Add pip view container and load pip view into it

Riot/Modules/Call/CallViewController.m

@@ -37,8 +37,11 @@
     BOOL promptForStunServerFallback;
 }
 
+@property (nonatomic, weak) IBOutlet UIView *pipViewContainer;
+
 @property (nonatomic, strong) id<Theme> overriddenTheme;
 @property (nonatomic, assign) BOOL inPiP;
+@property (nonatomic, strong) CallPiPView *pipView;
 
 @property (nonatomic, strong) CustomSizedPresentationController *customSizedPresentationController;
 
@@ -224,6 +227,8 @@
 - (void)call:(MXCall *)call stateDidChange:(MXCallState)state reason:(MXEvent *)event
 {
     [super call:call stateDidChange:state reason:event];
+    
+    [self configurePiPView];
 
     [self checkStunServerFallbackWithCallState:state];
 }
@@ -379,6 +384,22 @@
     return _overriddenTheme;
 }
 
+- (CallPiPView *)pipView
+{
+    if (_pipView == nil)
+    {
+        _pipView = [CallPiPView instantiateWithSession:self.mainSession];
+    }
+    return _pipView;
+}
+
+- (void)setMxCallOnHold:(MXCall *)mxCallOnHold
+{
+    [super setMxCallOnHold:mxCallOnHold];
+    
+    [self configurePiPView];
+}
+
 - (UIImage*)picturePlaceholder
 {
     CGFloat fontSize = floor(self.callerImageViewWidthConstraint.constant * 0.7);
@@ -502,9 +523,17 @@
         self.callStatusLabel.hidden = YES;
         self.localPreviewContainerView.hidden = YES;
         self.localPreviewActivityView.hidden = YES;
+        
+        if (self.pipViewContainer.subviews.count == 0)
+        {
+            [self.pipViewContainer vc_addSubViewMatchingParent:self.pipView];
+            [self configurePiPView];
+        }
+        self.pipViewContainer.hidden = NO;
     }
     else
     {
+        self.pipViewContainer.hidden = YES;
         self.localPreviewContainerView.hidden = NO;
         self.callerImageView.hidden = NO;
         self.callerNameLabel.hidden = NO;
@@ -644,6 +673,19 @@
     [viewController dismissViewControllerAnimated:YES completion:nil];
 }
 
+#pragma mark - PiP
+
+- (void)configurePiPView
+{
+    if (self.inPiP)
+    {
+        [self.pipView configureWithCall:self.mxCall
+                                   peer:self.peer
+                             onHoldCall:self.mxCallOnHold
+                             onHoldPeer:self.peerOnHold];
+    }
+}
+
 #pragma mark - PictureInPicturable
 
 - (void)enterPiP