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
  22 #include "gtkmm2ext/scroomer.h"
  23 #include "gtkmm2ext/keyboard.h"
  24
  25 using namespace Gtkmm2ext;
  26 using namespace Gtk;
  27 using namespace Gdk;
  28 using namespace std;
  29
  30 Scroomer::Scroomer(Gtk::Adjustment& adjustment)
  31         : adj(adjustment)
  32         , handle_size(0)
  33         , grab_comp(None)
  34 {
  35         position[TopBase] = 0;
  36         position[Handle1] = 0;
  37         position[Slider] = 0;
  38         position[Handle2] = 0;
  39         position[BottomBase] = 0;
  40         position[Total] = 0;
  41
  42         add_events (Gdk::BUTTON_PRESS_MASK |
  43                     Gdk::BUTTON_RELEASE_MASK |
  44                     Gdk::POINTER_MOTION_MASK |
  45                     Gdk::SCROLL_MASK);
  46
  47         adjustment.signal_value_changed().connect (mem_fun (*this, &Scroomer::adjustment_changed));
  48         //adjustment.signal_changed().connect (mem_fun (*this, &Scroomer::adjustment_changed));
  49 }
  50
  51 Scroomer::~Scroomer()
  52 {
  53 }
  54
  55 bool
  56 Scroomer::on_motion_notify_event (GdkEventMotion* ev)
  57 {
  58         double range = adj.get_upper() - adj.get_lower();
  59         double pixel2val = range / get_height();
  60         double val_at_pointer = ((get_height() - ev->y) * pixel2val) + adj.get_lower();
  61         double delta_y = ev->y - grab_y;
  62         double half_min_page = min_page_size / 2;
  63         double fract = delta_y / position[Total];
  64         double scale, temp, zoom;
  65         double val, page;
  66
  67         if (grab_comp == None || grab_comp == Total) {
  68                 return true;
  69         }
  70
  71         if (ev->window != grab_window) {
  72                 grab_y = ev->y;
  73                 grab_window = ev->window;
  74                 return true;
  75         }
  76
  77         grab_y = ev->y;
  78
  79         if (ev->state & Keyboard::PrimaryModifier) {
  80                 if (ev->state & Keyboard::SecondaryModifier) {
  81                         scale = 0.05;
  82                 } else {
  83                         scale = 0.1;
  84                 }
  85         } else {
  86                 scale = 1.0;
  87         }
  88
  89         fract = min (1.0, fract);
  90         fract = max (-1.0, fract);
  91         fract = -fract;
  92
  93         switch (grab_comp) {
  94         case TopBase:
  95         case BottomBase:
  96                 unzoomed_val += scale * fract * range;
  97                 unzoomed_val = min(unzoomed_val, adj.get_upper() - unzoomed_page);
  98                 unzoomed_val = max(unzoomed_val, adj.get_lower());
  99                 break;
 100         case Slider:
 101                 unzoomed_val += scale * fract * range;
 102                 unzoomed_val = min(unzoomed_val, adj.get_upper() - unzoomed_page);
 103                 unzoomed_val = max(unzoomed_val, adj.get_lower());
 104                 break;
 105         case Handle1:
 106
 107                 unzoomed_page += scale * fract * range;
 108                 unzoomed_page = min(unzoomed_page, adj.get_upper() - unzoomed_val);
 109                 unzoomed_page = max(unzoomed_page, min_page_size);
 110
 111                 if (pinch){
 112                         temp = unzoomed_val + unzoomed_page;
 113                         unzoomed_val -= scale * fract * range * 0.5;
 114                         unzoomed_val = min(unzoomed_val, temp - min_page_size);
 115                         unzoomed_val = max(unzoomed_val, adj.get_lower());
 116                 }
 117
 118                 break;
 119         case Handle2:
 120                 temp = unzoomed_val + unzoomed_page;
 121                 unzoomed_val += scale * fract * range;
 122                 unzoomed_val = min(unzoomed_val, temp - min_page_size);
 123                 unzoomed_val = max(unzoomed_val, adj.get_lower());
 124
 125                 unzoomed_page = temp - unzoomed_val;
 126
 127                 if (pinch){
 128
 129                         unzoomed_page -= scale * fract * range;
 130                 }
 131
 132                 unzoomed_page = min(unzoomed_page, adj.get_upper() - unzoomed_val);
 133                 unzoomed_page = max(unzoomed_page, min_page_size);
 134                 break;
 135         default:
 136                 break;
 137         }
 138
 139         /* Then we handle zoom, which is dragging horizontally. We zoom around the area that is
 140          * the current y pointer value, not from the area that was the start of the drag.
 141          * the point of zoom must have the same
 142          */
 143
 144         if (ev->x > get_width()) {
 145                 zoom = ev->x - get_width();
 146
 147                 double higher = unzoomed_val + unzoomed_page - half_min_page - val_at_pointer;
 148                 double lower = val_at_pointer - (unzoomed_val + half_min_page);
 149
 150                 higher *= zoom / 128;
 151                 lower *= zoom / 128;
 152
 153                 val = unzoomed_val + lower;
 154                 page = unzoomed_page - higher - lower;
 155
 156                 page = max(page, min_page_size);
 157
 158                 if (lower < 0) {
 159                         val = max(val, val_at_pointer - half_min_page);
 160                 } else if (lower > 0) {
 161                         val = min(val, val_at_pointer - half_min_page);
 162                 }
 163
 164                 val = min(val, adj.get_upper() - min_page_size);
 165                 page = min(page, adj.get_upper() - val);
 166         } else if (ev->x < 0) {
 167                 /* on zoom out increase the page size as well as moving the range towards the mouse pos*/
 168                 zoom = abs(ev->x);
 169
 170                 /*double higher = unzoomed_val + unzoomed_page - half_min_page - val_at_pointer;
 171                 double lower = val_at_pointer - (unzoomed_val + half_min_page);
 172
 173                 higher *= zoom / 128;
 174                 lower *= zoom / 128;
 175
 176                 val = unzoomed_val + lower;
 177                 page = unzoomed_page - higher - lower;
 178
 179                 page = max(page, min_page_size);
 180
 181                 if (lower < 0) {
 182                         val = max(val, val_at_pointer - half_min_page);
 183                 }
 184                 else if (lower > 0) {
 185                         val = min(val, val_at_pointer - half_min_page);
 186                 }
 187
 188                 val = min(val, adj.get_upper() - min_page_size);
 189                 page = min(page, adj.get_upper() - val);*/
 190
 191                 val = unzoomed_val;
 192                 page = unzoomed_page;
 193         } else {
 194                 val = unzoomed_val;
 195                 page = unzoomed_page;
 196         }
 197
 198         adj.set_page_size(page);
 199         adj.set_value(val);
 200         adj.value_changed();
 201
 202         return true;
 203 }
 204
 205 bool
 206 Scroomer::on_scroll_event (GdkEventScroll* ev)
 207 {
 208         switch (ev->direction) {
 209         case GDK_SCROLL_UP:
 210                 adj.set_value (adj.get_value() + adj.get_page_size() / 10.0);
 211                 break;
 212         case GDK_SCROLL_DOWN:
 213                 adj.set_value (adj.get_value() - adj.get_page_size() / 10.0);
 214                 break;
 215         default:
 216                 return false;
 217         }
 218
 219         return true;
 220 }
 221
 222 bool
 223 Scroomer::on_button_press_event (GdkEventButton* ev)
 224 {
 225         if (ev->button == 1 || ev->button == 3) {
 226                 Component comp = point_in(ev->y);
 227
 228                 if (comp == Total || comp == None) {
 229                         return false;
 230                 }
 231
 232                 add_modal_grab();
 233                 grab_comp = comp;
 234                 grab_y = ev->y;
 235                 unzoomed_val = adj.get_value();
 236                 unzoomed_page = adj.get_page_size();
 237                 grab_window = ev->window;
 238
 239                 if (ev->button == 3){
 240                         pinch = true;
 241                 } else {
 242                         pinch = false;
 243                 }
 244
 245                 DragStarting (); /* EMIT SIGNAL */
 246         }
 247
 248         return false;
 249 }
 250
 251 bool
 252 Scroomer::on_button_release_event (GdkEventButton* ev)
 253 {
 254         if (grab_comp == None || grab_comp == Total) {
 255                 return true;
 256         }
 257
 258         if (ev->window != grab_window) {
 259                 grab_y = ev->y;
 260                 grab_window = ev->window;
 261                 return true;
 262         }
 263
 264         if (ev->button != 1 && ev->button != 3) {
 265                 return true;
 266         }
 267
 268         switch (grab_comp) {
 269         case TopBase:
 270                 break;
 271         case Handle1:
 272                 break;
 273         case Slider:
 274                 break;
 275         case Handle2:
 276                 break;
 277         case BottomBase:
 278                 break;
 279         default:
 280                 break;
 281         }
 282
 283         grab_comp = None;
 284
 285         remove_modal_grab();
 286         DragFinishing (); /* EMIT SIGNAL */
 287         return true;
 288 }
 289
 290 void
 291 Scroomer::on_size_allocate (Allocation& a)
 292 {
 293         Gtk::DrawingArea::on_size_allocate(a);
 294
 295         position[Total] = a.get_height();
 296         set_min_page_size(min_page_size);
 297         update();
 298 }
 299
 300 /** Assumes that x and width are correct, and they will not be altered.
 301  */
 302 void
 303 Scroomer::set_comp_rect(GdkRectangle& r, Component c) const
 304 {
 305         int index = (int) c;
 306
 307         switch (c) {
 308         case None:
 309                 return;
 310         case Total:
 311                 r.y = 0;
 312                 r.height = position[Total];
 313                 break;
 314         default:
 315                 r.y = position[index];
 316                 r.height = position[index+1] - position[index];
 317                 break;
 318         }
 319 }
 320
 321 Scroomer::Component
 322 Scroomer::point_in(double point) const
 323 {
 324         for (int i = 0; i < Total; ++i) {
 325                 if (position[i+1] >= point) {
 326                         return (Component) i;
 327                 }
 328         }
 329
 330         return None;
 331 }
 332
 333 void
 334 Scroomer::set_min_page_size(double ps)
 335 {
 336         double coeff = ((double)position[Total]) / (adj.get_upper() - adj.get_lower());
 337
 338         min_page_size = ps;
 339         handle_size = (int) floor((ps * coeff) / 2);
 340 }
 341
 342 void
 343 Scroomer::update()
 344 {
 345         double range = adj.get_upper() - adj.get_lower();
 346         //double value = adj.get_value() - adj.get_lower();
 347         int height = position[Total];
 348         double coeff = ((double) height) / range;
 349
 350         /* save the old positions to calculate update regions later*/
 351         for (int i = Handle1; i < Total; ++i) {
 352                 old_pos[i] = position[i];
 353         }
 354
 355         position[BottomBase] = (int) floor(height - (adj.get_value() * coeff));
 356         position[Handle2] = position[BottomBase] - handle_size;
 357
 358         position[Handle1] = (int) floor(height - ((adj.get_value() + adj.get_page_size()) * coeff));
 359         position[Slider] = position[Handle1] + handle_size;
 360 }
 361
 362 void
 363 Scroomer::adjustment_changed()
 364 {
 365         //cerr << floor(adj.get_value()) << " " << floor(adj.get_value() + adj.get_page_size()) << endl;
 366         Gdk::Rectangle rect;
 367         Glib::RefPtr<Gdk::Window> win = get_window();
 368
 369         update();
 370
 371         if (!win) {
 372                 return;
 373         }
 374
 375         rect.set_x(0);
 376         rect.set_width(get_width());
 377
 378         if (position[Handle1] < old_pos[Handle1]) {
 379                 rect.set_y(position[Handle1]);
 380                 rect.set_height(old_pos[Slider] - position[Handle1]);
 381                 win->invalidate_rect(rect, false);
 382         } else if (position[Handle1] > old_pos[Handle1]) {
 383                 rect.set_y(old_pos[Handle1]);
 384                 rect.set_height(position[Slider] - old_pos[Handle1]);
 385                 win->invalidate_rect(rect, false);
 386         }
 387
 388         if (position[Handle2] < old_pos[Handle2]) {
 389                 rect.set_y(position[Handle2]);
 390                 rect.set_height(old_pos[BottomBase] - position[Handle2]);
 391                 win->invalidate_rect(rect, false);
 392         } else if (position[Handle2] > old_pos[Handle2]) {
 393                 rect.set_y(old_pos[Handle2]);
 394                 rect.set_height(position[BottomBase] - old_pos[Handle2]);
 395                 win->invalidate_rect(rect, false);
 396         }
 397 }
 398