Guidelines for multiple windows
Support for multiple windows enables your users to quickly switch back and forth between app windows. With multiple windows, users can compare content, or view a specific piece of content.
An example of an app that uses multiple windows is the Mail app. A user can view messages in the main app window or open a new window for the message. A user might want to compose a new message, but use the main windows at the same time to search for other messages. Having two windows for the mail app makes this possible.
In an app that supports multiple windows, each window behaves as if it was its own app. The user can resize each window, dismiss each window from the screen independently, and view each window separately in the list of recently used apps. Charms interact separately with each of the windows. When the user clicks the app's tile on the Start screen, the most recently used window of the app appears.
When you design your app, you decide if it makes sense to support multiple windows and what content you want to show in each window. For example, you can choose to have one main window and other secondary windows that have a specific, limited set of functionality, or you can choose to design each new window as a copy of the original app window.
You can specify the title of the secondary window, which is displayed when the user switches between apps.
You decide where new windows open on the screen, relative to the original app window. A new window can be placed in one of the following locations:
- Next to the original window, sharing the screen space.
- In place of the main window.
- Not on the screen at all.
Once the secondary window is initially displayed, the user controls the placement and size of the window.
Follow these guidelines when you design an app that supports multiple windows:
- Provide a way for the user to navigate from a secondary window back to the main window.
- Provide a clear action for the user to take to open a new window. For example, add a button to the app bar for opening a new window.
- Make sure the title of the new window reflects the contents of that window. The user should be able to differentiate between the windows of an app based on the title. For example, in the list of recently used apps on the left edge of the screen, the title of a draft message and the title of the main Mail window are different.
- Subscribe to the consolidated event and when the event fires, close the window's contents. The consolidated event occurs when the window is removed from the list of recently used apps or if the user executes a close gesture on it.
- If the new window replaces the original app window, provide custom animation when the windows switch.
- Do not automatically open a new window when a user navigates to a different part of the app. The user should initiate opening a new window.
- Enable new windows in an app for scenarios that enhance productivity and enable multitasking. Do not require the user to open a new window to complete the main functionality of the app. Similarly, design the new window so that the user can accomplish a task entirely within the window.