libs/gtkmm2ext/scroomer.cc

   1 /*
   2     Copyright (C) 2008 Paul Davis
   3
   4     This program is free software; you can redistribute it and/or modify
   5     it under the terms of the GNU General Public License as published by
   6     the Free Software Foundation; either version 2 of the License, or
   7     (at your option) any later version.
   8
   9     This program is distributed in the hope that it will be useful,
  10     but WITHOUT ANY WARRANTY; without even the implied warranty of
  11     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12     GNU General Public License for more details.
  13
  14     You should have received a copy of the GNU General Public License
  15     along with this program; if not, write to the Free Software
  16     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  17
  18 */
  19
  20 #include <iostream>
  21 #include <gtkmm2ext/scroomer.h>
  22
  23 using namespace Gtkmm2ext;
  24 using namespace Gtk;
  25 using namespace Gdk;
  26 using namespace std;
  27
  28 Scroomer::Scroomer(Gtk::Adjustment& adjustment)
  29         : adj(adjustment)
  30         , handle_size(0)
  31         , grab_comp(None) {
  32
  33         position[TopBase] = 0;
  34         position[Handle1] = 0;
  35         position[Slider] = 0;
  36         position[Handle2] = 0;
  37         position[BottomBase] = 0;
  38         position[Total] = 0;
  39
  40         add_events (Gdk::BUTTON_PRESS_MASK |
  41                     Gdk::BUTTON_RELEASE_MASK |
  42                     Gdk::POINTER_MOTION_MASK |
  43                     Gdk::SCROLL_MASK);
  44
  45         adjustment.signal_value_changed().connect (mem_fun (*this, &Scroomer::adjustment_changed));
  46         //adjustment.signal_changed().connect (mem_fun (*this, &Scroomer::adjustment_changed));
  47 }
  48
  49 Scroomer::~Scroomer()
  50 {
  51 }
  52
  53 bool
  54 Scroomer::on_motion_notify_event (GdkEventMotion* ev)
  55 {
  56         double range = adj.get_upper() - adj.get_lower();
  57         double pixel2val = range / get_height();
  58         double val_at_pointer = ((get_height() - ev->y) * pixel2val) + adj.get_lower();
  59         double delta_y = ev->y - grab_y;
  60         double half_min_page = min_page_size / 2;
  61         double fract = delta_y / position[Total];
  62         double scale, temp, zoom;
  63         double val, page;
  64
  65         if (grab_comp == None || grab_comp == Total) {
  66                 return true;
  67         }
  68
  69         if (ev->window != grab_window) {
  70                 grab_y = ev->y;
  71                 grab_window = ev->window;
  72                 return true;
  73         }
  74
  75         grab_y = ev->y;
  76
  77         if (ev->state & GDK_CONTROL_MASK) {
  78                 if (ev->state & GDK_MOD1_MASK) {
  79                         scale = 0.05;
  80                 } else {
  81                         scale = 0.1;
  82                 }
  83         } else {
  84                 scale = 1.0;
  85         }
  86
  87         fract = min (1.0, fract);
  88         fract = max (-1.0, fract);
  89         fract = -fract;
  90
  91         switch(grab_comp) {
  92         case TopBase:
  93         case BottomBase:
  94                 unzoomed_val += scale * fract * range;
  95                 unzoomed_val = min(unzoomed_val, adj.get_upper() - unzoomed_page);
  96                 unzoomed_val = max(unzoomed_val, adj.get_lower());
  97                 break;
  98         case Slider:
  99                 unzoomed_val += scale * fract * range;
 100                 unzoomed_val = min(unzoomed_val, adj.get_upper() - unzoomed_page);
 101                 unzoomed_val = max(unzoomed_val, adj.get_lower());
 102                 break;
 103         case Handle1:
 104                 unzoomed_page += scale * fract * range;
 105                 unzoomed_page = min(unzoomed_page, adj.get_upper() - unzoomed_val);
 106                 unzoomed_page = max(unzoomed_page, min_page_size);
 107                 break;
 108         case Handle2:
 109                 temp = unzoomed_val + unzoomed_page;
 110                 unzoomed_val += scale * fract * range;
 111                 unzoomed_val = min(unzoomed_val, temp - min_page_size);
 112                 unzoomed_val = max(unzoomed_val, adj.get_lower());
 113
 114                 unzoomed_page = temp - unzoomed_val;
 115                 unzoomed_page = max(unzoomed_page, min_page_size);
 116                 break;
 117         default:
 118                 break;
 119         }
 120
 121         /*
 122          * Then we handle zoom, which is dragging horizontally. We zoom around the area that is
 123          * the current y pointer value, not from the area that was the start of the drag.
 124          * the point of zoom must have the same
 125          */
 126
 127         if (ev->x > get_width()) {
 128                 zoom = ev->x - get_width();
 129
 130                 double higher = unzoomed_val + unzoomed_page - half_min_page - val_at_pointer;
 131                 double lower = val_at_pointer - (unzoomed_val + half_min_page);
 132
 133                 higher *= zoom / 128;
 134                 lower *= zoom / 128;
 135
 136                 val = unzoomed_val + lower;
 137                 page = unzoomed_page - higher - lower;
 138
 139                 page = max(page, min_page_size);
 140
 141                 if (lower < 0) {
 142                         val = max(val, val_at_pointer - half_min_page);
 143                 } else if (lower > 0) {
 144                         val = min(val, val_at_pointer - half_min_page);
 145                 }
 146
 147                 val = min(val, adj.get_upper() - min_page_size);
 148                 page = min(page, adj.get_upper() - val);
 149         } else if (ev->x < 0) {
 150                 /* on zoom out increase the page size as well as moving the range towards the mouse pos*/
 151                 zoom = abs(ev->x);
 152
 153                 /*double higher = unzoomed_val + unzoomed_page - half_min_page - val_at_pointer;
 154                 double lower = val_at_pointer - (unzoomed_val + half_min_page);
 155
 156                 higher *= zoom / 128;
 157                 lower *= zoom / 128;
 158
 159                 val = unzoomed_val + lower;
 160                 page = unzoomed_page - higher - lower;
 161
 162                 page = max(page, min_page_size);
 163
 164                 if (lower < 0) {
 165                         val = max(val, val_at_pointer - half_min_page);
 166                 }
 167                 else if (lower > 0) {
 168                         val = min(val, val_at_pointer - half_min_page);
 169                 }
 170
 171                 val = min(val, adj.get_upper() - min_page_size);
 172                 page = min(page, adj.get_upper() - val);*/
 173
 174                 val = unzoomed_val;
 175                 page = unzoomed_page;
 176         } else {
 177                 val = unzoomed_val;
 178                 page = unzoomed_page;
 179         }
 180
 181         adj.set_page_size(page);
 182
 183         if (val == adj.get_value()) {
 184                 adj.value_changed();
 185         }
 186
 187         if (val < adj.get_lower()) {
 188                 adj.value_changed();
 189         } else if (val > adj.get_upper()) {
 190                 adj.value_changed();
 191         } else {
 192                 adj.set_value(val);
 193         }
 194
 195         return true;
 196 }
 197
 198 bool
 199 Scroomer::on_button_press_event (GdkEventButton* ev)
 200 {
 201         if (ev->button == 1) {
 202                 Component comp = point_in(ev->y);
 203
 204                 if (comp == Total || comp == None) {
 205                         return false;
 206                 }
 207
 208                 add_modal_grab();
 209                 grab_comp = comp;
 210                 grab_y = ev->y;
 211                 unzoomed_val = adj.get_value();
 212                 unzoomed_page = adj.get_page_size();
 213                 grab_window = ev->window;
 214         }
 215         return false;
 216 }
 217
 218 bool
 219 Scroomer::on_button_release_event (GdkEventButton* ev)
 220 {
 221         if (grab_comp == None || grab_comp == Total) {
 222                 return true;
 223         }
 224
 225         if (ev->window != grab_window) {
 226                 grab_y = ev->y;
 227                 grab_window = ev->window;
 228                 return true;
 229         }
 230
 231         if (ev->button != 1) {
 232                 return true;
 233         }
 234
 235         switch(grab_comp) {
 236         case TopBase:
 237                 break;
 238         case Handle1:
 239                 break;
 240         case Slider:
 241                 break;
 242         case Handle2:
 243                 break;
 244         case BottomBase:
 245                 break;
 246         default:
 247                 break;
 248         }
 249
 250         grab_comp = None;
 251
 252         remove_modal_grab();
 253         return true;
 254 }
 255
 256 bool
 257 Scroomer::on_scroll_event (GdkEventScroll*)
 258 {
 259         return true;
 260 }
 261
 262 void
 263 Scroomer::on_size_allocate (Allocation& a)
 264 {
 265         Gtk::DrawingArea::on_size_allocate(a);
 266
 267         position[Total] = a.get_height();
 268         set_min_page_size(min_page_size);
 269         update();
 270 }
 271
 272 /*
 273  * assumes that x and width are correct, and they will not be altered
 274  */
 275 void
 276 Scroomer::set_comp_rect(GdkRectangle& r, Component c) const
 277 {
 278         int index = (int) c;
 279
 280         switch(c) {
 281         case None:
 282                 return;
 283         case Total:
 284                 r.y = 0;
 285                 r.height = position[Total];
 286                 break;
 287         default:
 288                 r.y = position[index];
 289                 r.height = position[index+1] - position[index];
 290                 break;
 291         }
 292 }
 293
 294 Scroomer::Component
 295 Scroomer::point_in(double point) const
 296 {
 297         for (int i = 0; i < Total; ++i) {
 298                 if (position[i+1] >= point) {
 299                         return (Component) i;
 300                 }
 301         }
 302
 303         return None;
 304 }
 305
 306 void
 307 Scroomer::set_min_page_size(double ps)
 308 {
 309         double coeff = ((double)position[Total]) / (adj.get_upper() - adj.get_lower());
 310
 311         min_page_size = ps;
 312         handle_size = (int) floor((ps * coeff) / 2);
 313 }
 314
 315 void
 316 Scroomer::update()
 317 {
 318         double range = adj.get_upper() - adj.get_lower();
 319         //double value = adj.get_value() - adj.get_lower();
 320         int height = position[Total];
 321         double coeff = ((double) height) / range;
 322
 323         /* save the old positions to calculate update regions later*/
 324         for (int i = Handle1; i < Total; ++i) {
 325                 old_pos[i] = position[i];
 326         }
 327
 328         position[BottomBase] = (int) floor(height - (adj.get_value() * coeff));
 329         position[Handle2] = position[BottomBase] - handle_size;
 330
 331         position[Handle1] = (int) floor(height - ((adj.get_value() + adj.get_page_size()) * coeff));
 332         position[Slider] = position[Handle1] + handle_size;
 333 }
 334
 335 void
 336 Scroomer::adjustment_changed()
 337 {
 338         //cerr << floor(adj.get_value()) << " " << floor(adj.get_value() + adj.get_page_size()) << endl;
 339         Gdk::Rectangle rect;
 340         Glib::RefPtr<Gdk::Window> win = get_window();
 341
 342         update();
 343
 344         if (!win) {
 345                 return;
 346         }
 347
 348         rect.set_x(0);
 349         rect.set_width(get_width());
 350
 351         if (position[Handle1] < old_pos[Handle1]) {
 352                 rect.set_y(position[Handle1]);
 353                 rect.set_height(old_pos[Slider] - position[Handle1]);
 354                 win->invalidate_rect(rect, false);
 355         } else if (position[Handle1] > old_pos[Handle1]) {
 356                 rect.set_y(old_pos[Handle1]);
 357                 rect.set_height(position[Slider] - old_pos[Handle1]);
 358                 win->invalidate_rect(rect, false);
 359         }
 360
 361         if (position[Handle2] < old_pos[Handle2]) {
 362                 rect.set_y(position[Handle2]);
 363                 rect.set_height(old_pos[BottomBase] - position[Handle2]);
 364                 win->invalidate_rect(rect, false);
 365         } else if (position[Handle2] > old_pos[Handle2]) {
 366                 rect.set_y(old_pos[Handle2]);
 367                 rect.set_height(position[BottomBase] - old_pos[Handle2]);
 368                 win->invalidate_rect(rect, false);
 369         }
 370
 371         win->process_updates(false);
 372 }
 373
 374 std::string
 375 Scroomer::get_comp_name(Component c)
 376 {
 377         switch(c) {
 378         case TopBase:
 379                 return "TopBase";
 380         case Handle1:
 381                 return "Handle1";
 382         case Slider:
 383                 return "Slider";
 384         case Handle2:
 385                 return "Handle2";
 386         case BottomBase:
 387                 return "BottomBase";
 388         case Total:
 389                 return "Total";
 390         case None:
 391                 return "None";
 392         default:
 393                 return "ERROR";
 394         }
 395 }