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                 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         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         return true;
 259 }
 260
 261 void
 262 Scroomer::on_size_allocate (Allocation& a) {
 263         Gtk::DrawingArea::on_size_allocate(a);
 264
 265         position[Total] = a.get_height();
 266         set_min_page_size(min_page_size);
 267         update();
 268 }
 269
 270 /*
 271  * assumes that x and width are correct, and they will not be altered
 272  */
 273 void
 274 Scroomer::set_comp_rect(GdkRectangle& r, Component c) const {
 275         int index = (int) c;
 276
 277         switch(c) {
 278         case None:
 279                 return;
 280         case Total:
 281                 r.y = 0;
 282                 r.height = position[Total];
 283                 break;
 284         default:
 285                 r.y = position[index];
 286                 r.height = position[index+1] - position[index];
 287                 break;
 288         }
 289 }
 290
 291 Scroomer::Component
 292 Scroomer::point_in(double point) const {
 293         for(int i = 0; i < Total; ++i) {
 294                 if(position[i+1] >= point) {
 295                         return (Component) i;
 296                 }
 297         }
 298
 299         return None;
 300 }
 301
 302 void
 303 Scroomer::set_min_page_size(double ps) {
 304         double coeff = ((double)position[Total]) / (adj.get_upper() - adj.get_lower());
 305
 306         min_page_size = ps;
 307         handle_size = (int) floor((ps * coeff) / 2);
 308 }
 309
 310 void
 311 Scroomer::update() {
 312         double range = adj.get_upper() - adj.get_lower();
 313         //double value = adj.get_value() - adj.get_lower();
 314         int height = position[Total];
 315         double coeff = ((double) height) / range;
 316
 317         /* save the old positions to calculate update regions later*/
 318         for(int i = Handle1; i < Total; ++i) {
 319                 old_pos[i] = position[i];
 320         }
 321
 322         position[BottomBase] = (int) floor(height - (adj.get_value() * coeff));
 323         position[Handle2] = position[BottomBase] - handle_size;
 324
 325         position[Handle1] = (int) floor(height - ((adj.get_value() + adj.get_page_size()) * coeff));
 326         position[Slider] = position[Handle1] + handle_size;
 327 }
 328
 329 void
 330 Scroomer::adjustment_changed() {
 331         //cerr << floor(adj.get_value()) << " " << floor(adj.get_value() + adj.get_page_size()) << endl;
 332         Gdk::Rectangle rect;
 333         Glib::RefPtr<Gdk::Window> win = get_window();
 334
 335         update();
 336
 337         if(!win) {
 338                 return;
 339         }
 340
 341         rect.set_x(0);
 342         rect.set_width(get_width());
 343
 344         if(position[Handle1] < old_pos[Handle1]) {
 345                 rect.set_y(position[Handle1]);
 346                 rect.set_height(old_pos[Slider] - position[Handle1]);
 347                 win->invalidate_rect(rect, false);
 348         }
 349         else if(position[Handle1] > old_pos[Handle1]) {
 350                 rect.set_y(old_pos[Handle1]);
 351                 rect.set_height(position[Slider] - old_pos[Handle1]);
 352                 win->invalidate_rect(rect, false);
 353         }
 354
 355         if(position[Handle2] < old_pos[Handle2]) {
 356                 rect.set_y(position[Handle2]);
 357                 rect.set_height(old_pos[BottomBase] - position[Handle2]);
 358                 win->invalidate_rect(rect, false);
 359         }
 360         else if(position[Handle2] > old_pos[Handle2]) {
 361                 rect.set_y(old_pos[Handle2]);
 362                 rect.set_height(position[BottomBase] - old_pos[Handle2]);
 363                 win->invalidate_rect(rect, false);
 364         }
 365
 366         win->process_updates(false);
 367 }
 368
 369 std::string
 370 Scroomer::get_comp_name(Component c) {
 371         switch(c) {
 372         case TopBase:
 373                 return "TopBase";
 374         case Handle1:
 375                 return "Handle1";
 376         case Slider:
 377                 return "Slider";
 378         case Handle2:
 379                 return "Handle2";
 380         case BottomBase:
 381                 return "BottomBase";
 382         case Total:
 383                 return "Total";
 384         case None:
 385                 return "None";
 386         default:
 387                 return "ERROR";
 388         }
 389 }