How to use corner radius options in Chart

In Chart, when the whole chart is selected, the Position and Size dialog has a Slant and Corner Radius page. There is little documentation about this page. I have two main questions:

Everything but the Slant option is grayed out. When are the other options active?

I can see how the slant option works, but it is not clear how the others work. If they can be activated, how are they used? I would imagine that the idea of a control point is to set the center of the circle for the radius, but then why are there two control points?

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I would appreciate any insights.

Short answer: Corner-Radius is not applicable to chart objects.

Corner Radius

Looking at file format: A draw:corner radius attribute is usable with draw:rect, draw:caption, draw:text-box and office:annotation elements. A chart is a draw:object element. Therefore it cannot have a corner radius. Not all options possible in file format are implemented in LibreOffice.

All objects, which are written as draw:rect elements in file format, are those, which are contained in the “Legacy Rectangles” toolbar. There exists rectangles too in the “Basic Shapes” toolbar. That are custom-shapes and do not have a corner-radius attribute. (If you are unsure, whether you have a custom-shape or not: If you can use the “Toggle Extrusion” command, then it as a custom-shape.)

The objects, which are written as draw:caption and draw:text-box in file format are those, which are contained in the “Text” toolbar. From those objects the simple text-box is so often used, that the command (icon T) has been included in other toolbars too. The presentation objects “Title”, “Subtitle” and “Outline” are text-box elements too, and can have corner radius. One exception is the Frame object in Writer. Although it is a text-box in file format, LibreOffice does not allow corner-radius for it.

The left top corner has a handle which you can use to change the radius with the mouse. You need to move the mouse a little bit around to find the active spot. For rectangles you need the point mode; the handle for text boxes is always available. If the radius is larger than half of width or height, you get an elliptical curve.

The office:annotation elements occur as Comment in Writer and Calc. Only the comments in Calc can show corner-radius, but LibreOffice does not offer an UI to set or alter the corner-radius.

Slant

“Slant” is for more objects available, because it is a transformation which is applied to the object after the object is constructed. It is a shearing were the horizontal middle line of the object is fix. The angle in the dialog is the angle from the vertical axis to the transformed vertical line of the object, with positive values result in clockwise angles. Shearing is written to file format as transformation matrix together with rotation, scaling and translation. There exists no mode to get this shearing with the mouse. In this shearing, the line between original point and sheared point is parallel to the middle horizontal line of the object. That is different from dragging the middle point of the frame rectangle of an object in rotation mode.

Control Point

A custom shapes can have handles to alter its outline, e.g. the handle to alter the mouth in the “Smiley” shape. Such handles can be dragged with the mouse. The part “Control Point” of the dialog allows to set the position of the handle as distance to the left-top corner of the frame rectangle (the rectangle with the resize handles) of the shape. “Control Point” means “handle” here. This feature was implemented in version 5.1, see https://wiki.documentfoundation.org/ReleaseNotes/5.1#View.2FEdit_Control_Points. The fact that there are exactly two control points is a compromise in order to be able to implement the feature at all with a reasonable effort.

The fields, which are not needed for a special shape, are disabled. So only the y-value of the first control point is enabled for the “Smiley” shape, because it has only one handle and this is only moveable vertically. Notice, that you enter length values too in case the handle is a polar handle as in case of the “Sector” shape.

Setting the position of a handle via this dialog works for most of the custom-shapes. Of cause those with more than two handles will not work for all handles. Some shapes, which are available in PowerPoint but not in LibreOffice will not work. And this feature only works on custom-shapes. You cannot use it to set the handles in an “Arc” shape of the “Legacy Circle and Ovals” toolbar.

Thank you.

This tab appears when the whole chart is selected (not in edit mode).

I need to explain how the corner radius option works but I can’t see what you are describing if the option is not active. Do you know if it is ever even active for charts?

Your answer made me realize that the title of my post referred to both the corner radius and slant options. However, it is obvious what the slant option does so I have modified the title of the post.

Thank you for revising your explanation and making it clear that the corner radius option does not work with Chart.
In case I or others need this information for Draw, could you please explain a little more about how to use it? Specifically, I still don’t understand why there are two control points.
If you can clarify that, I will change the title again so that the post is not specific to Chart.
I appreciate your helpfulness.

Here is an excerpt from the help (LO 6.2).


Here is the documentation for Calc. From page 105, with the topic “Resizing and moving the chart”.

I hope it helps you. I wish you success!

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Thank you. Unfortunately, the documentation is inadequate and does not answer my questions.