//
// "$Id: Fl_Group.cxx,v 1.4 1998/10/21 14:20:07 mike Exp $"
//
// Group widget 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".
//

// The Fl_Group is the only defined container type in fltk.

// Fl_Window itself is a subclass of this, and most of the event
// handling is designed so windows themselves work correctly.

#include <FL/Fl.H>
#include <FL/Fl_Group.H>
#include <FL/Fl_Window.H>
#include <FL/fl_draw.H>
#include <stdlib.h>

Fl_Group* Fl_Group::current_;

// Hack: A single child is stored in the pointer to the array, while
// multiple children are stored in an allocated array:
Fl_Widget*const* Fl_Group::array() const {
  return children_ <= 1 ? (Fl_Widget**)(&array_) : array_;
}

int Fl_Group::find(const Fl_Widget* o) const {
  Fl_Widget*const* a = array();
  int i; for (i=0; i < children_; i++) if (*a++ == o) break;
  return i;
}

extern Fl_Widget* fl_oldfocus; // set by Fl::focus

// For back-compatability, we must adjust all events sent to child
// windows so they are relative to that window.

static int send(Fl_Widget* o, int event) {
  if (o->type() < FL_WINDOW) return o->handle(event);
  int save_x = Fl::e_x; Fl::e_x -= o->x();
  int save_y = Fl::e_y; Fl::e_y -= o->y();
  int ret = o->handle(event);
  Fl::e_y = save_y;
  Fl::e_x = save_x;
  return ret;
}

int Fl_Group::handle(int event) {

  Fl_Widget*const* a = array();
  int i;
  Fl_Widget* o;

  switch (event) {

  case FL_FOCUS:
    if (savedfocus_ && savedfocus_->take_focus()) return 1;
    for (i = children(); i--;) if ((*a++)->take_focus()) return 1;
    return 0;

  case FL_UNFOCUS:
    savedfocus_ = fl_oldfocus;
    return 0;

  case FL_KEYBOARD:
    return navigation();

  case FL_SHORTCUT:
    for (i = children(); i--;) {
      o = a[i];
      if (o->takesevents() && Fl::event_inside(o) && send(o,FL_SHORTCUT))
	return 1;
    }
    for (i = children(); i--;) {
      o = a[i];
      if (o->takesevents() && !Fl::event_inside(o) && send(o,FL_SHORTCUT))
	return 1;
    }
    if (Fl::event_key() == FL_Enter) return navigation(FL_Down);
    return 0;

  case FL_ENTER:
  case FL_MOVE:
    for (i = children(); i--;) {
      o = a[i];
      if (o->takesevents() && Fl::event_inside(o)) {
	if (o->contains(Fl::belowmouse())) {
	  return send(o,FL_MOVE);
	} else if (send(o,FL_ENTER)) {
	  if (!o->contains(Fl::belowmouse())) Fl::belowmouse(o);
	  return 1;
	}
      }
    }
    Fl::belowmouse(this);
    return 1;

  case FL_PUSH:
    for (i = children(); i--;) {
      o = a[i];
      if (o->takesevents() && Fl::event_inside(o)) {
	if (send(o,FL_PUSH)) {
	  if (Fl::pushed() && !o->contains(Fl::pushed())) Fl::pushed(o);
	  return 1;
	}
      }
    }
    return 0;

  case FL_DEACTIVATE:
  case FL_ACTIVATE:
    for (i = children(); i--;) {
      o = *a++;
      if (o->active()) o->handle(event);
    }
    return 1;

  case FL_SHOW:
  case FL_HIDE:
    for (i = children(); i--;) {
      o = *a++;
      if (o->visible()) o->handle(event);
    }
    return 1;

  default:
    return 0;

  }
}

// translate the current keystroke into up/down/left/right for navigation:
#define ctrl(x) (x^0x40)
int navkey() {
  switch (Fl::event_key()) {
  case FL_Tab:
    return (Fl::event_state(FL_SHIFT) ? FL_Left : FL_Right);
  case FL_Right:
    return FL_Right;
  case FL_Left:
    return FL_Left;
  case FL_Up:
    return FL_Up;
  case FL_Down:
    return FL_Down;
  default:
    switch (Fl::event_text()[0]) {
    case ctrl('N') : return FL_Down;
    case ctrl('P') : return FL_Up;
    case ctrl('F') : return FL_Right;
    case ctrl('B') : return FL_Left;
    }
  }
  return 0;
}

//void Fl_Group::focus(Fl_Widget *o) {Fl::focus(o); o->handle(FL_FOCUS);}

#if 0
const char *nameof(Fl_Widget *o) {
  if (!o) return "NULL";
  if (!o->label()) return "<no label>";
  return o->label();
}
#endif

// try to move the focus in response to a keystroke:
int Fl_Group::navigation(int key) {
  if (children() <= 1) return 0;
  if (!key) {key = navkey(); if (!key) return 0;}
  Fl_Widget *focus_ = Fl::focus();
  int old_i;
  for (old_i=0;;old_i++) {
    if (old_i >= children_) return 0;
    if (array_[old_i]->contains(focus_)) break;
  }
  int i = old_i;

  for (;;) {
    switch (key) {
    case FL_Right:
    case FL_Down:
      i++; if (i >= children_) i = 0;
      break;
    case FL_Left:
    case FL_Up:
      if (i) i--; else i = children_-1;
      break;
    default:
      return 0;
    }
    if (i == old_i) return 0;
    Fl_Widget* o = array_[i];
    switch (key) {
    case FL_Down:
    case FL_Up:
      if (o->x() >= focus_->x()+focus_->w() ||
	  o->x()+o->w() <= focus_->x()) continue;
    }
    if (o->take_focus()) return 1;
  }
}

////////////////////////////////////////////////////////////////

Fl_Group::Fl_Group(int X,int Y,int W,int H,const char *l)
: Fl_Widget(X,Y,W,H,l) {
  align(FL_ALIGN_TOP);
  children_ = 0;
  array_ = 0;
  savedfocus_ = 0;
  resizable_ = this;
  sizes_ = 0; // this is allocated when first resize() is done
  // Subclasses may want to construct child objects as part of their
  // constructor, so make sure they are add()'d to this object.
  // But you must end() the object!
  begin();
}

void Fl_Group::clear() {
  Fl_Widget*const* a = array();
  for (int i=children(); i--;) {
    Fl_Widget* o = *a++;
    // test the parent to see if child already destructed:
    if (o->parent() == this) delete o;
  }
  if (children() > 1) free((void*)array_);
  children_ = 0;
  array_ = 0;
  savedfocus_ = 0;
  resizable_ = this;
  init_sizes();
}

Fl_Group::~Fl_Group() {clear();}

void Fl_Group::insert(Fl_Widget &o, int i) {
  if (o.parent()) ((Fl_Group*)(o.parent()))->remove(o);
  o.parent_ = this;
  if (children_ == 0) { // use array pointer to point at single child
    array_ = (Fl_Widget**)&o;
  } else if (children_ == 1) { // go from 1 to 2 children
    Fl_Widget* t = (Fl_Widget*)array_;
    array_ = (Fl_Widget**)malloc(2*sizeof(Fl_Widget*));
    array_[!i] = t; array_[i] = &o;
  } else {
    if (!(children_ & (children_-1))) // double number of children
      array_ = (Fl_Widget**)realloc((void*)array_,
				    2*children_*sizeof(Fl_Widget*));
    for (int j = children_; j > i; j--) array_[j] = array_[j-1];
    array_[i] = &o;
  }
  children_++;
  init_sizes();
}

void Fl_Group::add(Fl_Widget &o) {insert(o, children_);}

void Fl_Group::remove(Fl_Widget &o) {
  int i = find(o);
  if (i >= children_) return;
  if (&o == savedfocus_) savedfocus_ = 0;
  o.parent_ = 0;
  children_--;
  if (children_ == 1) { // go from 2 to 1 child
    Fl_Widget *t = array_[!i];
    free((void*)array_);
    array_ = (Fl_Widget**)t;
  } else if (children_ > 1) { // delete from array
    for (; i < children_; i++) array_[i] = array_[i+1];
  }
  init_sizes();
}

////////////////////////////////////////////////////////////////

// Rather lame kludge here, I need to detect windows and ignore the
// changes to X,Y, since all children are relative to X,Y.  That
// is why I check type():

// sizes array stores the initial positions of widgets as
// left,right,top,bottom quads.  The first quad is the group, the
// second is the resizable (clipped to the group), and the
// rest are the children.  This is a convienent order for the
// algorithim.  If you change this be sure to fix Fl_Tile which
// also uses this array!

void Fl_Group::init_sizes() {
  delete[] sizes_; sizes_ = 0;
}

short* Fl_Group::sizes() {
  if (!sizes_) {
    short* p = sizes_ = new short[4*(children_+2)];
    // first thing in sizes array is the group's size:
    if (type() < FL_WINDOW) {p[0] = x(); p[2] = y();} else {p[0] = p[2] = 0;}
    p[1] = p[0]+w(); p[3] = p[2]+h();
    // next is the resizable's size:
    p[4] = p[0]; // init to the group's size
    p[5] = p[1];
    p[6] = p[2];
    p[7] = p[3];
    Fl_Widget* r = resizable();
    if (r && r != this) { // then clip the resizable to it
      int t;
      t = r->x(); if (t > p[0]) p[4] = t;
      t +=r->w(); if (t < p[1]) p[5] = t;
      t = r->y(); if (t > p[2]) p[6] = t;
      t +=r->h(); if (t < p[3]) p[7] = t;
    }
    // next is all the children's sizes:
    p += 8;
    Fl_Widget*const* a = array();
    for (int i=children_; i--;) {
      Fl_Widget* o = *a++;
      *p++ = o->x();
      *p++ = o->x()+o->w();
      *p++ = o->y();
      *p++ = o->y()+o->h();
    }
  }
  return sizes_;
}

void Fl_Group::resize(int X, int Y, int W, int H) {

  if (!resizable() || W==w() && H==h()) {

    if (type() < FL_WINDOW) {
      int dx = X-x();
      int dy = Y-y();
      Fl_Widget*const* a = array();
      for (int i=children_; i--;) {
	Fl_Widget* o = *a++;
	o->resize(o->x()+dx, o->y()+dy, o->w(), o->h());
      }
    }

  } else if (children_) {

    short* p = sizes();

    // get changes in size/position from the initial size:
    int dx = X - p[0];
    int dw = W - (p[1]-p[0]);
    int dy = Y - p[2];
    int dh = H - (p[3]-p[2]);
    if (type() >= FL_WINDOW) dx = dy = 0;
    p += 4;

    // get initial size of resizable():
    int IX = *p++;
    int IR = *p++;
    int IY = *p++;
    int IB = *p++;

    Fl_Widget*const* a = array();
    for (int i=children_; i--;) {
      Fl_Widget* o = *a++;

      int X = *p++;
      if (X >= IR) X += dw;
      else if (X > IX) X = IX+((X-IX)*(IR+dw-IX)+(IR-IX)/2)/(IR-IX);
      int R = *p++;
      if (R >= IR) R += dw;
      else if (R > IX) R = IX+((R-IX)*(IR+dw-IX)+(IR-IX)/2)/(IR-IX);

      int Y = *p++;
      if (Y >= IB) Y += dh;
      else if (Y > IY) Y = IY+((Y-IY)*(IB+dh-IY)+(IB-IY)/2)/(IB-IY);
      int B = *p++;
      if (B >= IB) B += dh;
      else if (B > IY) B = IY+((B-IY)*(IB+dh-IY)+(IB-IY)/2)/(IB-IY);

      o->resize(X+dx, Y+dy, R-X, B-Y);
    }
  }

  Fl_Widget::resize(X,Y,W,H);
}

void Fl_Group::draw() {
  Fl_Widget*const* a = array();
  if (damage() & ~FL_DAMAGE_CHILD) { // redraw the entire thing:
    draw_box();
    draw_label();
    for (int i=children_; i--;) {
      Fl_Widget& o = **a++;
      draw_child(o);
      draw_outside_label(o);
    }
  } else {	// only redraw the children that need it:
    for (int i=children_; i--;) update_child(**a++);
  }
}

// Draw a child only if it needs it:
void Fl_Group::update_child(Fl_Widget& w) const {
  if (w.damage() && w.visible() && w.type() < FL_WINDOW &&
      fl_not_clipped(w.x(), w.y(), w.w(), w.h())) {
    w.draw();	
    w.clear_damage();
  }
}

// Force a child to redraw:
void Fl_Group::draw_child(Fl_Widget& w) const {
  if (w.visible() && w.type() < FL_WINDOW &&
      fl_not_clipped(w.x(), w.y(), w.w(), w.h())) {
    w.clear_damage(FL_DAMAGE_ALL);
    w.draw();
    w.clear_damage();
  }
}

extern char fl_draw_shortcut;

// Parents normally call this to draw outside labels:
void Fl_Group::draw_outside_label(const Fl_Widget& w) const {
  if (!w.visible()) return;
  // skip any labels that are inside the widget:
  if (!(w.align()&15) || (w.align() & FL_ALIGN_INSIDE)) return;
  // invent a box that is outside the widget:
  int align = w.align();
  int X = w.x();
  int Y = w.y();
  int W = w.w();
  int H = w.h();
  if (align & FL_ALIGN_TOP) {
    align ^= (FL_ALIGN_BOTTOM|FL_ALIGN_TOP);
    Y = y();
    H = w.y()-Y;
  } else if (align & FL_ALIGN_BOTTOM) {
    align ^= (FL_ALIGN_BOTTOM|FL_ALIGN_TOP);
    Y = Y+H;
    H = y()+h()-Y;
  } else if (align & FL_ALIGN_LEFT) {
    align ^= (FL_ALIGN_LEFT|FL_ALIGN_RIGHT);
    X = x();
    W = w.x()-X-3;
  } else if (align & FL_ALIGN_RIGHT) {
    align ^= (FL_ALIGN_LEFT|FL_ALIGN_RIGHT);
    X = X+W+3;
    W = x()+this->w()-X;
  }
  w.draw_label(X,Y,W,H,(Fl_Align)align);
}

//
// End of "$Id: Fl_Group.cxx,v 1.4 1998/10/21 14:20:07 mike Exp $".
//