fltk/src/Fl_Widget.cxx

//
// "$Id"
//
// Base widget class for the Fast Light Tool Kit (FLTK).
//
// Copyright 1998 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 to "fltk-bugs@easysw.com".
//

#include <FL/Fl.H>
#include <FL/Fl_Widget.H>
#include <FL/Fl_Group.H>

////////////////////////////////////////////////////////////////
// for compatability with Forms, all widgets without callbacks are
// inserted into a "queue" when they are activated, and the forms
// compatability interaction functions (fl_do_events, etc) will
// read one widget at a time from this queue and return it:

const int QUEUE_SIZE = 20;

static Fl_Widget *obj_queue[QUEUE_SIZE];
static int obj_head, obj_tail;

void Fl_Widget::default_callback(Fl_Widget *o, void * /*v*/) {
#if 0
  // This is necessary for strict forms compatability but is confusing.
  // Use the parent's callback if this widget does not have one.
  for (Fl_Widget *p = o->parent(); p; p = p->parent())
    if (p->callback() != default_callback) {
      p->do_callback(o,v);
      return;
    }
#endif
  obj_queue[obj_head++] = o;
  if (obj_head >= QUEUE_SIZE) obj_head = 0;
  if (obj_head == obj_tail) {
    obj_tail++;
    if (obj_tail >= QUEUE_SIZE) obj_tail = 0;
  }
}

Fl_Widget *Fl::readqueue() {
  if (obj_tail==obj_head) return 0;
  Fl_Widget *o = obj_queue[obj_tail++];
  if (obj_tail >= QUEUE_SIZE) obj_tail = 0;
  return o;
}
    
////////////////////////////////////////////////////////////////

int Fl_Widget::handle(int) {return 0;}

Fl_Widget::Fl_Widget(int X, int Y, int W, int H, const char* L) {

  x_ = X; y_ = Y; w_ = W; h_ = H;

  label_.value	= L;
  label_.type	= FL_NORMAL_LABEL;
  label_.font	= FL_HELVETICA;
  label_.size	= FL_NORMAL_SIZE;
  label_.color	= FL_BLACK;
  callback_	= default_callback;
  user_data_ 	= 0;
  type_		= 0;
  flags_	= 0;
  damage_	= 0;
  box_		= FL_NO_BOX;
  color_	= FL_GRAY;
  color2_	= FL_GRAY;
  align_	= FL_ALIGN_CENTER;
  when_		= FL_WHEN_RELEASE;

  parent_ = 0;
  if (Fl_Group::current()) Fl_Group::current()->add(this);
}

void Fl_Widget::resize(int X, int Y, int W, int H) {
  x_ = X; y_ = Y; w_ = W; h_ = H;
}

// this is useful for parent widgets to call to resize children:
int Fl_Widget::damage_resize(int X, int Y, int W, int H) {
  if (x() == X && y() == Y && w() == W && h() == H) return 0;
  resize(X, Y, W, H);
  redraw();
  return 1;
}

int Fl_Widget::take_focus() {
  if (!takesevents()) return 0;
  if (!handle(FL_FOCUS)) return 0; // see if it wants it
  if (contains(Fl::focus())) return 1; // it called Fl::focus for us
  Fl::focus(this);
  return 1;
}

extern void fl_throw_focus(Fl_Widget*); // in Fl_x.C

// Destruction does not remove from any parent group!  And groups when
// destroyed destroy all their children.  This is convienent and fast.
// However, it is only legal to destroy a "root" such as an Fl_Window,
// and automatic destructors may be called.
Fl_Widget::~Fl_Widget() {
  parent_ = 0; // kludge to prevent ~Fl_Group from destroying again
  fl_throw_focus(this);
}

// redraw this, plus redraw opaque object if there is an outside label
static void redraw_label(Fl_Widget* w) {
  w->redraw();
  if (w->label() && (w->align()&15) && !(w->align() & FL_ALIGN_INSIDE)) {
    for (Fl_Widget *p = w->parent(); p; p = p->parent())
      if (p->box() || !p->parent()) {p->redraw(); break;}
  }
}

void Fl_Widget::activate() {
  if (active()) return;
  clear_flag(INACTIVE);
  handle(FL_ACTIVATE);
  if (inside(Fl::focus())) Fl::focus()->take_focus();
  redraw_label(this);
}

void Fl_Widget::deactivate() {
  if (!active()) return;
  set_flag(INACTIVE);
  handle(FL_DEACTIVATE);
  fl_throw_focus(this);
  redraw_label(this);
}

int Fl_Widget::active_r() const {
  for (const Fl_Widget* o = this; o; o = o->parent())
    if (!o->active()) return 0;
  return 1;
}

void Fl_Widget::show() {
  if (visible()) return;
  clear_flag(INVISIBLE);
  handle(FL_SHOW);
  if (inside(Fl::focus())) Fl::focus()->take_focus();
  redraw_label(this);
}

void Fl_Widget::hide() {
  if (!visible()) return;
  set_flag(INVISIBLE);
  handle(FL_HIDE);
  fl_throw_focus(this);
  for (Fl_Widget *p = parent(); p; p = p->parent())
    if (p->box() || !p->parent()) {p->redraw(); break;}
}

int Fl_Widget::visible_r() const {
  for (const Fl_Widget* o = this; o; o = o->parent())
    if (!o->visible()) return 0;
  return 1;
}

// return true if widget is inside (or equal to) this:
// Returns false for null widgets.
int Fl_Widget::contains(const Fl_Widget *o) const {
  for (; o; o = o->parent_) if (o == this) return 1;
  return 0;
}

//
// End of "$Id: Fl_Widget.cxx,v 1.2 1998/10/19 20:46:08 mike Exp $".
//