From fd09783a450f262cf68fccba555551a70b5da1f2 Mon Sep 17 00:00:00 2001
From: David Lechner <david@pybricks.com>
Date: Tue, 28 Dec 2021 18:48:07 -0600
Subject: [PATCH] toolbar: work around tooltip bugs

This works around several bugs where tooltips don't close when expected.

Fixes: https://github.com/pybricks/pybricks-code/issues/275
---
 CHANGELOG.md                    |  7 +++
 src/toolbar/ActionButton.tsx    | 20 ++++++---
 src/toolbar/OpenFileButton.tsx  | 21 ++++++---
 src/utils/monkey-patch.test.tsx | 76 +++++++++++++++++++++++++++++++++
 src/utils/monkey-patch.ts       | 68 +++++++++++++++++++++++++++++
 5 files changed, 179 insertions(+), 13 deletions(-)
 create mode 100644 src/utils/monkey-patch.test.tsx
 create mode 100644 src/utils/monkey-patch.ts

diff --git a/CHANGELOG.md b/CHANGELOG.md
index d4302e63..797ddc16 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,13 @@
 
 # Changelog
 
+## [Unreleased]
+
+### Fixed
+- Fix tooltips not closing when expected ([pybricks-code#275]).
+
+[pybricks-code#275]: https://github.com/pybricks/pybricks-code/issues/275
+
 ## [1.2.0-beta.1] - 2021-12-27
 
 ### Added
diff --git a/src/toolbar/ActionButton.tsx b/src/toolbar/ActionButton.tsx
index 9f893e6d..8de557c3 100644
--- a/src/toolbar/ActionButton.tsx
+++ b/src/toolbar/ActionButton.tsx
@@ -13,6 +13,7 @@ import { Tooltip2 } from '@blueprintjs/popover2';
 import { useI18n } from '@shopify/react-i18n';
 import React, { useEffect, useMemo, useState } from 'react';
 import { tooltipDelay } from '../app/constants';
+import { closeTooltip2, useTooltip2MonkeyPatch } from '../utils/monkey-patch';
 import { TooltipId } from './i18n';
 import en from './i18n.en.json';
 
@@ -90,22 +91,29 @@ const ActionButton: React.FC<ActionButtonProps> = (props) => {
 
     useHotkeys(hotkeys);
 
+    const tooltipRef = useTooltip2MonkeyPatch();
+
     return (
         <Tooltip2
+            ref={tooltipRef}
             content={tooltipText}
             placement="bottom"
             hoverOpenDelay={tooltipDelay}
             renderTarget={({
-                ref: tooltipRef,
+                ref: tooltipTargetRef,
                 isOpen: _tooltipIsOpen,
-                ...tooltipProps
+                ...tooltipTargetProps
             }) => (
                 <Button
-                    elementRef={tooltipRef as IRef<HTMLButtonElement>}
-                    {...tooltipProps}
+                    elementRef={tooltipTargetRef as IRef<HTMLButtonElement>}
+                    {...tooltipTargetProps}
                     intent={Intent.PRIMARY}
-                    // prevent focus from mouse click
-                    onMouseDown={(e) => e.preventDefault()}
+                    onMouseDown={(e) => {
+                        // prevent focus from mouse click
+                        e.preventDefault();
+                        // close/prevent tooltip
+                        closeTooltip2(tooltipRef);
+                    }}
                     onClick={() => props.onAction()}
                     disabled={props.enabled === false}
                     style={
diff --git a/src/toolbar/OpenFileButton.tsx b/src/toolbar/OpenFileButton.tsx
index 28314af5..6d7bf042 100644
--- a/src/toolbar/OpenFileButton.tsx
+++ b/src/toolbar/OpenFileButton.tsx
@@ -7,11 +7,11 @@ import { useI18n } from '@shopify/react-i18n';
 import React, { useEffect, useState } from 'react';
 import { useDropzone } from 'react-dropzone';
 import { tooltipDelay } from '../app/constants';
+import { closeTooltip2, useTooltip2MonkeyPatch } from '../utils/monkey-patch';
 import { TooltipId } from './i18n';
 import en from './i18n.en.json';
 
 const smallScreenThreshold = 700;
-
 export interface OpenFileButtonProps {
     /** A unique id for each instance. */
     readonly id: string;
@@ -91,8 +91,11 @@ const OpenFileButton: React.FC<OpenFileButtonProps> = (props) => {
         },
     });
 
+    const tooltipRef = useTooltip2MonkeyPatch();
+
     return (
         <Tooltip2
+            ref={tooltipRef}
             content={i18n.translate(
                 props.tooltip,
                 props.tooltip === TooltipId.FlashProgress
@@ -107,23 +110,27 @@ const OpenFileButton: React.FC<OpenFileButtonProps> = (props) => {
             placement="bottom"
             hoverOpenDelay={tooltipDelay}
             renderTarget={({
-                ref: tooltipRef,
+                ref: tooltipTargetRef,
                 isOpen: _tooltipIsOpen,
-                ...tooltipProps
+                ...tooltipTargetProps
             }) => (
                 <Button
                     {...getRootProps({
                         refKey: 'elementRef',
-                        elementRef: tooltipRef as IRef<HTMLButtonElement>,
-                        ...tooltipProps,
+                        elementRef: tooltipTargetRef as IRef<HTMLButtonElement>,
+                        ...tooltipTargetProps,
                         intent: Intent.PRIMARY,
                         disabled: props.enabled === false,
                         style:
                             props.enabled === false
                                 ? { pointerEvents: 'none' }
                                 : undefined,
-                        // prevent focus from mouse click
-                        onMouseDown: (e) => e.preventDefault(),
+                        onMouseDown: (e) => {
+                            // prevent focus from mouse click
+                            e.preventDefault();
+                            // close/prevent tooltip
+                            closeTooltip2(tooltipRef);
+                        },
                         onClick: props.onClick,
                     })}
                 >
diff --git a/src/utils/monkey-patch.test.tsx b/src/utils/monkey-patch.test.tsx
new file mode 100644
index 00000000..4386a32c
--- /dev/null
+++ b/src/utils/monkey-patch.test.tsx
@@ -0,0 +1,76 @@
+// SPDX-License-Identifier: MIT
+// Copyright (c) 2021 The Pybricks Authors
+
+import { Button, IRef } from '@blueprintjs/core';
+import { Tooltip2 } from '@blueprintjs/popover2';
+import {
+    fireEvent,
+    render,
+    screen,
+    waitFor,
+    waitForElementToBeRemoved,
+} from '@testing-library/react';
+import userEvent from '@testing-library/user-event';
+import React from 'react';
+import { useTooltip2MonkeyPatch } from './monkey-patch';
+
+const testTooltipText = 'Test tooltip.';
+const testButtonId = 'test-button';
+
+type TestComponentProps = { monkeyPatch: boolean };
+
+const TestComponent: React.FC<TestComponentProps> = (props) => {
+    const tooltipRef = props.monkeyPatch ? useTooltip2MonkeyPatch() : undefined;
+
+    return (
+        <Tooltip2
+            ref={tooltipRef}
+            content={testTooltipText}
+            renderTarget={({
+                ref: tooltipTargetRef,
+                isOpen: _tooltipIsOpen,
+                ...tooltipTargetProps
+            }) => (
+                <Button
+                    data-testid={testButtonId}
+                    elementRef={tooltipTargetRef as IRef<HTMLButtonElement>}
+                    {...tooltipTargetProps}
+                >
+                    Press Me!
+                </Button>
+            )}
+        />
+    );
+};
+
+it.each([false, true])(
+    'should work around https://github.com/palantir/blueprint/issues/4503',
+    async (monkeyPatch) => {
+        render(<TestComponent monkeyPatch={monkeyPatch} />);
+
+        expect(screen.queryByText(testTooltipText)).not.toBeInTheDocument();
+
+        // pressing the tab key should focus the button and open the tooltip
+        userEvent.tab();
+
+        await waitFor(() => {
+            expect(screen.getByText(testTooltipText)).toBeInTheDocument();
+        });
+
+        // a blur event with renderTarget=null should trigger the bug and workaround
+        fireEvent.blur(screen.getByTestId(testButtonId));
+
+        if (monkeyPatch) {
+            // if the patch was applied, there should not be any error
+            await waitForElementToBeRemoved(screen.getByText(testTooltipText));
+        } else {
+            // if the patch was not applied, the bug should be triggered
+            try {
+                await waitForElementToBeRemoved(screen.getByText(testTooltipText));
+                fail('bug was not triggered');
+            } catch (err) {
+                // error was expected
+            }
+        }
+    },
+);
diff --git a/src/utils/monkey-patch.ts b/src/utils/monkey-patch.ts
new file mode 100644
index 00000000..4d16252b
--- /dev/null
+++ b/src/utils/monkey-patch.ts
@@ -0,0 +1,68 @@
+// SPDX-License-Identifier: MIT
+// Copyright (c) 2021 The Pybricks Authors
+
+import { Tooltip2 } from '@blueprintjs/popover2';
+import React, { useEffect, useRef } from 'react';
+
+/** Hack to access private members of Popover2. */
+interface Popover2Private {
+    handleTargetBlur: (e: React.FocusEvent<HTMLElement>) => void;
+    handleMouseLeave: (e: React.MouseEvent<HTMLElement>) => void;
+}
+/** Hack to access private members of Tooltip2. */
+interface Tooltip2Private {
+    popover: Popover2Private;
+}
+
+/**
+ * Monkey patch Popover2 blur event handler to make tooltips close when
+ * focus is lost.
+ *
+ * https://github.com/palantir/blueprint/issues/4503
+ *
+ * @returns A React ref to be attached to the Tooltip2 component.
+ */
+export function useTooltip2MonkeyPatch<T>(): React.RefObject<Tooltip2<T>> {
+    const tooltipRef = useRef<Tooltip2<T>>(null);
+
+    useEffect(() => {
+        if (!tooltipRef.current) {
+            return;
+        }
+
+        const tooltip = tooltipRef.current as unknown as Tooltip2Private;
+
+        const oldHandleTargetBlur = tooltip.popover.handleTargetBlur;
+
+        tooltip.popover.handleTargetBlur = (e) => {
+            if (e.relatedTarget) {
+                oldHandleTargetBlur(e);
+            } else {
+                closeTooltip2(tooltipRef);
+            }
+        };
+
+        return () => {
+            tooltip.popover.handleTargetBlur = oldHandleTargetBlur;
+        };
+    }, [tooltipRef]);
+
+    return tooltipRef;
+}
+
+/**
+ * Hack to access private members of Tooltip2 to programmatically close the tooltip.
+ * @param tooltipRef The reference returned from useTooltip2MonkeyPatch()
+ */
+export function closeTooltip2<T>(tooltipRef: React.RefObject<Tooltip2<T>>): void {
+    if (!tooltipRef.current) {
+        return;
+    }
+
+    const tooltip = tooltipRef.current as unknown as Tooltip2Private;
+
+    // Currently, the event arg is not used so it should be safe to pass undefined.
+    tooltip.popover.handleMouseLeave(
+        undefined as unknown as React.MouseEvent<HTMLElement>,
+    );
+}