Fix text selection during scanning (#1508)

* Move function * Add _onSearchClick function * Move _onSearchClick after event prevention * Prevent search if selection is changed before a click occurs
FooSoft · Mar 10, 2021 · ea8fa9c · ea8fa9c
1 parent 3a7cee9
commit ea8fa9c
Showing 1 changed file with 73 additions and 12 deletions.
diff --git a/ext/js/language/text-scanner.js b/ext/js/language/text-scanner.js
@@ -71,6 +71,11 @@ class TextScanner extends EventDispatcher {
         this._enabledValue = false;
         this._eventListeners = new EventListenerCollection();
 
+        this._preventNextClickScan = false;
+        this._preventNextClickScanTimer = null;
+        this._preventNextClickScanTimerDuration = 50;
+        this._preventNextClickScanTimerCallback = this._onPreventNextClickScanTimeout.bind(this);
+
         this._primaryTouchIdentifier = null;
         this._preventNextContextMenu = false;
         this._preventNextMouseDown = false;
@@ -350,6 +355,30 @@ class TextScanner extends EventDispatcher {
         return results;
     }
 
+    _resetPreventNextClickScan() {
+        this._preventNextClickScan = false;
+        if (this._preventNextClickScanTimer !== null) { clearTimeout(this._preventNextClickScanTimer); }
+        this._preventNextClickScanTimer = setTimeout(this._preventNextClickScanTimerCallback, this._preventNextClickScanTimerDuration);
+    }
+
+    _onPreventNextClickScanTimeout() {
+        this._preventNextClickScanTimer = null;
+    }
+
+    _onSelectionChange() {
+        if (this._preventNextClickScanTimer !== null) { return; } // Ignore deselection that occurs at the start of the click
+        this._preventNextClickScan = true;
+    }
+
+    _onSearchClickMouseDown(e) {
+        if (e.button !== 0) { return; }
+        this._resetPreventNextClickScan();
+    }
+
+    _onSearchClickTouchStart() {
+        this._resetPreventNextClickScan();
+    }
+
     _onMouseOver(e) {
         if (this._ignoreElements !== null && this._ignoreElements().includes(e.target)) {
             this._scanTimerClear();
@@ -376,6 +405,7 @@ class TextScanner extends EventDispatcher {
 
         switch (e.button) {
             case 0: // Primary
+                if (this._searchOnClick) { this._resetPreventNextClickScan(); }
                 this._scanTimerClear();
                 this.clearSelection(false);
                 break;
@@ -394,19 +424,32 @@ class TextScanner extends EventDispatcher {
     }
 
     _onClick(e) {
-        if (this._searchOnClick) {
-            const modifiers = DocumentUtil.getActiveModifiersAndButtons(e);
-            const modifierKeys = DocumentUtil.getActiveModifiers(e);
-            const inputInfo = this._createInputInfo(null, 'mouse', 'click', false, modifiers, modifierKeys);
-            this._searchAt(e.clientX, e.clientY, inputInfo);
-        }
-
         if (this._preventNextClick) {
             this._preventNextClick = false;
             e.preventDefault();
             e.stopPropagation();
             return false;
         }
+
+        if (this._searchOnClick) {
+            this._onSearchClick(e);
+        }
+    }
+
+    _onSearchClick(e) {
+        const preventNextClickScan = this._preventNextClickScan;
+        this._preventNextClickScan = false;
+        if (this._preventNextClickScanTimer !== null) {
+            clearTimeout(this._preventNextClickScanTimer);
+            this._preventNextClickScanTimer = null;
+        }
+
+        if (preventNextClickScan) { return; }
+
+        const modifiers = DocumentUtil.getActiveModifiersAndButtons(e);
+        const modifierKeys = DocumentUtil.getActiveModifiers(e);
+        const inputInfo = this._createInputInfo(null, 'mouse', 'click', false, modifiers, modifierKeys);
+        this._searchAt(e.clientX, e.clientY, inputInfo);
     }
 
     _onAuxClick() {
@@ -687,6 +730,9 @@ class TextScanner extends EventDispatcher {
                 eventListenerInfos.push(...this._getTouchEventListeners());
             }
         }
+        if (this._searchOnClick) {
+            eventListenerInfos.push(...this._getMouseClickOnlyEventListeners2());
+        }
 
         for (const args of eventListenerInfos) {
             this._eventListeners.addEventListener(...args);
@@ -718,11 +764,6 @@ class TextScanner extends EventDispatcher {
         ];
     }
 
-    _getMouseClickOnlyEventListeners() {
-        return [
-            [this._node, 'click', this._onClick.bind(this)]
-        ];
-    }
     _getTouchEventListeners() {
         return [
             [this._node, 'auxclick', this._onAuxClick.bind(this)],
@@ -734,6 +775,26 @@ class TextScanner extends EventDispatcher {
         ];
     }
 
+    _getMouseClickOnlyEventListeners() {
+        return [
+            [this._node, 'click', this._onClick.bind(this)]
+        ];
+    }
+
+    _getMouseClickOnlyEventListeners2() {
+        const {documentElement} = document;
+        const entries = [
+            [document, 'selectionchange', this._onSelectionChange.bind(this)]
+        ];
+        if (documentElement !== null) {
+            entries.push([documentElement, 'mousedown', this._onSearchClickMouseDown.bind(this)]);
+            if (this._touchInputEnabled) {
+                entries.push([documentElement, 'touchstart', this._onSearchClickTouchStart.bind(this)]);
+            }
+        }
+        return entries;
+    }
+
     _getTouch(touchList, identifier) {
         for (const touch of touchList) {
             if (touch.identifier === identifier) {