fix: shift + tap selection behaviour

Author: 1Code-JS

src/lib/editorManager.js

@@ -172,6 +172,39 @@ async function EditorManager($header, $body) {
 		},
 	);
 
+	const shiftTapSelectionFix = EditorView.domEventHandlers({
+		mousedown(event, view) {
+			// Check if Shift is held during the tap/click
+			if (event.shiftKey) {
+				// Get the current document position of the tap
+				const pos = view.posAtCoords({ x: event.clientX, y: event.clientY });
+
+				if (pos !== null) {
+					const { state } = view;
+					const currentSelection = state.selection.main;
+
+					// Create a new selection: keep the existing anchor, move the head to the tap position
+					const newSelection = EditorSelection.range(
+						currentSelection.anchor,
+						pos,
+					);
+
+					// Dispatch the transaction to update the UI
+					view.dispatch({
+						selection: newSelection,
+						scrollIntoView: true,
+						userEvent: "select.extend",
+					});
+
+					// Prevent the default behavior which might reset the anchor
+					event.preventDefault();
+					return true;
+				}
+			}
+			return false;
+		},
+	});
+
 	const touchSelectionUpdateExtension = EditorView.updateListener.of(
 		(update) => {
 			if (!touchSelectionController) return;
@@ -725,6 +758,7 @@ async function EditorManager($header, $body) {
 			fixedHeightTheme,
 			scrollPastEnd(),
 			pointerCursorVisibilityExtension,
+			shiftTapSelectionFix,
 			touchSelectionUpdateExtension,
 			search(),
 			// Ensure read-only can be toggled later via compartment
@@ -1088,6 +1122,7 @@ async function EditorManager($header, $body) {
 			fixedHeightTheme,
 			scrollPastEnd(),
 			pointerCursorVisibilityExtension,
+			shiftTapSelectionFix,
 			touchSelectionUpdateExtension,
 			search(),
 			// Keep dynamic compartments across state swaps