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         /* Then we handle zoom, which is dragging horizontally. We zoom around the area that is
 122          * the current y pointer value, not from the area that was the start of the drag.
 123          * the point of zoom must have the same
 124          */
 125
 126         if (ev->x > get_width()) {
 127                 zoom = ev->x - get_width();
 128
 129                 double higher = unzoomed_val + unzoomed_page - half_min_page - val_at_pointer;
 130                 double lower = val_at_pointer - (unzoomed_val + half_min_page);
 131
 132                 higher *= zoom / 128;
 133                 lower *= zoom / 128;
 134
 135                 val = unzoomed_val + lower;
 136                 page = unzoomed_page - higher - lower;
 137
 138                 page = max(page, min_page_size);
 139
 140                 if (lower < 0) {
 141                         val = max(val, val_at_pointer - half_min_page);
 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         } else if (ev->x < 0) {
 149                 /* on zoom out increase the page size as well as moving the range towards the mouse pos*/
 150                 zoom = abs(ev->x);
 151
 152                 /*double higher = unzoomed_val + unzoomed_page - half_min_page - val_at_pointer;
 153                 double lower = val_at_pointer - (unzoomed_val + half_min_page);
 154
 155                 higher *= zoom / 128;
 156                 lower *= zoom / 128;
 157
 158                 val = unzoomed_val + lower;
 159                 page = unzoomed_page - higher - lower;
 160
 161                 page = max(page, min_page_size);
 162
 163                 if (lower < 0) {
 164                         val = max(val, val_at_pointer - half_min_page);
 165                 }
 166                 else if (lower > 0) {
 167                         val = min(val, val_at_pointer - half_min_page);
 168                 }
 169
 170                 val = min(val, adj.get_upper() - min_page_size);
 171                 page = min(page, adj.get_upper() - val);*/
 172
 173                 val = unzoomed_val;
 174                 page = unzoomed_page;
 175         } else {
 176                 val = unzoomed_val;
 177                 page = unzoomed_page;
 178         }
 179
 180         adj.set_page_size(page);
 181
 182         if (val == adj.get_value()) {
 183                 adj.value_changed();
 184         }
 185
 186         if (val < adj.get_lower()) {
 187                 adj.value_changed();
 188         } else if (val > adj.get_upper()) {
 189                 adj.value_changed();
 190         } else {
 191                 adj.set_value(val);
 192         }
 193
 194         return true;
 195 }
 196
 197 bool
 198 Scroomer::on_button_press_event (GdkEventButton* ev)
 199 {
 200         if (ev->button == 1) {
 201                 Component comp = point_in(ev->y);
 202
 203                 if (comp == Total || comp == None) {
 204                         return false;
 205                 }
 206
 207                 add_modal_grab();
 208                 grab_comp = comp;
 209                 grab_y = ev->y;
 210                 unzoomed_val = adj.get_value();
 211                 unzoomed_page = adj.get_page_size();
 212                 grab_window = ev->window;
 213         }
 214         return false;
 215 }
 216
 217 bool
 218 Scroomer::on_button_release_event (GdkEventButton* ev)
 219 {
 220         if (grab_comp == None || grab_comp == Total) {
 221                 return true;
 222         }
 223
 224         if (ev->window != grab_window) {
 225                 grab_y = ev->y;
 226                 grab_window = ev->window;
 227                 return true;
 228         }
 229
 230         if (ev->button != 1) {
 231                 return true;
 232         }
 233
 234         switch (grab_comp) {
 235         case TopBase:
 236                 break;
 237         case Handle1:
 238                 break;
 239         case Slider:
 240                 break;
 241         case Handle2:
 242                 break;
 243         case BottomBase:
 244                 break;
 245         default:
 246                 break;
 247         }
 248
 249         grab_comp = None;
 250
 251         remove_modal_grab();
 252         return true;
 253 }
 254
 255 bool
 256 Scroomer::on_scroll_event (GdkEventScroll*)
 257 {
 258         return true;
 259 }
 260
 261 void
 262 Scroomer::on_size_allocate (Allocation& a)
 263 {
 264         Gtk::DrawingArea::on_size_allocate(a);
 265
 266         position[Total] = a.get_height();
 267         set_min_page_size(min_page_size);
 268         update();
 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 {
 276         int index = (int) c;
 277
 278         switch (c) {
 279         case None:
 280                 return;
 281         case Total:
 282                 r.y = 0;
 283                 r.height = position[Total];
 284                 break;
 285         default:
 286                 r.y = position[index];
 287                 r.height = position[index+1] - position[index];
 288                 break;
 289         }
 290 }
 291
 292 Scroomer::Component
 293 Scroomer::point_in(double point) const
 294 {
 295         for (int i = 0; i < Total; ++i) {
 296                 if (position[i+1] >= point) {
 297                         return (Component) i;
 298                 }
 299         }
 300
 301         return None;
 302 }
 303
 304 void
 305 Scroomer::set_min_page_size(double ps)
 306 {
 307         double coeff = ((double)position[Total]) / (adj.get_upper() - adj.get_lower());
 308
 309         min_page_size = ps;
 310         handle_size = (int) floor((ps * coeff) / 2);
 311 }
 312
 313 void
 314 Scroomer::update()
 315 {
 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 {
 336         //cerr << floor(adj.get_value()) << " " << floor(adj.get_value() + adj.get_page_size()) << endl;
 337         Gdk::Rectangle rect;
 338         Glib::RefPtr<Gdk::Window> win = get_window();
 339
 340         update();
 341
 342         if (!win) {
 343                 return;
 344         }
 345
 346         rect.set_x(0);
 347         rect.set_width(get_width());
 348
 349         if (position[Handle1] < old_pos[Handle1]) {
 350                 rect.set_y(position[Handle1]);
 351                 rect.set_height(old_pos[Slider] - position[Handle1]);
 352                 win->invalidate_rect(rect, false);
 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         } else if (position[Handle2] > old_pos[Handle2]) {
 364                 rect.set_y(old_pos[Handle2]);
 365                 rect.set_height(position[BottomBase] - old_pos[Handle2]);
 366                 win->invalidate_rect(rect, false);
 367         }
 368
 369         win->process_updates(false);
 370 }
 371
 372 std::string
 373 Scroomer::get_comp_name(Component c)
 374 {
 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 }