EPUB: Fix page swipes while selecting text

CHANGELOG.md

@@ -59,6 +59,8 @@ All notable changes to this project will be documented in this file. Take a look
 * [swift-toolkit#61](https://github.com/readium/swift-toolkit/issues/61) Fixed serving EPUB resources when the HREF contains an anchor or query parameters.
 * Fixed emitting `currentLocator` with fixed layout EPUBs.
 * Prevent refreshing an already loaded EPUB resource when jumping to a `Locator` in it.
+* [#86](https://github.com/readium/kotlin-toolkit/issues/86) Fixed page swipes while selecting text in an EPUB resource.
+* The `onTap` event is not sent when an EPUB text selection is active anymore, to prevent showing the app bar while dismissing a selection.
 
 
 ## [2.2.0]

readium/navigator/src/main/assets/_scripts/src/selection.js

@@ -4,7 +4,7 @@
 //  available in the top-level LICENSE file of the project.
 //
 
-import { log as logNative, logError } from "./utils";
+import { log as logNative, logError, snapCurrentOffset } from "./utils";
 import { toNativeRect } from "./rect";
 import { TextRange } from "./vendor/hypothesis/anchoring/text-range";
 
@@ -14,6 +14,28 @@ matchAll.shim();
 
 const debug = true;
 
+// Notify native code that the selection changes.
+window.addEventListener(
+  "load",
+  function () {
+    var isSelecting = false;
+    document.addEventListener("selectionchange", function () {
+      const collapsed = window.getSelection().isCollapsed;
+
+      if (collapsed && isSelecting) {
+        isSelecting = false;
+        Android.onSelectionEnd();
+        // Snaps the current column in case the user shifted the scroll by dragging the text selection.
+        snapCurrentOffset();
+      } else if (!collapsed && !isSelecting) {
+        isSelecting = true;
+        Android.onSelectionStart();
+      }
+    });
+  },
+  false
+);
+
 export function getCurrentSelection() {
   const text = getCurrentSelectionText();
   if (!text) {

readium/navigator/src/main/assets/_scripts/src/utils.js

@@ -15,7 +15,6 @@ window.addEventListener(
   false
 );
 
-// Notify native code that the page has loaded.
 window.addEventListener(
   "load",
   function () {
@@ -220,7 +219,7 @@ function snapOffset(offset) {
 }
 
 // Snaps the current offset to the page width.
-function snapCurrentOffset() {
+export function snapCurrentOffset() {
   //        Android.log("snapCurrentOffset");
   if (isScrollModeEnabled()) {
     return;

readium/navigator/src/main/java/org/readium/r2/navigator/R2BasicWebView.kt

@@ -84,6 +84,9 @@ open class R2BasicWebView(context: Context, attrs: AttributeSet) : WebView(conte
     var resourceUrl: String? = null
 
     internal val scrollModeFlow = MutableStateFlow(false)
+
+    /** Indicates that a user text selection is active. */
+    internal var isSelecting = false
 
     val scrollMode: Boolean get() = scrollModeFlow.value
 
@@ -224,6 +227,11 @@ open class R2BasicWebView(context: Context, attrs: AttributeSet) : WebView(conte
      */
     @android.webkit.JavascriptInterface
     fun onTap(eventJson: String): Boolean {
+        // If there's an on-going selection, the tap will dismiss it so we don't forward it.
+        if (isSelecting) {
+            return false
+        }
+
         val event = TapEvent.fromJSON(eventJson) ?: return false
 
         // The script prevented the default behavior.
@@ -393,6 +401,16 @@ open class R2BasicWebView(context: Context, attrs: AttributeSet) : WebView(conte
         return runBlocking(uiScope.coroutineContext) { listener.onDragEnd(event) }
     }
 
+    @android.webkit.JavascriptInterface
+    fun onSelectionStart() {
+        isSelecting = true
+    }
+
+    @android.webkit.JavascriptInterface
+    fun onSelectionEnd() {
+        isSelecting = false
+    }
+
     /** Produced by gestures.js */
     data class DragEvent(
         val defaultPrevented: Boolean,

readium/navigator/src/main/java/org/readium/r2/navigator/R2WebView.kt

@@ -688,13 +688,12 @@ class R2WebView(context: Context, attrs: AttributeSet) : R2BasicWebView(context,
                 mActivePointerId = ev.getPointerId(0)
             }
             MotionEvent.ACTION_MOVE -> {
-
                 if ((mLastMotionX > (width - mGutterSize)) || (mLastMotionX < mGutterSize)) {
                     requestDisallowInterceptTouchEvent(true)
                     return false
                 }
 
-                if (!mIsBeingDragged) {
+                if (!isSelecting && !mIsBeingDragged) {
                     mInitialVelocity = getCurrentXVelocity()
                     val pointerIndex = ev.findPointerIndex(mActivePointerId)
                     val x = ev.getX(pointerIndex)