src/zoom-context.cpp

   1 /*
   2  * Handy zooming tool
   3  *
   4  * Authors:
   5  *   Lauris Kaplinski <lauris@kaplinski.com>
   6  *   Frank Felfe <innerspace@iname.com>
   7  *   bulia byak <buliabyak@users.sf.net>
   8  *
   9  * Copyright (C) 1999-2002 Authors
  10  *
  11  * Released under GNU GPL, read the file 'COPYING' for more information
  12  */
  13
  14
  15 #include <gdk/gdkkeysyms.h>
  16
  17 #include "macros.h"
  18 #include "rubberband.h"
  19 #include "display/sp-canvas-item.h"
  20 #include "display/sp-canvas-util.h"
  21 #include "desktop.h"
  22 #include "pixmaps/cursor-zoom.xpm"
  23 #include "pixmaps/cursor-zoom-out.xpm"
  24 #include "preferences.h"
  25
  26 #include "zoom-context.h"
  27
  28 static void sp_zoom_context_class_init(SPZoomContextClass *klass);
  29 static void sp_zoom_context_init(SPZoomContext *zoom_context);
  30 static void sp_zoom_context_setup(SPEventContext *ec);
  31 static void sp_zoom_context_finish (SPEventContext *ec);
  32
  33 static gint sp_zoom_context_root_handler(SPEventContext *event_context, GdkEvent *event);
  34 static gint sp_zoom_context_item_handler(SPEventContext *event_context, SPItem *item, GdkEvent *event);
  35
  36 static SPEventContextClass *parent_class;
  37
  38 static gint xp = 0, yp = 0; // where drag started
  39 static gint tolerance = 0;
  40 static bool within_tolerance = false;
  41 static bool escaped;
  42
  43 GType sp_zoom_context_get_type(void)
  44 {
  45     static GType type = 0;
  46
  47     if (!type) {
  48         GTypeInfo info = {
  49             sizeof(SPZoomContextClass),
  50             NULL, NULL,
  51             (GClassInitFunc) sp_zoom_context_class_init,
  52             NULL, NULL,
  53             sizeof(SPZoomContext),
  54             4,
  55             (GInstanceInitFunc) sp_zoom_context_init,
  56             NULL,       /* value_table */
  57         };
  58         type = g_type_register_static(SP_TYPE_EVENT_CONTEXT, "SPZoomContext", &info, (GTypeFlags) 0);
  59     }
  60
  61     return type;
  62 }
  63
  64 static void sp_zoom_context_class_init(SPZoomContextClass *klass)
  65 {
  66     SPEventContextClass *event_context_class = (SPEventContextClass *) klass;
  67
  68     parent_class = (SPEventContextClass*) g_type_class_peek_parent(klass);
  69
  70     event_context_class->setup = sp_zoom_context_setup;
  71     event_context_class->finish = sp_zoom_context_finish;
  72
  73     event_context_class->root_handler = sp_zoom_context_root_handler;
  74     event_context_class->item_handler = sp_zoom_context_item_handler;
  75 }
  76
  77 static void sp_zoom_context_init (SPZoomContext *zoom_context)
  78 {
  79     SPEventContext *event_context = SP_EVENT_CONTEXT(zoom_context);
  80
  81     event_context->cursor_shape = cursor_zoom_xpm;
  82     event_context->hot_x = 6;
  83     event_context->hot_y = 6;
  84 }
  85
  86 static void
  87 sp_zoom_context_finish (SPEventContext *ec)
  88 {
  89         SPZoomContext *zc = SP_ZOOM_CONTEXT(ec);
  90
  91         ec->enableGrDrag(false);
  92
  93     if (zc->grabbed) {
  94         sp_canvas_item_ungrab(zc->grabbed, GDK_CURRENT_TIME);
  95         zc->grabbed = NULL;
  96     }
  97 }
  98
  99 static void sp_zoom_context_setup(SPEventContext *ec)
 100 {
 101     Inkscape::Preferences *prefs = Inkscape::Preferences::get();
 102     if (prefs->getBool("/tools/zoom/selcue")) {
 103         ec->enableSelectionCue();
 104     }
 105     if (prefs->getBool("/tools/zoom/gradientdrag")) {
 106         ec->enableGrDrag();
 107     }
 108
 109     if (((SPEventContextClass *) parent_class)->setup) {
 110         ((SPEventContextClass *) parent_class)->setup(ec);
 111     }
 112 }
 113
 114 static gint sp_zoom_context_item_handler(SPEventContext *event_context, SPItem *item, GdkEvent *event)
 115 {
 116     gint ret = FALSE;
 117
 118     if (((SPEventContextClass *) parent_class)->item_handler) {
 119         ret = ((SPEventContextClass *) parent_class)->item_handler (event_context, item, event);
 120     }
 121
 122     return ret;
 123 }
 124
 125 static gint sp_zoom_context_root_handler(SPEventContext *event_context, GdkEvent *event)
 126 {
 127     SPDesktop *desktop = event_context->desktop;
 128     Inkscape::Preferences *prefs = Inkscape::Preferences::get();
 129
 130         SPZoomContext *zc = SP_ZOOM_CONTEXT(event_context);
 131     tolerance = prefs->getIntLimited("/options/dragtolerance/value", 0, 0, 100);
 132     double const zoom_inc = prefs->getDoubleLimited("/options/zoomincrement/value", M_SQRT2, 1.01, 10);
 133
 134     gint ret = FALSE;
 135
 136     switch (event->type) {
 137         case GDK_BUTTON_PRESS:
 138         {
 139             Geom::Point const button_w(event->button.x, event->button.y);
 140             Geom::Point const button_dt(desktop->w2d(button_w));
 141             if (event->button.button == 1 && !event_context->space_panning) {
 142                 // save drag origin
 143                 xp = (gint) event->button.x;
 144                 yp = (gint) event->button.y;
 145                 within_tolerance = true;
 146
 147                 Inkscape::Rubberband::get(desktop)->start(desktop, button_dt);
 148
 149                 escaped = false;
 150
 151                 ret = TRUE;
 152             } else if (event->button.button == 3) {
 153                 double const zoom_rel( (event->button.state & GDK_SHIFT_MASK)
 154                                        ? zoom_inc
 155                                        : 1 / zoom_inc );
 156                 desktop->zoom_relative_keep_point(button_dt, zoom_rel);
 157                 ret = TRUE;
 158             }
 159
 160                         sp_canvas_item_grab(SP_CANVAS_ITEM(desktop->acetate),
 161                                                                 GDK_KEY_PRESS_MASK | GDK_KEY_RELEASE_MASK | GDK_BUTTON_RELEASE_MASK | GDK_POINTER_MOTION_MASK | GDK_POINTER_MOTION_HINT_MASK | GDK_BUTTON_PRESS_MASK,
 162                                                                 NULL, event->button.time);
 163                         zc->grabbed = SP_CANVAS_ITEM(desktop->acetate);
 164
 165             break;
 166         }
 167
 168         case GDK_MOTION_NOTIFY:
 169             if (event->motion.state & GDK_BUTTON1_MASK && !event_context->space_panning) {
 170                 ret = TRUE;
 171
 172                 if ( within_tolerance
 173                      && ( abs( (gint) event->motion.x - xp ) < tolerance )
 174                      && ( abs( (gint) event->motion.y - yp ) < tolerance ) ) {
 175                     break; // do not drag if we're within tolerance from origin
 176                 }
 177                 // Once the user has moved farther than tolerance from the original location
 178                 // (indicating they intend to move the object, not click), then always process the
 179                 // motion notify coordinates as given (no snapping back to origin)
 180                 within_tolerance = false;
 181
 182                 Geom::Point const motion_w(event->motion.x, event->motion.y);
 183                 Geom::Point const motion_dt(desktop->w2d(motion_w));
 184                 Inkscape::Rubberband::get(desktop)->move(motion_dt);
 185                 gobble_motion_events(GDK_BUTTON1_MASK);
 186             }
 187             break;
 188
 189         case GDK_BUTTON_RELEASE:
 190         {
 191             Geom::Point const button_w(event->button.x, event->button.y);
 192             Geom::Point const button_dt(desktop->w2d(button_w));
 193             if ( event->button.button == 1  && !event_context->space_panning) {
 194                 Geom::OptRect const b = Inkscape::Rubberband::get(desktop)->getRectangle();
 195                 if (b && !within_tolerance) {
 196                     desktop->set_display_area(*b, 10);
 197                 } else if (!escaped) {
 198                     double const zoom_rel( (event->button.state & GDK_SHIFT_MASK)
 199                                            ? 1 / zoom_inc
 200                                            : zoom_inc );
 201                     desktop->zoom_relative_keep_point(button_dt, zoom_rel);
 202                 }
 203                 ret = TRUE;
 204             }
 205             Inkscape::Rubberband::get(desktop)->stop();
 206
 207                         if (zc->grabbed) {
 208                                 sp_canvas_item_ungrab(zc->grabbed, event->button.time);
 209                                 zc->grabbed = NULL;
 210                         }
 211
 212             xp = yp = 0;
 213             escaped = false;
 214             break;
 215         }
 216         case GDK_KEY_PRESS:
 217             switch (get_group0_keyval (&event->key)) {
 218                 case GDK_Escape:
 219                     Inkscape::Rubberband::get(desktop)->stop();
 220                     xp = yp = 0;
 221                     escaped = true;
 222                     ret = TRUE;
 223                     break;
 224                 case GDK_Up:
 225                 case GDK_Down:
 226                 case GDK_KP_Up:
 227                 case GDK_KP_Down:
 228                     // prevent the zoom field from activation
 229                     if (!MOD__CTRL_ONLY)
 230                         ret = TRUE;
 231                     break;
 232                 case GDK_Shift_L:
 233                 case GDK_Shift_R:
 234                     event_context->cursor_shape = cursor_zoom_out_xpm;
 235                     sp_event_context_update_cursor(event_context);
 236                     break;
 237                 default:
 238                         break;
 239                 }
 240                 break;
 241         case GDK_KEY_RELEASE:
 242             switch (get_group0_keyval (&event->key)) {
 243                 case GDK_Shift_L:
 244                 case GDK_Shift_R:
 245                     event_context->cursor_shape = cursor_zoom_xpm;
 246                     sp_event_context_update_cursor(event_context);
 247                     break;
 248                 default:
 249                     break;
 250                 }
 251             break;
 252         default:
 253             break;
 254     }
 255
 256     if (!ret) {
 257         if (((SPEventContextClass *) parent_class)->root_handler) {
 258             ret = ((SPEventContextClass *) parent_class)->root_handler(event_context, event);
 259         }
 260     }
 261
 262     return ret;
 263 }
 264
 265 /*
 266   Local Variables:
 267   mode:c++
 268   c-file-style:"stroustrup"
 269   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
 270   indent-tabs-mode:nil
 271   fill-column:99
 272   End:
 273 */
 274 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :