CallHeader: Remove the HStack, use manual constraints instead

This allows hiding the members button when there is no one in the
call. It will also be useful for the redesigned lobby screen where the
info is in the middle of the screen instead of at the top.

Signal/src/Calls/UserInterface/CallHeader.swift

@@ -53,16 +53,6 @@ class CallHeader: UIView {
         addSubview(gradientView)
         gradientView.autoPinEdgesToSuperviewEdges()
 
-        let hStack = UIStackView()
-        hStack.axis = .horizontal
-        hStack.spacing = 13
-        hStack.layoutMargins = UIEdgeInsets(top: 0, left: 8, bottom: 0, right: 8)
-        hStack.isLayoutMarginsRelativeArrangement = true
-        addSubview(hStack)
-        hStack.autoPinWidthToSuperview()
-        hStack.autoPinEdge(toSuperviewMargin: .top)
-        hStack.autoPinEdge(toSuperviewEdge: .bottom, withInset: 46)
-
         // Back button
 
         let backButton = UIButton()
@@ -73,7 +63,22 @@ class CallHeader: UIView {
         backButton.addTarget(delegate, action: #selector(CallHeaderDelegate.didTapBackButton), for: .touchUpInside)
         addShadow(to: backButton)
 
-        hStack.addArrangedSubview(backButton)
+        addSubview(backButton)
+        backButton.autoPinLeadingToSuperviewMargin(withInset: 8)
+        backButton.autoPinTopToSuperviewMargin()
+
+        // Group members button
+
+        groupMembersButton.addTarget(
+            delegate,
+            action: #selector(CallHeaderDelegate.didTapMembersButton),
+            for: .touchUpInside
+        )
+        addShadow(to: groupMembersButton)
+
+        addSubview(groupMembersButton)
+        groupMembersButton.autoPinTrailingToSuperviewMargin(withInset: 8)
+        groupMembersButton.autoPinTopToSuperviewMargin()
 
         // vStack
 
@@ -81,7 +86,11 @@ class CallHeader: UIView {
         vStack.axis = .vertical
         vStack.spacing = 4
 
-        hStack.addArrangedSubview(vStack)
+        addSubview(vStack)
+        vStack.autoPinLeading(toTrailingEdgeOf: backButton, offset: 13)
+        vStack.autoPinTrailing(toLeadingEdgeOf: groupMembersButton, offset: 13)
+        vStack.autoPinTopToSuperviewMargin()
+        vStack.autoPinBottomToSuperviewMargin(withInset: 46)
 
         // Name Label
 
@@ -110,17 +119,6 @@ class CallHeader: UIView {
 
         vStack.addArrangedSubview(callStatusLabel)
 
-        // Group members button
-
-        groupMembersButton.addTarget(
-            delegate,
-            action: #selector(CallHeaderDelegate.didTapMembersButton),
-            for: .touchUpInside
-        )
-        addShadow(to: groupMembersButton)
-
-        hStack.addArrangedSubview(groupMembersButton)
-
         updateCallTitleLabel()
         updateCallStatusLabel()
         updateGroupMembersButton()
@@ -328,6 +326,7 @@ private class GroupMembersButton: UIButton {
 
     func updateMemberCount(_ count: Int) {
         countLabel.text = String(OWSFormat.formatInt(count))
+        self.isHidden = count == 0
     }
 
     required init?(coder: NSCoder) {