Moving the Cursor

Most of the time, cursor movement in MathFlow Editor works as you would expect, and you don't need to think too hard about it. However, as the cursor moves through your equation, its shape changes to give you extra information about the equation structure. Spending a few minutes learning about the subtleties of cursor movement will have a big payoff in the long run.

MathFlow Editor tries to make cursor movement as natural and intuitive as possible. In general, the left, right, up and down arrows move the cursor to the next valid insertion point in the corresponding direction. Similarly, clicking the mouse anywhere in an equation moves the cursor to the closest valid location to the click.

Behind the scenes, the MathFlow Editor is negotiating a potentially complicated nested structure of MathML templates. Moving the cursor to the right on the screen can involve jumping in and out of MathML structures behind the scenes.

The cursor may occasionally not move exactly as you would expect on account of the nesting of the MathML structure. In these cases, the cursor movement is giving you additional information about the structure of your equation.

To help you follow where the cursor is in the MathML structure of the equation, the MathFlow Editor gives two visual cues. The cursor position is represented by a blinking red vertical bar. However, note that there is a faint gray rectangle as well. This gray rectangle is outlining the equation template containing the cursor location, and is the first cue about the MathML structure near the cursor.

To illustrate, consider stepping through the following equation with the right arrow.

As the cursor moves to the right, note that when it moves into the fraction, the gray rectangle shifts to the fraction, instead of the entire equation.

The second visual cue about the location of the cursor in the nested MathML template structure is the MathML Ancestry panel. As you move the cursor, you can see the nesting of MathML templates, with the innermost template or symbol that the cursor is on at the far right of the Ancestry panel, and the outermost <math> template on the left.

In more complicated situations, one might have several nested rows, whose right edges all line up. When this happens, hitting the right arrow will move the cursor from an inner template to an outer template in the nesting. Although you will see the gray rectangle outlining the parent template and MathML Ancestry panel change, the actual cursor position stays the same.

By spending a few minutes playing with cursor movement and nested templates, you will rapidly get the hang of navigating around in a structured MathML equation.