Allow inline comments to be individually hidden

Summary:
Ref T7447. Implements per-viewer comment hiding. Once a comment is obsolete or uninteresting, you can hide it completely.

This is sticky per-user.

My hope is that this will strike a better balance between concerns than some of the other approaches (conservative porting, summarization, hide-all).

Specifically, this adds a new action here:

{F435621}

Clicking it completely collapses the comment into a small icon on the previous line, and saves the comment state as hidden for you:

{F435626}

You can click the icon to reveal all hidden comments below the line.

Test Plan:
  - Hid comments.
  - Showed comments.
  - Created, edited, deleted and submitted comments.
  - Used Diffusion comments (hiding is not implemented there yet, but I'd plan to bring it there eventually if it works out in Differential).

Reviewers: btrahan, chad

Reviewed By: btrahan

Subscribers: jparise, yelirekim, epriestley

Maniphest Tasks: T7447

Differential Revision: https://secure.phabricator.com/D13009

resources/celerity/map.php

@@ -10,8 +10,8 @@ return array(
     'core.pkg.css' => '439658b5',
     'core.pkg.js' => '328799d0',
     'darkconsole.pkg.js' => 'e7393ebb',
-    'differential.pkg.css' => 'bb338e4b',
+    'differential.pkg.css' => '30602b8c',
-    'differential.pkg.js' => '63a77807',
+    'differential.pkg.js' => '8c98ce21',
     'diffusion.pkg.css' => '591664fa',
     'diffusion.pkg.js' => '0115b37c',
     'maniphest.pkg.css' => '68d4dd3d',
@@ -60,7 +60,7 @@ return array(
     'rsrc/css/application/differential/add-comment.css' => 'c47f8c40',
     'rsrc/css/application/differential/changeset-view.css' => 'e19cfd6e',
     'rsrc/css/application/differential/core.css' => '7ac3cabc',
-    'rsrc/css/application/differential/phui-inline-comment.css' => '2174771a',
+    'rsrc/css/application/differential/phui-inline-comment.css' => 'aa16f165',
     'rsrc/css/application/differential/results-table.css' => '181aa9d9',
     'rsrc/css/application/differential/revision-comment.css' => '14b8565a',
     'rsrc/css/application/differential/revision-history.css' => '0e8eb855',
@@ -353,7 +353,7 @@ return array(
     'rsrc/js/application/differential/behavior-comment-preview.js' => 'b064af76',
     'rsrc/js/application/differential/behavior-diff-radios.js' => 'e1ff79b1',
     'rsrc/js/application/differential/behavior-dropdown-menus.js' => '2035b9cb',
-    'rsrc/js/application/differential/behavior-edit-inline-comments.js' => 'e723c323',
+    'rsrc/js/application/differential/behavior-edit-inline-comments.js' => '037b59eb',
     'rsrc/js/application/differential/behavior-keyboard-nav.js' => '2c426492',
     'rsrc/js/application/differential/behavior-populate.js' => '8694b1df',
     'rsrc/js/application/differential/behavior-show-field-details.js' => 'bba9eedf',
@@ -443,7 +443,7 @@ return array(
     'rsrc/js/core/behavior-device.js' => 'a205cf28',
     'rsrc/js/core/behavior-drag-and-drop-textarea.js' => '6d49590e',
     'rsrc/js/core/behavior-error-log.js' => '6882e80a',
-    'rsrc/js/core/behavior-fancy-datepicker.js' => '2d4029a8',
+    'rsrc/js/core/behavior-fancy-datepicker.js' => '5c0f680f',
     'rsrc/js/core/behavior-file-tree.js' => '88236f00',
     'rsrc/js/core/behavior-form.js' => '5c54cbf3',
     'rsrc/js/core/behavior-gesture.js' => '3ab51e2c',
@@ -560,7 +560,7 @@ return array(
     'javelin-behavior-differential-comment-jump' => '4fdb476d',
     'javelin-behavior-differential-diff-radios' => 'e1ff79b1',
     'javelin-behavior-differential-dropdown-menus' => '2035b9cb',
-    'javelin-behavior-differential-edit-inline-comments' => 'e723c323',
+    'javelin-behavior-differential-edit-inline-comments' => '037b59eb',
     'javelin-behavior-differential-feedback-preview' => 'b064af76',
     'javelin-behavior-differential-keyboard-navigation' => '2c426492',
     'javelin-behavior-differential-populate' => '8694b1df',
@@ -576,7 +576,7 @@ return array(
     'javelin-behavior-durable-column' => '16c695bf',
     'javelin-behavior-error-log' => '6882e80a',
     'javelin-behavior-event-all-day' => '38dcf3c8',
-    'javelin-behavior-fancy-datepicker' => '2d4029a8',
+    'javelin-behavior-fancy-datepicker' => '5c0f680f',
     'javelin-behavior-global-drag-and-drop' => 'c8e57404',
     'javelin-behavior-herald-rule-editor' => '7ebaeed3',
     'javelin-behavior-high-security-warning' => 'a464fe03',
@@ -782,7 +782,7 @@ return array(
     'phui-image-mask-css' => '5a8b09c8',
     'phui-info-panel-css' => '27ea50a1',
     'phui-info-view-css' => 'c6f0aef8',
-    'phui-inline-comment-view-css' => '2174771a',
+    'phui-inline-comment-view-css' => 'aa16f165',
     'phui-list-view-css' => '2e25ebfb',
     'phui-object-box-css' => '7d160002',
     'phui-object-item-list-view-css' => 'f3a22696',
@@ -830,6 +830,14 @@ return array(
     '029a133d' => array(
       'aphront-dialog-view-css',
     ),
+    '037b59eb' => array(
+      'javelin-behavior',
+      'javelin-stratcom',
+      'javelin-dom',
+      'javelin-util',
+      'javelin-vector',
+      'differential-inline-comment-editor',
+    ),
     '048330fa' => array(
       'javelin-behavior',
       'javelin-typeahead-ondemand-source',
@@ -1042,13 +1050,6 @@ return array(
       'javelin-install',
       'javelin-event',
     ),
-    '2d4029a8' => array(
-      'javelin-behavior',
-      'javelin-util',
-      'javelin-dom',
-      'javelin-stratcom',
-      'javelin-vector',
-    ),
     '331b1611' => array(
       'javelin-install',
     ),
@@ -1241,6 +1242,13 @@ return array(
       'javelin-uri',
       'javelin-routable',
     ),
+    '5c0f680f' => array(
+      'javelin-behavior',
+      'javelin-util',
+      'javelin-dom',
+      'javelin-stratcom',
+      'javelin-vector',
+    ),
     '5c54cbf3' => array(
       'javelin-behavior',
       'javelin-stratcom',
@@ -1925,14 +1933,6 @@ return array(
     'e6e25838' => array(
       'javelin-install',
     ),
-    'e723c323' => array(
-      'javelin-behavior',
-      'javelin-stratcom',
-      'javelin-dom',
-      'javelin-util',
-      'javelin-vector',
-      'differential-inline-comment-editor',
-    ),
     'e9581f08' => array(
       'javelin-behavior',
       'javelin-stratcom',

resources/sql/autopatches/20150525.diff.hidden.1.sql

@@ -0,0 +1,7 @@
+CREATE TABLE {$NAMESPACE}_differential.differential_hiddencomment (
+  id INT UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY,
+  userPHID VARBINARY(64) NOT NULL,
+  commentID INT UNSIGNED NOT NULL,
+  UNIQUE KEY `key_user` (userPHID, commentID),
+  KEY `key_comment` (commentID)
+) ENGINE=InnoDB, COLLATE {$COLLATE_TEXT};

src/__phutil_library_map__.php

@@ -374,6 +374,7 @@ phutil_register_library_map(array(
     'DifferentialGetWorkingCopy' => 'applications/differential/DifferentialGetWorkingCopy.php',
     'DifferentialGitHubLandingStrategy' => 'applications/differential/landing/DifferentialGitHubLandingStrategy.php',
     'DifferentialGitSVNIDField' => 'applications/differential/customfield/DifferentialGitSVNIDField.php',
+    'DifferentialHiddenComment' => 'applications/differential/storage/DifferentialHiddenComment.php',
     'DifferentialHostField' => 'applications/differential/customfield/DifferentialHostField.php',
     'DifferentialHostedGitLandingStrategy' => 'applications/differential/landing/DifferentialHostedGitLandingStrategy.php',
     'DifferentialHostedMercurialLandingStrategy' => 'applications/differential/landing/DifferentialHostedMercurialLandingStrategy.php',
@@ -1178,6 +1179,7 @@ phutil_register_library_map(array(
     'PHUIDiffInlineCommentUndoView' => 'infrastructure/diff/view/PHUIDiffInlineCommentUndoView.php',
     'PHUIDiffInlineCommentView' => 'infrastructure/diff/view/PHUIDiffInlineCommentView.php',
     'PHUIDiffOneUpInlineCommentRowScaffold' => 'infrastructure/diff/view/PHUIDiffOneUpInlineCommentRowScaffold.php',
+    'PHUIDiffRevealIconView' => 'infrastructure/diff/view/PHUIDiffRevealIconView.php',
     'PHUIDiffTwoUpInlineCommentRowScaffold' => 'infrastructure/diff/view/PHUIDiffTwoUpInlineCommentRowScaffold.php',
     'PHUIDocumentExample' => 'applications/uiexample/examples/PHUIDocumentExample.php',
     'PHUIDocumentView' => 'view/phui/PHUIDocumentView.php',
@@ -3616,6 +3618,7 @@ phutil_register_library_map(array(
     'DifferentialGetRevisionConduitAPIMethod' => 'DifferentialConduitAPIMethod',
     'DifferentialGitHubLandingStrategy' => 'DifferentialLandingStrategy',
     'DifferentialGitSVNIDField' => 'DifferentialCustomField',
+    'DifferentialHiddenComment' => 'DifferentialDAO',
     'DifferentialHostField' => 'DifferentialCustomField',
     'DifferentialHostedGitLandingStrategy' => 'DifferentialLandingStrategy',
     'DifferentialHostedMercurialLandingStrategy' => 'DifferentialLandingStrategy',
@@ -4506,6 +4509,7 @@ phutil_register_library_map(array(
     'PHUIDiffInlineCommentUndoView' => 'PHUIDiffInlineCommentView',
     'PHUIDiffInlineCommentView' => 'AphrontView',
     'PHUIDiffOneUpInlineCommentRowScaffold' => 'PHUIDiffInlineCommentRowScaffold',
+    'PHUIDiffRevealIconView' => 'AphrontView',
     'PHUIDiffTwoUpInlineCommentRowScaffold' => 'PHUIDiffInlineCommentRowScaffold',
     'PHUIDocumentExample' => 'PhabricatorUIExample',
     'PHUIDocumentView' => 'AphrontTagView',

src/applications/audit/storage/PhabricatorAuditInlineComment.php

@@ -23,6 +23,14 @@ final class PhabricatorAuditInlineComment
     return $this->proxy;
   }
 
+  public function supportsHiding() {
+    return false;
+  }
+
+  public function isHidden() {
+    return false;
+  }
+
   public function getTransactionCommentForSave() {
     $content_source = PhabricatorContentSource::newForSource(
       PhabricatorContentSource::SOURCE_LEGACY,

src/applications/differential/controller/DifferentialChangesetViewController.php

@@ -191,6 +191,7 @@ final class DifferentialChangesetViewController extends DifferentialController {
     if ($revision) {
       $query = id(new DifferentialInlineCommentQuery())
         ->setViewer($viewer)
+        ->needHidden(true)
         ->withRevisionPHIDs(array($revision->getPHID()));
       $inlines = $query->execute();
       $inlines = $query->adjustInlinesForChangesets(

src/applications/differential/controller/DifferentialInlineCommentEditController.php

@@ -42,6 +42,7 @@ final class DifferentialInlineCommentEditController
       ->setViewer($this->getViewer())
       ->withIDs(array($id))
       ->withDeletedDrafts(true)
+      ->needHidden(true)
       ->executeOne();
   }
 
@@ -50,6 +51,7 @@ final class DifferentialInlineCommentEditController
       ->setViewer($this->getViewer())
       ->withPHIDs(array($phid))
       ->withDeletedDrafts(true)
+      ->needHidden(true)
       ->executeOne();
   }
 
@@ -152,4 +154,38 @@ final class DifferentialInlineCommentEditController
     return $this->loadRevision()->getAuthorPHID();
   }
 
+  protected function hideComments(array $ids) {
+    $viewer = $this->getViewer();
+    $table = new DifferentialHiddenComment();
+    $conn_w = $table->establishConnection('w');
+
+    $sql = array();
+    foreach ($ids as $id) {
+      $sql[] = qsprintf(
+        $conn_w,
+        '(%s, %d)',
+        $viewer->getPHID(),
+        $id);
+    }
+
+    queryfx(
+      $conn_w,
+      'INSERT IGNORE INTO %T (userPHID, commentID) VALUES %Q',
+      $table->getTableName(),
+      implode(', ', $sql));
+  }
+
+  protected function showComments(array $ids) {
+    $viewer = $this->getViewer();
+    $table = new DifferentialHiddenComment();
+    $conn_w = $table->establishConnection('w');
+
+    queryfx(
+      $conn_w,
+      'DELETE FROM %T WHERE userPHID = %s AND commentID IN (%Ld)',
+      $table->getTableName(),
+      $viewer->getPHID(),
+      $ids);
+  }
+
 }

src/applications/differential/controller/DifferentialInlineCommentPreviewController.php

@@ -19,6 +19,7 @@ extends PhabricatorInlineCommentPreviewController {
       ->withDrafts(true)
       ->withAuthorPHIDs(array($viewer->getPHID()))
       ->withRevisionPHIDs(array($revision->getPHID()))
+      ->needHidden(true)
       ->execute();
   }
 

src/applications/differential/controller/DifferentialRevisionViewController.php

@@ -175,6 +175,7 @@ final class DifferentialRevisionViewController extends DifferentialController {
 
       $query = id(new DifferentialInlineCommentQuery())
         ->setViewer($user)
+        ->needHidden(true)
         ->withRevisionPHIDs(array($revision->getPHID()));
       $inlines = $query->execute();
       $inlines = $query->adjustInlinesForChangesets(

src/applications/differential/query/DifferentialInlineCommentQuery.php

@@ -15,6 +15,7 @@ final class DifferentialInlineCommentQuery
   private $authorPHIDs;
   private $revisionPHIDs;
   private $deletedDrafts;
+  private $needHidden;
 
   public function setViewer(PhabricatorUser $viewer) {
     $this->viewer = $viewer;
@@ -55,6 +56,11 @@ final class DifferentialInlineCommentQuery
     return $this;
   }
 
+  public function needHidden($need) {
+    $this->needHidden = $need;
+    return $this;
+  }
+
   public function execute() {
     $table = new DifferentialTransactionComment();
     $conn_r = $table->establishConnection('r');
@@ -68,6 +74,26 @@ final class DifferentialInlineCommentQuery
 
     $comments = $table->loadAllFromArray($data);
 
+    if ($this->needHidden) {
+      $viewer_phid = $this->getViewer()->getPHID();
+      if ($viewer_phid && $comments) {
+        $hidden = queryfx_all(
+          $conn_r,
+          'SELECT commentID FROM %T WHERE userPHID = %s
+            AND commentID IN (%Ls)',
+          id(new DifferentialHiddenComment())->getTableName(),
+          $viewer_phid,
+          mpull($comments, 'getID'));
+        $hidden = array_fuse(ipull($hidden, 'commentID'));
+      } else {
+        $hidden = array();
+      }
+
+      foreach ($comments as $inline) {
+        $inline->attachIsHidden(isset($hidden[$inline->getID()]));
+      }
+    }
+
     foreach ($comments as $key => $value) {
       $comments[$key] = DifferentialInlineComment::newFromModernComment(
         $value);

src/applications/differential/render/DifferentialChangesetOneUpRenderer.php

@@ -41,8 +41,10 @@ final class DifferentialChangesetOneUpRenderer
 
     $column_width = 4;
 
+    $hidden = new PHUIDiffRevealIconView();
+
     $out = array();
-    foreach ($primitives as $p) {
+    foreach ($primitives as $k => $p) {
       $type = $p['type'];
       switch ($type) {
         case 'old':
@@ -51,6 +53,27 @@ final class DifferentialChangesetOneUpRenderer
         case 'new-file':
           $is_old = ($type == 'old' || $type == 'old-file');
 
+          $o_hidden = array();
+          $n_hidden = array();
+
+          for ($look = $k + 1; isset($primitives[$look]); $look++) {
+            $next = $primitives[$look];
+            switch ($next['type']) {
+              case 'inline':
+                $comment = $next['comment'];
+                if ($comment->isHidden()) {
+                  if ($next['right']) {
+                    $n_hidden[] = $comment;
+                  } else {
+                    $o_hidden[] = $comment;
+                  }
+                }
+                break;
+              default:
+                break 2;
+            }
+          }
+
           $cells = array();
           if ($is_old) {
             if ($p['htype']) {
@@ -68,7 +91,13 @@ final class DifferentialChangesetOneUpRenderer
             } else {
               $left_id = null;
             }
-            $cells[] = phutil_tag('th', array('id' => $left_id), $p['line']);
+
+            $line = $p['line'];
+            if ($o_hidden) {
+              $line = array($hidden, $line);
+            }
+
+            $cells[] = phutil_tag('th', array('id' => $left_id), $line);
 
             $cells[] = phutil_tag('th', array());
             $cells[] = $no_copy;
@@ -85,7 +114,13 @@ final class DifferentialChangesetOneUpRenderer
               } else {
                 $left_id = null;
               }
-              $cells[] = phutil_tag('th', array('id' => $left_id), $p['oline']);
+
+              $oline = $p['oline'];
+              if ($o_hidden) {
+                $oline = array($hidden, $oline);
+              }
+
+              $cells[] = phutil_tag('th', array('id' => $left_id), $oline);
             }
 
             if ($type == 'new-file') {
@@ -97,8 +132,13 @@ final class DifferentialChangesetOneUpRenderer
             } else {
               $right_id = null;
             }
-            $cells[] = phutil_tag('th', array('id' => $right_id), $p['line']);
 
+            $line = $p['line'];
+            if ($n_hidden) {
+              $line = array($hidden, $line);
+            }
+
+            $cells[] = phutil_tag('th', array('id' => $right_id), $line);
 
             $cells[] = $no_copy;
             $cells[] = phutil_tag('td', array('class' => $class), $p['render']);

src/applications/differential/render/DifferentialChangesetTwoUpRenderer.php

@@ -69,6 +69,8 @@ final class DifferentialChangesetTwoUpRenderer
     $depths = $this->getDepths();
     $mask = $this->getMask();
 
+    $hidden = new PHUIDiffRevealIconView();
+
     for ($ii = $range_start; $ii < $range_start + $range_len; $ii++) {
       if (empty($mask[$ii])) {
         // If we aren't going to show this line, we've just entered a gap.
@@ -235,6 +237,69 @@ final class DifferentialChangesetTwoUpRenderer
         $n_id = null;
       }
 
+      $old_comments = $this->getOldComments();
+      $new_comments = $this->getNewComments();
+      $scaffolds = array();
+
+      $o_hidden = array();
+      $n_hidden = array();
+
+      if ($o_num && isset($old_comments[$o_num])) {
+        foreach ($old_comments[$o_num] as $comment) {
+          $inline = $this->buildInlineComment(
+            $comment,
+            $on_right = false);
+          $scaffold = $this->getRowScaffoldForInline($inline);
+
+          if ($comment->isHidden()) {
+            $o_hidden[] = $comment;
+          }
+
+          if ($n_num && isset($new_comments[$n_num])) {
+            foreach ($new_comments[$n_num] as $key => $new_comment) {
+              if ($comment->isCompatible($new_comment)) {
+                $companion = $this->buildInlineComment(
+                  $new_comment,
+                  $on_right = true);
+
+                if ($new_comment->isHidden()) {
+                  $n_hidden = $new_comment;
+                }
+
+                $scaffold->addInlineView($companion);
+                unset($new_comments[$n_num][$key]);
+                break;
+              }
+            }
+          }
+
+
+          $scaffolds[] = $scaffold;
+        }
+      }
+
+      if ($n_num && isset($new_comments[$n_num])) {
+        foreach ($new_comments[$n_num] as $comment) {
+          $inline = $this->buildInlineComment(
+            $comment,
+            $on_right = true);
+
+          if ($comment->isHidden()) {
+            $n_hidden[] = $comment;
+          }
+
+          $scaffolds[] = $this->getRowScaffoldForInline($inline);
+        }
+      }
+
+      if ($o_hidden) {
+        $o_num = array($hidden, $o_num);
+      }
+
+      if ($n_hidden) {
+        $n_num = array($hidden, $n_num);
+      }
+
       // NOTE: This is a unicode zero-width space, which we use as a hint when
       // intercepting 'copy' events to make sure sensible text ends up on the
       // clipboard. See the 'phabricator-oncopy' behavior.
@@ -259,42 +324,10 @@ final class DifferentialChangesetTwoUpRenderer
         $html[] = $context_not_available;
       }
 
-      $old_comments = $this->getOldComments();
+      foreach ($scaffolds as $scaffold) {
-      $new_comments = $this->getNewComments();
-
-      if ($o_num && isset($old_comments[$o_num])) {
-        foreach ($old_comments[$o_num] as $comment) {
-          $inline = $this->buildInlineComment(
-            $comment,
-            $on_right = false);
-          $scaffold = $this->getRowScaffoldForInline($inline);
-
-          if ($n_num && isset($new_comments[$n_num])) {
-            foreach ($new_comments[$n_num] as $key => $new_comment) {
-              if ($comment->isCompatible($new_comment)) {
-                $companion = $this->buildInlineComment(
-                  $new_comment,
-                  $on_right = true);
-
-                $scaffold->addInlineView($companion);
-                unset($new_comments[$n_num][$key]);
-                break;
-              }
-            }
-          }
-
         $html[] = $scaffold;
       }
     }
-      if ($n_num && isset($new_comments[$n_num])) {
-        foreach ($new_comments[$n_num] as $comment) {
-          $inline = $this->buildInlineComment(
-            $comment,
-            $on_right = true);
-          $html[] = $this->getRowScaffoldForInline($inline);
-        }
-      }
-    }
 
     return $this->wrapChangeInTable(phutil_implode_html('', $html));
   }

src/applications/differential/storage/DifferentialHiddenComment.php

@@ -0,0 +1,24 @@
+<?php
+
+final class DifferentialHiddenComment
+  extends DifferentialDAO {
+
+  protected $userPHID;
+  protected $commentID;
+
+  protected function getConfiguration() {
+    return array(
+      self::CONFIG_TIMESTAMPS => false,
+      self::CONFIG_KEY_SCHEMA => array(
+        'key_user' => array(
+          'columns' => array('userPHID', 'commentID'),
+          'unique' => true,
+        ),
+        'key_comment' => array(
+          'columns' => array('commentID'),
+        ),
+      ),
+    ) + parent::getConfiguration();
+  }
+
+}

src/applications/differential/storage/DifferentialInlineComment.php

@@ -24,6 +24,7 @@ final class DifferentialInlineComment
       ->setViewPolicy('public')
       ->setEditPolicy($this->getAuthorPHID())
       ->setContentSource($content_source)
+      ->attachIsHidden(false)
       ->setCommentVersion(1);
 
     return $this->proxy;
@@ -49,6 +50,14 @@ final class DifferentialInlineComment
     return $this;
   }
 
+  public function supportsHiding() {
+    return true;
+  }
+
+  public function isHidden() {
+    return $this->proxy->getIsHidden();
+  }
+
   public function getID() {
     return $this->proxy->getID();
   }

src/applications/differential/storage/DifferentialRevision.php

@@ -522,6 +522,7 @@ final class DifferentialRevision extends DifferentialDAO
     }
 
     $query = id(new DifferentialInlineCommentQuery())
+      ->needHidden(true)
       ->setViewer($viewer);
 
     // NOTE: This is a bit sketchy: this method adjusts the inlines as a

src/applications/differential/storage/DifferentialTransactionComment.php

@@ -13,6 +13,7 @@ final class DifferentialTransactionComment
   protected $replyToCommentPHID;
 
   private $replyToComment = self::ATTACHABLE;
+  private $isHidden = self::ATTACHABLE;
 
   public function getApplicationTransactionObject() {
     return new DifferentialTransaction();
@@ -99,4 +100,13 @@ final class DifferentialTransactionComment
     return $inline_groups;
   }
 
+  public function getIsHidden() {
+    return $this->assertAttached($this->isHidden);
+  }
+
+  public function attachIsHidden($hidden) {
+    $this->isHidden = $hidden;
+    return $this;
+  }
+
 }

src/applications/differential/view/DifferentialChangesetListView.php

@@ -234,6 +234,7 @@ final class DifferentialChangesetListView extends AphrontView {
       Javelin::initBehavior('differential-edit-inline-comments', array(
         'uri' => $this->inlineURI,
         'stage' => 'differential-review-stage',
+        'revealIcon' => hsprintf('%s', new PHUIDiffRevealIconView()),
       ));
     }
 

src/infrastructure/diff/PhabricatorInlineCommentController.php

@@ -15,6 +15,14 @@ abstract class PhabricatorInlineCommentController
   abstract protected function saveComment(
     PhabricatorInlineCommentInterface $inline);
 
+  protected function hideComments(array $ids) {
+    throw new PhutilMethodNotImplementedException();
+  }
+
+  protected function showComments(array $ids) {
+    throw new PhutilMethodNotImplementedException();
+  }
+
   private $changesetID;
   private $isNewFile;
   private $isOnRight;
@@ -84,6 +92,22 @@ abstract class PhabricatorInlineCommentController
 
     $op = $this->getOperation();
     switch ($op) {
+      case 'hide':
+      case 'show':
+        if (!$request->validateCSRF()) {
+          return new Aphront404Response();
+        }
+
+        $ids = $request->getStrList('ids');
+        if ($ids) {
+          if ($op == 'hide') {
+            $this->hideComments($ids);
+          } else {
+            $this->showComments($ids);
+          }
+        }
+
+        return id(new AphrontAjaxResponse())->setContent(array());
       case 'done':
         if (!$request->validateCSRF()) {
           return new Aphront404Response();

src/infrastructure/diff/interface/PhabricatorInlineCommentInterface.php

@@ -57,4 +57,7 @@ interface PhabricatorInlineCommentInterface extends PhabricatorMarkupInterface {
   public function setIsGhost($is_ghost);
   public function getIsGhost();
 
+  public function supportsHiding();
+  public function isHidden();
+
 }

src/infrastructure/diff/view/PHUIDiffInlineCommentDetailView.php

@@ -18,6 +18,10 @@ final class PHUIDiffInlineCommentDetailView
     return $this;
   }
 
+  public function isHidden() {
+    return $this->inlineComment->isHidden();
+  }
+
   public function setHandles(array $handles) {
     assert_instances_of($handles, 'PhabricatorObjectHandle');
     $this->handles = $handles;
@@ -192,6 +196,8 @@ final class PHUIDiffInlineCommentDetailView
     if (!$this->preview) {
       $nextprev = new PHUIButtonBarView();
       $nextprev->addClass('mml');
+
+
       $up = id(new PHUIButtonView())
         ->setTag('a')
         ->setColor(PHUIButtonView::SIMPLE)
@@ -208,6 +214,18 @@ final class PHUIDiffInlineCommentDetailView
         ->addSigil('differential-inline-next')
         ->setMustCapture(true);
 
+      $hide = id(new PHUIButtonView())
+        ->setTag('a')
+        ->setColor(PHUIButtonView::SIMPLE)
+        ->setTooltip(pht('Hide Comment'))
+        ->setIconFont('fa-times')
+        ->addSigil('hide-inline')
+        ->setMustCapture(true);
+
+      if ($viewer_phid && $inline->getID() && $inline->supportsHiding()) {
+        $nextprev->addButton($hide);
+      }
+
       $nextprev->addButton($up);
       $nextprev->addButton($down);
 

src/infrastructure/diff/view/PHUIDiffInlineCommentRowScaffold.php

@@ -23,8 +23,18 @@ abstract class PHUIDiffInlineCommentRowScaffold extends AphrontView {
   protected function getRowAttributes() {
     // TODO: This is semantic information used by the JS when placing comments
     // and using keyboard navigation; we should move it out of class names.
+
+    $style = null;
+    foreach ($this->getInlineViews() as $view) {
+      if ($view->isHidden()) {
+        $style = 'display: none';
+      }
+    }
+
     return array(
       'class' => 'inline',
+      'sigil' => 'inline-row',
+      'style' => $style,
     );
   }
 

src/infrastructure/diff/view/PHUIDiffInlineCommentView.php

@@ -17,4 +17,8 @@ abstract class PHUIDiffInlineCommentView extends AphrontView {
     return null;
   }
 
+  public function isHidden() {
+    return false;
+  }
+
 }

src/infrastructure/diff/view/PHUIDiffOneUpInlineCommentRowScaffold.php

@@ -28,7 +28,7 @@ final class PHUIDiffOneUpInlineCommentRowScaffold
       phutil_tag('td', $attrs, $inline),
     );
 
-    return phutil_tag('tr', $this->getRowAttributes(), $cells);
+    return javelin_tag('tr', $this->getRowAttributes(), $cells);
   }
 
 }

src/infrastructure/diff/view/PHUIDiffRevealIconView.php

@@ -0,0 +1,27 @@
+<?php
+
+final class PHUIDiffRevealIconView extends AphrontView {
+
+  public function render() {
+    $icon = id(new PHUIIconView())
+      ->setIconFont('fa-comment')
+      ->addSigil('has-tooltip')
+      ->setMetadata(
+        array(
+          'tip' => pht('Show Hidden Comments'),
+          'align' => 'E',
+          'size' => 275,
+        ));
+
+    return javelin_tag(
+      'a',
+      array(
+        'href' => '#',
+        'class' => 'reveal-inlines',
+        'sigil' => 'reveal-inlines',
+        'mustcapture' => true,
+      ),
+      $icon);
+  }
+
+}

src/infrastructure/diff/view/PHUIDiffTwoUpInlineCommentRowScaffold.php

@@ -68,7 +68,7 @@ final class PHUIDiffTwoUpInlineCommentRowScaffold
       phutil_tag('td', $right_attrs, $right_side),
     );
 
-    return phutil_tag('tr', $this->getRowAttributes(), $cells);
+    return javelin_tag('tr', $this->getRowAttributes(), $cells);
   }
 
 }

webroot/rsrc/css/application/differential/phui-inline-comment.css

@@ -434,3 +434,21 @@
     border-color: {$lightgreyborder};
     color: {$lightgreytext};
 }
+
+
+/* - Hiding Inlines ------------------------------------------------------------
+*/
+
+.reveal-inlines {
+  float: left;
+  margin-left: 4px;
+  color: {$lightbluetext};
+}
+
+.reveal-inlines span.phui-icon-view {
+  color: {$lightbluetext};
+}
+
+.reveal-inlines:hover span.phui-icon-view {
+  color: {$darkbluetext};
+}

webroot/rsrc/js/application/differential/behavior-edit-inline-comments.js

@@ -395,4 +395,87 @@ JX.behavior('differential-edit-inline-comments', function(config) {
       handle_inline_action(data.node, data.op);
     });
 
+  // Respond to the user clicking the "Hide Inline" button on an inline
+  // comment.
+  JX.Stratcom.listen('click', 'hide-inline', function(e) {
+    e.kill();
+
+    var row = e.getNode('inline-row');
+    JX.DOM.hide(row);
+
+    var prev = row.previousSibling;
+    while (prev && JX.Stratcom.hasSigil(prev, 'inline-row')) {
+      prev = prev.previousSibling;
+    }
+
+    if (!prev) {
+      return;
+    }
+
+    var comment = e.getNodeData('differential-inline-comment');
+
+    var slots = [];
+    for (var ii = 0; ii < prev.childNodes.length; ii++) {
+      if (JX.DOM.isType(prev.childNodes[ii], 'th')) {
+        slots.push(prev.childNodes[ii]);
+      }
+    }
+
+    // Select the right-hand side if the comment is on the right.
+    var slot = (comment.on_right && slots[1]) || slots[0];
+
+    var reveal = JX.DOM.scry(slot, 'a', 'reveal-inlines')[0];
+    if (!reveal) {
+      reveal = JX.$N(
+        'a',
+        {
+          className: 'reveal-inlines',
+          sigil: 'reveal-inlines'
+        },
+        JX.$H(config.revealIcon));
+
+      JX.DOM.prependContent(slot, reveal);
+    }
+
+    new JX.Workflow(config.uri, {op: 'hide', ids: comment.id})
+      .setHandler(JX.bag)
+      .start();
+  });
+
+  JX.Stratcom.listen('click', 'reveal-inlines', function(e) {
+    e.kill();
+
+    var row = e.getNode('tag:tr');
+    var next = row.nextSibling;
+
+    var ids = [];
+    var ii;
+
+    // Show any hidden inline comment rows directly below this one.
+    while (next && JX.Stratcom.hasSigil(next, 'inline-row')) {
+      JX.DOM.show(next);
+
+      var comments = JX.DOM.scry(next, 'div', 'differential-inline-comment');
+      for (ii = 0; ii < comments.length; ii++) {
+        var id = JX.Stratcom.getData(comments[ii]).id;
+        if (id) {
+          ids.push(id);
+        }
+      }
+
+      next = next.nextSibling;
+    }
+
+    // Remove any "reveal" icons on the row.
+    var reveals = JX.DOM.scry(row, 'a', 'reveal-inlines');
+    for (ii = 0; ii < reveals.length; ii++) {
+      JX.DOM.remove(reveals[ii]);
+    }
+
+    new JX.Workflow(config.uri, {op: 'show', ids: ids.join(',')})
+      .setHandler(JX.bag)
+      .start();
+  });
+
+
 });