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2020-present Cloudogu GmbH and Contributors
+ *
+ * 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 { Dispatch, useReducer, useRef } from "react";
+
+type EnterTrigger = {
+  type: "enter-trigger";
+  offsetTop: number;
+  offsetLeft: number;
+};
+
+type LeaveTrigger = {
+  type: "leave-trigger";
+};
+
+type EnterPopover = {
+  type: "enter-popover";
+};
+
+type LeavePopover = {
+  type: "leave-popover";
+};
+
+export type Action = EnterTrigger | LeaveTrigger | EnterPopover | LeavePopover;
+
+type State = {
+  offsetTop?: number;
+  offsetLeft?: number;
+  onPopover: boolean;
+  onTrigger: boolean;
+};
+
+const initialState = {
+  onPopover: false,
+  onTrigger: false
+};
+
+const reducer = (state: State, action: Action): State => {
+  switch (action.type) {
+    case "enter-trigger": {
+      if (state.onPopover) {
+        return state;
+      }
+      return {
+        offsetTop: action.offsetTop,
+        offsetLeft: action.offsetLeft,
+        onTrigger: true,
+        onPopover: false
+      };
+    }
+    case "leave-trigger": {
+      if (state.onPopover) {
+        return {
+          ...state,
+          onTrigger: false
+        };
+      }
+      return initialState;
+    }
+    case "enter-popover": {
+      return {
+        ...state,
+        onPopover: true
+      };
+    }
+    case "leave-popover": {
+      if (state.onTrigger) {
+        return {
+          ...state,
+          onPopover: false
+        };
+      }
+      return initialState;
+    }
+  }
+};
+
+const dispatchDeferred = (dispatch: Dispatch<Action>, action: Action) => {
+  setTimeout(() => dispatch(action), 250);
+};
+
+const usePopover = () => {
+  const [state, dispatch] = useReducer(reducer, initialState);
+  const triggerRef = useRef<HTMLElement | null>(null);
+
+  const onMouseOver = () => {
+    const current = triggerRef.current!;
+    dispatchDeferred(dispatch, {
+      type: "enter-trigger",
+      offsetTop: current.offsetTop,
+      offsetLeft: current.offsetLeft + current.offsetWidth / 2
+    });
+  };
+
+  const onMouseLeave = () => {
+    dispatchDeferred(dispatch, {
+      type: "leave-trigger"
+    });
+  };
+
+  return {
+    triggerProps: {
+      onMouseOver,
+      onMouseLeave,
+      ref: (node: HTMLElement | null) => (triggerRef.current = node)
+    },
+    popoverProps: {
+      dispatch,
+      show: state.onPopover || state.onTrigger,
+      offsetTop: state.offsetTop,
+      offsetLeft: state.offsetLeft
+    }
+  };
+};
+
+export default usePopover;