Merge pull request #2036 from matrix-org/dbkr/many_persistedelements

Give PersistedElement a key

src/components/views/elements/PersistedElement.js

@@ -16,28 +16,24 @@ limitations under the License.
 
 const React = require('react');
 const ReactDOM = require('react-dom');
+const PropTypes = require('prop-types');
 
 // Shamelessly ripped off Modal.js.  There's probably a better way
 // of doing reusable widgets like dialog boxes & menus where we go and
 // pass in a custom control as the actual body.
 
-const ContainerId = "mx_PersistedElement";
-
-function getOrCreateContainer() {
-    let container = document.getElementById(ContainerId);
+function getOrCreateContainer(containerId) {
+    let container = document.getElementById(containerId);
 
     if (!container) {
         container = document.createElement("div");
-        container.id = ContainerId;
+        container.id = containerId;
         document.body.appendChild(container);
     }
 
     return container;
 }
 
-// Greater than that of the ContextualMenu
-const PE_Z_INDEX = 5000;
-
 /*
  * Class of component that renders its children in a separate ReactDOM virtual tree
  * in a container element appended to document.body.
@@ -50,6 +46,14 @@ const PE_Z_INDEX = 5000;
  * bounding rect as the parent of PE.
  */
 export default class PersistedElement extends React.Component {
+
+    static propTypes = {
+        // Unique identifier for this PersistedElement instance
+        // Any PersistedElements with the same persistKey will use
+        // the same DOM container.
+        persistKey: PropTypes.string.isRequired,
+    };
+
     constructor() {
         super();
         this.collectChildContainer = this.collectChildContainer.bind(this);
@@ -97,18 +101,16 @@ export default class PersistedElement extends React.Component {
             left: parentRect.left + 'px',
             width: parentRect.width + 'px',
             height: parentRect.height + 'px',
-            zIndex: PE_Z_INDEX,
         });
     }
 
     render() {
-        const content = <div ref={this.collectChild}>
+        const content = <div ref={this.collectChild} style={this.props.style}>
             {this.props.children}
         </div>;
 
-        ReactDOM.render(content, getOrCreateContainer());
+        ReactDOM.render(content, getOrCreateContainer('mx_persistedElement_'+this.props.persistKey));
 
         return <div ref={this.collectChildContainer}></div>;
     }
 }
-

src/components/views/rooms/Stickerpicker.js

@@ -27,6 +27,10 @@ import WidgetUtils from '../../../utils/WidgetUtils';
 
 const widgetType = 'm.stickerpicker';
 
+// We sit in a context menu, so the persisted element container needs to float
+// above it, so it needs a greater z-index than the ContextMenu
+const STICKERPICKER_Z_INDEX = 5000;
+
 export default class Stickerpicker extends React.Component {
     constructor(props) {
         super(props);
@@ -211,7 +215,7 @@ export default class Stickerpicker extends React.Component {
                             width: this.popoverWidth,
                         }}
                     >
-                    <PersistedElement>
+                    <PersistedElement containerId="mx_persisted_stickerPicker" style={{zIndex: STICKERPICKER_Z_INDEX}}>
                         <AppTile
                             collectWidgetMessaging={this._collectWidgetMessaging}
                             id={stickerpickerWidget.id}