90 lines
2.1 KiB
Dart
90 lines
2.1 KiB
Dart
import 'package:flutter/widgets.dart';
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/// utililty class for traversing through multiline text
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class TextLinesIterator extends Iterator {
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String text;
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int beg;
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int end;
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TextSelection? selection;
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TextLinesIterator(this.text, {this.selection})
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: end = -1,
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beg = -1;
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TextLinesIterator.fromController(TextEditingController controller)
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: this(controller.text, selection: controller.selection);
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bool get isWithinSelection {
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final selection = this.selection;
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if (selection == null || beg == -1) {
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return false;
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} else {
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return (selection.end >= beg && beg >= selection.start) ||
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(selection.end >= end && end >= selection.start) ||
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(end >= selection.start && selection.start >= beg) ||
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(end >= selection.end && selection.end >= beg) ||
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(beg <= selection.start &&
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selection.start <= end &&
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beg <= selection.end &&
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selection.end <= end);
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}
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}
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@override
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String get current {
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return text.substring(beg, end);
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}
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set current(String newVal) {
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final selected = isWithinSelection;
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text = text.replaceRange(beg, end, newVal);
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final wordLen = end - beg;
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final dif = newVal.length - wordLen;
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end += dif;
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final selection = this.selection;
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if (selection == null) return;
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if (selected || selection.baseOffset > end) {
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this.selection =
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selection.copyWith(extentOffset: selection.extentOffset + dif);
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}
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}
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void reset() {
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end = -1;
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beg = -1;
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}
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@override
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bool moveNext() {
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if (end == text.length) {
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return false;
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}
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if (beg == -1) {
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end = 0;
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beg = 0;
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} else {
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end += 1;
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beg = end;
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}
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for (; end < text.length; end++) {
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if (text[end] == '\n') {
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return true;
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}
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}
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end = text.length;
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return true;
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}
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/// returns the lines as a list but also moves the pointer to the back
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List<String> get asList {
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reset();
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final list = <String>[];
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while (moveNext()) {
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list.add(current);
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}
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return list;
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}
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}
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