fix: Preserve the previous cursor position on `undo/redo` in StatusChatInput

storybook/qmlTests/tests/tst_StatusChatInput.qml

@@ -288,6 +288,124 @@ Item {
             verify(textWithPubKey.includes("@0x0JohnDoe"),
                    "Expected @pubKey to replace @contactName")
         }
+
+//      Scenario: The user can undo and redo text changes
+//      Given the user has typed text in StatusChatInput
+//      """
+//      123456789
+//      """
+//      When the user hits undo shortcut
+//      Then the last text change is reverted
+//      And the cursor position is reverted
+//      And the user can redo the text change
+//      And the cursor position is restored
+        function test_user_can_undo_and_redo_text_changes() {
+            testHelper.when_text_is_typed(statusChatInputKeyboardInputExpectedAsText,
+                                                    "123456789", (typedText) => {})
+
+            keySequence(StandardKey.Undo)
+            compare(controlUnderTest.getPlainText(), "12345678")
+            compare(controlUnderTest.textInput.cursorPosition, 8)
+
+            keySequence(StandardKey.Redo)
+            compare(controlUnderTest.getPlainText(), "123456789")
+            compare(controlUnderTest.textInput.cursorPosition, 9)
+
+            keySequence(StandardKey.Undo)
+            keySequence(StandardKey.Undo)
+            keySequence(StandardKey.Undo)
+            compare(controlUnderTest.getPlainText(), "123456")
+            compare(controlUnderTest.textInput.cursorPosition, 6)
+
+            keySequence(StandardKey.Redo)
+            keySequence(StandardKey.Redo)
+            keySequence(StandardKey.Redo)
+            compare(controlUnderTest.getPlainText(), "123456789")
+            compare(controlUnderTest.textInput.cursorPosition, 9)
+
+            keyClick(Qt.Key_Backspace)
+            compare(controlUnderTest.getPlainText(), "12345678")
+            compare(controlUnderTest.textInput.cursorPosition, 8)
+
+            keySequence(StandardKey.Undo)
+            compare(controlUnderTest.getPlainText(), "123456789")
+            compare(controlUnderTest.textInput.cursorPosition, 9)
+
+            keyClick(Qt.Key_Backspace)
+            compare(controlUnderTest.getPlainText(), "12345678")
+            compare(controlUnderTest.textInput.cursorPosition, 8)
+
+            keySequence(StandardKey.Undo)
+            compare(controlUnderTest.getPlainText(), "123456789")
+            compare(controlUnderTest.textInput.cursorPosition, 9)
+        }
+
+//      Scenario: The user can undo and redo text changes with selection
+//      Given the user has typed text in StatusChatInput
+//      """
+//      123456789
+//      """
+//      And cursor is moved to the middle of the text, at position 5
+//      And the user selects and deletes text from position 5 to 3
+//      When the user hits undo shortcut
+//      Then the last text change is reverted
+
+        function test_user_can_undo_and_redo_text_changes_with_selection() {
+            testHelper.when_text_is_typed(statusChatInputKeyboardInputExpectedAsText,
+                                                    "123456789", (typedText) => {})
+
+            controlUnderTest.textInput.cursorPosition = 5
+            controlUnderTest.textInput.select(5, 3)
+            keySequence(StandardKey.Delete)
+            compare(controlUnderTest.getPlainText(), "1236789")
+
+            keySequence(StandardKey.Undo)
+            compare(controlUnderTest.getPlainText(), "123456789")
+            compare(controlUnderTest.textInput.cursorPosition, 5)
+
+
+            controlUnderTest.textInput.select(5, 3)
+            keySequence(StandardKey.Delete)
+            compare(controlUnderTest.getPlainText(), "1236789")
+
+            keySequence(StandardKey.Undo)
+            compare(controlUnderTest.getPlainText(), "123456789")
+            compare(controlUnderTest.textInput.cursorPosition, 5)
+
+            controlUnderTest.textInput.cursorPosition = 4
+            controlUnderTest.textInput.select(4, 2)
+            keySequence(StandardKey.Delete)
+            compare(controlUnderTest.getPlainText(), "1256789")
+
+            keySequence(StandardKey.Undo)
+            compare(controlUnderTest.getPlainText(), "123456789")
+            compare(controlUnderTest.textInput.cursorPosition, 4)
+        }
+
+//      Scenario: The user can undo and redo the entire text
+//      Given the user has typed text in StatusChatInput
+//      """
+//      123456789
+//      """
+//      And the user selects and deletes the entire text
+//      When the user hits undo shortcut
+//      Then the last text change is reverted
+        function test_user_can_undo_and_redo_the_entire_text() {
+            testHelper.when_text_is_typed(statusChatInputKeyboardInputExpectedAsText,
+                                                    "123456789", (typedText) => {})
+
+            controlUnderTest.textInput.select(0, 9)
+            keySequence(StandardKey.Delete)
+            compare(controlUnderTest.getPlainText(), "")
+
+            keySequence(StandardKey.Undo)
+            compare(controlUnderTest.getPlainText(), "123456789")
+            compare(controlUnderTest.textInput.cursorPosition, 9)
+
+            keySequence(StandardKey.Redo)
+            compare(controlUnderTest.getPlainText(), "")
+            compare(controlUnderTest.textInput.cursorPosition, 0)
+        }
     }
 
     TestCase {

ui/imports/utils/UndoStackManager.qml

@@ -122,25 +122,46 @@ Item {
             }
         }
 
+        function extrapolatePreviousCursorPosition() {
+            const previousText = root.textEdit.getText(0, root.textEdit.length)
+            const previousCursorPosition = root.textEdit.cursorPosition - root.textEdit.length + d.previousText.length
+            return previousCursorPosition
+        }
+
         readonly property Connections textChangedConnection: Connections {
             target: root.textEdit
             enabled: root.enabled && !d.aboutToChangeText
             function onTextChanged() {
                 const unformattedText = root.textEdit.getText(0, root.textEdit.length)
+
                 if(d.previousText !== unformattedText) {
                     const newFormattedText = root.textEdit.text
+                    const newCursorPosition = root.textEdit.cursorPosition
+
                     const previousFormattedTextCopy = d.previousFormattedText
+                    const previousCursorPosition = d.extrapolatePreviousCursorPosition()
+
                     d.undoStack.push({
                         undo: function() {
                             d.aboutToChangeText = true
+                            //restore
                             root.textEdit.text = previousFormattedTextCopy
-                            root.textEdit.cursorPosition = root.textEdit.length
+                            root.textEdit.cursorPosition = previousCursorPosition
+                            //snapshot
+                            d.previousText = root.textEdit.getText(0, root.textEdit.length)
+                            d.previousFormattedText = root.textEdit.text
+
                             d.aboutToChangeText = false
                         },
                         redo: function() {
                             d.aboutToChangeText = true
+                            //restore
                             root.textEdit.text = newFormattedText
-                            root.textEdit.cursorPosition = root.textEdit.length
+                            root.textEdit.cursorPosition = newCursorPosition
+                            //snapshot
+                            d.previousText = root.textEdit.getText(0, root.textEdit.length)
+                            d.previousFormattedText = root.textEdit.text
+
                             d.aboutToChangeText = false
                         }
                     })