The normal flow for a keyDown event when sent to a text input enabled view (NSTextInputClient), is that it's sent through interpretKeyEvents, which in turn goes through the input methods, and result in either composing (marking) text, inserting text, or executing a text editing command such as moving the cursor to the beginning of the line. https://apple.co/3qDhwNb In our case, we prefer to treat "simple" text insertion (non-composed text) outside of the Qt input method protocol, and send these as normal key events instead. The same applies when a key event results in a text editing command that we don't handle. The problem is that in the latter case, the key event would contain the text that resulted from e.g. ⌘+K, or one of the function or arrow keys, which in many cases would not be suitable for inserting into a text field by a naive client that trusted the text property of the QKeyEvent. To work around this two exceptions were added; first in 4dbce2a4696081 to ignore text when inside the U+F700-U+F8FF unicode range (arrow keys, function keys, etc), and second in 933fab137dcaa8 to ignore text for events that had one or both of the control or command modifiers. Unfortunately this hard-coded logic was not taking into account that some keyboard layouts may produce text that match these exceptions, for example ^⌥+ю with a Russian keyboard layout should result in inserting a period. Instead of continuing to add hard-coded exceptions to this logic, (for example by only filtering out single-modifier events), we instead use the information that the text input system gives us via doCommandBySelector to decide whether the key event should have text or not. Note: We have similar workarounds for detecting text that is not suitable for text insertion in other places of Qt, for example in QInputControl::isAcceptableInput(), but since we can't assume the client uses QInputControl for their text input needs we need to filter out the text earlier than that. Fixes: QTBUG-106393 Task-number: QTBUG-36281 Task-number: QTBUG-35734 Pick-to: 6.4 Change-Id: I7769098cba1c605f6fdb6b23964eb614578724bb Reviewed-by: Timur Pocheptsov <timur.pocheptsov@qt.io> Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>