fix: allow selection within link, b=closes #8391, p=#11394

* fix: allow selection within link

fixes: #8391

The glance feature was clashing with the possibility to select text within a link.
To avoid the conflict, glance will only open upon mouseup and only if the mouse hasn't moved since the mouse was pressed.

* remove redundant condition

* register listeners in correct place

* feat: Listen to mouse move only once, b=no-bug, c=common, glance

---------

Co-authored-by: mr. m <[email protected]>

Author: Spissable

src/zen/common/sys/ZenActorsManager.sys.mjs

@@ -45,6 +45,9 @@ let JSWINDOWACTORS = {
         mousedown: {
           capture: true,
         },
+        mouseup: {
+          capture: true,
+        },
         keydown: {
           capture: true,
         },

src/zen/glance/actors/ZenGlanceChild.sys.mjs

@@ -3,9 +3,11 @@
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 export class ZenGlanceChild extends JSWindowActorChild {
   #activationMethod;
+  #glanceTarget = null;
 
   constructor() {
     super();
+    this.mousemoveCallback = this.mousemoveCallback.bind(this);
   }
 
   async handleEvent(event) {
@@ -80,11 +82,23 @@ export class ZenGlanceChild extends JSWindowActorChild {
     } else if (activationMethod === 'meta' && !event.metaKey) {
       return;
     }
-    if (target) {
+    this.#glanceTarget = target;
+    window.addEventListener('mousemove', this.mousemoveCallback, { once: true });
+  }
+
+  on_mouseup(event) {
+    if (this.#glanceTarget) {
       event.preventDefault();
       event.stopPropagation();
+      this.#openGlance(this.#glanceTarget);
+      this.#glanceTarget = null;
+      window.removeEventListener('mousemove', this.mousemoveCallback);
+    }
+  }
 
-      this.#openGlance(target);
+  mousemoveCallback() {
+    if (this.#glanceTarget) {
+      this.#glanceTarget = null;
     }
   }