Skip to content

Fix AdvancedPaste auto-copy failing on Electron/Chromium apps #46486

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
yeelam-gordon merged 1 commit into from
Apr 16, 2026
+121 −67
Merged

Fix AdvancedPaste auto-copy failing on Electron/Chromium apps #46486

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
188 changes: 121 additions & 67 deletions src/modules/AdvancedPaste/AdvancedPasteModuleInterface/dllmain.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -496,23 +496,119 @@ class AdvancedPaste : public PowertoyModuleIface

if (!GetGUIThreadInfo(0, &gui_info))
{
Logger::warn(L"Auto-copy: GetGUIThreadInfo failed (error={})", GetLastError());
return false;
}

HWND target = gui_info.hwndFocus ? gui_info.hwndFocus : gui_info.hwndActive;
if (!target)
{
Logger::warn(L"Auto-copy: no focused or active window found");
return false;
}

DWORD_PTR result = 0;
return SendMessageTimeout(target,
WM_COPY,
0,
0,
SMTO_ABORTIFHUNG | SMTO_BLOCK,
50,
&result) != 0;
auto sendResult = SendMessageTimeout(target, WM_COPY, 0, 0, SMTO_ABORTIFHUNG | SMTO_BLOCK, 50, &result);
return sendResult != 0;
}

// Helper: poll clipboard sequence number for a change from initial_sequence.
// Returns true if the sequence number changed within the given number of polls.
bool poll_clipboard_sequence(DWORD initial_sequence, int poll_attempts, std::chrono::milliseconds poll_delay)
{
for (int poll = 0; poll < poll_attempts; ++poll)
{
if (GetClipboardSequenceNumber() != initial_sequence)
{
return true;
}
std::this_thread::sleep_for(poll_delay);
}
return false;
}

// Helper: send Ctrl+C via SendInput, releasing any held modifier keys first
// (the hotkey combination may still have modifiers physically pressed).
bool send_ctrl_c_input()
{
std::vector<INPUT> inputs;

// Release all modifier keys that are currently held down from the hotkey.
// Without this, the target app sees e.g. Win+Shift+Ctrl+C instead of just Ctrl+C.
try_inject_modifier_key_up(inputs, VK_LCONTROL);
try_inject_modifier_key_up(inputs, VK_RCONTROL);
try_inject_modifier_key_up(inputs, VK_LWIN);
try_inject_modifier_key_up(inputs, VK_RWIN);
try_inject_modifier_key_up(inputs, VK_LSHIFT);
try_inject_modifier_key_up(inputs, VK_RSHIFT);
try_inject_modifier_key_up(inputs, VK_LMENU);
try_inject_modifier_key_up(inputs, VK_RMENU);

// Ctrl down
{
INPUT input_event = {};
input_event.type = INPUT_KEYBOARD;
input_event.ki.wVk = VK_CONTROL;
input_event.ki.dwExtraInfo = CENTRALIZED_KEYBOARD_HOOK_DONT_TRIGGER_FLAG;
inputs.push_back(input_event);
}

// C down
{
INPUT input_event = {};
input_event.type = INPUT_KEYBOARD;
input_event.ki.wVk = 0x43; // C
input_event.ki.dwExtraInfo = CENTRALIZED_KEYBOARD_HOOK_DONT_TRIGGER_FLAG;
inputs.push_back(input_event);
}

// C up
{
INPUT input_event = {};
input_event.type = INPUT_KEYBOARD;
input_event.ki.wVk = 0x43; // C
input_event.ki.dwFlags = KEYEVENTF_KEYUP;
input_event.ki.dwExtraInfo = CENTRALIZED_KEYBOARD_HOOK_DONT_TRIGGER_FLAG;
inputs.push_back(input_event);
}

// Ctrl up
{
INPUT input_event = {};
input_event.type = INPUT_KEYBOARD;
input_event.ki.wVk = VK_CONTROL;
input_event.ki.dwFlags = KEYEVENTF_KEYUP;
input_event.ki.dwExtraInfo = CENTRALIZED_KEYBOARD_HOOK_DONT_TRIGGER_FLAG;
inputs.push_back(input_event);
}

// Restore modifiers that were held down
try_inject_modifier_key_restore(inputs, VK_LCONTROL);
try_inject_modifier_key_restore(inputs, VK_RCONTROL);
try_inject_modifier_key_restore(inputs, VK_LWIN);
try_inject_modifier_key_restore(inputs, VK_RWIN);
try_inject_modifier_key_restore(inputs, VK_LSHIFT);
try_inject_modifier_key_restore(inputs, VK_RSHIFT);
try_inject_modifier_key_restore(inputs, VK_LMENU);
try_inject_modifier_key_restore(inputs, VK_RMENU);

// Prevent Start Menu from activating after Win key release/restore
INPUT dummyEvent = {};
dummyEvent.type = INPUT_KEYBOARD;
dummyEvent.ki.wVk = 0xFF;
dummyEvent.ki.dwFlags = KEYEVENTF_KEYUP;
inputs.push_back(dummyEvent);

auto uSent = SendInput(static_cast<UINT>(inputs.size()), inputs.data(), sizeof(INPUT));
if (uSent != inputs.size())
{
DWORD errorCode = GetLastError();
auto errorMessage = get_last_error_message(errorCode);
Logger::error(L"SendInput failed for Ctrl+C. Expected to send {} inputs and sent only {}. {}", inputs.size(), uSent, errorMessage.has_value() ? errorMessage.value() : L"");
Trace::AdvancedPaste_Error(errorCode, errorMessage.has_value() ? errorMessage.value() : L"", L"input.SendInput");
return false;
}
return true;
}

bool send_copy_selection()
Expand All @@ -526,78 +622,30 @@ class AdvancedPaste : public PowertoyModuleIface
for (int attempt = 0; attempt < copy_attempts; ++attempt)
{
const auto initial_sequence = GetClipboardSequenceNumber();
copy_succeeded = try_send_copy_message();

if (!copy_succeeded)
{
std::vector<INPUT> inputs;
// Strategy 1: Try WM_COPY message (works for standard Win32 controls)
bool wm_copy_sent = try_send_copy_message();

// send Ctrl+C (key downs and key ups)
{
INPUT input_event = {};
input_event.type = INPUT_KEYBOARD;
input_event.ki.wVk = VK_CONTROL;
input_event.ki.dwExtraInfo = CENTRALIZED_KEYBOARD_HOOK_DONT_TRIGGER_FLAG;
inputs.push_back(input_event);
}

{
INPUT input_event = {};
input_event.type = INPUT_KEYBOARD;
input_event.ki.wVk = 0x43; // C
// Avoid triggering detection by the centralized keyboard hook.
input_event.ki.dwExtraInfo = CENTRALIZED_KEYBOARD_HOOK_DONT_TRIGGER_FLAG;
inputs.push_back(input_event);
}

{
INPUT input_event = {};
input_event.type = INPUT_KEYBOARD;
input_event.ki.wVk = 0x43; // C
input_event.ki.dwFlags = KEYEVENTF_KEYUP;
// Avoid triggering detection by the centralized keyboard hook.
input_event.ki.dwExtraInfo = CENTRALIZED_KEYBOARD_HOOK_DONT_TRIGGER_FLAG;
inputs.push_back(input_event);
}

{
INPUT input_event = {};
input_event.type = INPUT_KEYBOARD;
input_event.ki.wVk = VK_CONTROL;
input_event.ki.dwFlags = KEYEVENTF_KEYUP;
input_event.ki.dwExtraInfo = CENTRALIZED_KEYBOARD_HOOK_DONT_TRIGGER_FLAG;
inputs.push_back(input_event);
}

auto uSent = SendInput(static_cast<UINT>(inputs.size()), inputs.data(), sizeof(INPUT));
if (uSent != inputs.size())
{
DWORD errorCode = GetLastError();
auto errorMessage = get_last_error_message(errorCode);
Logger::error(L"SendInput failed for Ctrl+C. Expected to send {} inputs and sent only {}. {}", inputs.size(), uSent, errorMessage.has_value() ? errorMessage.value() : L"");
Trace::AdvancedPaste_Error(errorCode, errorMessage.has_value() ? errorMessage.value() : L"", L"input.SendInput");
}
else
if (wm_copy_sent)
{
if (poll_clipboard_sequence(initial_sequence, clipboard_poll_attempts, clipboard_poll_delay))
{
copy_succeeded = true;
}
}

if (copy_succeeded)
// Strategy 2: If WM_COPY didn't work, try SendInput Ctrl+C (works for Electron, browsers, etc.)
if (!copy_succeeded)
{
bool sequence_changed = false;
for (int poll_attempt = 0; poll_attempt < clipboard_poll_attempts; ++poll_attempt)
const auto sequence_before_ctrl_c = GetClipboardSequenceNumber();

if (send_ctrl_c_input())
{
if (GetClipboardSequenceNumber() != initial_sequence)
if (poll_clipboard_sequence(sequence_before_ctrl_c, clipboard_poll_attempts, clipboard_poll_delay))
{
sequence_changed = true;
break;
copy_succeeded = true;
}

std::this_thread::sleep_for(clipboard_poll_delay);
}

copy_succeeded = sequence_changed;
}

if (copy_succeeded)
Expand All @@ -611,6 +659,11 @@ class AdvancedPaste : public PowertoyModuleIface
}
}

if (!copy_succeeded)
{
Logger::warn(L"Auto-copy: all {} copy attempts failed — the target application did not update the clipboard after WM_COPY and Ctrl+C", copy_attempts);
}

return copy_succeeded;
}

Expand Down Expand Up @@ -977,6 +1030,7 @@ class AdvancedPaste : public PowertoyModuleIface
{
if (!send_copy_selection())
{
Logger::warn(L"Auto-copy: failed to copy selection for custom action index {} — aborting action", custom_action_index);
return false;
}
}
Expand Down
Loading