diff options
Diffstat (limited to 'documentation/src')
| -rw-r--r-- | documentation/src/drawing.dox | 21 |
1 files changed, 16 insertions, 5 deletions
diff --git a/documentation/src/drawing.dox b/documentation/src/drawing.dox index c523bd4eb..b36bd3c6a 100644 --- a/documentation/src/drawing.dox +++ b/documentation/src/drawing.dox @@ -659,19 +659,21 @@ white space in the string, kerning, etc. \par If the incoming \p w is non-zero it will wrap to that width. \par +This will probably give unexpected values unless you have called +\ref drawing_fl_font "fl_font()" explicitly in your own code. Refer to the full documentation for fl_measure() for details on usage and how to avoid common pitfalls. \see fl_text_extents() -- measure the 'inked' area of a string \see fl_width() -- measure the pixel width of a string or single character -\see fl_height() -- measure the pixel height of the current font -\see fl_descent() -- the height of the descender for the current font +\see fl_height() -- measure the pixel height of the \ref drawing_fl_font "current font" +\see fl_descent() -- the height of the descender for the \ref drawing_fl_font "current font" int fl_height() \par -Recommended minimum line spacing for the current font. You -can also just use the value of \p size passed to +Recommended minimum line spacing for the \ref drawing_fl_font "current font". +You can also just use the value of \p size passed to \ref drawing_fl_font "fl_font()". \see fl_text_extents(), fl_measure(), fl_width(), fl_descent() @@ -688,7 +690,7 @@ double fl_width(unsigned int unicode_char) \par Return the pixel width of a nul-terminated string, a sequence of \p n -characters, or a single character in the current font. +characters, or a single character in the \ref drawing_fl_font "current font". \see fl_measure(), fl_text_extents(), fl_height(), fl_descent() @@ -733,6 +735,15 @@ these, and FL_SYMBOL and FL_ZAPF_DINGBATS. Faces greater than 255 cannot be used in Fl_Widget labels, since Fl_Widget stores the index as a byte. +One important thing to note about 'current font' is that there +are so many paths through the GUI event handling code as widgets +are partially or completely hidden, exposed and then re-drawn +and therefore you can not guarantee that 'current font' contains +the same value that you set on the other side of the event loop. +Your value may have been superseded when a widget was redrawn. +You are strongly advised to set the font explicitly before you +draw any text or query the width and height of text strings, etc. + \anchor drawing_fl_font void fl_font(int face, int size) |