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 bool
  53 Scroomer::on_motion_notify_event (GdkEventMotion* ev) {
  54         double range = adj.get_upper() - adj.get_lower();
  55         double pixel2val = range / get_height();
  56         double val_at_pointer = ((get_height() - ev->y) * pixel2val) + adj.get_lower();
  57         double delta_y = ev->y - grab_y;
  58         double half_min_page = min_page_size / 2;
  59         double fract = delta_y / position[Total];
  60         double scale, temp, zoom;
  61         double val, page;
  62
  63         if(grab_comp == None || grab_comp == Total) {
  64                 return true;
  65         }
  66
  67         if (ev->window != grab_window) {
  68                 grab_y = ev->y;
  69                 grab_window = ev->window;
  70                 return true;
  71         }
  72
  73         grab_y = ev->y;
  74
  75         if (ev->state & GDK_CONTROL_MASK) {
  76                 if (ev->state & GDK_MOD1_MASK) {
  77                         scale = 0.05;
  78                 } else {
  79                         scale = 0.1;
  80                 }
  81         } else {
  82                 scale = 1.0;
  83         }
  84
  85         fract = min (1.0, fract);
  86         fract = max (-1.0, fract);
  87         fract = -fract;
  88
  89         switch(grab_comp) {
  90         case TopBase:
  91         case BottomBase:
  92                 unzoomed_val += scale * fract * range;
  93                 unzoomed_val = min(unzoomed_val, adj.get_upper() - unzoomed_page);
  94                 unzoomed_val = max(unzoomed_val, adj.get_lower());
  95                 break;
  96         case Slider:
  97                 unzoomed_val += scale * fract * range;
  98                 unzoomed_val = min(unzoomed_val, adj.get_upper() - unzoomed_page);
  99                 unzoomed_val = max(unzoomed_val, adj.get_lower());
 100                 break;
 101         case Handle1:
 102                 unzoomed_page += scale * fract * range;
 103                 unzoomed_page = min(unzoomed_page, adj.get_upper() - unzoomed_val);
 104                 unzoomed_page = max(unzoomed_page, min_page_size);
 105                 break;
 106         case Handle2:
 107                 temp = unzoomed_val + unzoomed_page;
 108                 unzoomed_val += scale * fract * range;
 109                 unzoomed_val = min(unzoomed_val, temp - min_page_size);
 110                 unzoomed_val = max(unzoomed_val, adj.get_lower());
 111
 112                 unzoomed_page = temp - unzoomed_val;
 113                 unzoomed_page = max(unzoomed_page, min_page_size);
 114                 break;
 115         default:
 116                 break;
 117         }
 118
 119         /*
 120          * Then we handle zoom, which is dragging horizontally. We zoom around the area that is
 121          * the current y pointer value, not from the area that was the start of the drag.
 122          * the point of zoom must have the same
 123          */
 124
 125         if(ev->x > get_width()) {
 126                 zoom = ev->x - get_width();
 127
 128                 double higher = unzoomed_val + unzoomed_page - half_min_page - val_at_pointer;
 129                 double lower = val_at_pointer - (unzoomed_val + half_min_page);
 130
 131                 higher *= zoom / 128;
 132                 lower *= zoom / 128;
 133
 134                 val = unzoomed_val + lower;
 135                 page = unzoomed_page - higher - lower;
 136
 137                 page = max(page, min_page_size);
 138
 139                 if(lower < 0) {
 140                         val = max(val, val_at_pointer - half_min_page);
 141                 }
 142                 else if(lower > 0) {
 143                         val = min(val, val_at_pointer - half_min_page);
 144                 }
 145
 146                 val = min(val, adj.get_upper() - min_page_size);
 147                 page = min(page, adj.get_upper() - val);
 148         }
 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         }
 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         if(val < adj.get_lower()) {
 188                 adj.value_changed();
 189         }
 190         else if(val > adj.get_upper()) {
 191                 adj.value_changed();
 192         }
 193         else {
 194                 adj.set_value(val);
 195         }
 196
 197         return true;
 198 }
 199
 200 bool
 201 Scroomer::on_button_press_event (GdkEventButton* ev) {
 202         if(ev->button == 1) {
 203                 Component comp = point_in(ev->y);
 204
 205                 cerr << get_comp_name(comp) << " pressed" << endl;
 206
 207                 if(comp == Total || comp == None) {
 208                         return false;
 209                 }
 210
 211                 add_modal_grab();
 212                 grab_comp = comp;
 213                 grab_y = ev->y;
 214                 unzoomed_val = adj.get_value();
 215                 unzoomed_page = adj.get_page_size();
 216                 grab_window = ev->window;
 217         }
 218         return false;
 219 }
 220
 221 bool
 222 Scroomer::on_button_release_event (GdkEventButton* ev) {
 223         if(grab_comp == None || grab_comp == Total) {
 224                 return true;
 225         }
 226
 227         if (ev->window != grab_window) {
 228                 grab_y = ev->y;
 229                 grab_window = ev->window;
 230                 return true;
 231         }
 232
 233         if (ev->button != 1) {
 234                 return true;
 235         }
 236
 237         switch(grab_comp) {
 238         case TopBase:
 239                 break;
 240         case Handle1:
 241                 break;
 242         case Slider:
 243                 break;
 244         case Handle2:
 245                 break;
 246         case BottomBase:
 247                 break;
 248         default:
 249                 break;
 250         }
 251
 252         grab_comp = None;
 253
 254         remove_modal_grab();
 255         return true;
 256 }
 257
 258 bool
 259 Scroomer::on_scroll_event (GdkEventScroll*) {
 260         return true;
 261 }
 262
 263 void
 264 Scroomer::on_size_allocate (Allocation& a) {
 265         Gtk::DrawingArea::on_size_allocate(a);
 266
 267         cerr << "allocate" << endl;
 268
 269         position[Total] = a.get_height();
 270         set_min_page_size(min_page_size);
 271         update();
 272 }
 273
 274 /*
 275  * assumes that x and width are correct, and they will not be altered
 276  */
 277 void
 278 Scroomer::set_comp_rect(GdkRectangle& r, Component c) const {
 279         int index = (int) c;
 280
 281         switch(c) {
 282         case None:
 283                 return;
 284         case Total:
 285                 r.y = 0;
 286                 r.height = position[Total];
 287                 break;
 288         default:
 289                 r.y = position[index];
 290                 r.height = position[index+1] - position[index];
 291                 break;
 292         }
 293 }
 294
 295 Scroomer::Component
 296 Scroomer::point_in(double point) const {
 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         double coeff = ((double)position[Total]) / (adj.get_upper() - adj.get_lower());
 309
 310         min_page_size = ps;
 311         handle_size = (int) floor((ps * coeff) / 2);
 312 }
 313
 314 void
 315 Scroomer::update() {
 316         double range = adj.get_upper() - adj.get_lower();
 317         double value = adj.get_value() - adj.get_lower();
 318         int height = position[Total];
 319         double coeff = ((double) height) / range;
 320
 321         /* save the old positions to calculate update regions later*/
 322         for(int i = Handle1; i < Total; ++i) {
 323                 old_pos[i] = position[i];
 324         }
 325
 326         position[BottomBase] = (int) floor(height - (adj.get_value() * coeff));
 327         position[Handle2] = position[BottomBase] - handle_size;
 328
 329         position[Handle1] = (int) floor(height - ((adj.get_value() + adj.get_page_size()) * coeff));
 330         position[Slider] = position[Handle1] + handle_size;
 331 }
 332
 333 void
 334 Scroomer::adjustment_changed() {
 335         //cerr << floor(adj.get_value()) << " " << floor(adj.get_value() + adj.get_page_size()) << endl;
 336         Gdk::Rectangle rect;
 337         Glib::RefPtr<Gdk::Window> win = get_window();
 338
 339         update();
 340
 341         if(!win) {
 342                 return;
 343         }
 344
 345         rect.set_x(0);
 346         rect.set_width(get_width());
 347
 348         if(position[Handle1] < old_pos[Handle1]) {
 349                 rect.set_y(position[Handle1]);
 350                 rect.set_height(old_pos[Slider] - position[Handle1]);
 351                 win->invalidate_rect(rect, false);
 352         }
 353         else if(position[Handle1] > old_pos[Handle1]) {
 354                 rect.set_y(old_pos[Handle1]);
 355                 rect.set_height(position[Slider] - old_pos[Handle1]);
 356                 win->invalidate_rect(rect, false);
 357         }
 358
 359         if(position[Handle2] < old_pos[Handle2]) {
 360                 rect.set_y(position[Handle2]);
 361                 rect.set_height(old_pos[BottomBase] - position[Handle2]);
 362                 win->invalidate_rect(rect, false);
 363         }
 364         else if(position[Handle2] > old_pos[Handle2]) {
 365                 rect.set_y(old_pos[Handle2]);
 366                 rect.set_height(position[BottomBase] - old_pos[Handle2]);
 367                 win->invalidate_rect(rect, false);
 368         }
 369
 370         win->process_updates(false);
 371 }
 372
 373 std::string
 374 Scroomer::get_comp_name(Component c) {
 375         switch(c) {
 376         case TopBase:
 377                 return "TopBase";
 378         case Handle1:
 379                 return "Handle1";
 380         case Slider:
 381                 return "Slider";
 382         case Handle2:
 383                 return "Handle2";
 384         case BottomBase:
 385                 return "BottomBase";
 386         case Total:
 387                 return "Total";
 388         case None:
 389                 return "None";
 390         default:
 391                 return "ERROR";
 392         }
 393 }