Some controls use lateral movement to communicate their meaning. For example, a progress indicator or slider can move through values in a range, next or previous and forward or back buttons enable navigation, and a toggle or switch can indicate its state by revealing the accent color on one side or the other. In general, controls that use lateral movement to communicate need to flip to match the current context, unless the control refers to a specific direction like left or East.
Flip controls that show progress from one value to another. Because people tend to view forward progress as moving in the same direction as the language they read, it makes sense to flip controls like sliders and progress indicators in the right-to-left (RTL) context. When you do this, also be sure to reverse the positions of the accompanying glyphs or images that depict the beginning and ending values of the control.
Flip controls that help people navigate or access items in a fixed order. For example, in the RTL context, a back button must point to the right so the flow of screens matches the reading order of the RTL language. Similarly, next or previous buttons that let people access items in an ordered list need to flip in the RTL context to match the reading order.
Preserve the direction of a control that refers to an actual direction or points to an onscreen area. For example, if you provide a control that means “to the right,” it must always point right, regardless of the current context.
Visually balance adjacent Latin and right-to-left scripts when necessary. In buttons, labels, and titles, Arabic or Hebrew text can appear too small when it’s next to uppercased Latin text, because Arabic and Hebrew don’t include uppercase letters. To visually balance Arabic or Hebrew text with Latin text that uses all capitals, it often works well to increase the RTL font size by about 2 points.