Hide selection to provide a visual cue about clipboard JS magic in Differential

Summary: Inspired by D2242.

Test Plan:
Select text in left pane.
Select text in right pane.
Select all.

Reviewers: epriestley

Reviewed By: epriestley

CC: aran, Koolvin

Differential Revision: https://secure.phabricator.com/D2249

src/__celerity_resource_map__.php

@@ -533,7 +533,7 @@ celerity_register_resource_map(array(
   ),
   'differential-core-view-css' =>
   array(
-    'uri' => '/res/0bc9223a/rsrc/css/application/differential/core.css',
+    'uri' => '/res/2303c309/rsrc/css/application/differential/core.css',
     'type' => 'css',
     'requires' =>
     array(
@@ -994,6 +994,18 @@ celerity_register_resource_map(array(
     ),
     'disk' => '/rsrc/js/application/differential/behavior-show-more.js',
   ),
+  'javelin-behavior-differential-user-select' =>
+  array(
+    'uri' => '/res/f0e3b555/rsrc/js/application/differential/behavior-user-select.js',
+    'type' => 'js',
+    'requires' =>
+    array(
+      0 => 'javelin-behavior',
+      1 => 'javelin-dom',
+      2 => 'javelin-stratcom',
+    ),
+    'disk' => '/rsrc/js/application/differential/behavior-user-select.js',
+  ),
   'javelin-behavior-diffusion-commit-graph' =>
   array(
     'uri' => '/res/cfe336e8/rsrc/js/application/diffusion/behavior-commit-graph.js',
@@ -2472,7 +2484,7 @@ celerity_register_resource_map(array(
       'uri' => '/res/pkg/0c96375e/core.pkg.js',
       'type' => 'js',
     ),
-    '1138d3d1' =>
+    'a841d960' =>
     array(
       'name' => 'differential.pkg.css',
       'symbols' =>
@@ -2491,7 +2503,7 @@ celerity_register_resource_map(array(
         11 => 'differential-local-commits-view-css',
         12 => 'inline-comment-summary-css',
       ),
-      'uri' => '/res/pkg/1138d3d1/differential.pkg.css',
+      'uri' => '/res/pkg/a841d960/differential.pkg.css',
       'type' => 'css',
     ),
     'e4ddcab5' =>
@@ -2614,7 +2626,7 @@ celerity_register_resource_map(array(
     'aphront-dialog-view-css' => '9c4e265b',
     'aphront-error-view-css' => '9c4e265b',
     'aphront-form-view-css' => '9c4e265b',
-    'aphront-headsup-action-list-view-css' => '1138d3d1',
+    'aphront-headsup-action-list-view-css' => 'a841d960',
     'aphront-headsup-view-css' => '9c4e265b',
     'aphront-list-filter-view-css' => '9c4e265b',
     'aphront-pager-view-css' => '9c4e265b',
@@ -2624,19 +2636,19 @@ celerity_register_resource_map(array(
     'aphront-tokenizer-control-css' => '9c4e265b',
     'aphront-tooltip-css' => '9c4e265b',
     'aphront-typeahead-control-css' => '9c4e265b',
-    'differential-changeset-view-css' => '1138d3d1',
-    'differential-core-view-css' => '1138d3d1',
+    'differential-changeset-view-css' => 'a841d960',
+    'differential-core-view-css' => 'a841d960',
     'differential-inline-comment-editor' => 'e4ddcab5',
-    'differential-local-commits-view-css' => '1138d3d1',
-    'differential-revision-add-comment-css' => '1138d3d1',
-    'differential-revision-comment-css' => '1138d3d1',
-    'differential-revision-comment-list-css' => '1138d3d1',
-    'differential-revision-detail-css' => '1138d3d1',
-    'differential-revision-history-css' => '1138d3d1',
-    'differential-table-of-contents-css' => '1138d3d1',
+    'differential-local-commits-view-css' => 'a841d960',
+    'differential-revision-add-comment-css' => 'a841d960',
+    'differential-revision-comment-css' => 'a841d960',
+    'differential-revision-comment-list-css' => 'a841d960',
+    'differential-revision-detail-css' => 'a841d960',
+    'differential-revision-history-css' => 'a841d960',
+    'differential-table-of-contents-css' => 'a841d960',
     'diffusion-commit-view-css' => 'c8ce2d88',
     'diffusion-icons-css' => 'c8ce2d88',
-    'inline-comment-summary-css' => '1138d3d1',
+    'inline-comment-summary-css' => 'a841d960',
     'javelin-behavior' => '8a5de8a3',
     'javelin-behavior-aphront-basic-tokenizer' => '97f65640',
     'javelin-behavior-aphront-drag-and-drop' => 'e4ddcab5',
@@ -2690,7 +2702,7 @@ celerity_register_resource_map(array(
     'maniphest-task-summary-css' => '7839ae2d',
     'maniphest-transaction-detail-css' => '7839ae2d',
     'phabricator-app-buttons-css' => '9c4e265b',
-    'phabricator-content-source-view-css' => '1138d3d1',
+    'phabricator-content-source-view-css' => 'a841d960',
     'phabricator-core-buttons-css' => '9c4e265b',
     'phabricator-core-css' => '9c4e265b',
     'phabricator-directory-css' => '9c4e265b',
@@ -2701,7 +2713,7 @@ celerity_register_resource_map(array(
     'phabricator-keyboard-shortcut' => '0c96375e',
     'phabricator-keyboard-shortcut-manager' => '0c96375e',
     'phabricator-menu-item' => '0c96375e',
-    'phabricator-object-selector-css' => '1138d3d1',
+    'phabricator-object-selector-css' => 'a841d960',
     'phabricator-paste-file-upload' => '0c96375e',
     'phabricator-prefab' => '0c96375e',
     'phabricator-project-tag-css' => '7839ae2d',

src/applications/differential/controller/revisionview/DifferentialRevisionViewController.php

@@ -324,6 +324,7 @@ final class DifferentialRevisionViewController extends DifferentialController {
       array(
         'haunt' => $pane_id,
       ));
+    Javelin::initBehavior('differential-user-select');
 
     $page_pane = id(new DifferentialPrimaryPaneView())
       ->setLineWidthFromChangesets($changesets)

src/applications/differential/parser/changeset/DifferentialChangesetParser.php

@@ -1579,10 +1579,13 @@ final class DifferentialChangesetParser {
     $props  = $this->renderPropertyChangeHeader($this->changeset);
     $table = null;
     if ($contents) {
-      $table =
-        '<table class="differential-diff remarkup-code PhabricatorMonospaced">'.
-          $contents.
-        '</table>';
+      $table = javelin_render_tag(
+        'table',
+        array(
+          'class' => 'differential-diff remarkup-code PhabricatorMonospaced',
+          'sigil' => 'differential-diff',
+        ),
+        $contents);
     }
 
     if (!$table && !$props) {

webroot/rsrc/css/application/differential/core.css

@@ -27,3 +27,11 @@
   padding-bottom: 8px;
   margin-bottom: 8px;
 }
+
+.differential-unselectable tr td:nth-of-type(1) {
+  -moz-user-select: -moz-none;
+  -khtml-user-select: none;
+  -webkit-user-select: none;
+  -ms-user-select: none;
+  user-select: none;
+}

webroot/rsrc/js/application/differential/behavior-user-select.js

@@ -0,0 +1,32 @@
+/**
+ * @provides javelin-behavior-differential-user-select
+ * @requires javelin-behavior
+ *           javelin-dom
+ *           javelin-stratcom
+ */
+
+JX.behavior('differential-user-select', function() {
+
+  var unselectable;
+
+  function isOnRight(node) {
+    return node.parentNode.firstChild != node.previousSibling;
+  }
+
+  JX.Stratcom.listen(
+    'mousedown',
+    null,
+    function(e) {
+      var key = 'differential-unselectable';
+      if (unselectable) {
+        JX.DOM.alterClass(unselectable, key, false);
+      }
+      var diff = e.getNode('differential-diff');
+      var td = e.getNode('tag:td');
+      if (diff && td && isOnRight(td)) {
+        unselectable = diff;
+        JX.DOM.alterClass(diff, key, true);
+      }
+    });
+
+});