fl_browser_.cxx

SRI international 发布的OAA框架软件

//
// "$Id: Fl_Browser_.cxx,v 1.1.1.1 2003/06/03 22:25:41 agno Exp $"
//
// Base Browser widget class for the Fast Light Tool Kit (FLTK).
//
// Copyright 1998-2003 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 "[e-mail]".
//

#define DISPLAY_SEARCH_BOTH_WAYS_AT_ONCE

#include <stdio.h>
#include <FL/Fl.H>
#include <FL/Fl_Widget.H>
#include <FL/Fl_Browser_.H>
#include <FL/fl_draw.H>


// This is the base class for browsers.  To be useful it must be
// subclassed and several virtual functions defined.  The
// Forms-compatable browser and the file chooser's browser are
// subclassed off of this.

// Yes, I know this should be a template...

// This has been designed so that the subclass has complete control
// over the storage of the data, although because next() and prev()
// functions are used to index, it works best as a linked list or as a
// large block of characters in which the line breaks must be searched
// for.

// A great deal of work has been done so that the "height" of a data
// object does not need to be determined until it is drawn.  This was
// done for the file chooser, because the height requires doing stat()
// to see if the file is a directory, which can be annoyingly slow
// over the network.

/* redraw bits:
   1 = redraw children (the scrollbar)
   2 = redraw one or two items
   4 = redraw all items
*/

static void scrollbar_callback(Fl_Widget* s, void*) {
  ((Fl_Browser_*)(s->parent()))->position(int(((Fl_Scrollbar*)s)->value()));
}

static void hscrollbar_callback(Fl_Widget* s, void*) {
  ((Fl_Browser_*)(s->parent()))->hposition(int(((Fl_Scrollbar*)s)->value()));
}

int Fl_Browser_::scrollbar_width_ = 16;

// return where to draw the actual box:
void Fl_Browser_::bbox(int& X, int& Y, int& W, int& H) const {
  Fl_Boxtype b = box() ? box() : FL_DOWN_BOX;
  X = x()+Fl::box_dx(b);
  Y = y()+Fl::box_dy(b);
  W = w()-Fl::box_dw(b);
  H = h()-Fl::box_dh(b);
  if (scrollbar.visible()) {
    W -= scrollbar_width_;
    if (scrollbar.align() & FL_ALIGN_LEFT) X += scrollbar_width_;
  }
  if (W < 0) W = 0;
  if (hscrollbar.visible()) {
    H -= scrollbar_width_;
    if (scrollbar.align() & FL_ALIGN_TOP) Y += scrollbar_width_;
  }
  if (H < 0) H = 0;
}

int Fl_Browser_::leftedge() const {
  int X, Y, W, H; bbox(X, Y, W, H);
  return X;
}

// The scrollbars may be moved again by draw(), since each one's size
// depends on whether the other is visible or not.  This skips over
// Fl_Group::resize since it moves the scrollbars uselessly.
void Fl_Browser_::resize(int X, int Y, int W, int H) {
  Fl_Widget::resize(X, Y, W, H);
  // move the scrollbars so they can respond to events:
  bbox(X,Y,W,H);
  scrollbar.resize(
	scrollbar.align()&FL_ALIGN_LEFT ? X-scrollbar_width_ : X+W,
	Y, scrollbar_width_, H);
  hscrollbar.resize(
	X, scrollbar.align()&FL_ALIGN_TOP ? Y-scrollbar_width_ : Y+H,
	W, scrollbar_width_);
}

// Cause minimal update to redraw the given item:
void Fl_Browser_::redraw_line(void* l) {
  if (!redraw1 || redraw1 == l) {redraw1 = l; damage(FL_DAMAGE_EXPOSE);}
  else if (!redraw2 || redraw2 == l) {redraw2 = l; damage(FL_DAMAGE_EXPOSE);}
  else damage(FL_DAMAGE_SCROLL);
}

// Figure out top() based on position():
void Fl_Browser_::update_top() {
  if (!top_) top_ = item_first();
  if (position_ != real_position_) {
    void* l;
    int ly;
    int yy = position_;
    // start from either head or current position, whichever is closer:
    if (!top_ || yy <= (real_position_/2)) {
      l = item_first();
      ly = 0;
    } else {
      l = top_;
      ly = real_position_-offset_;
    }
    if (!l) {
      top_ = 0;
      offset_ = 0;
      real_position_ = 0;
    } else {
      int hh = item_quick_height(l);
      // step through list until we find line containing this point:
      while (ly > yy) {
	void* l1 = item_prev(l);
	if (!l1) {ly = 0; break;} // hit the top
	l  = l1;
	hh = item_quick_height(l);
	ly -= hh;
      }
      while ((ly+hh) <= yy) {
	void* l1 = item_next(l);
	if (!l1) {yy = ly+hh-1; break;}
	l = l1;
	ly += hh;
	hh = item_quick_height(l);
      }
      // top item must *really* be visible, use slow height:
      for (;;) {
	hh = item_height(l);
	if ((ly+hh) > yy) break; // it is big enough to see
	// go up to top of previous item:
	void* l1 = item_prev(l);
	if (!l1) {ly = yy = 0; break;} // hit the top
	l = l1; yy = position_ = ly = ly-item_quick_height(l);
      }
      // use it:
      top_ = l;
      offset_ = yy-ly;
      real_position_ = yy;
    }
    damage(FL_DAMAGE_SCROLL);
  }
}

// Change position(), top() will update when update_top() is called
// (probably by draw() or handle()):
void Fl_Browser_::position(int yy) {
  if (yy < 0) yy = 0;
  if (yy == position_) return;
  position_ = yy;
  if (yy != real_position_) redraw_lines();
}

void Fl_Browser_::hposition(int xx) {
  if (xx < 0) xx = 0;
  if (xx == hposition_) return;
  hposition_ = xx;
  if (xx != real_hposition_) redraw_lines();
}

// Tell whether item is currently displayed:
int Fl_Browser_::displayed(void* p) const {
  int X, Y, W, H; bbox(X, Y, W, H);
  int yy = H+offset_;
  for (void* l = top_; l && yy > 0; l = item_next(l)) {
    if (l == p) return 1;
    yy -= item_height(l);
  }
  return 0;
}

// Ensure this item is displayed:
// Messy because we have no idea if it is before top or after bottom:
void Fl_Browser_::display(void* p) {

  // First special case - want to display first item in the list?
  update_top();
  if (p == item_first()) {position(0); return;}

  int X, Y, W, H, Yp; bbox(X, Y, W, H);
  void* l = top_;
  Y = Yp = -offset_;
  int h1;

  // 2nd special case - want to display item already displayed at top of browser?
  if (l == p) {position(real_position_+Y); return;} // scroll up a bit

  // 3rd special case - want to display item just above top of browser?
  void* lp = item_prev(l);
  if (lp == p) {position(real_position_+Y-item_quick_height(lp)); return;}

#ifdef DISPLAY_SEARCH_BOTH_WAYS_AT_ONCE
  // search for item.  We search both up and down the list at the same time,
  // this evens up the execution time for the two cases - the old way was
  // much slower for going up than for going down.
  while (l || lp) {
    if (l) {
      h1 = item_quick_height(l);
      if (l == p) {
	if (Y <= H) { // it is visible or right at bottom
	  Y = Y+h1-H; // find where bottom edge is
	  if (Y > 0) position(real_position_+Y); // scroll down a bit
	} else {
	  position(real_position_+Y-(H-h1)/2); // center it
	}
	return;
      }
      Y += h1;
      l = item_next(l);
    }
    if (lp) {
      h1 = item_quick_height(lp);
      Yp -= h1;
      if (lp == p) {
	if ((Yp + h1) >= 0) position(real_position_+Yp);
	else position(real_position_+Yp-(H-h1)/2);
	return;
      }
      lp = item_prev(lp);
    }
  }
#else
  // Old version went forwards and then backwards:
  // search forward for it:
  l = top_;
  for (; l; l = item_next(l)) {
    h1 = item_quick_height(l);
    if (l == p) {
      if (Y <= H) { // it is visible or right at bottom
	Y = Y+h1-H; // find where bottom edge is
	if (Y > 0) position(real_position_+Y); // scroll down a bit
      } else {
	position(real_position_+Y-(H-h1)/2); // center it
      }
      return;
    }
    Y += h1;
  }
  // search backward for it, if found center it:
  l = lp;
  Y = -offset_;
  for (; l; l = item_prev(l)) {
    h1 = item_quick_height(l);
    Y -= h1;
    if (l == p) {
      if ((Y + h1) >= 0) position(real_position_+Y);
      else position(real_position_+Y-(H-h1)/2);
      return;
    }
  }
#endif
}

// redraw, has side effect of updating top and setting scrollbar:

void Fl_Browser_::draw() {
  int drawsquare = 0;
  if (damage() & FL_DAMAGE_ALL) { // redraw the box if full redraw
    Fl_Boxtype b = box() ? box() : FL_DOWN_BOX;
    draw_box(b, x(), y(), w(), h(), color());
    drawsquare = 1;
  }

  update_top();
  int full_width_ = full_width();
  int full_height_ = full_height();
  int X, Y, W, H; bbox(X, Y, W, H);
  int dont_repeat = 0;
J1:
  // see if scrollbar needs to be switched on/off:
  if ((has_scrollbar_ & VERTICAL) && (
	(has_scrollbar_ & ALWAYS_ON) || position_ || full_height_ > H)) {
    if (!scrollbar.visible()) {
      scrollbar.set_visible();
      drawsquare = 1;
      bbox(X, Y, W, H);
    }
  } else {
    top_ = item_first(); real_position_ = offset_ = 0;
    if (scrollbar.visible()) {
      scrollbar.clear_visible();
      clear_damage((uchar)(damage()|FL_DAMAGE_SCROLL));
    }
  }

  if ((has_scrollbar_ & HORIZONTAL) && (
	(has_scrollbar_ & ALWAYS_ON) || hposition_ || full_width_ > W)) {
    if (!hscrollbar.visible()) {
      hscrollbar.set_visible();
      drawsquare = 1;
      bbox(X, Y, W, H);
    }
  } else {
    real_hposition_ = 0;
    if (hscrollbar.visible()) {
      hscrollbar.clear_visible();
      clear_damage((uchar)(damage()|FL_DAMAGE_SCROLL));
    }
  }

  // Check the vertical scrollbar again, just in case it needs to be drawn
  // because the horizontal one is drawn.  There should be a cleaner way
  // to do this besides copying the same code...
  if ((has_scrollbar_ & VERTICAL) && (
	(has_scrollbar_ & ALWAYS_ON) || position_ || full_height_ > H)) {
    if (!scrollbar.visible()) {
      scrollbar.set_visible();
      drawsquare = 1;
      bbox(X, Y, W, H);
    }
  } else {
    top_ = item_first(); real_position_ = offset_ = 0;
    if (scrollbar.visible()) {
      scrollbar.clear_visible();
      clear_damage((uchar)(damage()|FL_DAMAGE_SCROLL));
    }
  }

  bbox(X, Y, W, H);

  fl_clip(X, Y, W, H);
  // for each line, draw it if full redraw or scrolled.  Erase background
  // if not a full redraw or if it is selected:
  void* l = top();
  int yy = -offset_;
  for (; l && yy < H; l = item_next(l)) {
    int hh = item_height(l);
    if (hh <= 0) continue;
    if ((damage()&(FL_DAMAGE_SCROLL|FL_DAMAGE_ALL)) || l == redraw1 || l == redraw2) {
      if (item_selected(l)) {
	fl_color(active_r() ? selection_color() : fl_inactive(selection_color()));
	fl_rectf(X, yy+Y, W, hh);
      } else if (!(damage()&FL_DAMAGE_ALL)) {
	fl_push_clip(X, yy+Y, W, hh);
	draw_box(box() ? box() : FL_DOWN_BOX, x(), y(), w(), h(), color());
	fl_pop_clip();
      }
      item_draw(l, X-hposition_, yy+Y, W+hposition_, hh);
      if (l == selection_ && Fl::focus() == this) {
	draw_focus(FL_NO_BOX, X, yy+Y+1, W, hh);
      }
      int ww = item_width(l);
      if (ww > max_width) {max_width = ww; max_width_item = l;}
    }
    yy += hh;
  }
  // erase the area below last line:
  if (!(damage()&FL_DAMAGE_ALL) && yy < H) {
    fl_push_clip(X, yy+Y, W, H-yy);
    draw_box(box() ? box() : FL_DOWN_BOX, x(), y(), w(), h(), color());
    fl_pop_clip();
  }
  fl_pop_clip();
  redraw1 = redraw2 = 0;

  if (!dont_repeat) {