Disable "Subprojects" menu item for milestone projects

Summary:
Ref T10010. Milestones can't have subprojects, so this item isn't very useful.

I think there is also an argument for disabling "Members", but that panel is a little less useless and explains the membership rule, so I'm less certain about removing it. I do generally lean toward removing it at some point, though.

Test Plan:
  - Viewed a milestone, no "Subprojects" menu item.
  - Viewed a normal project, saw item.
  - Edited both menus, saw consistent UI.

Reviewers: chad

Reviewed By: chad

Maniphest Tasks: T10010

Differential Revision: https://secure.phabricator.com/D15200

src/applications/project/profilepanel/PhabricatorProjectSubprojectsProfilePanel.php

@@ -13,6 +13,14 @@ final class PhabricatorProjectSubprojectsProfilePanel
     return pht('Subprojects');
   }
 
+  public function shouldEnableForObject($object) {
+    if ($object->isMilestone()) {
+      return false;
+    }
+
+    return true;
+  }
+
   public function getDisplayName(
     PhabricatorProfilePanelConfiguration $config) {
     $name = $config->getPanelProperty('name');

src/applications/search/engine/PhabricatorProfilePanelEngine.php

@@ -239,6 +239,10 @@ abstract class PhabricatorProfilePanelEngine extends Phobject {
     // Merge the stored panels into the builtin panels. If a builtin panel has
     // a stored version, replace the defaults with the stored changes.
     foreach ($stored_panels as $stored_panel) {
+      if (!$stored_panel->shouldEnableForObject($object)) {
+        continue;
+      }
+
       $builtin_key = $stored_panel->getBuiltinKey();
       if ($builtin_key !== null) {
         // If this builtin actually exists, replace the builtin with the
@@ -341,6 +345,10 @@ abstract class PhabricatorProfilePanelEngine extends Phobject {
         ->attachProfileObject($object)
         ->setPanelOrder($order);
 
+      if (!$builtin->shouldEnableForObject($object)) {
+        continue;
+      }
+
       $map[$builtin_key] = $builtin;
 
       $order++;

src/applications/search/profilepanel/PhabricatorProfilePanel.php

@@ -30,6 +30,10 @@ abstract class PhabricatorProfilePanel extends Phobject {
     return false;
   }
 
+  public function shouldEnableForObject($object) {
+    return true;
+  }
+
   public function canHidePanel(
     PhabricatorProfilePanelConfiguration $config) {
     return true;

src/applications/search/storage/PhabricatorProfilePanelConfiguration.php

@@ -109,6 +109,10 @@ final class PhabricatorProfilePanelConfiguration
     return $this->getPanel()->canHidePanel($this);
   }
 
+  public function shouldEnableForObject($object) {
+    return $this->getPanel()->shouldEnableForObject($object);
+  }
+
   public function getSortKey() {
     $order = $this->getPanelOrder();
     if ($order === null) {