Bug 1714846 - Really hide panels on hide, r=robwu,emilio

Differential Revision: https://phabricator.services.mozilla.com/D132574

browser/base/content/appmenu-viewcache.inc.xhtml

@@ -406,6 +406,7 @@
   <panelview id="PanelUI-savetopocket"
              flex="1" class="PanelUI-subView"
              remote="true"
+             neverhidden="true"
              closemenu="none">
     <vbox class="PanelUI-savetopocket-container">
     </vbox>

browser/components/customizableui/content/panelUI.js

@@ -463,6 +463,9 @@ const PanelUI = {
       let tempPanel = document.createXULElement("panel");
       tempPanel.setAttribute("type", "arrow");
       tempPanel.setAttribute("id", "customizationui-widget-panel");
+      if (viewNode.hasAttribute("neverhidden")) {
+        tempPanel.setAttribute("neverhidden", "true");
+      }
 
       tempPanel.setAttribute("class", "cui-widget-panel panel-no-padding");
       tempPanel.setAttribute("viewId", aViewId);

browser/components/extensions/ExtensionPopups.jsm

@@ -495,6 +495,7 @@ class PanelPopup extends BasePopup {
     if (extension.remote) {
       panel.setAttribute("remote", "true");
     }
+    panel.setAttribute("neverhidden", "true");
 
     document.getElementById("mainPopupSet").appendChild(panel);
 
@@ -550,6 +551,7 @@ class ViewPopup extends BasePopup {
       if (remote) {
         panel.setAttribute("remote", "true");
       }
+      panel.setAttribute("neverhidden", "true");
 
       document.getElementById("mainPopupSet").appendChild(panel);
       return panel;

browser/components/extensions/parent/ext-browserAction.js

@@ -212,6 +212,7 @@ this.browserAction = class extends ExtensionAPI {
         view.id = this.viewId;
         view.setAttribute("flex", "1");
         view.setAttribute("extension", true);
+        view.setAttribute("neverhidden", true);
 
         document.getElementById("appMenu-viewCache").appendChild(view);
 

toolkit/content/widgets/panel.js

@@ -9,7 +9,7 @@
 {
   class MozPanel extends MozElements.MozElementMixin(XULPopupElement) {
     static get markup() {
-      return `<html:slot part="content" style="display: none"/>`;
+      return `<html:slot part="content" style="display: none !important"/>`;
     }
     constructor() {
       super();
@@ -59,13 +59,9 @@
 
       this.attachShadow({ mode: "open" });
 
-      if (!this.isArrowPanel) {
-        let slot = document.createElement("slot");
-        slot.part = "content";
-        slot.style.display = "none";
-        this.shadowRoot.appendChild(slot);
-      } else {
-        this.shadowRoot.appendChild(this.constructor.fragment);
+      this.shadowRoot.appendChild(this.constructor.fragment);
+      if (this.hasAttribute("neverhidden")) {
+        this.panelContent.style.display = "";
       }
     }
 
@@ -214,8 +210,8 @@
     }
 
     on_popuphidden(event) {
-      if (event.target == this) {
-        this.panelContent.style.display = "none";
+      if (event.target == this && !this.hasAttribute("neverhidden")) {
+        this.panelContent.style.setProperty("display", "none", "important");
       }
       if (this.isArrowPanel && event.target == this) {
         this.removeAttribute("panelopen");