on-print-major-label

Arguments: chart-axis

Returns the value of the on-print-major-label property of a chart-axis. The value may be set at creation time by passing the on-print-major-label initarg, or any time later by calling (setf on-print-major-label).

A function that returns a label for a major tic position of a chart-axis in a chart-widget.

The value of this property should be a function or a function name, or else nil to default to princ-to-string. The function should take a chart value as a single argument and return a string to display for that value. The default value is princ-to-string.

For a value-axis, the argument to the function will be a real number between the range-bottom and range-top of the axis (inclusive).

For an item-axis, the argument will be a chart item ID. A chart item ID may be any arbitrary value that has been passed as the item-id argument to set-chart-value or returned from a chart-value-returner function when its value-type argument is :id. If no such explicit ID has been provided for a particular chart item, then the chart item ID defaults to the zero-based integer index of the chart item.

The returned string may contain embedded newline characters to wrap labels onto multiple lines. The widget will leave enough space for the multiple lines of text. For an item-axis, the printed string will be wrapped at all spaces automatically if the major-label-wrapping property is true.

This property is used only when the draw-major-labels property of the chart-axis is true. See also major-label-frequency, on-print-minor-label, and on-print-chart-object.

See chart-widget and also cg-chart-widget.htm.

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This page was not revised from the 10.0 page.
Created 2019.8.20.