src/fisheye.vala

   1 /*
   2  * zavai - simple interface to the OpenMoko (or to the FSO stack)
   3  *
   4  * Copyright (C) 2009  Enrico Zini <enrico@enricozini.org>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  */
  20
  21 using GLib;
  22
  23 public class FisheyeList : Gtk.DrawingArea
  24 {
  25         protected Gtk.TreeModel model;
  26         protected Gdk.Pixmap background;
  27         protected Gdk.Pixmap backing_store;
  28
  29         // Pango layouts cached for speed
  30         protected const int steps = 5;
  31         protected Gtk.CellRendererText[] renderers;
  32
  33         // Labels to show, extracted from the model
  34         protected string[] label_cache;
  35         protected bool base_layout_needed;
  36
  37         protected int cur_el;
  38
  39         // Layout information
  40         protected int focus_first;
  41         protected int focus_end;
  42         protected int[] focus_starts;
  43         protected bool focus_locked;
  44         protected bool focus_layout_needed;
  45
  46         protected int _focus_size;
  47         public int focus_size {
  48                 get { return _focus_size; }
  49                 set {
  50                         _focus_size = value;
  51                         focus_starts = new int[value+1];
  52                         focus_layout_needed = true;
  53                         queue_draw();
  54                 }
  55         }
  56
  57         protected int _label_column;
  58         public int label_column {
  59                 get { return _label_column; }
  60                 set {
  61                         _label_column = value;
  62                         base_layout_needed = true;
  63                         queue_draw();
  64                 }
  65         }
  66
  67         //public virtual signal void cursor_changed ();
  68         public signal void row_activated(Gtk.TreePath path);
  69
  70         public FisheyeList()
  71         {
  72                 model = null;
  73                 backing_store = null;
  74
  75                 label_cache = null;
  76
  77                 renderers = new Gtk.CellRendererText[steps];
  78
  79                 // Defaults for properties
  80                 focus_size = 21;
  81                 label_column = 0;
  82
  83                 cur_el = 0;
  84                 focus_locked = false;
  85
  86                 add_events(Gdk.EventMask.POINTER_MOTION_MASK
  87                          | Gdk.EventMask.BUTTON_PRESS_MASK
  88                          | Gdk.EventMask.BUTTON_RELEASE_MASK);
  89         }
  90
  91         public unowned Gtk.TreeModel get_model() { return model; }
  92         public void set_model (Gtk.TreeModel? model)
  93         {
  94                 if (this.model != null)
  95                 {
  96                         this.model.row_changed -= on_row_changed;
  97                         this.model.row_deleted -= on_row_deleted;
  98                         this.model.row_has_child_toggled -= on_row_has_child_toggled;
  99                         this.model.row_inserted -= on_row_inserted;
 100                         this.model.rows_reordered -= on_rows_reordered;
 101                 }
 102                 this.model = model;
 103                 this.model.row_changed += on_row_changed;
 104                 this.model.row_deleted += on_row_deleted;
 105                 this.model.row_has_child_toggled += on_row_has_child_toggled;
 106                 this.model.row_inserted += on_row_inserted;
 107                 this.model.rows_reordered += on_rows_reordered;
 108                 base_layout_needed = true;
 109                 queue_draw();
 110         }
 111
 112         private void on_row_changed(Gtk.TreePath path, Gtk.TreeIter iter) { base_layout_needed = true; }
 113         private void on_row_deleted(Gtk.TreePath path) { base_layout_needed = true; }
 114         private void on_row_has_child_toggled(Gtk.TreePath path, Gtk.TreeIter iter) { base_layout_needed = true; }
 115         private void on_row_inserted(Gtk.TreePath path, Gtk.TreeIter iter) { base_layout_needed = true; }
 116         private void on_rows_reordered(Gtk.TreePath path, Gtk.TreeIter iter, void* new_order) { base_layout_needed = true; }
 117
 118         /* Mouse button got pressed over widget */
 119         /*
 120         public override bool button_press_event(Gdk.EventButton event)
 121         {
 122                 stderr.printf("Mouse pressed on %d %s\n", cur_el, label_cache[cur_el]);
 123                 return false;
 124         }
 125         */
 126
 127         /* Mouse button got released */
 128         public override bool button_release_event(Gdk.EventButton event)
 129         {
 130                 stderr.printf("Mouse released on %d %s\n", cur_el, label_cache[cur_el]);
 131
 132                 // Emit row_activated if applicable
 133                 if (model != null)
 134                 {
 135                         Gtk.TreeIter iter;
 136                         if (model.iter_nth_child(out iter, null, cur_el))
 137                         {
 138                                 Gtk.TreePath path = model.get_path(iter);
 139                                 row_activated(path);
 140                         }
 141                 }
 142                 return false;
 143         }
 144
 145         /* Mouse pointer moved over widget */
 146         public override bool motion_notify_event(Gdk.EventMotion event)
 147         {
 148                 int old_cur_el = cur_el;
 149                 int x = (int)event.x;
 150                 int y = (int)event.y;
 151
 152                 focus_locked = !focus_layout_needed && x < allocation.width/2 && y >= focus_starts[0] && y < focus_starts[focus_end - focus_first];
 153
 154                 if (focus_locked)
 155                 {
 156                         for (int idx = focus_first; idx < focus_end; ++idx)
 157                                 if (y < focus_starts[idx-focus_first+1])
 158                                 {
 159                                         cur_el = idx;
 160                                         break;
 161                                 }
 162
 163                 } else {
 164                         cur_el = y * label_cache.length / allocation.height;
 165                         if (old_cur_el != cur_el)
 166                                 focus_layout_needed = true;
 167                 }
 168
 169                 //stderr.printf("MOTION %f %f CE %d\n", event.x, event.y, cur_el);
 170                 if (old_cur_el != cur_el)
 171                 {
 172                         queue_draw();
 173                         old_cur_el = cur_el;
 174                 }
 175                 return false;
 176         }
 177
 178         public override bool configure_event (Gdk.EventConfigure event)
 179         {
 180                 base_layout_needed = true;
 181                 queue_draw();
 182                 return false;
 183         }
 184
 185         /* Widget is asked to draw itself */
 186         public override bool expose_event (Gdk.EventExpose event)
 187         {
 188                 draw();
 189
 190                 window.draw_drawable(
 191                         get_style().fg_gc[Gtk.StateType.NORMAL],
 192                         backing_store,
 193                         event.area.x, event.area.y,
 194                         event.area.x, event.area.y,
 195                         event.area.width, event.area.height);
 196
 197                 return false;
 198         }
 199
 200         public override void style_set(Gtk.Style? previous_style)
 201         {
 202                 base_layout_needed = true;
 203         }
 204         public override void direction_changed(Gtk.TextDirection previous_direction)
 205         {
 206                 base_layout_needed = true;
 207         }
 208
 209         protected int el_y(int idx)
 210         {
 211                 // Distorted position
 212                 int pos = fisheye(idx);
 213                 //stderr.printf("%d %f %f\n", idx, undy, pos);
 214                 return pos;
 215         }
 216
 217         protected Gtk.CellRendererText make_cell_renderer()
 218         {
 219                 var res = new Gtk.CellRendererText();
 220                 res.font_desc = get_style().font_desc;
 221                 return res;
 222         }
 223
 224         protected void base_layout()
 225         {
 226                 background = new Gdk.Pixmap(window, allocation.width, allocation.height, -1);
 227                 backing_store = new Gdk.Pixmap(window, allocation.width, allocation.height, -1);
 228
 229                 // Recreate the renderers
 230                 renderers[renderers.length-1] = make_cell_renderer();
 231                 renderers[renderers.length-1].set_fixed_height_from_font(1);
 232
 233                 renderers[0] = make_cell_renderer();
 234                 renderers[0].size = Pango.SCALE;
 235                 renderers[0].set_fixed_height_from_font(1);
 236
 237                 for (int i = 1; i < renderers.length-1; ++i)
 238                 {
 239                         renderers[i] = make_cell_renderer();
 240                         renderers[i].scale = (double)i / renderers.length;
 241                         renderers[i].set_fixed_height_from_font(1);
 242                 }
 243
 244                 if (model == null)
 245                 {
 246                         label_cache = new string[0];
 247                 } else {
 248                         Gtk.TreeIter iter;
 249                         if (!model.get_iter_first(out iter))
 250                         {
 251                                 label_cache = new string[0];
 252                         }
 253                         else
 254                         {
 255                                 int count = model.iter_n_children(null);
 256                                 label_cache = new string[count];
 257
 258                                 int i = 0;
 259                                 do {
 260                                         string val;
 261                                         model.get(iter, _label_column, out val, -1);
 262                                         label_cache[i] = val;
 263                                         ++i;
 264                                 } while (model.iter_next(ref iter));
 265                         }
 266                 }
 267
 268                 // Draw background
 269                 draw_background(background);
 270
 271                 base_layout_needed = false;
 272                 focus_layout_needed = true;
 273         }
 274
 275         protected void focus_layout()
 276         {
 277                 if (label_cache.length == 0)
 278                 {
 279                         focus_first = 0;
 280                         focus_end = 0;
 281                         focus_starts[0] = 0;
 282                 } else {
 283                         if (_focus_size >= label_cache.length)
 284                         {
 285                                 focus_first = 0;
 286                                 focus_end = label_cache.length;
 287                         } else {
 288                                 focus_first = cur_el -_focus_size/2;
 289                                 if (focus_first < 0) focus_first = 0;
 290
 291                                 focus_end = focus_first + _focus_size;
 292                                 if (focus_end > label_cache.length)
 293                                 {
 294                                         focus_end = label_cache.length;
 295                                         focus_first = focus_end - _focus_size;
 296                                 }
 297                         }
 298
 299                         // Compute starting positions for all items in focus
 300                         for (int idx = focus_first; idx <= focus_end; ++idx)
 301                                 focus_starts[idx - focus_first] = el_y(idx);
 302                 }
 303                 focus_layout_needed = false;
 304         }
 305
 306         protected void draw_background(Gdk.Drawable drawable)
 307         {
 308                 Gtk.Style style = get_style();
 309
 310                 // Background
 311                 drawable.draw_rectangle(style.bg_gc[Gtk.StateType.NORMAL], true, 0, 0, allocation.width, allocation.height);
 312
 313                 // Focus movement area
 314                 drawable.draw_rectangle(style.bg_gc[Gtk.StateType.INSENSITIVE], true,
 315                         allocation.width/2, 0, allocation.width, allocation.height);
 316
 317                 Gdk.Rectangle expose_area = Gdk.Rectangle();
 318                 expose_area.x = expose_area.y = 0;
 319                 expose_area.width = allocation.width;
 320                 expose_area.height = allocation.height;
 321
 322                 stderr.printf("BG %d %d\n", label_cache.length, allocation.height);
 323                 if (label_cache.length >= allocation.height)
 324                 {
 325                         stderr.printf("LABELS\n");
 326                         Gdk.Rectangle cell_area = Gdk.Rectangle();
 327                         cell_area.x = 0;
 328                         cell_area.width = allocation.width;
 329                         cell_area.height = 1;
 330                         for (int y = 0; y < allocation.height; ++y)
 331                         {
 332                                 int idx = y * label_cache.length / allocation.height;
 333                                 cell_area.y = y;
 334                                 renderers[0].text = label_cache[idx];
 335                                 renderers[0].render((Gdk.Window*)drawable, this,
 336                                                 cell_area,
 337                                                 cell_area,
 338                                                 expose_area,
 339                                                 0);
 340                         }
 341                 }
 342         }
 343
 344         protected void draw()
 345         {
 346                 if (base_layout_needed)
 347                         base_layout();
 348                 if (focus_layout_needed)
 349                         focus_layout();
 350
 351                 var drawable = backing_store;
 352                 Gtk.Style style = get_style();
 353                 Gdk.Rectangle expose_area = Gdk.Rectangle();
 354                 expose_area.x = expose_area.y = 0;
 355                 expose_area.width = allocation.width;
 356                 expose_area.height = allocation.height;
 357
 358                 // Background
 359                 drawable.draw_drawable(
 360                         get_style().fg_gc[Gtk.StateType.NORMAL],
 361                         background,
 362                         0, 0, 0, 0,
 363                         allocation.width, allocation.height);
 364
 365                 // Focus lock area
 366                 drawable.draw_rectangle(style.bg_gc[Gtk.StateType.ACTIVE], true,
 367                         0, focus_starts[0], allocation.width/2, focus_starts[focus_end - focus_first]-focus_starts[0]);
 368
 369                 // Paint items around focus
 370                 Gdk.Rectangle cell_area = Gdk.Rectangle();
 371                 cell_area.x = 0;
 372                 cell_area.width = allocation.width;
 373                 for (int idx = 0; idx < focus_end-focus_first; ++idx)
 374                 {
 375                         int y0 = focus_starts[idx];
 376                         int y1 = focus_starts[idx + 1];
 377                         cell_area.y = y0;
 378                         cell_area.height = y1-y0;
 379
 380                         Gtk.CellRendererState rflags = 0;
 381                         if (idx + focus_first == cur_el)
 382                         {
 383                                 rflags |= Gtk.CellRendererState.SELECTED | Gtk.CellRendererState.FOCUSED;
 384                                 drawable.draw_rectangle(style.bg_gc[Gtk.StateType.SELECTED], true,
 385                                                 cell_area.x, cell_area.y, cell_area.width, cell_area.height);
 386                         }
 387
 388                         int size = (y1-y0);
 389                         if (size <= 0) size = 1;
 390                         if (size >= renderers.length) size = renderers.length - 1;
 391                         renderers[size].text = label_cache[idx + focus_first];
 392                         renderers[size].render((Gdk.Window*)drawable, this,
 393                                         cell_area,
 394                                         cell_area,
 395                                         expose_area,
 396                                         rflags);
 397
 398                         //Gdk.draw_line(drawable, style.fg_gc[itemState], 0, y0, allocation.width, y0);
 399                 }
 400         }
 401
 402         /*
 403          * The following function is adapted from Prefuse's FisheyeDistortion.java.
 404          *
 405          * A relevant annotation from Prefuse:
 406          *
 407          * For more details on this form of transformation, see Manojit Sarkar and
 408          * Marc H. Brown, "Graphical Fisheye Views of Graphs", in Proceedings of
 409          * CHI'92, Human Factors in Computing Systems, p. 83-91, 1992. Available
 410          * online at <a href="http://citeseer.ist.psu.edu/sarkar92graphical.html">
 411          * http://citeseer.ist.psu.edu/sarkar92graphical.html</a>.
 412          */
 413
 414         /*
 415          * Distorts an item's coordinate.
 416          * @param x the undistorted coordinate
 417          * @param coordinate of the anchor or focus point
 418          * @param d disortion factor
 419          * @param min the beginning of the display
 420          * @param max the end of the display
 421          * @return the distorted coordinate
 422          */
 423         private int fisheye(int idx)
 424         {
 425                 // Autocompute distortion factor
 426                 // 20 is the pixel size of the item at centre of focus
 427                 double d = label_cache.length * 20 / allocation.height;
 428                 if ( d <= 1 )
 429                         return idx * allocation.height / label_cache.length;
 430
 431                 double a = (double)cur_el * allocation.height / label_cache.length;
 432                 double x = (double)idx * allocation.height / label_cache.length;
 433                 double max = (double)allocation.height;
 434
 435                 if (idx < cur_el)
 436                 {
 437                         double m = a;
 438                         if ( m == 0 ) m = max;
 439                         double v = (double)(a - x) / m;
 440                         v = (double)(d+1)/(d+(1/v));
 441                         return (int)Math.round(a - m*v);
 442                 } else {
 443                         double m = max-a;
 444                         if ( m == 0 ) m = max;
 445                         double v = (double)(x - a) / m;
 446                         v = (double)(d+1)/(d+(1/v));
 447                         return (int)Math.round(a + m*v);
 448                 }
 449         }
 450 }
 451
 452 public class Fisheye : Gtk.Window
 453 {
 454         public Fisheye()
 455         {
 456                 title = "Fisheye";
 457                 destroy += Gtk.main_quit;
 458
 459                 var list = new FisheyeList();
 460                 add(list);
 461
 462                 var store = new Gtk.ListStore(1, typeof(string));
 463                 Gtk.TreeIter iter;
 464                 var infd = FileStream.open("/tmp/names", "r");
 465                 if (infd == null)
 466                 {
 467                         for (int i = 0; i < 300; ++i)
 468                         {
 469                                 store.append(out iter);
 470                                 store.set(iter, 0, "Antani %d".printf(i), -1);
 471                         }
 472                 } else {
 473                         char buf[255];
 474                         while (true)
 475                         {
 476                                 string line = infd.gets(buf);
 477                                 if (line == null)
 478                                         break;
 479                                 store.append(out iter);
 480                                 store.set(iter, 0, line, -1);
 481                         }
 482                 }
 483
 484                 list.set_model(store);
 485         }
 486 }
 487
 488 static int main (string[] args) {
 489         Gtk.init (ref args);
 490
 491         var fe = new Fisheye();
 492         fe.set_size_request(200, 300);
 493         fe.show_all();
 494
 495         Gtk.main();
 496
 497         return 0;
 498 }