Repository navigation
Make Focus() / Blur() reliable and let Blur() return focus to the previous app #69
Description
Activity
- added a commit that references this issue
on Oct 6, 2026 Implemented in 8553d4d (workspace: libnativeapi/nativeapi@02c2e5a). No signature changes; the platform behavior is documented on
Focus()/Blur().Focus()andShow()remember the window or app that had the focus.Blur()hands it back, falls back to the window the platform would pick next, and does nothing on a window without focus.- macOS: activates the app (unless non-activating) and deminiaturizes;
Blur()keys the previous own window, or yields activation to the previous app and activates it. - Windows: restores a minimized window and retries through
AttachThreadInputwhen the foreground lock refuses; doesn't steal a child HWND's focus (Flutter).Blur()gives the foreground to the recorded window, else the next one down the Z order. - Linux: presents with the event/X server time as before;
Blur()presents the previous own window, or on X11 activates the previous client's window (else the next in_NET_CLIENT_LIST_STACKING) through_NET_ACTIVE_WINDOWas a pager. Wayland can only return focus to another window of the same app.
Verified (no mouse or keyboard input; the anchor is a second process):
- macOS (real window server): 14 checks, 5/5 runs.
- Windows 11: 7/8 runs fully green; one early run failed the cross-process return once and did not reproduce in 6 consecutive reruns.
- Linux X11 (Xvfb + Openbox): 5/5.
Tests:
tests/window_focus_return_test.cpp(Windows, Linux X11),tests/window_focus_return_macos_test.mm.Still open: a real GNOME/KDE desktop run. Keeping this open until then.
GNOME result (Ubuntu 24.04, GNOME 46, core 1097ca6):
tests/window_focus_return_testpasses completely under GNOME's Xwayland with Mutter as the window manager:Focus()from a background process,Blur()back to the previous own window and to another process's window, and the fallback to the next window in_NET_CLIENT_LIST_STACKING.Still not covered: native Wayland clients (Wayland only allows returning focus to the same app's windows, as documented) and KDE.
Window::Focus()andBlur()follow the platforms' simplest calls and fail in common cases:Focus()isSetForegroundWindow+SetFocus, which the foreground lock refuses when the app isn't in the foreground (only the taskbar flashes). Consider theAttachThreadInput/AllowSetForegroundWindowapproaches, and checkIsFocused()after focus changes.gtk_window_present()without a timestamp is subject to focus-stealing prevention; usegtk_window_present_with_time()with the last event time.Blur()should hand focus back to the previously active window or app. On macOS it only doesorderBack:, and on WindowsSetFocus(nullptr), which leaves the app active. Typical use: a launcher/search bar that hides and pastes into the previous app. Related: libnativeapi/nativeapi#59 (app-level hide on macOS).Background: