first commit

apps/miniprogram/pages/terminal/touchShiftState.js

@@ -0,0 +1,123 @@
+/* global module */
+
+const TOUCH_SHIFT_MODE_OFF = "off";
+const TOUCH_SHIFT_MODE_ONCE = "once";
+const TOUCH_SHIFT_MODE_LOCK = "lock";
+const TOUCH_SHIFT_DOUBLE_TAP_MS = 320;
+
+function normalizeTouchShiftMode(value) {
+  const normalized = String(value || "")
+    .trim()
+    .toLowerCase();
+  if (normalized === TOUCH_SHIFT_MODE_ONCE) return TOUCH_SHIFT_MODE_ONCE;
+  if (normalized === TOUCH_SHIFT_MODE_LOCK) return TOUCH_SHIFT_MODE_LOCK;
+  return TOUCH_SHIFT_MODE_OFF;
+}
+
+function isTouchShiftActive(mode) {
+  const normalized = normalizeTouchShiftMode(mode);
+  return normalized === TOUCH_SHIFT_MODE_ONCE || normalized === TOUCH_SHIFT_MODE_LOCK;
+}
+
+function isAsciiLetter(value) {
+  return /[A-Za-z]/.test(String(value || ""));
+}
+
+function resolveTouchShiftModeOnTap(currentMode, lastTapAt, now, doubleTapWindowMs) {
+  const normalizedMode = normalizeTouchShiftMode(currentMode);
+  const currentTime = Number.isFinite(Number(now)) ? Number(now) : Date.now();
+  const previousTapAt = Number(lastTapAt);
+  const windowMs = Number.isFinite(Number(doubleTapWindowMs))
+    ? Math.max(0, Number(doubleTapWindowMs))
+    : TOUCH_SHIFT_DOUBLE_TAP_MS;
+
+  if (normalizedMode === TOUCH_SHIFT_MODE_LOCK) {
+    return TOUCH_SHIFT_MODE_OFF;
+  }
+  if (
+    normalizedMode === TOUCH_SHIFT_MODE_ONCE &&
+    Number.isFinite(previousTapAt) &&
+    currentTime >= previousTapAt &&
+    currentTime - previousTapAt <= windowMs
+  ) {
+    return TOUCH_SHIFT_MODE_LOCK;
+  }
+  return TOUCH_SHIFT_MODE_ONCE;
+}
+
+function findCommonPrefixLength(previousValue, nextValue) {
+  const max = Math.min(previousValue.length, nextValue.length);
+  let index = 0;
+  while (index < max && previousValue[index] === nextValue[index]) {
+    index += 1;
+  }
+  return index;
+}
+
+function findCommonSuffixLength(previousValue, nextValue, prefixLength) {
+  const previousRemain = previousValue.length - prefixLength;
+  const nextRemain = nextValue.length - prefixLength;
+  const max = Math.min(previousRemain, nextRemain);
+  let index = 0;
+  while (
+    index < max &&
+    previousValue[previousValue.length - 1 - index] === nextValue[nextValue.length - 1 - index]
+  ) {
+    index += 1;
+  }
+  return index;
+}
+
+function applyTouchShiftToValue(previousValue, nextValue, mode) {
+  const previousText = String(previousValue || "");
+  const nextText = String(nextValue || "");
+  const normalizedMode = normalizeTouchShiftMode(mode);
+
+  if (!isTouchShiftActive(normalizedMode) || !nextText) {
+    return {
+      value: nextText,
+      consumedOnce: false,
+      touchedLetter: false,
+      transformed: false
+    };
+  }
+
+  const prefixLength = findCommonPrefixLength(previousText, nextText);
+  const suffixLength = findCommonSuffixLength(previousText, nextText, prefixLength);
+  const insertedEnd = nextText.length - suffixLength;
+  const insertedText = nextText.slice(prefixLength, insertedEnd);
+
+  if (!insertedText) {
+    return {
+      value: nextText,
+      consumedOnce: false,
+      touchedLetter: false,
+      transformed: false
+    };
+  }
+
+  const touchedLetter = isAsciiLetter(insertedText);
+  const transformedInserted = insertedText.replace(/[a-z]/g, (match) => match.toUpperCase());
+  const transformed = transformedInserted !== insertedText;
+  const value = transformed
+    ? `${nextText.slice(0, prefixLength)}${transformedInserted}${nextText.slice(insertedEnd)}`
+    : nextText;
+
+  return {
+    value,
+    consumedOnce: normalizedMode === TOUCH_SHIFT_MODE_ONCE && touchedLetter,
+    touchedLetter,
+    transformed
+  };
+}
+
+module.exports = {
+  TOUCH_SHIFT_DOUBLE_TAP_MS,
+  TOUCH_SHIFT_MODE_LOCK,
+  TOUCH_SHIFT_MODE_OFF,
+  TOUCH_SHIFT_MODE_ONCE,
+  applyTouchShiftToValue,
+  isTouchShiftActive,
+  normalizeTouchShiftMode,
+  resolveTouchShiftModeOnTap
+};