Chart Interactions
A dump of Alan's gist notes for the moment.
* Data entry panel * Hover or focus over a legend row highlights the corresponding chart and legend elements
 * Labels * Must have content; will default to placeholder content (Section 1, Section 2, etc) if content is completely cleared * Begin with placeholder content (Section 1, Section 2, etc) * Editing a row's label updates the corresponding Legend labeling, but only if a Value has already been entered * Values * Validates that any entered Value is a number (integer or float) and is greater than or equal to 0 * Display a warning and does not update chart preview if entry is invalid * Filling in a valid value and moving focus off the entry box updates the chart and legend (adding or updating) * Clearing a value and moving focus off the entry box updates the chart and legend to remove the corresponding chart and legend elements * Focus on label or value fields
* If fields are empty, screen readers read for labels "section 1, enter the label", for values: "section 1, enter the value"
* If fields are not empty, screen readers read for labels: "user label", for values: "user label, the calculated percentage is 8"
* Chart preview panel * When focus moves to the chart preview panel, a screen reader user should hear an overall description of the current chart * When focus on the pie shape, highlight the round cicle
* Legend elements are focusable and navigable via the arrow keys * Title and Description * Begin with placeholder content * Inline edited * No undo * Legend * Focus over a legend row highlights the corresponding chart and data entry elements * Label, value and percentage should be read by screen reader for each row (accessible data table) * Total should be focusable as well * Navigation via arrow keys * Chart * Hover or focus over a chart element (pie slice) highlights the corresponding legend and data entry elements