Adds tests for buttons hooks

Tests folowing:
 * `register_page_listing_buttons`
 * `register_page_listing_more_buttons`
 * Custom hook produced by non-default `ButtonWithDropdownFromHook` instance

organised indicator color state variables into main variables.scss file

wagtail/wagtailadmin/static_src/wagtailadmin/scss/_variables.scss

@@ -65,6 +65,12 @@ $color-link-hover: $color-teal-dark;
 $color-text-base: $color-grey-2;
 $color-text-input: $color-grey-1;
 
+// Color states
+$color-state-live: #59b524;
+$color-state-draft: #808080;
+$color-state-absent: #ff8f11;
+$color-state-live-draft: #43b1b0;
+
 // Fonts
 $font-sans: Open Sans, Arial, sans-serif;
 $font-serif: Roboto Slab, Georgia, serif;
@@ -72,3 +78,6 @@ $font-serif: Roboto Slab, Georgia, serif;
 // misc sizing
 $thumbnail-width: 130px;
 $menu-width: 180px;
+
+
+

wagtail/wagtailadmin/static_src/wagtailadmin/scss/components/_indicator.scss

@@ -24,10 +24,6 @@ $c-indicator-margin: .25rem;
 // States
 // =============================================================================
 
-$color-state-live: #59b524;
-$color-state-draft: #808080;
-$color-state-absent: #ff8f11;
-$color-state-live-draft: #43b1b0;
 
 .is-absent .c-indicator {
     background: $color-state-absent;

wagtail/wagtailadmin/tests/test_buttons_hooks.py

@@ -0,0 +1,83 @@
+from django.core.urlresolvers import reverse
+from django.test import TestCase
+
+from wagtail.tests.utils import WagtailTestUtils
+from wagtail.wagtailadmin import widgets as wagtailadmin_widgets
+from wagtail.wagtailcore import hooks
+from wagtail.wagtailcore.models import Page
+
+
+class TestButtonsHooks(TestCase, WagtailTestUtils):
+    def setUp(self):
+        self.root_page = Page.objects.get(id=2)
+        self.login()
+
+    def test_register_page_listing_buttons(self):
+        @hooks.register('register_page_listing_buttons')
+        def page_listing_buttons(page, page_perms, is_parent=False):
+            yield wagtailadmin_widgets.PageListingButton(
+                'Another useless page listing button',
+                '/custom-url',
+                priority=10
+            )
+
+        response = self.client.get(
+            reverse('wagtailadmin_explore', args=(self.root_page.id, ))
+        )
+
+        self.assertEqual(response.status_code, 200)
+        self.assertTemplateUsed(response, 'wagtailadmin/pages/listing/_button_with_dropdown.html')
+        self.assertTemplateUsed(response, 'wagtailadmin/pages/listing/_buttons.html')
+
+        self.assertContains(response, 'Another useless page listing button')
+
+    def test_register_page_listing_more_buttons(self):
+        @hooks.register('register_page_listing_more_buttons')
+        def page_listing_more_buttons(page, page_perms, is_parent=False):
+            yield wagtailadmin_widgets.Button(
+                'Another useless button in default "More" dropdown',
+                '/custom-url',
+                priority=10
+            )
+
+        response = self.client.get(
+            reverse('wagtailadmin_explore', args=(self.root_page.id, ))
+        )
+
+        self.assertEqual(response.status_code, 200)
+        self.assertTemplateUsed(response, 'wagtailadmin/pages/listing/_button_with_dropdown.html')
+        self.assertTemplateUsed(response, 'wagtailadmin/pages/listing/_buttons.html')
+
+        self.assertContains(response, 'Another useless button in default "More" dropdown')
+
+    def test_custom_button_with_dropdown(self):
+        @hooks.register('register_page_listing_buttons')
+        def page_custom_listing_buttons(page, page_perms, is_parent=False):
+            yield wagtailadmin_widgets.ButtonWithDropdownFromHook(
+                'One more more button',
+                hook_name='register_page_listing_one_more_more_buttons',
+                page=page,
+                page_perms=page_perms,
+                is_parent=is_parent,
+                attrs={'target': '_blank'},
+                priority=50
+            )
+
+        @hooks.register('register_page_listing_one_more_more_buttons')
+        def page_custom_listing_more_buttons(page, page_perms, is_parent=False):
+            yield wagtailadmin_widgets.Button(
+                'Another useless dropdown button in "One more more button" dropdown',
+                '/custom-url',
+                priority=10
+            )
+
+        response = self.client.get(
+            reverse('wagtailadmin_explore', args=(self.root_page.id, ))
+        )
+
+        self.assertEqual(response.status_code, 200)
+        self.assertTemplateUsed(response, 'wagtailadmin/pages/listing/_button_with_dropdown.html')
+        self.assertTemplateUsed(response, 'wagtailadmin/pages/listing/_buttons.html')
+
+        self.assertContains(response, 'One more more button')
+        self.assertContains(response, 'Another useless dropdown button in "One more more button" dropdown')