Add a view option to disable blame in Diffusion and fix some view transition bugs

Summary:
See PHI604. Ref T13130. Ref T13105. There's currently no way to turn blame off in Diffusion. Add a "Hide Blame" option to the "View Options" dropdown so it can be toggled off.

Also fix a couple of bugs around this: for example, if you loaded a Jupyter notebook and then switched to "Source" view, blame would incorrectly fail to activate because the original rendering of the "stage" used an asynchronous engine so `willRenderRef()` wasn't called to populate blame.

Test Plan:
  - Viewed a source file, toggled blame off/on, reloaded page to see state stick in URL.
  - Viewed a Jupyter notebook, toggled to "Source" view, saw blame.
  - Viewed stuff in Files (no blame UI options).
  - Tried to do some invalid stuff like toggle blame on a non-blame engine (options disable properly).

Reviewers: amckinley

Reviewed By: amckinley

Maniphest Tasks: T13130, T13105

Differential Revision: https://secure.phabricator.com/D19414

src/applications/diffusion/document/DiffusionDocumentRenderingEngine.php

@@ -69,7 +69,7 @@ final class DiffusionDocumentRenderingEngine
     return;
   }
 
-  protected function willRenderRef(PhabricatorDocumentRef $ref) {
+  protected function willStageRef(PhabricatorDocumentRef $ref) {
     $drequest = $this->getDiffusionRequest();
 
     $blame_uri = (string)$drequest->generateURI(
@@ -78,9 +78,13 @@ final class DiffusionDocumentRenderingEngine
         'stable' => true,
       ));
 
-    $ref
-      ->setSymbolMetadata($this->getSymbolMetadata())
-      ->setBlameURI($blame_uri);
+    $ref->setBlameURI($blame_uri);
+  }
+
+  protected function willRenderRef(PhabricatorDocumentRef $ref) {
+    $drequest = $this->getDiffusionRequest();
+
+    $ref->setSymbolMetadata($this->getSymbolMetadata());
 
     $coverage = $drequest->loadCoverage();
     if (strlen($coverage)) {

src/applications/files/document/PhabricatorDocumentEngine.php

@@ -7,6 +7,7 @@ abstract class PhabricatorDocumentEngine
   private $highlightedLines = array();
   private $encodingConfiguration;
   private $highlightingConfiguration;
+  private $blameConfiguration = true;
 
   final public function setViewer(PhabricatorUser $viewer) {
     $this->viewer = $viewer;
@@ -60,6 +61,19 @@ abstract class PhabricatorDocumentEngine
     return $this->highlightingConfiguration;
   }
 
+  final public function setBlameConfiguration($blame_configuration) {
+    $this->blameConfiguration = $blame_configuration;
+    return $this;
+  }
+
+  final public function getBlameConfiguration() {
+    return $this->blameConfiguration;
+  }
+
+  final protected function getBlameEnabled() {
+    return $this->blameConfiguration;
+  }
+
   public function shouldRenderAsync(PhabricatorDocumentRef $ref) {
     return false;
   }

src/applications/files/document/PhabricatorSourceDocumentEngine.php

@@ -50,7 +50,7 @@ final class PhabricatorSourceDocumentEngine
     }
 
     $options = array();
-    if ($ref->getBlameURI()) {
+    if ($ref->getBlameURI() && $this->getBlameEnabled()) {
       $content = phutil_split_lines($content);
       $blame = range(1, count($content));
       $blame = array_fuse($blame);

src/applications/files/document/render/PhabricatorDocumentRenderingEngine.php

@@ -69,6 +69,9 @@ abstract class PhabricatorDocumentRenderingEngine
       $engine->setHighlightingConfiguration($highlight_setting);
     }
 
+    $blame_setting = ($request->getStr('blame') !== 'off');
+    $engine->setBlameConfiguration($blame_setting);
+
     $views = array();
     foreach ($engines as $candidate_key => $candidate_engine) {
       $label = $candidate_engine->getViewAsLabel($ref);
@@ -104,6 +107,8 @@ abstract class PhabricatorDocumentRenderingEngine
       'controlID' => $control_id,
     );
 
+    $this->willStageRef($ref);
+
     if ($engine->shouldRenderAsync($ref)) {
       $content = $engine->newLoadingContent($ref);
       $config['next'] = 'render';
@@ -142,7 +147,11 @@ abstract class PhabricatorDocumentRenderingEngine
         'value' => $highlight_setting,
       ),
       'blame' => array(
+        'icon' => 'fa-backward',
+        'hide' => pht('Hide Blame'),
+        'show' => pht('Show Blame'),
         'uri' => $ref->getBlameURI(),
+        'enabled' => $blame_setting,
         'value' => null,
       ),
       'coverage' => array(
@@ -180,6 +189,7 @@ abstract class PhabricatorDocumentRenderingEngine
   }
 
   final public function newRenderResponse(PhabricatorDocumentRef $ref) {
+    $this->willStageRef($ref);
     $this->willRenderRef($ref);
 
     $request = $this->getRequest();
@@ -207,6 +217,9 @@ abstract class PhabricatorDocumentRenderingEngine
       $engine->setHighlightingConfiguration($highlight_setting);
     }
 
+    $blame_setting = ($request->getStr('blame') !== 'off');
+    $engine->setBlameConfiguration($blame_setting);
+
     try {
       $content = $engine->newDocument($ref);
     } catch (Exception $ex) {
@@ -314,6 +327,10 @@ abstract class PhabricatorDocumentRenderingEngine
     return;
   }
 
+  protected function willStageRef(PhabricatorDocumentRef $ref) {
+    return;
+  }
+
   protected function willRenderRef(PhabricatorDocumentRef $ref) {
     return;
   }