Pie chart — version history

u_pbt_chartpie · Introduced in 5.0

A pie, a doughnut or a half wheel in which each angle is a share of the whole: labels inside or outside, a total in the hole, a legend that hides a slice, and every slice reachable from the keyboard. Introduced in 5.0.

5.0 #

New #

• Slices added with a key, a name and a value (of_add_slice), with a colour of their own or from a palette that has one set for light themes and one for dark themes, and follows a change of theme.
• Each angle is the share of the slice in the total of the slices shown; a negative value has no angle. of_total and the id_percent of a slice read the total and the shares as the chart shows them.
• A hole as a fraction of the radius (id_inner_radius) turns the pie into a doughnut, and a text in the hole (is_center_text) can say #total# and #count#.
• A start angle (ii_start_angle, 0 at the top) and a sweep angle (ii_sweep_angle) draw part of a circle — a half wheel makes a gauge — fitted to the room it takes; slices follow one another clockwise or not (ib_clockwise).
• Data labels (ib_data_labels) say what a template says (is_label_format: #value#, #percent#, #label#, #key#, #total#), inside the slices in a colour readable over them, or outside the wheel, joined to their slice by a line and spread so that none sits on another (is_label_position). A slice too narrow for its label inside drops it.
• The legend goes beside, above or below the wheel (is_legend_location), can give the value and the share of each slice (ib_legend_values), and a click on an entry hides its slice: the others share the wheel again and ue_slice_toggled says which one. ib_visible hides a slice from the code.
• A panel names the slice under the pointer with its value and its share (ib_value_tooltip), and the slice slides out (id_hover_push_out); id_push_out pushes a slice out for good.
• ue_slice_clicked gives the key and the value of a clicked slice, ue_slice_rclicked the key of a right-clicked one; ue_slice_hovered reports the slice under the pointer to an application that asks for it (ib_track_hover).
• New values for several slices in one call (of_set_values) slide every slice to its new angle together; of_get_values reads them back.
• The wheel arrives animated, each slice opening its angle, with the duration, the curve and the delay between slices of your choice (ib_animated, ii_anim_duration, is_anim_easing, ii_anim_delay); a workstation set to reduce motion is followed.
• Keyboard: Tab reaches the chart, the arrows, Home and End walk the slices, Enter or Space raises ue_slice_clicked, the Menu key or Shift+F10 ue_slice_rclicked; the slice reached is outlined, pushed out and named to screen readers.
• Number format of the labels, the legend, the panel and the centre text (of_set_value_format, of_clear_value_format), with the separators of the display language.
• An empty wheel is drawn when there is nothing to share. The component reports its ideal height on demand (ib_auto_height), greys out and leaves the Tab order when disabled (ib_enabled).
• An add never replaces a slice: a key already held, empty or holding / or | is refused with -5, as is a removal of an unknown key; a removed slice takes its handle with it.
• Right-to-left applications are followed for the legend; the wheel keeps its drawing direction.