安卓划线自动翻页问题

assets/foliate-js/src/book.js

@@ -171,6 +171,72 @@ const handleSelection = (view, doc, index) => {
   });
 };
 
+const AUTO_PAGE_DELAY_MS = 1000;
+const AUTO_PAGE_SCREEN_BOTTOM_THRESHOLD = 0.9;
+const AUTO_PAGE_POST_NEXT_RECHECK_INTERVAL_MS = 120;
+const AUTO_PAGE_POST_NEXT_RECHECK_MAX_ATTEMPTS = 12;
+const AUTO_PAGE_POST_NEXT_RECHECK_INITIAL_DELAY_MS = 80;
+
+const getAutoPageState = (view) => {
+  if (!view.__anxAutoPageState) {
+    view.__anxAutoPageState = {
+      sessionId: 0,
+      currentPageKey: null,
+      triggeredPages: new Set(),
+      pendingFromPageKey: null,
+      pendingTimer: null,
+      postNextRecheckTimer: null,
+      postNextRecheckAttempts: 0,
+      awaitingPageAdvanceFromKey: null,
+    };
+  }
+  return view.__anxAutoPageState;
+};
+
+const clearAutoPageTimer = (state) => {
+  if (!state.pendingTimer) return;
+  clearTimeout(state.pendingTimer);
+  state.pendingTimer = null;
+};
+
+const clearAutoPagePostNextRecheck = (state) => {
+  if (!state.postNextRecheckTimer) return;
+  clearTimeout(state.postNextRecheckTimer);
+  state.postNextRecheckTimer = null;
+};
+
+const resetAutoPageSessionState = (state) => {
+  state.currentPageKey = null;
+  state.triggeredPages.clear();
+  state.pendingFromPageKey = null;
+  state.postNextRecheckAttempts = 0;
+  state.awaitingPageAdvanceFromKey = null;
+};
+
+const startAutoPageSession = (view) => {
+  const state = getAutoPageState(view);
+  clearAutoPageTimer(state);
+  clearAutoPagePostNextRecheck(state);
+  state.sessionId += 1;
+  resetAutoPageSessionState(state);
+  return state;
+};
+
+const stopAutoPageSession = (view) => {
+  const state = getAutoPageState(view);
+  clearAutoPageTimer(state);
+  clearAutoPagePostNextRecheck(state);
+  resetAutoPageSessionState(state);
+};
+
+const getAutoPageLocationKey = (lastLocation, index) => {
+  if (!lastLocation) return `index:${index}:none`;
+  const cfi = lastLocation.cfi ?? '';
+  const current = lastLocation.location?.current ?? '';
+  const chapter = lastLocation.chapterLocation?.current ?? '';
+  return `index:${index}|cfi:${cfi}|loc:${current}|chapter:${chapter}`;
+};
+
 const setSelectionHandler = (view, doc, index) => {
   let hasActiveSelection = false;
   let lastPointerUpRange = null;
@@ -192,6 +258,7 @@ const setSelectionHandler = (view, doc, index) => {
     lastPointerUpRange = null;
     doc.__anxSelectionClearedAt = Date.now();
     doc.__anxSuppressClick = true;
+    stopAutoPageSession(view);
     callFlutter('onSelectionCleared');
   };
 
@@ -346,6 +413,7 @@ const setSelectionHandler = (view, doc, index) => {
       const container = view.shadowRoot.querySelector('foliate-paginator').shadowRoot.querySelector("#container");
       if (!container) return;
       globalThis.originalScrollLeft = container.scrollLeft;
+      startAutoPageSession(view);
     });
 
 
@@ -356,21 +424,103 @@ const setSelectionHandler = (view, doc, index) => {
 
       const selRange = getSelectionRange(doc.getSelection())
       if (!selRange) return
+      if (!lastLocation.range) return;
 
-      if (globalThis.pageDebounceTimer) {
-        clearTimeout(globalThis.pageDebounceTimer);
-        globalThis.pageDebounceTimer = null;
+      const container = view.shadowRoot.querySelector('foliate-paginator').shadowRoot.querySelector("#container");
+      if (!container) return;
+
+      const state = getAutoPageState(view);
+      if (state.sessionId === 0) {
+        startAutoPageSession(view);
       }
 
-      const container = view.shadowRoot.querySelector('foliate-paginator').shadowRoot.querySelector("#container");
+      const pageKey = getAutoPageLocationKey(lastLocation, index);
+      if (state.currentPageKey !== pageKey) {
+        if (
+          state.awaitingPageAdvanceFromKey
+          && state.awaitingPageAdvanceFromKey !== pageKey
+        ) {
+          state.awaitingPageAdvanceFromKey = null;
+          state.postNextRecheckAttempts = 0;
+          clearAutoPagePostNextRecheck(state);
+        }
+        state.currentPageKey = pageKey;
+      }
+
+      if (state.pendingFromPageKey && state.pendingFromPageKey !== pageKey) {
+        clearAutoPageTimer(state);
+        state.pendingFromPageKey = null;
+      }
 
-      if (selRange.compareBoundaryPoints(Range.END_TO_END, lastLocation.range) >= 0) {
-        globalThis.pageDebounceTimer = setTimeout(async () => {
-          await view.next();
-          globalThis.originalScrollLeft = container.scrollLeft;
-          globalThis.pageDebounceTimer = null;
-        }, 1000);
-        return
+      let compareToPageEnd;
+      try {
+        compareToPageEnd = selRange.compareBoundaryPoints(Range.END_TO_END, lastLocation.range);
+      } catch {
+        return;
+      }
+      const rangeReachedPageEnd = compareToPageEnd >= 0;
+      const selectionPos = getPosition(selRange);
+      const nearScreenBottom = selectionPos.bottom >= AUTO_PAGE_SCREEN_BOTTOM_THRESHOLD;
+      const reachedCurrentPageBottom = rangeReachedPageEnd && nearScreenBottom;
+
+      if (!reachedCurrentPageBottom && state.pendingFromPageKey === pageKey) {
+        clearAutoPageTimer(state);
+        state.pendingFromPageKey = null;
+      }
+
+      if (reachedCurrentPageBottom) {
+        if (state.pendingFromPageKey === pageKey) {
+          if (state.pendingTimer) return;
+          state.pendingFromPageKey = null;
+        }
+        if (state.triggeredPages.has(pageKey)) return;
+
+        state.pendingFromPageKey = pageKey;
+        clearAutoPagePostNextRecheck(state);
+        state.awaitingPageAdvanceFromKey = null;
+        state.postNextRecheckAttempts = 0;
+        clearAutoPageTimer(state);
+        const scheduledSessionId = state.sessionId;
+        state.pendingTimer = setTimeout(async () => {
+          state.pendingTimer = null;
+          if (scheduledSessionId !== state.sessionId) return;
+          state.triggeredPages.add(pageKey);
+          try {
+            await view.next();
+            const latestContainer = view.shadowRoot.querySelector('foliate-paginator').shadowRoot.querySelector("#container");
+            if (latestContainer) {
+              globalThis.originalScrollLeft = latestContainer.scrollLeft;
+            }
+          } finally {
+            if (state.pendingFromPageKey === pageKey) {
+              state.pendingFromPageKey = null;
+            }
+            state.awaitingPageAdvanceFromKey = pageKey;
+            state.postNextRecheckAttempts = 0;
+            clearAutoPagePostNextRecheck(state);
+            const runPostNextSelectionRecheck = () => {
+              state.postNextRecheckTimer = null;
+              if (scheduledSessionId !== state.sessionId) return;
+              if (state.awaitingPageAdvanceFromKey !== pageKey) return;
+              state.postNextRecheckAttempts += 1;
+              try {
+                doc.dispatchEvent(new Event('selectionchange'));
+              } catch {
+                return;
+              }
+              if (state.postNextRecheckAttempts >= AUTO_PAGE_POST_NEXT_RECHECK_MAX_ATTEMPTS) return;
+              state.postNextRecheckTimer = setTimeout(
+                runPostNextSelectionRecheck,
+                AUTO_PAGE_POST_NEXT_RECHECK_INTERVAL_MS,
+              );
+            };
+            state.postNextRecheckTimer = setTimeout(
+              runPostNextSelectionRecheck,
+              AUTO_PAGE_POST_NEXT_RECHECK_INITIAL_DELAY_MS,
+            );
+          }
+        }, AUTO_PAGE_DELAY_MS);
+        return;
       }
 
       const preventScroll = () => {