One or two panes

The same application displays as a split view application with two panes on some devices, yet displays as a single pane on other devices. What controls this?

With split views, you open two windows, assigning one to the left pane and one to the right pane of the split view. Not all mobile devices, however, can display multiple panes on the same screen. While the application code is the same, the mobile client displays either one pane (typical for phones) or two panes (typical for tablets).

If the device only allows a single pane to display, the window in the left pane is the first window displayed.

The rules for single-pane or two-pane display differ depending on the mobile platform:

On Android™ devices, the two-pane mode is activated if the width of the screen is more than 900 density-independent pixels (dp). The width of the screen depends on the orientation; you may notice that you have two panes when the tablet is held in landscape mode (width greater than height), yet only one pane when the tablet is held in portrait mode (height greater than width).
Note: A density-independent pixel (dp) is an abstract unit that is based on the physical density of the screen. The unit is relative to a 160 dpi screen, so one dp is one pixel on a 160 dpi screen. The ratio of dp-to-pixel will change with the screen density, but not necessarily in direct proportion.
On iOS devices:
- With the iPad, the two-pane mode is activated, regardless of the orientation of the tablet.
- With the iPhone® or iTouch devices, only a single pane displays.