Merge pull request #4735 from matrix-org/travis/room-list/breadcrumbs

Reimplement breadcrumbs for new room list

res/css/_components.scss

@@ -179,6 +179,7 @@
 @import "./views/rooms/_PresenceLabel.scss";
 @import "./views/rooms/_ReplyPreview.scss";
 @import "./views/rooms/_RoomBreadcrumbs.scss";
+@import "./views/rooms/_RoomBreadcrumbs2.scss";
 @import "./views/rooms/_RoomDropTarget.scss";
 @import "./views/rooms/_RoomHeader.scss";
 @import "./views/rooms/_RoomList.scss";

res/css/structures/_LeftPanel2.scss

@@ -81,9 +81,9 @@ $roomListMinimizedWidth: 50px;
             }
 
             .mx_LeftPanel2_breadcrumbsContainer {
-                // TODO: Improve CSS for breadcrumbs (currently shoved into the view rather than placed)
                 width: 100%;
                 overflow: hidden;
+                margin-top: 8px;
             }
         }
 

res/css/views/rooms/_RoomBreadcrumbs2.scss

@@ -0,0 +1,51 @@
+/*
+Copyright 2020 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+.mx_RoomBreadcrumbs2 {
+    width: 100%;
+
+    // Create a flexbox for the crumbs
+    display: flex;
+    flex-direction: row;
+    align-items: flex-start;
+
+    .mx_RoomBreadcrumbs2_crumb {
+        margin-right: 8px;
+        width: 32px;
+    }
+
+    // These classes come from the CSSTransition component. There's many more classes we
+    // could care about, but this is all we worried about for now. The animation works by
+    // first triggering the enter state with the newest breadcrumb off screen (-40px) then
+    // sliding it into view.
+    &.mx_RoomBreadcrumbs2-enter {
+        margin-left: -40px; // 32px for the avatar, 8px for the margin
+    }
+    &.mx_RoomBreadcrumbs2-enter-active {
+        margin-left: 0;
+
+        // Timing function is as-requested by design.
+        // NOTE: The transition time MUST match the value passed to CSSTransition!
+        transition: margin-left 640ms cubic-bezier(0.66, 0.02, 0.36, 1);
+    }
+
+    .mx_RoomBreadcrumbs2_placeholder {
+        font-weight: 600;
+        font-size: $font-14px;
+        line-height: 32px; // specifically to match the height this is not scaled
+        height: 32px;
+    }
+}