perf(event-monitor): fix menu bar hover lag on high-frequency mouse events by MoonMao42 · Pull Request #1118 · tisfeng/Easydict

MoonMao42 · 2026-03-15T13:45:21Z

Summary

handleMonitorEvent calls NSWorkspace.shared.frontmostApplication on every event including mouseMoved (~60–100 Hz). The original ObjC implementation only fetched it on demand inside specific handlers like leftMouseDown and leftMouseUp.

Changes

Return early for mouseMoved and scrollWheel before the frontmostApplication lookup
Add 100ms throttle to mouse-moved handling with a visibility guard — isMouseInPopButtonExpandedFrame() now only runs when the pop button is visible
Replace pow(x, 2) with x * x in GeometryHelper

Before / After

Before: every mouse-move event triggers a frontmostApplication lookup and pop-button frame check, even when the button is hidden.

After: high-frequency events skip the lookup entirely. The frame check runs at most 10 times per second and only while the button is on screen.

Test plan

Hover over the menu bar icon repeatedly — no system lag
Keep the app running for 30+ min, verify hover stays smooth
Select text via drag / double-click / triple-click — pop button appears and dismisses correctly
Scroll while pop button is visible — still dismisses
Shortcut translation still works normally

…vents

github-actions

Hello MKY508, Thank you for your first PR contribution 🎉 MKY508

tisfeng · 2026-03-19T02:46:04Z

Thanks your PR, we will review it later

Copilot

Pull request overview

This PR reduces UI lag in the EventMonitor by avoiding expensive work on high-frequency mouse events and adding throttling around pop-button hover dismissal checks.

Changes:

Short-circuit handling for .mouseMoved and .scrollWheel to avoid per-event frontmostApplication lookups.
Add a 100ms throttle for mouse-move handling, gated by pop-button visibility.
Micro-optimize circle hit-testing by replacing pow(x, 2) with x * x in GeometryHelper.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
`Easydict/Swift/Utility/EventMonitor/Core/EventMonitor.swift`	Skips expensive operations for high-frequency events and throttles mouse-moved hover checks.
`Easydict/Swift/Utility/EventMonitor/Utilities/GeometryHelper.swift`	Replaces `pow` calls with multiplication for faster distance-squared computation.

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

Easydict/Swift/Utility/EventMonitor/Core/EventMonitor.swift

Jerry23011 · 2026-03-21T06:21:56Z

The mouse movements on menubar were fine for me, even with the current release version.

The movements were fine with this PR. Perhaps we can have someone who was experiencing issues in #747 wants to test?

MoonMao42 · 2026-03-21T07:21:13Z

The mouse movements on menubar were fine for me, even with the current release version.

The movements were fine with this PR. Perhaps we can have someone who was experiencing issues in #747 wants to test?

I see that the current release version works fine for you, but I submitted this PR to address issues I've observed in specific scenarios, particularly right after a fresh download and initial installation, or in some other edge cases.
It seems that the lag or performance issue is more likely to be reproduced in those initial-setup environments rather than after the application has been running for a while. This PR is intended to fix the issue described in #747 for everyone, under all conditions.

tisfeng · 2026-03-22T04:23:12Z

The code looks good, and in theory it can indeed be optimized for performance.

Move the mouse-moved throttle logic into a reusable `ThrottleGate` utility and update `EventMonitor` to use synchronous allow/reset checks. Split the gate tests into a dedicated suite and register the new source files in the Xcode project.

tisfeng · 2026-03-22T04:48:26Z

I have fixed this small issue in #1118 (comment) , and refactor the code.

Please review it.

MoonMao42 · 2026-03-22T05:11:52Z

@tisfeng Your changes look good. I've pushed some additional fixes on top of them.

I found that EventTapMonitor.start() and stop() are called from different threads — start() runs inside a Task {} in SelectionWorkflow (background thread), while stop() is called from dismissPopButton() on the main thread. They both used CFRunLoopGetCurrent(), which gives different RunLoops on different threads, so CFRunLoopRemoveSource in stop() silently fails and leaks a CFMachPort + CFRunLoopSource every time you select text. I fixed this by switching to CFRunLoopGetMain() and keeping a reference to the installed RunLoop.

I also noticed that a few ObjC view classes (EZQueryView, EZBaseQueryViewController, EZTitlebar, EZTextView) register NotificationCenter observers but never remove them. The EZQueryView one is the worst — the didChangeFontSize block captures self strongly without weakify, so the view never gets deallocated and observers just keep piling up over time. Fixed those too.

I'm not sure these are the full root cause of the reported issues since some users see lag even without frequent text selection, so there might be more to it. I think we can merge this branch as an optimization, but we probably shouldn't close those issues yet until we can confirm the fix actually resolves them.

There are also some smaller fixes in the commit — leaked keyDown monitor, missing cancel before rescheduling delayDismissPopButton, redundant NSEvent.mouseLocation and frontmostApplication calls, and a DEBUG-only slow event handler log.

Fix CGEventTap RunLoop thread mismatch: - EventTapMonitor.start() was called from a background Swift concurrency Task, while stop() was called from the main thread. Both used CFRunLoopGetCurrent(), which returns different RunLoops on different threads. CFRunLoopRemoveSource in stop() silently failed, leaking a CFMachPort + CFRunLoopSource on every text selection cycle. - Fixed by using CFRunLoopGetMain() and storing the installed RunLoop reference so add/remove always target the same RunLoop. Fix NotificationCenter observer leaks in ObjC view classes: - EZQueryView: didChangeFontSize block captured self strongly without weakify, creating a retain cycle. Observer token was never stored. - EZBaseQueryViewController: didChangeFontSize block observer token was not stored. removeObserver:self in dealloc cannot remove block-based observers. - EZTitlebar: selector-based observers never removed (no dealloc). - EZTextView: selector-based observers never removed (no dealloc). Other minor fixes: - Fix leaked keyDown NSEvent monitor (return value was never stored) - Cancel previous pending timer before scheduling in delayDismissPopButton - Pass mouseLocation as parameter to avoid redundant NSEvent.mouseLocation calls - Remove duplicate frontmostApplication query in handleLeftMouseDown - Add DEBUG-only slow event handler logging (>16ms warning)

Copilot

Pull request overview

Improves menu bar hover responsiveness by reducing work performed on high-frequency input events in the event-monitoring pipeline, and adds a small throttling utility with unit tests.

Changes:

Skip frontmostApplication lookup for .mouseMoved / .scrollWheel, and throttle mouse-move handling while the pop button is visible.
Introduce ThrottleGate + unit tests to support synchronous throttling.
Minor robustness/perf improvements: fix observer lifetime handling in ObjC views/controllers, optimize geometry distance math, and make EventTapMonitor run-loop installation consistent.

Reviewed changes

Copilot reviewed 10 out of 10 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
EasydictTests/Utility/ThrottleGateTests.swift	Adds unit coverage for the new throttle gate behavior.
Easydict/Swift/Utility/ThrottleGate.swift	Introduces a small synchronous throttle primitive used by the event monitor.
Easydict/Swift/Utility/EventMonitor/Core/EventMonitor.swift	Early-returns on high-frequency events and throttles `.mouseMoved`; fixes local monitor removal; resets throttle across visibility sessions.
Easydict/Swift/Utility/EventMonitor/Engine/EventTapMonitor.swift	Attempts to make run-loop add/remove consistent by targeting the main run loop.
Easydict/Swift/Utility/EventMonitor/Utilities/GeometryHelper.swift	Replaces `pow` calls with multiplication for faster distance-squared math.
Easydict/objc/ViewController/Window/BaseQueryWindow/EZBaseQueryViewController.m	Stores/removes the block-based font-size observer token to avoid leaks.
Easydict/objc/ViewController/View/QueryView/EZQueryView.m	Stores/removes the block-based font-size observer token and avoids strong capture.
Easydict/objc/ViewController/View/Titlebar/EZTitlebar.m	Removes notification observers in `dealloc` to prevent callbacks after deallocation.
Easydict/objc/ViewController/View/TextView/EZTextView.m	Removes notification observers in `dealloc` to prevent callbacks after deallocation.
Easydict.xcodeproj/project.pbxproj	Registers new Swift source and test files in the Xcode project.

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

Easydict/Swift/Utility/EventMonitor/Engine/EventTapMonitor.swift

Add missing `mm_strongify(self)` to the query and result view callbacks that were still referencing `self` directly after `mm_weakify(self)`. This restores the intended weak/strong pattern and prevents retain cycles between the views and their block handlers.

tisfeng · 2026-03-28T13:15:06Z

@tisfeng Your changes look good. I've pushed some additional fixes on top of them.

I found that EventTapMonitor.start() and stop() are called from different threads — start() runs inside a Task {} in SelectionWorkflow (background thread), while stop() is called from dismissPopButton() on the main thread. They both used CFRunLoopGetCurrent(), which gives different RunLoops on different threads, so CFRunLoopRemoveSource in stop() silently fails and leaks a CFMachPort + CFRunLoopSource every time you select text. I fixed this by switching to CFRunLoopGetMain() and keeping a reference to the installed RunLoop.

I also noticed that a few ObjC view classes (EZQueryView, EZBaseQueryViewController, EZTitlebar, EZTextView) register NotificationCenter observers but never remove them. The EZQueryView one is the worst — the didChangeFontSize block captures self strongly without weakify, so the view never gets deallocated and observers just keep piling up over time. Fixed those too.

I'm not sure these are the full root cause of the reported issues since some users see lag even without frequent text selection, so there might be more to it. I think we can merge this branch as an optimization, but we probably shouldn't close those issues yet until we can confirm the fix actually resolves them.

There are also some smaller fixes in the commit — leaked keyDown monitor, missing cancel before rescheduling delayDismissPopButton, redundant NSEvent.mouseLocation and frontmostApplication calls, and a DEBUG-only slow event handler log.

Good, I reviewed the code, looks fine

tisfeng

LGTM

perf(event-monitor): fix menu bar hover lag on high-frequency mouse e…

fe44fc7

…vents

github-actions bot reviewed Mar 15, 2026

View reviewed changes

tisfeng requested review from Jerry23011, Copilot and phlpsong March 19, 2026 02:46

Copilot AI reviewed Mar 19, 2026

View reviewed changes

Easydict/Swift/Utility/EventMonitor/Core/EventMonitor.swift Show resolved Hide resolved

Easydict/Swift/Utility/EventMonitor/Core/EventMonitor.swift Outdated Show resolved Hide resolved

Merge branch 'dev' into fix/menu-bar-hover-lag

0f52a0f

Jerry23011 mentioned this pull request Mar 21, 2026

🐞 反馈问题：App 运行时间长了，导致交互卡顿 #747

Closed

6 tasks

MoonMao42 force-pushed the fix/menu-bar-hover-lag branch from 1b8a3fc to acb7bce Compare March 22, 2026 05:29

tisfeng requested a review from Copilot March 25, 2026 15:26

Copilot started reviewing on behalf of tisfeng March 25, 2026 15:27 View session

Copilot AI reviewed Mar 25, 2026

View reviewed changes

Easydict/Swift/Utility/EventMonitor/Engine/EventTapMonitor.swift Show resolved Hide resolved

tisfeng added 2 commits March 27, 2026 01:14

Merge branch 'dev' into fix/menu-bar-hover-lag

7988f42

tisfeng approved these changes Mar 28, 2026

View reviewed changes

tisfeng merged commit 38a85af into tisfeng:dev Mar 28, 2026
4 checks passed

This was referenced Mar 29, 2026

🪲反馈问题:mac明显卡顿 #1102

Closed

fix(event-monitor): scope high-frequency monitors to pop button #1128

Merged

Fix UI lag from unthrottled high-frequency event monitoring #1027

Closed

MoonMao42 mentioned this pull request Mar 29, 2026

Refactor view and appearance handling to prevent retain cycles and leaks #1127

Merged

MoonMao42 deleted the fix/menu-bar-hover-lag branch March 30, 2026 16:33

Conversation

MoonMao42 commented Mar 15, 2026 • edited by tisfeng Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Summary

Changes

Before / After

Test plan

Uh oh!

github-actions bot left a comment

Choose a reason for hiding this comment

Uh oh!

tisfeng commented Mar 19, 2026

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Reviewed changes

Uh oh!

Uh oh!

Uh oh!

Jerry23011 commented Mar 21, 2026

Uh oh!

MoonMao42 commented Mar 21, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

tisfeng commented Mar 22, 2026

Uh oh!

tisfeng commented Mar 22, 2026

Uh oh!

MoonMao42 commented Mar 22, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Reviewed changes

Uh oh!

Uh oh!

tisfeng commented Mar 28, 2026

Uh oh!

tisfeng left a comment

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

4 participants

MoonMao42 commented Mar 15, 2026 •

edited by tisfeng

Loading

MoonMao42 commented Mar 21, 2026 •

edited

Loading

MoonMao42 commented Mar 22, 2026 •

edited

Loading