Improve separation of concerns for `RawEditor` by moving the code for the keyboard to a separate class, furthermore add more comments. The PR does not change the functionality of the code.pull/228/head
Till Friebe
4 years ago
parent
90e7f0ef43
commit
ad47991bf6
3 changed files with 357 additions and 307 deletions
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import 'dart:ui'; |
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import 'package:characters/characters.dart'; |
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import 'package:flutter/services.dart'; |
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import '../../models/documents/document.dart'; |
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import '../../utils/diff_delta.dart'; |
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import '../editor.dart'; |
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import '../keyboard_listener.dart'; |
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mixin RawEditorStateKeyboardMixin on EditorState { |
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// Holds the last cursor location the user selected in the case the user tries |
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// to select vertically past the end or beginning of the field. If they do, |
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// then we need to keep the old cursor location so that we can go back to it |
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// if they change their minds. Only used for moving selection up and down in a |
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// multiline text field when selecting using the keyboard. |
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int _cursorResetLocation = -1; |
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// Whether we should reset the location of the cursor in the case the user |
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// tries to select vertically past the end or beginning of the field. If they |
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// do, then we need to keep the old cursor location so that we can go back to |
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// it if they change their minds. Only used for resetting selection up and |
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// down in a multiline text field when selecting using the keyboard. |
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bool _wasSelectingVerticallyWithKeyboard = false; |
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void handleCursorMovement( |
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LogicalKeyboardKey key, |
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bool wordModifier, |
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bool lineModifier, |
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bool shift, |
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) { |
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if (wordModifier && lineModifier) { |
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// If both modifiers are down, nothing happens on any of the platforms. |
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return; |
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} |
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final selection = widget.controller.selection; |
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var newSelection = widget.controller.selection; |
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final plainText = getTextEditingValue().text; |
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final rightKey = key == LogicalKeyboardKey.arrowRight, |
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leftKey = key == LogicalKeyboardKey.arrowLeft, |
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upKey = key == LogicalKeyboardKey.arrowUp, |
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downKey = key == LogicalKeyboardKey.arrowDown; |
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if ((rightKey || leftKey) && !(rightKey && leftKey)) { |
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newSelection = _jumpToBeginOrEndOfWord(newSelection, wordModifier, |
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leftKey, rightKey, plainText, lineModifier, shift); |
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} |
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if (downKey || upKey) { |
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newSelection = _handleMovingCursorVertically( |
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upKey, downKey, shift, selection, newSelection, plainText); |
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} |
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if (!shift) { |
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newSelection = |
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_placeCollapsedSelection(selection, newSelection, leftKey, rightKey); |
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} |
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widget.controller.updateSelection(newSelection, ChangeSource.LOCAL); |
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} |
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// Handles shortcut functionality including cut, copy, paste and select all |
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// using control/command + (X, C, V, A). |
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// TODO: Add support for formatting shortcuts: Cmd+B (bold), Cmd+I (italic) |
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Future<void> handleShortcut(InputShortcut? shortcut) async { |
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final selection = widget.controller.selection; |
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final plainText = getTextEditingValue().text; |
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if (shortcut == InputShortcut.COPY) { |
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if (!selection.isCollapsed) { |
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await Clipboard.setData( |
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ClipboardData(text: selection.textInside(plainText))); |
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} |
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return; |
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} |
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if (shortcut == InputShortcut.CUT && !widget.readOnly) { |
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if (!selection.isCollapsed) { |
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final data = selection.textInside(plainText); |
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await Clipboard.setData(ClipboardData(text: data)); |
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widget.controller.replaceText( |
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selection.start, |
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data.length, |
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'', |
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TextSelection.collapsed(offset: selection.start), |
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); |
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setTextEditingValue(TextEditingValue( |
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text: |
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selection.textBefore(plainText) + selection.textAfter(plainText), |
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selection: TextSelection.collapsed(offset: selection.start), |
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)); |
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} |
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return; |
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} |
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if (shortcut == InputShortcut.PASTE && !widget.readOnly) { |
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final data = await Clipboard.getData(Clipboard.kTextPlain); |
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if (data != null) { |
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widget.controller.replaceText( |
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selection.start, |
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selection.end - selection.start, |
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data.text, |
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TextSelection.collapsed(offset: selection.start + data.text!.length), |
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); |
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} |
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return; |
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} |
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if (shortcut == InputShortcut.SELECT_ALL && |
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widget.enableInteractiveSelection) { |
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widget.controller.updateSelection( |
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selection.copyWith( |
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baseOffset: 0, |
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extentOffset: getTextEditingValue().text.length, |
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), |
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ChangeSource.REMOTE); |
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return; |
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} |
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} |
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void handleDelete(bool forward) { |
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final selection = widget.controller.selection; |
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final plainText = getTextEditingValue().text; |
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var cursorPosition = selection.start; |
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var textBefore = selection.textBefore(plainText); |
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var textAfter = selection.textAfter(plainText); |
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if (selection.isCollapsed) { |
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if (!forward && textBefore.isNotEmpty) { |
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final characterBoundary = |
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_previousCharacter(textBefore.length, textBefore, true); |
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textBefore = textBefore.substring(0, characterBoundary); |
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cursorPosition = characterBoundary; |
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} |
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if (forward && textAfter.isNotEmpty && textAfter != '\n') { |
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final deleteCount = _nextCharacter(0, textAfter, true); |
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textAfter = textAfter.substring(deleteCount); |
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} |
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} |
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final newSelection = TextSelection.collapsed(offset: cursorPosition); |
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final newText = textBefore + textAfter; |
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final size = plainText.length - newText.length; |
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widget.controller.replaceText( |
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cursorPosition, |
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size, |
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'', |
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newSelection, |
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); |
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} |
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TextSelection _jumpToBeginOrEndOfWord( |
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TextSelection newSelection, |
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bool wordModifier, |
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bool leftKey, |
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bool rightKey, |
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String plainText, |
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bool lineModifier, |
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bool shift) { |
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if (wordModifier) { |
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if (leftKey) { |
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final textSelection = getRenderEditor()!.selectWordAtPosition( |
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TextPosition( |
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offset: _previousCharacter( |
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newSelection.extentOffset, plainText, false))); |
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return newSelection.copyWith(extentOffset: textSelection.baseOffset); |
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} |
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final textSelection = getRenderEditor()!.selectWordAtPosition( |
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TextPosition( |
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offset: |
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_nextCharacter(newSelection.extentOffset, plainText, false))); |
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return newSelection.copyWith(extentOffset: textSelection.extentOffset); |
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} else if (lineModifier) { |
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if (leftKey) { |
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final textSelection = getRenderEditor()!.selectLineAtPosition( |
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TextPosition( |
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offset: _previousCharacter( |
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newSelection.extentOffset, plainText, false))); |
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return newSelection.copyWith(extentOffset: textSelection.baseOffset); |
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} |
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final startPoint = newSelection.extentOffset; |
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if (startPoint < plainText.length) { |
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final textSelection = getRenderEditor()! |
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.selectLineAtPosition(TextPosition(offset: startPoint)); |
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return newSelection.copyWith(extentOffset: textSelection.extentOffset); |
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} |
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return newSelection; |
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} |
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if (rightKey && newSelection.extentOffset < plainText.length) { |
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final nextExtent = |
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_nextCharacter(newSelection.extentOffset, plainText, true); |
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final distance = nextExtent - newSelection.extentOffset; |
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newSelection = newSelection.copyWith(extentOffset: nextExtent); |
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if (shift) { |
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_cursorResetLocation += distance; |
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} |
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return newSelection; |
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} |
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if (leftKey && newSelection.extentOffset > 0) { |
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final previousExtent = |
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_previousCharacter(newSelection.extentOffset, plainText, true); |
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final distance = newSelection.extentOffset - previousExtent; |
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newSelection = newSelection.copyWith(extentOffset: previousExtent); |
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if (shift) { |
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_cursorResetLocation -= distance; |
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} |
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return newSelection; |
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} |
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return newSelection; |
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} |
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/// Returns the index into the string of the next character boundary after the |
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/// given index. |
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/// |
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/// The character boundary is determined by the characters package, so |
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/// surrogate pairs and extended grapheme clusters are considered. |
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/// |
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/// The index must be between 0 and string.length, inclusive. If given |
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/// string.length, string.length is returned. |
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/// |
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/// Setting includeWhitespace to false will only return the index of non-space |
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/// characters. |
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int _nextCharacter(int index, String string, bool includeWhitespace) { |
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assert(index >= 0 && index <= string.length); |
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if (index == string.length) { |
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return string.length; |
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} |
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var count = 0; |
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final remain = string.characters.skipWhile((currentString) { |
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if (count <= index) { |
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count += currentString.length; |
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return true; |
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} |
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if (includeWhitespace) { |
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return false; |
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} |
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return WHITE_SPACE.contains(currentString.codeUnitAt(0)); |
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}); |
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return string.length - remain.toString().length; |
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} |
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/// Returns the index into the string of the previous character boundary |
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/// before the given index. |
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/// |
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/// The character boundary is determined by the characters package, so |
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/// surrogate pairs and extended grapheme clusters are considered. |
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/// |
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/// The index must be between 0 and string.length, inclusive. If index is 0, |
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/// 0 will be returned. |
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/// |
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/// Setting includeWhitespace to false will only return the index of non-space |
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/// characters. |
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int _previousCharacter(int index, String string, includeWhitespace) { |
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assert(index >= 0 && index <= string.length); |
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if (index == 0) { |
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return 0; |
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} |
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var count = 0; |
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int? lastNonWhitespace; |
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for (final currentString in string.characters) { |
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if (!includeWhitespace && |
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!WHITE_SPACE.contains( |
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currentString.characters.first.toString().codeUnitAt(0))) { |
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lastNonWhitespace = count; |
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} |
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if (count + currentString.length >= index) { |
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return includeWhitespace ? count : lastNonWhitespace ?? 0; |
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} |
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count += currentString.length; |
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} |
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return 0; |
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} |
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TextSelection _handleMovingCursorVertically( |
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bool upKey, |
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bool downKey, |
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bool shift, |
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TextSelection selection, |
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TextSelection newSelection, |
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String plainText) { |
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final originPosition = TextPosition( |
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offset: upKey ? selection.baseOffset : selection.extentOffset); |
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final child = getRenderEditor()!.childAtPosition(originPosition); |
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final localPosition = TextPosition( |
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offset: originPosition.offset - child.getContainer().documentOffset); |
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var position = upKey |
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? child.getPositionAbove(localPosition) |
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: child.getPositionBelow(localPosition); |
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if (position == null) { |
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final sibling = upKey |
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? getRenderEditor()!.childBefore(child) |
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: getRenderEditor()!.childAfter(child); |
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if (sibling == null) { |
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position = TextPosition(offset: upKey ? 0 : plainText.length - 1); |
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} else { |
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final finalOffset = Offset( |
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child.getOffsetForCaret(localPosition).dx, |
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sibling |
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.getOffsetForCaret(TextPosition( |
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offset: upKey ? sibling.getContainer().length - 1 : 0)) |
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.dy); |
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final siblingPosition = sibling.getPositionForOffset(finalOffset); |
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position = TextPosition( |
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offset: |
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sibling.getContainer().documentOffset + siblingPosition.offset); |
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} |
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} else { |
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position = TextPosition( |
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offset: child.getContainer().documentOffset + position.offset); |
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} |
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if (position.offset == newSelection.extentOffset) { |
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if (downKey) { |
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newSelection = newSelection.copyWith(extentOffset: plainText.length); |
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} else if (upKey) { |
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newSelection = newSelection.copyWith(extentOffset: 0); |
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} |
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_wasSelectingVerticallyWithKeyboard = shift; |
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return newSelection; |
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} |
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if (_wasSelectingVerticallyWithKeyboard && shift) { |
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newSelection = newSelection.copyWith(extentOffset: _cursorResetLocation); |
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_wasSelectingVerticallyWithKeyboard = false; |
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return newSelection; |
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} |
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newSelection = newSelection.copyWith(extentOffset: position.offset); |
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_cursorResetLocation = newSelection.extentOffset; |
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return newSelection; |
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} |
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TextSelection _placeCollapsedSelection(TextSelection selection, |
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TextSelection newSelection, bool leftKey, bool rightKey) { |
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var newOffset = newSelection.extentOffset; |
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if (!selection.isCollapsed) { |
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if (leftKey) { |
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newOffset = newSelection.baseOffset < newSelection.extentOffset |
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? newSelection.baseOffset |
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: newSelection.extentOffset; |
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} else if (rightKey) { |
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newOffset = newSelection.baseOffset > newSelection.extentOffset |
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? newSelection.baseOffset |
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: newSelection.extentOffset; |
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} |
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} |
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return TextSelection.fromPosition(TextPosition(offset: newOffset)); |
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} |
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} |
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