Convert ReorderDisplays to use table rendering and remove theme function

Related: #1968596: New displays are not ordered correctly. @damiankloip said in IRC that this issue will probably solve that one.

+++ b/core/modules/views/views_ui/lib/Drupal/views_ui/Form/Ajax/ReorderDisplays.phpundefined
@@ -35,57 +35,90 @@ public function buildForm(array $form, array &$form_state) {
+    $form['#title'] = t('Displays Reorder');

This is sort of out of scope, but I was about to file a separate issue for it that will just collide with this: Can we change this title to "Reorder displays" (sentence case)?

So, something's not working yet:
https://www.dropbox.com/sh/sv7ullcn9i7wpxk/Bwkhf5Et-i#f:reorder.mp4

Actually, it appears that #9 also happens in HEAD, if there are no new displays being created. If you save the view with the patch, though, the displays are in the correct order once you go back to edit a second time. So basically there are like four kinds of broken with display ordering currently, and we can solve those other bugs in the other issue.

+++ b/core/modules/views/views_ui/lib/Drupal/views_ui/Form/Ajax/ReorderDisplays.phpundefined
@@ -143,26 +143,29 @@ public function submitForm(array &$form, array &$form_state) {
-      $order[$display] = $position++;
+      $order[$display] = $position;
+      $position++;

Isn't the code doing exactly the same as before? Why bother with adding a new line.

+++ b/core/modules/views_ui/lib/Drupal/views_ui/Form/Ajax/ReorderDisplays.phpundefined
@@ -35,57 +35,90 @@ public function buildForm(array $form, array &$form_state) {
+      '#empty' => t('No displays available.'),

You must be really good, if you manage to have no displays at all :)

+++ b/core/modules/views_ui/lib/Drupal/views_ui/Form/Ajax/ReorderDisplays.phpundefined
@@ -35,57 +35,90 @@ public function buildForm(array $form, array &$form_state) {
+        $form['displays'][$id]['#attributes']['style'] = 'display: none;';

You can use the element-hidden class.

+++ b/core/modules/views/views_ui/lib/Drupal/views_ui/Form/Ajax/ReorderDisplays.phpundefined
@@ -143,26 +143,29 @@ public function submitForm(array &$form, array &$form_state) {
-      $order[$display] = $position++;
+      $order[$display] = $position;
+      $position++;

Isn't the code doing exactly the same as before? Why bother with adding a new line.

I really love to kill all these totally useless theme functions! That's a great patch.

You never know, someone might manage something with no displays, that should not be possible, and should break before that anyway. I think it might as well stay there.

Oh I absolutely agree. It should stay there and is it just because of consistency.

+++ b/core/modules/views_ui/lib/Drupal/views_ui/Form/Ajax/ReorderDisplays.phpundefined
@@ -35,57 +35,91 @@ public function buildForm(array $form, array &$form_state) {
     foreach ($displays as $display) {
...
+      $id = $display['id'];

What about just using foreach ( ... $id => $display)

+++ b/core/modules/views_ui/lib/Drupal/views_ui/Form/Ajax/ReorderDisplays.phpundefined
@@ -35,57 +35,91 @@ public function buildForm(array $form, array &$form_state) {
+          'class' => array(),

Just wondering whether it is necessary to set an empty class here.

I just had a manual try and realized that the remove link is not working. What can we do about it?

Aside from that, do you think we should hide the link for NON-js users? The link will not work for them anyway.

We could hide the link for non js users, as they will just have the checkbox anyway. What do you think, hide the link and make it visible with js? I will take a look at adding that.

Yeah that's what I meant. 'js-show' is the needed css class for that.

Well I think the remove link doesn't work currently before this patch, and neither do any of the remove links actually. So I think that should be another issue.

I had in mind that changing this to a proper build array would maybe solve the loading of the javascript, but well maybe it's just a bug in the ajax system
which will be solved over time.

Manually using the patch works pretty fine, but there are just a few minor things in the code (points etc.).

Removing and reordering works fine, though there is a unrelated problem that the reorder just happens on a save on the actual views page (but this is unrelated for now).

+++ b/core/modules/views_ui/views_ui.moduleundefined
@@ -135,6 +135,12 @@
+    // Reordering displays.
+    'views_ui_reorder_displays_form' => array(
+      'render element' => 'form',
+      'file' => 'views_ui.theme.inc',
+    ),
+
     // On behalf of a plugin
     'views_ui_style_plugin_table' => array(
       'render element' => 'form',
@@ -144,12 +150,6 @@

@@ -144,12 +150,6 @@
       'file' => 'views_ui.theme.inc',
     ),
 
-    // Reordering displays.
-    'views_ui_reorder_displays_form' => array(
-      'render element' => 'form',
-      'file' => 'views_ui.theme.inc',
-    ),
-

The idea was to actually remove the hook_theme entry.

Committed d556b32 and pushed to 8.x. Thanks!