src/zoom-context.cpp

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