Tabbed Windows with Prism 7 Mac running under MacOS Sierra

A new feature in MacOS Sierra, released Sept. 20 2016, lets you put several files into one window and navigate between them using tabs.  This is a great way to work on multiple files at once, especially on a small screen. Apple calls this feature "Tabbed Windows".

Creating a tabbed window

When you create or open multiple files with Prism Mac, it looks like this. Each project file is in its own window with its own toolbar. 

Until Apple released MacOS Sierra, this was the only way to work with multiple files in Prism Mac. But Sierra lets you put them all into one Window. Drop the Window menu on any of the Prism files, and choose "Merge All Windows". 

Now there is only one Prism Window, with a set of tabs just below the toolbar that let you choose which project file you are working on:

Note that putting multiple files in one tabbed window is simply a convenience to make it a bit easier to work on several files at once. The files are still all distinct, saved in different names. Putting multiple files into one tabbed window does not merge the files. There is no way to save all the files in one file as a batch, or to later open those files with one command.

Working with tabbed windows

• To create a new tab for a new (or existing) file, click the + button to the right of the file selection tabs which will create a new tab and bring up the Welcome dialog so you can choose a file to open or begin to create a new file. 
• There are three ways to move a file into its own window and away from the tabbed window:  Control-click on the tab and choose Move Tab to New Window; grab the tab and drag it away from the joint window; or drop the Window menu and choose Move Tab to New Window.
• A window that contains only one project file usually doesn't show the tab bar. To show it, drop the View menu (in Prism) and choose the first choice "Show Tab Bar". When you have two or more Prism windows showing the tab bar, you can drag tabs from one window to another. 
• Keyboard shortcut: Hold Control and click Tab to move to the next project file in the tabbed window. Hold shift and control and click tab to go to the prior project file. 

Default

When  you already have a Prism window open, what happens when you open another file or create a new file? It depends on a setting in the Dock tab of the system Preference dialog, "Prefer tabs when opening documents". (Note this setting is in the system preferences dialog, not in Prism's preference dialog.) There are three settings.

• Always.  When you open or create a file, it will be added to a new tab on the open Prism window and will not create a new window. 
• In full screen mode only. If you have maximized the Prism window to full screen, opening or creating files will add a new tab to the existing window. If you are not in full screen mode, new and opened files will be placed in new windows. 
• Manually. New files (and newly opened files) always go into new windows unless you use the + button to the right of the last tab to create a new one.