fltk/FL/Fl_Scroll.H

141 lines
4.9 KiB
C++

//
// "$Id$"
//
// Scroll header file for the Fast Light Tool Kit (FLTK).
//
// Copyright 1998-2008 by Bill Spitzak and others.
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Library General Public
// License as published by the Free Software Foundation; either
// version 2 of the License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// Library General Public License for more details.
//
// You should have received a copy of the GNU Library General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
// USA.
//
// Please report all bugs and problems on the following page:
//
// http://www.fltk.org/str.php
//
/* \file
Fl_Scroll widget . */
#ifndef Fl_Scroll_H
#define Fl_Scroll_H
#include "Fl_Group.H"
#include "Fl_Scrollbar.H"
/**
This container widget lets you maneuver around a set of widgets much
larger than your window. If the child widgets are larger than the size
of this object then scrollbars will appear so that you can scroll over
to them:
<P ALIGN=CENTER>\image html Fl_Scroll.gif </P>
\image latex Fl_Scroll.eps "Fl_Scroll" width=4cm
<P>If all of the child widgets are packed together into a solid
rectangle then you want to set box() to FL_NO_BOX or
one of the _FRAME types. This will result in the best output.
However, if the child widgets are a sparse arrangment you must set
box() to a real _BOX type. This can result in some
blinking during redrawing, but that can be solved by using a
Fl_Double_Window. </P>
By default you can scroll in both directions, and the scrollbars
disappear if the data will fit in the area of the scroll.
<P>Use Fl_Scroll::type() to change this as follows :
<UL>
<LI>0 - No scrollbars </LI>
<LI>Fl_Scroll::HORIZONTAL - Only a horizontal scrollbar. </LI>
<LI>Fl_Scroll::VERTICAL - Only a vertical scrollbar. </LI>
<LI>Fl_Scroll::BOTH - The default is both scrollbars. </LI>
<LI>Fl_Scroll::HORIZONTAL_ALWAYS - Horizontal scrollbar always on, vertical always off. </LI>
<LI>Fl_Scroll::VERTICAL_ALWAYS - Vertical scrollbar always on, horizontal always off. </LI>
<LI>Fl_Scroll::BOTH_ALWAYS - Both always on. </LI>
</UL>
<P> Use <B> scrollbar.align(int) ( see void Fl_Widget::align(Fl_Align) ) :</B>
to change what side the scrollbars are drawn on.<BR>If the
FL_ALIGN_LEFT bit is on, the vertical scrollbar is on the left.
If the FL_ALIGN_TOP bit is on, the horizontal scrollbar is on
the top. Note that only the alignment flags in scrollbar are
considered. The flags in hscrollbar however are ignored.
<P>This widget can also be used to pan around a single child widget
"canvas". This child widget should be of your own class, with a
draw() method that draws the contents. The scrolling is done by
changing the x() and y() of the widget, so this child
must use the x() and y() to position it's drawing.
To speed up drawing it should test fl_push_clip().
<P>Another very useful child is a single
Fl_Pack, which is itself a group that packs it's children
together and changes size to surround them. Filling the Fl_Pack
with Fl_Tabs groups (and then putting
normal widgets inside those) gives you a very powerful scrolling list
of individually-openable panels. </P>
<P>Fluid lets you create these, but you can only lay out objects that
fit inside the Fl_Scroll without scrolling. Be sure to leave
space for the scrollbars, as Fluid won't show these either. </P>
<P><I>You cannot use Fl_Window as a child of this since the
clipping is not conveyed to it when drawn, and it will draw over the
scrollbars and neighboring objects.</I>
*/
class FL_EXPORT Fl_Scroll : public Fl_Group {
int xposition_, yposition_;
int width_, height_;
int oldx, oldy;
static void hscrollbar_cb(Fl_Widget*, void*);
static void scrollbar_cb(Fl_Widget*, void*);
void fix_scrollbar_order();
static void draw_clip(void*,int,int,int,int);
protected:
void bbox(int&,int&,int&,int&);
void draw();
public:
Fl_Scrollbar scrollbar;
Fl_Scrollbar hscrollbar;
void resize(int,int,int,int);
int handle(int);
Fl_Scroll(int X,int Y,int W,int H,const char*l=0);
enum { // values for type()
HORIZONTAL = 1,
VERTICAL = 2,
BOTH = 3,
ALWAYS_ON = 4,
HORIZONTAL_ALWAYS = 5,
VERTICAL_ALWAYS = 6,
BOTH_ALWAYS = 7
};
/** Gets the current horizontal scrolling position. */
int xposition() const {return xposition_;}
/** Gets the current vertical scrolling position. */
int yposition() const {return yposition_;}
void scroll_to(int, int);
void clear();
};
#endif
//
// End of "$Id$".
//