Keyboard navigation

You can select every part of a diagram without touching the mouse. That includes blocks, their edges, paths, the ends of paths, and the labels and badges attached to any of them. Three kinds of key work together:

• Arrow keys move to a neighbour: across the canvas, and along the paths that connect blocks.
• [ and ] move up and down a level: from a container to its contents, and from an edge or path to its attachments.
• Tab moves to the next peer: the next item that shares the same parent.

Moving between blocks and edges

Each block takes two presses to cross. The first press selects the edge you are leaving, and the second carries on to the neighbouring block beyond it. You arrive at a block from the outside, so the whole block is selected, not the edge you came in through.

When several neighbours are equally close, the arrow picks the one furthest to your left as you travel. So with four blocks in a square, pressing each arrow twice in turn walks you round them clockwise.

Levels and attachments

] moves down a level and [ moves back up.

Selected	] selects	[ selects
A block	Its contents, never its attachments	The container around it
An edge	Everything attached to that edge, including the corners at either end	Its block
A path	All of its labels	The container it sits in
The end of a path	The labels at that end	The path
An attachment		The edge it is attached to, or the block for a corner

Escape also climbs one level at a time: from an edge to its block, from the end of a path to the path, and then clears the selection.

Walking along paths

Paths take two presses to cross, the same as blocks. A path stops first on its far end. To walk from one block to the next, you press through the block, its edge, the path, the end of the path, and arrive at the next block.

An edge can have several paths leaving it. The arrow picks the one furthest to your left as you travel. So when two blocks are joined by two paths, walking right takes the upper path and walking back left takes the lower one: you go round the pair clockwise.

An edge with no paths behaves as described above: the arrow carries on to the neighbouring block.

Moving along a path

Once a path is selected, the arrow keys follow the direction the path leaves its start, not the direction it happens to point on screen. Take a path that leaves the right side of a block:

• ← selects its start and → selects its end, even if the path bends upward or downward on the way.
• ↓ and ↑ step to the next or previous path on the same edge, going clockwise round the block.

For a path that leaves a different side of its block, the four arrows turn with it.

With the end of a path selected:

• The arrow pointing back into the path selects the path again.
• The arrow pointing away from the path selects the block at that end. That is the block, not its edge: you arrive at blocks from the outside, the same as when you walk between them.
• The other two arrows step to the neighbouring path ends on the same edge.

The end of a path is selected with a halo round its arrow head and the last stretch of its line. It looks like a slice of the halo of the whole path, in the same way a selected edge looks like a slice of the halo round its block. With the mouse, click the end of a selected path to select it. On a path that is not selected, the first click selects the whole path, just as the first click on the edge of a block selects the block. Dragging the end still reconnects it.

Tab through peers

Tab selects the next item that shares the selection’s parent, and ShiftTab the previous one. Items are ordered as you would read them: top to bottom, then left to right. The order wraps round at the end.

• The peers of a block are the other blocks and paths in the same container.
• The peers of an attachment are the other attachments of the same block or path.
• The peers of an edge are the four edges of its block.
• The peers of a path end are the two ends of the path.

With nothing selected, Tab starts at the first item. Straight after Escape has cleared the selection, Tab moves focus off the canvas instead, so the canvas never traps your keyboard.

While you are editing text, Tab finishes editing and leaves the text selected, ready to Tab onward. Inside a list, Tab still indents the item and ShiftTab outdents it.

Every shortcut is listed on the keyboard shortcuts page.