Merge branch 'ux-guide-animation' into 'master'

UX Guide - add initial animation guidance

Adding guidance to our UX Guide around animation. This is to help us implement #24831 and add polished, consistent animation throughout GitLab.

See merge request !7780

doc/development/ux_guide/animation.md

+# Animation
+
+Motion is a tool to help convey important relationships, changes or transitions between elements. It should be used sparingly and intentionally, highlighting the right elements at the right moment.
+
+## Timings
+
+The longer distance an object travel, the timing should be longer for the animation. However, when in doubt, we should avoid large, full screen animations.
+
+Subtle animations, or objects leaving the screen should take **100-200 milliseconds**. Objects entering the screen, or motion we want to use to direct user attention can take between **200-400 milliseconds**. We should avoid animations of longer than 400 milliseconds as they will make the experience appear sluggish. If a specific animation feels like it will need more than 400 milliseconds, revisit the animation to see if there is a simpler, easier, shorter animation to implement.
+
+## Easing
+
+Easing specifies the rate of change of a parameter over time (see [easings.net](http://easings.net/)). Adding an easing curve will make the motion feel more natural. Being consistent with the easing curves will make the whole experience feel more cohesive and connected.
+
+* When an object is entering the screen, or transforming the scale, position, or shape, use the **easeOutQuint** curve (`cubic-bezier(0.23, 1, 0.32, 1)`)
+* When an object is leaving the screen, or transforming the opacity or color, no easing curve is needed. It shouldn't _slow down_ as it is exiting the screen, as that draws attention on the leaving object, where we don't want it. Adding easing to opacity and color transitions will make the motion appear less smooth. Therefore, for these cases, motion should just be **linear**.
+
+## Types of animations
+
+### Hover
+
+Interactive elements (links, buttons, etc.) should have a hover state. A subtle animation for this transition adds a polished feel. We should target a `200ms linear` transition for a color hover effect.
+
+View the [interactive example](http://codepen.io/awhildy/full/GNyEvM/) here.
+
+![Hover animation](img/animation-hover.gif)
+
+### Dropdowns
+
+The dropdown menu should feel like it is appearing from the triggering element. Combining a position shift `400ms cubic-bezier(0.23, 1, 0.32, 1)` with a opacity animation `200ms linear` on the second half of the motion achieves this affect.
+
+View the [interactive example](http://codepen.io/awhildy/full/jVLJpb/) here.
+
+![Dropdown animation](img/animation-dropdown.gif)
+
+### Quick update
+
+When information is updating in place, a quick, subtle animation is needed. The previous content should cut out, and the new content should have a quick, `200ms linear` fade in.
+
+![Quick update animation](img/animation-quickupdate.gif)
+
+> TODO: Add guidance for other kinds of animation 
\ No newline at end of file

doc/development/ux_guide/basics.md

@@ -5,8 +5,6 @@
 * [Typography](#typography)
 * [Icons](#icons)
 * [Color](#color)
-* [Motion](#motion)
-* [Voice and tone](#voice-and-tone)
 
 ---
 
@@ -61,16 +59,3 @@ GitLab uses Font Awesome icons throughout our interface.
 
 > TODO: Establish a perspective for color in terms of our personality and rationalize with Marketing usage.
 
----
-
-## Motion
-
-Motion is a tool to help convey important relationships, changes or transitions between elements. It should be used sparingly and intentionally, highlighting the right elements at the right moment.
-
-> TODO: Determine a more concrete perspective on motion, create consistent easing/timing curves to follow.
-
----
-
-## Voice and tone
-
-The copy for GitLab is clear and direct. We strike a clear balance between professional and friendly. We can empathesize with users (such as celebrating completing all Todos), and remain respectful of the importance of the work. We are that trusted, friendly coworker that is helpful and understanding.

doc/development/ux_guide/copy.md

 # Copy
 
+The copy for GitLab is clear and direct. We strike a clear balance between professional and friendly. We can empathesize with users (such as celebrating completing all Todos), and remain respectful of the importance of the work. We are that trusted, friendly coworker that is helpful and understanding.
+
 The copy and messaging is a core part of the experience of GitLab and the conversation with our users. Follow the below conventions throughout GitLab. 
 
 >**Note:**

doc/development/ux_guide/index.md

@@ -12,7 +12,17 @@ These guiding principles set a solid foundation for our design system, and shoul
 ---
 
 ### [Basics](basics.md)
-The basic ingredients of our experience establish our personality and feel. This section includes details about typography, color, and motion.
+The basic ingredients of our experience establish our personality and feel. This section includes details about typography, iconography, and color.
+
+---
+
+### [Animation](animation.md)
+Guidance on the timing, curving and motion for GitLab.
+
+---
+
+### [Copy](copy.md)
+Conventions on text and messaging within labels, buttons, and other components.
 
 ---
 
@@ -26,11 +36,6 @@ The GitLab experience is broken apart into several surfaces. Each of these surfa
 
 ---
 
-### [Copy](copy.md)
-Conventions on text and messaging within labels, buttons, and other components.
-
----
-
 ### [Features](features.md)
 The previous building blocks are combined into complete features in the GitLab UX. Examples include our navigation, filters, search results, and empty states.