null, which is a promise whose associated
operation is to lock the screen orientation.
- *-primary
- and *-secondary values at will. For example, if
- 90 is associated with landscape-primary and
- 270 with landscape-secondary for one
- document , another one MAY get the opposite relationship.
+
+ + One primary orientation will always be determined by the natural + orientation of the device and this will then determine the secondary + value of its related orientation. +
++ For example a device held in its natural portrait orientation would + have a current orientation of portrait-primary and its + portrait-secondary orientation would be its position when + rotated 180°. +
+
+ The user agent can associate the other *-primary
+ and *-secondary values at will. For example, it can be
+ based on the device preferred angles, the user's preferred
+ orientations or the current orientation when the application starts.
+
+ The screen orientation values table presents the primary and + secondary values that are determined by the device's natural + orientation and the possibilities available to the user agent + for setting the other primary and secondary orientation values. +
+| + Natural Orientation + | ++ Primary Orientation 1 + | ++ Secondary Orientation 1 + | ++ Primary Orientation 2 + | ++ Secondary Orientation 2 + | +
|---|---|---|---|---|
| + Portrait + | +
+ portrait-primary + Angle 0
+ |
+
+ portrait-secondary + Angle 180
+ |
+
+ landscape-primary + User agent to set at either Angle 90 or
+ Angle 270
+ |
+
+ landscape-secondary + Set at the angle not used for landscape-primary + |
+
| + Landscape + | +
+ landscape-primary + Angle 0
+ |
+
+ landscape-secondary + Angle 180
+ |
+
+ portrait-primary + User agent to set at either Angle 90 or
+ Angle 270
+ |
+
+ portrait-secondary + Set at the angle not used for portrait-primary + |
+
+ Once the user agent has set the primary and secondary values + from the options in the screen orientation values table, the + current orientation type and the current orientation + angle relation MUST be kept consistent for any given + document.
- The decision whether the document's current orientation
- type should be set to *-primary or
- *-secondary is up to the user agent. For example,
- it can be based on the device preferred angles, the user's preferred
- orientations or the current orientation when the application starts.
- However, a user agent MUST keep the current orientation
- type and the current orientation angle relation consistent
- for any given document.
-