Tabs and panes

Several documents in one window, and any of them side by side.

Tabs

Each open document is a tab. Clicking a tab brings that document forward. Clicking in a document's page area does the same. This matters once there is more than one pane: the lists, the window title and the status line all follow whichever document you are working in.

⌘W closes the tab in front, not the window. A tab with unsaved changes asks before it closes. Declining the save closes that tab and leaves the rest of the window alone.

If a snapshot window is open, ⌘W closes it instead, even if you just clicked in the document's window. The first ⌘W closes the snapshot; the document stays open.

Putting a document beside another

Drag its tab to an edge of the window. The left or right edge puts the two documents side by side. The top or bottom edge stacks them. Either way you end up with two panes. The drop zone reaches 90 points in from the edge, so you do not have to aim precisely.

There is no tab strip to drag until a second document is open. Once you have two panes, if a document is alone in its pane, dragging it to the side it is already on does nothing. Your place in the document is kept.

Opening a document and arranging a window are two different things. You open documents however you like. Then you put the ones you want side by side by dragging their tabs. There is no command that opens a document beside another.

Which pane you are in

The tab strip of the pane you are working in is drawn differently from the others. This lets you see at a glance which document a command will act on. Marking, blacking out, signing and measuring all act on the document being worked in.

The tool in hand

The picker on the tool bar says what the next drag will draw. It does not follow the tab in front, unlike everything else described on this page. Arm the highlighter, turn to another document, and you are still holding the highlighter. Closing the window does not leave it armed over whatever opens next.

The picker, the column of tools down the left edge and the number keys all control the same choice, so they move together. Each tool's number is written into its tip.

A fresh window holds text selection rather than the pointer, because a reader opening a document reaches for the words first. Arming the highlighter with words already selected highlights them at once.

Both panes get the armed tool the moment it changes. Moving the pointer from one half of a split to the other never changes what a drag will do. Arming a tool also puts that tool's kind back on the marks filter; see The Marks list.

A document read beside another

A document opened into an existing window is carried there. Reading it, searching it, marking it, editing its history, bookmarks and snapshots, and following its links all work. The acts that rewrite the file itself or its page boxes, such as cropping, attaching a file, recording, retyping a page or recognising a region, wait until it has a window of its own. Each one says so, rather than silently doing nothing: