src/fl_overlay.cxx

   1 //
   2 // "$Id: fl_overlay.cxx 7903 2010-11-28 21:06:39Z matt $"
   3 //
   4 // Overlay support for the Fast Light Tool Kit (FLTK).
   5 //
   6 // Copyright 1998-2010 by Bill Spitzak and others.
   7 //
   8 // This library is free software; you can redistribute it and/or
   9 // modify it under the terms of the GNU Library General Public
  10 // License as published by the Free Software Foundation; either
  11 // version 2 of the License, or (at your option) any later version.
  12 //
  13 // This library is distributed in the hope that it will be useful,
  14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16 // Library General Public License for more details.
  17 //
  18 // You should have received a copy of the GNU Library General Public
  19 // License along with this library; if not, write to the Free Software
  20 // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  21 // USA.
  22 //
  23 // Please report all bugs and problems on the following page:
  24 //
  25 //     http://www.fltk.org/str.php
  26 //
  27
  28 // Extremely limited "overlay" support.  You can use this to drag out
  29 // a rectangle in response to mouse events.  It is your responsibility
  30 // to erase the overlay before drawing anything that might intersect
  31 // it.
  32
  33 #include <FL/x.H>
  34 #include <FL/fl_draw.H>
  35 #ifdef __APPLE__
  36 #include <config.h>
  37 #endif
  38
  39 //#define USE_XOR
  40
  41 static int px,py,pw,ph;
  42
  43 #ifndef USE_XOR
  44 #include <stdlib.h>
  45 static uchar *bgN = 0L, *bgS = 0L, *bgE = 0L, *bgW = 0L;
  46 static int bgx, bgy, bgw, bgh;
  47 #endif
  48
  49 static void draw_current_rect() {
  50 #ifdef USE_XOR
  51 # if defined(USE_X11)
  52   XSetFunction(fl_display, fl_gc, GXxor);
  53   XSetForeground(fl_display, fl_gc, 0xffffffff);
  54   XDrawRectangle(fl_display, fl_window, fl_gc, px, py, pw, ph);
  55   XSetFunction(fl_display, fl_gc, GXcopy);
  56 # elif defined(WIN32)
  57   int old = SetROP2(fl_gc, R2_NOT);
  58   fl_rect(px, py, pw, ph);
  59   SetROP2(fl_gc, old);
  60 # elif defined(__APPLE_QUARTZ__)
  61   // warning: Quartz does not support xor drawing
  62   // Use the Fl_Overlay_Window instead.
  63   fl_color(FL_WHITE);
  64   fl_rect(px, py, pw, ph);
  65 # else
  66 #  error unsupported platform
  67 # endif
  68 #else
  69   if (bgN) { free(bgN); bgN = 0L; }
  70   if (bgS) { free(bgS); bgS = 0L; }
  71   if (bgE) { free(bgE); bgE = 0L; }
  72   if (bgW) { free(bgW); bgW = 0L; }
  73   if (pw>0 && ph>0) {
  74     bgE = fl_read_image(0L, px+pw-1, py, 1, ph);
  75     bgW = fl_read_image(0L, px, py, 1, ph);
  76     bgS = fl_read_image(0L, px, py+ph-1, pw, 1);
  77     bgN = fl_read_image(0L, px, py, pw, 1);
  78     bgx = px; bgy = py;
  79     bgw = pw; bgh = ph;
  80   }
  81   fl_color(FL_WHITE);
  82   fl_line_style(FL_SOLID);
  83   fl_rect(px, py, pw, ph);
  84   fl_color(FL_BLACK);
  85   fl_line_style(FL_DOT);
  86   fl_rect(px, py, pw, ph);
  87   fl_line_style(FL_SOLID);
  88 #endif
  89 }
  90
  91 static void erase_current_rect() {
  92 #ifdef USE_XOR
  93 # ifdef __APPLE_QUARTZ__
  94   fl_rect(px, py, pw, ph);
  95 # else
  96   draw_current_rect();
  97 # endif
  98 #else
  99   if (bgN) fl_draw_image(bgN, bgx, bgy, bgw, 1);
 100   if (bgS) fl_draw_image(bgS, bgx, bgy+bgh-1, bgw, 1);
 101   if (bgW) fl_draw_image(bgW, bgx, bgy, 1, bgh);
 102   if (bgE) fl_draw_image(bgE, bgx+bgw-1, bgy, 1, bgh);
 103 #endif
 104 }
 105
 106 /**
 107   Erase a selection rectangle without drawing a new one
 108   */
 109 void fl_overlay_clear() {
 110   if (pw > 0) {erase_current_rect(); pw = 0;}
 111 }
 112
 113 /**
 114   Draws a selection rectangle, erasing a previous one by XOR'ing it first.
 115   */
 116 void fl_overlay_rect(int x, int y, int w, int h) {
 117   if (w < 0) {x += w; w = -w;} else if (!w) w = 1;
 118   if (h < 0) {y += h; h = -h;} else if (!h) h = 1;
 119   if (pw > 0) {
 120     if (x==px && y==py && w==pw && h==ph) return;
 121     erase_current_rect();
 122   }
 123   px = x; py = y; pw = w; ph = h;
 124   draw_current_rect();
 125 }
 126
 127 //
 128 // End of "$Id: fl_overlay.cxx 7903 2010-11-28 21:06:39Z matt $".
 129 //