Make the scrollpanel update itself correctly on video resize.

When we first get video, the video component will resize itself. This will
cause the page to be reflowed, but that doesn't trigger an update on the gemini
scrollbar. We therefore need to force an update on the messagepanel. Implement
this by providing an onResize property on the CallView component.

We need to do the same when we change the maxHeight on the video panel.

The same applies to resizing of the MessageComposer. That was previously
handled with a fugly roomView.forceUpdate() from MessageComposer - make it use
the same mechanism.

Finally: the messageComposer is at least 70 pixels, and up to 100 pixels high -
not 36. Fix the auxPanelMaxHeight calculation - and use a static constant
rather than hardcoding the number to avoid this happening again.

src/components/structures/RoomView.js

@@ -1064,17 +1064,23 @@ module.exports = React.createClass({
         // a maxHeight on the underlying remote video tag.
         var auxPanelMaxHeight;
         if (this.refs.callView) {
-            // XXX: don't understand why we have to call findDOMNode here in react 0.14 - it should already be a DOM node.
-            var video = ReactDOM.findDOMNode(this.refs.callView.refs.video.refs.remote);
+            var video = this.refs.callView.getVideoView().getRemoteVideoElement();
 
             // header + footer + status + give us at least 100px of scrollback at all times.
-            auxPanelMaxHeight = window.innerHeight - (83 + 72 + 36 + 100);
+            auxPanelMaxHeight = window.innerHeight -
+                (83 + 72 +
+                 sdk.getComponent('rooms.MessageComposer').MAX_HEIGHT +
+                 100);
 
             // XXX: this is a bit of a hack and might possibly cause the video to push out the page anyway
             // but it's better than the video going missing entirely
             if (auxPanelMaxHeight < 50) auxPanelMaxHeight = 50;
 
             video.style.maxHeight = auxPanelMaxHeight + "px";
+
+            // the above might have made the video panel resize itself, so now
+            // we need to tell the gemini panel to adapt.
+            this.onChildResize();
         }
     },
 
@@ -1109,6 +1115,15 @@ module.exports = React.createClass({
         });
     },
 
+    onChildResize: function() {
+        // When the video or the message composer resizes, the scroll panel
+        // also changes size.  Work around GeminiScrollBar fail by telling it
+        // about it. This also ensures that the scroll offset is updated.
+        if (this.refs.messagePanel) {
+            this.refs.messagePanel.forceUpdate();
+        }
+    },
+
     render: function() {
         var RoomHeader = sdk.getComponent('rooms.RoomHeader');
         var MessageComposer = sdk.getComponent('rooms.MessageComposer');
@@ -1299,7 +1314,7 @@ module.exports = React.createClass({
             if (canSpeak) {
                 messageComposer =
                     <MessageComposer
-                        room={this.state.room} roomView={this} uploadFile={this.uploadFile}
+                        room={this.state.room} onResize={this.onChildResize} uploadFile={this.uploadFile}
                         callState={this.state.callState} tabComplete={this.tabComplete} />
             }
 
@@ -1402,7 +1417,8 @@ module.exports = React.createClass({
                         } />
                     { fileDropTarget }    
                     <div className="mx_RoomView_auxPanel">
-                        <CallView ref="callView" room={this.state.room} ConferenceHandler={this.props.ConferenceHandler}/>
+                        <CallView ref="callView" room={this.state.room} ConferenceHandler={this.props.ConferenceHandler}
+                            onResize={this.onChildResize} />
                         { conferenceCallNotification }
                         { aux }
                     </div>

src/components/views/rooms/MessageComposer.js

@@ -65,8 +65,17 @@ function mdownToHtml(mdown) {
 module.exports = React.createClass({
     displayName: 'MessageComposer',
 
+    statics: {
+        // the height we limit the composer to
+        MAX_HEIGHT: 100,
+    },
+
     propTypes: {
-        tabComplete: React.PropTypes.any
+        tabComplete: React.PropTypes.any,
+
+        // a callback which is called when the height of the composer is
+        // changed due to a change in content.
+        onResize: React.PropTypes.function,
     },
 
     componentWillMount: function() {
@@ -237,13 +246,15 @@ module.exports = React.createClass({
         // scrollHeight is at least equal to clientHeight, so we have to
         // temporarily crimp clientHeight to 0 to get an accurate scrollHeight value
         this.refs.textarea.style.height = "0px";
-        var newHeight = this.refs.textarea.scrollHeight < 100 ? this.refs.textarea.scrollHeight : 100;
+        var newHeight = Math.min(this.refs.textarea.scrollHeight,
+                                 this.constructor.MAX_HEIGHT);
         this.refs.textarea.style.height = Math.ceil(newHeight) + "px";
-        if (this.props.roomView) {
-            // kick gemini-scrollbar to re-layout
-            this.props.roomView.forceUpdate();
-        }
         this.oldScrollHeight = this.refs.textarea.scrollHeight;
+
+        if (this.props.onResize) {
+            // kick gemini-scrollbar to re-layout
+            this.props.onResize();
+        }
     },
 
     onKeyUp: function(ev) {

src/components/views/voip/CallView.js

@@ -33,6 +33,12 @@ var MatrixClientPeg = require("../../../MatrixClientPeg");
 module.exports = React.createClass({
     displayName: 'CallView',
 
+    propTypes: {
+        // a callback which is called when the video within the callview
+        // due to a change in video metadata
+        onResize: React.PropTypes.function,
+    },
+
     componentDidMount: function() {
         this.dispatcherRef = dis.register(this.onAction);
         if (this.props.room) {
@@ -97,7 +103,7 @@ module.exports = React.createClass({
     render: function(){
         var VideoView = sdk.getComponent('voip.VideoView');
         return (
-            <VideoView ref="video" onClick={ this.props.onClick }/>
+            <VideoView ref="video" onClick={ this.props.onClick } onResize={ this.props.onResize }/>
         );
     }
 });

src/components/views/voip/VideoFeed.js

@@ -21,9 +21,29 @@ var React = require('react');
 module.exports = React.createClass({
     displayName: 'VideoFeed',
 
+    propTypes: {
+        // a callback which is called when the video element is resized
+        // due to a change in video metadata
+        onResize: React.PropTypes.function,
+    },
+
+    componentDidMount() {
+        this.refs.vid.addEventListener('resize', this.onResize);
+    },
+
+    componentWillUnmount() {
+        this.refs.vid.removeEventListener('resize', this.onResize);
+    },
+
+    onResize: function(e) {
+        if(this.props.onResize) {
+            this.props.onResize(e);
+        }
+    },
+
     render: function() {
         return (
-            <video>
+            <video ref="vid">
             </video>
         );
     },

src/components/views/voip/VideoView.js

@@ -85,7 +85,7 @@ module.exports = React.createClass({
         return (
             <div className="mx_VideoView" ref={this.setContainer} onClick={ this.props.onClick }>
                 <div className="mx_VideoView_remoteVideoFeed">
-                    <VideoFeed ref="remote"/>
+                    <VideoFeed ref="remote" onResize={this.props.onResize}/>
                     <audio ref="remoteAudio"/>
                 </div>
                 <div className="mx_VideoView_localVideoFeed">