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 "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         ec->enableGrDrag(false);
  90 }
  91
  92 static void sp_zoom_context_setup(SPEventContext *ec)
  93 {
  94     Inkscape::Preferences *prefs = Inkscape::Preferences::get();
  95     if (prefs->getBool("/tools/zoom/selcue")) {
  96         ec->enableSelectionCue();
  97     }
  98     if (prefs->getBool("/tools/zoom/gradientdrag")) {
  99         ec->enableGrDrag();
 100     }
 101
 102     if (((SPEventContextClass *) parent_class)->setup) {
 103         ((SPEventContextClass *) parent_class)->setup(ec);
 104     }
 105 }
 106
 107 static gint sp_zoom_context_item_handler(SPEventContext *event_context, SPItem *item, GdkEvent *event)
 108 {
 109     gint ret = FALSE;
 110
 111     if (((SPEventContextClass *) parent_class)->item_handler) {
 112         ret = ((SPEventContextClass *) parent_class)->item_handler (event_context, item, event);
 113     }
 114
 115     return ret;
 116 }
 117
 118 static gint sp_zoom_context_root_handler(SPEventContext *event_context, GdkEvent *event)
 119 {
 120     SPDesktop *desktop = event_context->desktop;
 121     Inkscape::Preferences *prefs = Inkscape::Preferences::get();
 122     tolerance = prefs->getIntLimited("/options/dragtolerance/value", 0, 0, 100);
 123     double const zoom_inc = prefs->getDoubleLimited("/options/zoomincrement/value", M_SQRT2, 1.01, 10);
 124
 125     gint ret = FALSE;
 126
 127     switch (event->type) {
 128         case GDK_BUTTON_PRESS:
 129         {
 130             Geom::Point const button_w(event->button.x, event->button.y);
 131             Geom::Point const button_dt(desktop->w2d(button_w));
 132             if (event->button.button == 1 && !event_context->space_panning) {
 133                 // save drag origin
 134                 xp = (gint) event->button.x;
 135                 yp = (gint) event->button.y;
 136                 within_tolerance = true;
 137
 138                 Inkscape::Rubberband::get(desktop)->start(desktop, button_dt);
 139
 140                 escaped = false;
 141
 142                 ret = TRUE;
 143             } else if (event->button.button == 3) {
 144                 double const zoom_rel( (event->button.state & GDK_SHIFT_MASK)
 145                                        ? zoom_inc
 146                                        : 1 / zoom_inc );
 147                 desktop->zoom_relative_keep_point(button_dt, zoom_rel);
 148                 ret = TRUE;
 149             }
 150             break;
 151         }
 152
 153         case GDK_MOTION_NOTIFY:
 154             if (event->motion.state & GDK_BUTTON1_MASK && !event_context->space_panning) {
 155                 ret = TRUE;
 156
 157                 if ( within_tolerance
 158                      && ( abs( (gint) event->motion.x - xp ) < tolerance )
 159                      && ( abs( (gint) event->motion.y - yp ) < tolerance ) ) {
 160                     break; // do not drag if we're within tolerance from origin
 161                 }
 162                 // Once the user has moved farther than tolerance from the original location
 163                 // (indicating they intend to move the object, not click), then always process the
 164                 // motion notify coordinates as given (no snapping back to origin)
 165                 within_tolerance = false;
 166
 167                 Geom::Point const motion_w(event->motion.x, event->motion.y);
 168                 Geom::Point const motion_dt(desktop->w2d(motion_w));
 169                 Inkscape::Rubberband::get(desktop)->move(motion_dt);
 170                 gobble_motion_events(GDK_BUTTON1_MASK);
 171             }
 172             break;
 173
 174         case GDK_BUTTON_RELEASE:
 175         {
 176             Geom::Point const button_w(event->button.x, event->button.y);
 177             Geom::Point const button_dt(desktop->w2d(button_w));
 178             if ( event->button.button == 1  && !event_context->space_panning) {
 179                 Geom::OptRect const b = Inkscape::Rubberband::get(desktop)->getRectangle();
 180                 if (b && !within_tolerance) {
 181                     desktop->set_display_area(*b, 10);
 182                 } else if (!escaped) {
 183                     double const zoom_rel( (event->button.state & GDK_SHIFT_MASK)
 184                                            ? 1 / zoom_inc
 185                                            : zoom_inc );
 186                     desktop->zoom_relative_keep_point(button_dt, zoom_rel);
 187                 }
 188                 ret = TRUE;
 189             }
 190             Inkscape::Rubberband::get(desktop)->stop();
 191             xp = yp = 0;
 192             escaped = false;
 193             break;
 194         }
 195         case GDK_KEY_PRESS:
 196             switch (get_group0_keyval (&event->key)) {
 197                 case GDK_Escape:
 198                     Inkscape::Rubberband::get(desktop)->stop();
 199                     xp = yp = 0;
 200                     escaped = true;
 201                     ret = TRUE;
 202                     break;
 203                 case GDK_Up:
 204                 case GDK_Down:
 205                 case GDK_KP_Up:
 206                 case GDK_KP_Down:
 207                     // prevent the zoom field from activation
 208                     if (!MOD__CTRL_ONLY)
 209                         ret = TRUE;
 210                     break;
 211                 case GDK_Shift_L:
 212                 case GDK_Shift_R:
 213                     event_context->cursor_shape = cursor_zoom_out_xpm;
 214                     sp_event_context_update_cursor(event_context);
 215                     break;
 216                 default:
 217                         break;
 218                 }
 219                 break;
 220         case GDK_KEY_RELEASE:
 221             switch (get_group0_keyval (&event->key)) {
 222                 case GDK_Shift_L:
 223                 case GDK_Shift_R:
 224                     event_context->cursor_shape = cursor_zoom_xpm;
 225                     sp_event_context_update_cursor(event_context);
 226                     break;
 227                 default:
 228                     break;
 229                 }
 230             break;
 231         default:
 232             break;
 233     }
 234
 235     if (!ret) {
 236         if (((SPEventContextClass *) parent_class)->root_handler) {
 237             ret = ((SPEventContextClass *) parent_class)->root_handler(event_context, event);
 238         }
 239     }
 240
 241     return ret;
 242 }
 243
 244 /*
 245   Local Variables:
 246   mode:c++
 247   c-file-style:"stroustrup"
 248   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
 249   indent-tabs-mode:nil
 250   fill-column:99
 251   End:
 252 */
 253 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :