text_cursor.md
In rswipl: Embed 'SWI'-'Prolog'

class text_cursor {#class-text_cursor}

A text_cursor is used to visualise the editor <-caret in an editor object. Class text_cursor is closely linked to class editor and not meant to be used outside the context of editors.

The only interesting behaviour to the application programmer is:

| ->style | Change the `look` of the caret |
| ->image | Create custom caret.           |

Bugs:

The behaviour of this class is not complete. It performs satisfactory in the context of class editor, but is not very generic.

text_cursor<-active: bool Indicate whether or not typing will affect this caret. The visual feedback depends on the <-style.
text_cursor<-hot_spot: point* When <->style is image; this point describes how the image object is positioned relative to the character.
text_cursor<-image: image* When <->style is image; this is the image object.
text_cursor<-style: {arrow,image,block,open_look} Style of the text_cursor. Values are:
- arrow A small triangle with a vertical line. Normally used with proportional fonts.
- open_look Triangle when the cursor is ->active, grey diamond otherwise. Used for OpenLook compatibility.
- block Static inverting block, Normally used with fixed-width fonts on monochrome screens.
- bitmap Arbitrary pattern.
The default style used by an editor is determined by the font associated with the editor. See text_cursor ->font.

text_cursor->font: font Sets the ->style according to the font. If the font has font<-fixed_width: @on font, it will invoke ->style using font.fixed_font_style. Otherwise it will use font.proportional_font_style.
text_cursor->image: image* @see text_cursor->style
text_cursor->initialise: for=[font] Create a text_cursor object from the specified font object. Class text_cursor is currently only used by class editor. See also ->font and editor <-text_cursor.
text_cursor->set: x=int, y=int, width=int, height=int, baseline=int Specify all dimension parameters of the text_cursor. This method is used by class editor to position the caret. The x, y, width and height parameters describe the character-box. baseline is the depth of the baseline of the current font.
text_cursor->style: {arrow,image,block,open_look} @see text_cursor->image