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                 unzoomed_page += scale * fract * range;
 107                 unzoomed_page = min(unzoomed_page, adj.get_upper() - unzoomed_val);
 108                 unzoomed_page = max(unzoomed_page, min_page_size);
 109                 break;
 110         case Handle2:
 111                 temp = unzoomed_val + unzoomed_page;
 112                 unzoomed_val += scale * fract * range;
 113                 unzoomed_val = min(unzoomed_val, temp - min_page_size);
 114                 unzoomed_val = max(unzoomed_val, adj.get_lower());
 115
 116                 unzoomed_page = temp - unzoomed_val;
 117                 unzoomed_page = max(unzoomed_page, min_page_size);
 118                 break;
 119         default:
 120                 break;
 121         }
 122
 123         /* Then we handle zoom, which is dragging horizontally. We zoom around the area that is
 124          * the current y pointer value, not from the area that was the start of the drag.
 125          * the point of zoom must have the same
 126          */
 127
 128         if (ev->x > get_width()) {
 129                 zoom = ev->x - get_width();
 130
 131                 double higher = unzoomed_val + unzoomed_page - half_min_page - val_at_pointer;
 132                 double lower = val_at_pointer - (unzoomed_val + half_min_page);
 133
 134                 higher *= zoom / 128;
 135                 lower *= zoom / 128;
 136
 137                 val = unzoomed_val + lower;
 138                 page = unzoomed_page - higher - lower;
 139
 140                 page = max(page, min_page_size);
 141
 142                 if (lower < 0) {
 143                         val = max(val, val_at_pointer - half_min_page);
 144                 } else if (lower > 0) {
 145                         val = min(val, val_at_pointer - half_min_page);
 146                 }
 147
 148                 val = min(val, adj.get_upper() - min_page_size);
 149                 page = min(page, adj.get_upper() - val);
 150         } else if (ev->x < 0) {
 151                 /* on zoom out increase the page size as well as moving the range towards the mouse pos*/
 152                 zoom = abs(ev->x);
 153
 154                 /*double higher = unzoomed_val + unzoomed_page - half_min_page - val_at_pointer;
 155                 double lower = val_at_pointer - (unzoomed_val + half_min_page);
 156
 157                 higher *= zoom / 128;
 158                 lower *= zoom / 128;
 159
 160                 val = unzoomed_val + lower;
 161                 page = unzoomed_page - higher - lower;
 162
 163                 page = max(page, min_page_size);
 164
 165                 if (lower < 0) {
 166                         val = max(val, val_at_pointer - half_min_page);
 167                 }
 168                 else if (lower > 0) {
 169                         val = min(val, val_at_pointer - half_min_page);
 170                 }
 171
 172                 val = min(val, adj.get_upper() - min_page_size);
 173                 page = min(page, adj.get_upper() - val);*/
 174
 175                 val = unzoomed_val;
 176                 page = unzoomed_page;
 177         } else {
 178                 val = unzoomed_val;
 179                 page = unzoomed_page;
 180         }
 181
 182         adj.set_page_size(page);
 183
 184         if (val == adj.get_value()) {
 185                 adj.value_changed();
 186         }
 187
 188         if (val < adj.get_lower()) {
 189                 adj.value_changed();
 190         } else if (val > adj.get_upper()) {
 191                 adj.value_changed();
 192         } else {
 193                 adj.set_value(val);
 194         }
 195
 196         return true;
 197 }
 198
 199 bool
 200 Scroomer::on_button_press_event (GdkEventButton* ev)
 201 {
 202         if (ev->button == 1) {
 203                 Component comp = point_in(ev->y);
 204
 205                 if (comp == Total || comp == None) {
 206                         return false;
 207                 }
 208
 209                 add_modal_grab();
 210                 grab_comp = comp;
 211                 grab_y = ev->y;
 212                 unzoomed_val = adj.get_value();
 213                 unzoomed_page = adj.get_page_size();
 214                 grab_window = ev->window;
 215         }
 216         return false;
 217 }
 218
 219 bool
 220 Scroomer::on_button_release_event (GdkEventButton* ev)
 221 {
 222         if (grab_comp == None || grab_comp == Total) {
 223                 return true;
 224         }
 225
 226         if (ev->window != grab_window) {
 227                 grab_y = ev->y;
 228                 grab_window = ev->window;
 229                 return true;
 230         }
 231
 232         if (ev->button != 1) {
 233                 return true;
 234         }
 235
 236         switch (grab_comp) {
 237         case TopBase:
 238                 break;
 239         case Handle1:
 240                 break;
 241         case Slider:
 242                 break;
 243         case Handle2:
 244                 break;
 245         case BottomBase:
 246                 break;
 247         default:
 248                 break;
 249         }
 250
 251         grab_comp = None;
 252
 253         remove_modal_grab();
 254         return true;
 255 }
 256
 257 bool
 258 Scroomer::on_scroll_event (GdkEventScroll*)
 259 {
 260         return true;
 261 }
 262
 263 void
 264 Scroomer::on_size_allocate (Allocation& a)
 265 {
 266         Gtk::DrawingArea::on_size_allocate(a);
 267
 268         position[Total] = a.get_height();
 269         set_min_page_size(min_page_size);
 270         update();
 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 }