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Diffstat (limited to 'documentation/Fl.html')
| -rw-r--r-- | documentation/Fl.html | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/documentation/Fl.html b/documentation/Fl.html index a20e913d4..701e9c314 100644 --- a/documentation/Fl.html +++ b/documentation/Fl.html @@ -424,19 +424,43 @@ handle()</tt>). <H4><A NAME="Fl.box_dh">int box_dh(Fl_Boxtype);</A></H4> <P>Returns the height offset for the given boxtype. +See <tt><a href="#Fl.box_dy">box_dy</a></tt>. <H4><A NAME="Fl.box_dw">int box_dw(Fl_Boxtype);</A></H4> <P>Returns the width offset for the given boxtype. +See <tt><a href="#Fl.box_dy">box_dy</a></tt>. <H4><A NAME="Fl.box_dx">int box_dx(Fl_Boxtype);</A></H4> <P>Returns the X offset for the given boxtype. +See <tt><a href="#Fl.box_dy">box_dy</a></tt>. <H4><A NAME="Fl.box_dy">int box_dy(Fl_Boxtype);</A></H4> <P>Returns the Y offset for the given boxtype. +<P>These functions return the offset values necessary for a given +boxtype, useful for computing the area inside a box's borders, to +prevent overdrawing the borders. + +<P>For instance, in the case of a boxtype like <tt>FL_DOWN_BOX</tt> +where the border width might be 2 pixels all around, the above +functions would return 2, 2, 4, and 4 for <tt>box_dx</tt>, +<tt>box_dy</tt>, <tt>box_dw</tt>, and <tt>box_dh</tt> +respectively. + +<P>An example to compute the area inside a widget's box(): +<pre> + int X = yourwidget->x() + Fl::box_dx(yourwidget->box()); + int Y = yourwidget->y() + Fl::box_dy(yourwidget->box()); + int W = yourwidget->w() - Fl::box_dw(yourwidget->box()); + int H = yourwidget->h() - Fl::box_dh(yourwidget->box()); +</pre> +<P>These functions are mainly useful in the <tt>draw()</tt> code +for deriving custom widgets, where one wants to avoid drawing +over the widget's own border <tt>box()</tt>. + <H4><A NAME="Fl.check">int check();</A></H4> <P>Same as <tt>Fl::wait(0)</tt>. Calling this during a big calculation |