Game browser: Backspace goes up a directory, Windows raw input flags key repeats

With no type-to-search active, Backspace goes to the parent directory. Never
on a repeat, so holding it doesn't climb to the root. Not every platform
flags repeats, so the browser also tracks whether it's held.

Windows raw input now flags auto-repeated key downs as IS_REPEAT, like
Android and UWP, and forgets the held keys it releases on losing focus. The
UI drops OS repeats of a key it's already repeating itself, so held arrows
don't double up (they were dropped before too, a step later).

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

Common/UI/Root.cpp

@@ -257,6 +257,18 @@ static bool KeyToFocusMove(const KeyInput &key, FocusMove *move) {
 
 KeyEventResult KeyEventToFocusMoves(const KeyInput &key) {
 	KeyEventResult retval = KeyEventResult::PASS_THROUGH;
+	// The OS's own repeats of a key we're already repeating (see ProcessHeldKeys) would double
+	// up with ours, in a text field for example.
+	if ((key.flags & KeyInputFlags::DOWN) && (key.flags & KeyInputFlags::IS_REPEAT) && !heldKeys.empty()) {
+		HeldKey hk;
+		hk.key = key.keyCode;
+		hk.deviceId = key.deviceId;
+		hk.triggerTime = 0.0;  // irrelevant
+		hk.move = FocusMove::NEXT;  // irrelevant, not part of the comparison
+		if (heldKeys.find(hk) != heldKeys.end()) {
+			return KeyEventResult::IGNORE_KEY;
+		}
+	}
 	// Ignore repeats for focus moves.
 	if ((key.flags & KeyInputFlags::DOWN) && !(key.flags & KeyInputFlags::IS_REPEAT)) {
 		FocusMove move;

UI/GameBrowser.cpp

@@ -781,6 +781,22 @@ bool GameBrowser::Key(const KeyInput &input) {
 		}
 	}
 
+	// Backspace with no search going also goes to the parent directory, as in file managers. Never on
+	// a repeat, or holding it would climb to the root (or carry on up after clearing a search). Not
+	// every platform flags repeats, so this also tracks whether it's held.
+	if (input.keyCode == NKCODE_DEL && input.deviceId == DEVICE_ID_KEYBOARD) {
+		if (input.flags & KeyInputFlags::UP) {
+			backspaceHeld_ = false;
+		} else if (input.flags & KeyInputFlags::DOWN) {
+			const bool repeat = backspaceHeld_ || (input.flags & KeyInputFlags::IS_REPEAT);
+			backspaceHeld_ = true;
+			if (!repeat && search_.searchFilter.empty() && (browseFlags_ & BrowseFlags::NAVIGATE) && path_.CanNavigateUp()) {
+				NavigateUp();
+				return true;
+			}
+		}
+	}
+
 	bool retval = LinearLayout::Key(input);
 	if (retval) {
 		return true;

UI/GameBrowser.h

@@ -90,6 +90,7 @@ private:
 	Path focusPath_;
 	// Set when entering a directory, for Refresh to focus its first entry.
 	bool focusFirstItem_ = false;
+	bool backspaceHeld_ = false;
 	bool listingPending_ = false;
 	bool refreshPending_ = false;
 	float lastScale_ = 1.0f;

UI/MiscViews.cpp

@@ -507,9 +507,8 @@ bool ViewSearch::Key(UI::ViewGroup *viewGroup, const KeyInput &input) {
 					// TODO: Restore focus state here.
 					UI::EnableFocusMovement(false);
 				}
-			} else {
-				// Empty search filter. Navigate upwards on backspace?
 			}
+			// With an empty filter, it's up to the owner (the game browser goes up a directory).
 		} else if (!searchFilter.empty() && input.keyCode == NKCODE_ESCAPE) {
 			searchFilter.clear();
 			ApplySearchFilter(viewGroup, false);

Windows/RawInput.cpp

@@ -264,8 +264,11 @@ namespace WindowsRawInput {
 			key.keyCode = GetTrueVKey(raw->data.keyboard);
 
 			if (key.keyCode) {
+				// Windows auto-repeats a held key as more key downs. Flag them, like other platforms do.
+				if (!keyboardKeysDown.insert(key.keyCode).second) {
+					key.flags |= KeyInputFlags::IS_REPEAT;
+				}
 				NativeKey(key);
-				keyboardKeysDown.insert(key.keyCode);
 			}
 		} else if (raw->data.keyboard.Message == WM_KEYUP || raw->data.keyboard.Message == WM_SYSKEYUP) {
 			// A key released while Alt is held comes as WM_SYSKEYUP.
@@ -434,6 +437,8 @@ namespace WindowsRawInput {
 			key.keyCode = *i;
 			NativeKey(key);
 		}
+		// Or the next press of one would count as a repeat.
+		keyboardKeysDown.clear();
 		focused = false;
 	}