C++ SPDesktop::w2d方法代码示例

static bool
sp_gradient_context_is_over_line (SPGradientContext *rc, SPItem *item, Geom::Point event_p)
{
    SPDesktop *desktop = SP_EVENT_CONTEXT (rc)->desktop;

    //Translate mouse point into proper coord system
    rc->mousepoint_doc = desktop->w2d(event_p);

    SPCtrlLine* line = SP_CTRLLINE(item);

    Geom::Point nearest = snap_vector_midpoint (rc->mousepoint_doc, line->s, line->e, 0);
    double dist_screen = Geom::L2 (rc->mousepoint_doc - nearest) * desktop->current_zoom();

    double tolerance = (double) SP_EVENT_CONTEXT(rc)->tolerance;

    bool close = (dist_screen < tolerance);

    return close;
}

/**
Returns true if mouse cursor over mesh edge.
*/
static bool
sp_mesh_context_is_over_line (SPMeshContext *rc, SPItem *item, Geom::Point event_p)
{
    SPDesktop *desktop = SP_EVENT_CONTEXT (rc)->desktop;

    //Translate mouse point into proper coord system
    rc->mousepoint_doc = desktop->w2d(event_p);

    SPCtrlCurve *curve = SP_CTRLCURVE(item);
    Geom::BezierCurveN<3> b( curve->p0, curve->p1, curve->p2, curve->p3 );
    Geom::Coord coord = b.nearestPoint( rc->mousepoint_doc ); // Coord == double
    Geom::Point nearest = b( coord );

    double dist_screen = Geom::L2 (rc->mousepoint_doc - nearest) * desktop->current_zoom();

    double tolerance = (double) SP_EVENT_CONTEXT(rc)->tolerance;

    bool close = (dist_screen < tolerance);

    return close;
}

static gint
sp_select_context_root_handler(SPEventContext *event_context, GdkEvent *event)
{
    SPItem *item = NULL;
    SPItem *item_at_point = NULL, *group_at_point = NULL, *item_in_group = NULL;
    gint ret = FALSE;

    SPDesktop *desktop = event_context->desktop;
    SPSelectContext *sc = SP_SELECT_CONTEXT(event_context);
    Inkscape::SelTrans *seltrans = sc->_seltrans;
    Inkscape::Selection *selection = sp_desktop_selection(desktop);
    Inkscape::Preferences *prefs = Inkscape::Preferences::get();

    // make sure we still have valid objects to move around
    if (sc->item && SP_OBJECT_DOCUMENT( SP_OBJECT(sc->item))==NULL) {
        sp_select_context_abort(event_context);
    }

    switch (event->type) {
        case GDK_2BUTTON_PRESS:
            if (event->button.button == 1) {
                if (!selection->isEmpty()) {
                    SPItem *clicked_item = (SPItem *) selection->itemList()->data;
                    if (SP_IS_GROUP(clicked_item) && !SP_IS_BOX3D(clicked_item)) { // enter group if it's not a 3D box
                        desktop->setCurrentLayer(reinterpret_cast<SPObject *>(clicked_item));
                        sp_desktop_selection(desktop)->clear();
                        sc->dragging = false;
                        sp_event_context_discard_delayed_snap_event(event_context);

                        desktop->canvas->end_forced_full_redraws();
                    } else { // switch tool
                        Geom::Point const button_pt(event->button.x, event->button.y);
                        Geom::Point const p(desktop->w2d(button_pt));
                        tools_switch_by_item (desktop, clicked_item, p);
                    }
                } else {
                    sp_select_context_up_one_layer(desktop);
                }
                ret = TRUE;
            }
            break;
        case GDK_BUTTON_PRESS:
            if (event->button.button == 1 && !event_context->space_panning) {

                // save drag origin
                xp = (gint) event->button.x;
                yp = (gint) event->button.y;
                within_tolerance = true;

                Geom::Point const button_pt(event->button.x, event->button.y);
                Geom::Point const p(desktop->w2d(button_pt));
                if (event->button.state & GDK_MOD1_MASK)
                    Inkscape::Rubberband::get(desktop)->setMode(RUBBERBAND_MODE_TOUCHPATH);
                Inkscape::Rubberband::get(desktop)->start(desktop, p);
                if (sc->grabbed) {
                    sp_canvas_item_ungrab(sc->grabbed, event->button.time);
                    sc->grabbed = NULL;
                }
                sp_canvas_item_grab(SP_CANVAS_ITEM(desktop->acetate),
                                    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,
                                    NULL, event->button.time);
                sc->grabbed = SP_CANVAS_ITEM(desktop->acetate);

                // remember what modifiers were on before button press
                sc->button_press_shift = (event->button.state & GDK_SHIFT_MASK) ? true : false;
                sc->button_press_ctrl = (event->button.state & GDK_CONTROL_MASK) ? true : false;
                sc->button_press_alt = (event->button.state & GDK_MOD1_MASK) ? true : false;

                sc->moved = FALSE;

                rb_escaped = drag_escaped = 0;

                ret = TRUE;
            } else if (event->button.button == 3) {
                // right click; do not eat it so that right-click menu can appear, but cancel dragging & rubberband
                sp_select_context_abort(event_context);
            }
            break;

        case GDK_MOTION_NOTIFY:
        	tolerance = prefs->getIntLimited("/options/dragtolerance/value", 0, 0, 100);
        	if (event->motion.state & GDK_BUTTON1_MASK && !event_context->space_panning) {
                Geom::Point const motion_pt(event->motion.x, event->motion.y);
                Geom::Point const p(desktop->w2d(motion_pt));

                if ( within_tolerance
                     && ( abs( (gint) event->motion.x - xp ) < tolerance )
                     && ( abs( (gint) event->motion.y - yp ) < tolerance ) ) {
                    break; // do not drag if we're within tolerance from origin
                }
                // Once the user has moved farther than tolerance from the original location
                // (indicating they intend to move the object, not click), then always process the
                // motion notify coordinates as given (no snapping back to origin)
                within_tolerance = false;

                if (sc->button_press_ctrl || (sc->button_press_alt && !sc->button_press_shift && !selection->isEmpty())) {
                    // if it's not click and ctrl or alt was pressed (the latter with some selection
                    // but not with shift) we want to drag rather than rubberband
                  	sc->dragging = TRUE;
                    desktop->setCursor(SP_SELECT_D_CURSOR);
//.........这里部分代码省略.........

static gint sp_box3d_context_root_handler(SPEventContext *event_context, GdkEvent *event)
{
    static bool dragging;

    SPDesktop *desktop = event_context->desktop;
    SPDocument *document = sp_desktop_document (desktop);
    Inkscape::Selection *selection = sp_desktop_selection (desktop);
    Inkscape::Preferences *prefs = Inkscape::Preferences::get();
    int const snaps = prefs->getInt("/options/rotationsnapsperpi/value", 12);

    Box3DContext *bc = SP_BOX3D_CONTEXT(event_context);
    Persp3D *cur_persp = document->getCurrentPersp3D();

    event_context->tolerance = prefs->getIntLimited("/options/dragtolerance/value", 0, 0, 100);

    gint ret = FALSE;
    switch (event->type) {
    case GDK_BUTTON_PRESS:
        if ( event->button.button == 1  && !event_context->space_panning) {
            Geom::Point const button_w(event->button.x,
                                       event->button.y);

            // save drag origin
            event_context->xp = (gint) button_w[Geom::X];
            event_context->yp = (gint) button_w[Geom::Y];
            event_context->within_tolerance = true;

            // remember clicked item, *not* disregarding groups (since a 3D box is a group), honoring Alt
            event_context->item_to_select = sp_event_context_find_item (desktop, button_w, event->button.state & GDK_MOD1_MASK, event->button.state & GDK_CONTROL_MASK);

            dragging = true;

            /*  */
            Geom::Point button_dt(desktop->w2d(button_w));
            bc->drag_origin = from_2geom(button_dt);
            bc->drag_ptB = from_2geom(button_dt);
            bc->drag_ptC = from_2geom(button_dt);

            // This can happen after saving when the last remaining perspective was purged and must be recreated.
            if (!cur_persp) {
                sp_box3d_context_ensure_persp_in_defs(document);
                cur_persp = document->getCurrentPersp3D();
            }

            /* Projective preimages of clicked point under current perspective */
            bc->drag_origin_proj = cur_persp->perspective_impl->tmat.preimage (from_2geom(button_dt), 0, Proj::Z);
            bc->drag_ptB_proj = bc->drag_origin_proj;
            bc->drag_ptC_proj = bc->drag_origin_proj;
            bc->drag_ptC_proj.normalize();
            bc->drag_ptC_proj[Proj::Z] = 0.25;

            /* Snap center */
            SnapManager &m = desktop->namedview->snap_manager;
            m.setup(desktop, true, bc->item);
            m.freeSnapReturnByRef(button_dt, Inkscape::SNAPSOURCE_NODE_HANDLE);
            bc->center = from_2geom(button_dt);

            sp_canvas_item_grab(SP_CANVAS_ITEM(desktop->acetate),
                                ( GDK_KEY_PRESS_MASK |
                                  GDK_BUTTON_RELEASE_MASK       |
                                  GDK_POINTER_MOTION_MASK | GDK_POINTER_MOTION_HINT_MASK       |
                                  GDK_BUTTON_PRESS_MASK ),
                                NULL, event->button.time);
            ret = TRUE;
        }
        break;
    case GDK_MOTION_NOTIFY:
        if ( dragging
             && ( event->motion.state & GDK_BUTTON1_MASK )  && !event_context->space_panning)
        {
            if ( event_context->within_tolerance
                 && ( abs( (gint) event->motion.x - event_context->xp ) < event_context->tolerance )
                 && ( abs( (gint) event->motion.y - event_context->yp ) < event_context->tolerance ) ) {
                break; // do not drag if we're within tolerance from origin
            }
            // Once the user has moved farther than tolerance from the original location
            // (indicating they intend to draw, not click), then always process the
            // motion notify coordinates as given (no snapping back to origin)
            event_context->within_tolerance = false;

            Geom::Point const motion_w(event->motion.x,
                                       event->motion.y);
            Geom::Point motion_dt(desktop->w2d(motion_w));

            SnapManager &m = desktop->namedview->snap_manager;
            m.setup(desktop, true, bc->item);
            m.freeSnapReturnByRef(motion_dt, Inkscape::SNAPSOURCE_NODE_HANDLE);

            bc->ctrl_dragged  = event->motion.state & GDK_CONTROL_MASK;

            if (event->motion.state & GDK_SHIFT_MASK && !bc->extruded && bc->item) {
                // once shift is pressed, set bc->extruded
                bc->extruded = true;
            }

            if (!bc->extruded) {
                bc->drag_ptB = from_2geom(motion_dt);
                bc->drag_ptC = from_2geom(motion_dt);

                bc->drag_ptB_proj = cur_persp->perspective_impl->tmat.preimage (from_2geom(motion_dt), 0, Proj::Z);
//.........这里部分代码省略.........

static gint sp_dt_ruler_event(GtkWidget *widget, GdkEvent *event, SPDesktopWidget *dtw, bool horiz)
{
    static bool clicked = false;
    static bool dragged = false;
    static SPCanvasItem *guide = NULL;
    static Geom::Point normal;
    int wx, wy;
    static gint xp = 0, yp = 0; // where drag started

    SPDesktop *desktop = dtw->desktop;
    GdkWindow *window = gtk_widget_get_window(GTK_WIDGET(dtw->canvas));

    gint width, height;

#if GTK_CHECK_VERSION(3,0,0)
    GdkDevice *device = gdk_event_get_device(event);
    gdk_window_get_device_position(window, device, &wx, &wy, NULL);
    gdk_window_get_geometry(window, NULL /*x*/, NULL /*y*/, &width, &height);
#else
    gdk_window_get_pointer(window, &wx, &wy, NULL);
    gdk_window_get_geometry(window, NULL /*x*/, NULL /*y*/, &width, &height, NULL/*depth*/);
#endif
    
    Geom::Point const event_win(wx, wy);

    switch (event->type) {
    case GDK_BUTTON_PRESS:
            if (event->button.button == 1) {
                clicked = true;
                dragged = false;
                // save click origin
                xp = (gint) event->button.x;
                yp = (gint) event->button.y;

                Geom::Point const event_w(sp_canvas_window_to_world(dtw->canvas, event_win));
                Geom::Point const event_dt(desktop->w2d(event_w));

                // calculate the normal of the guidelines when dragged from the edges of rulers.
                Geom::Point normal_bl_to_tr(-1.,1.); //bottomleft to topright
                Geom::Point normal_tr_to_bl(1.,1.); //topright to bottomleft
                normal_bl_to_tr.normalize();
                normal_tr_to_bl.normalize();
                Inkscape::CanvasGrid * grid = sp_namedview_get_first_enabled_grid(desktop->namedview);
                if (grid){
                    if (grid->getGridType() == Inkscape::GRID_AXONOMETRIC ) {
                        Inkscape::CanvasAxonomGrid *axonomgrid = dynamic_cast<Inkscape::CanvasAxonomGrid *>(grid);
                        if (event->button.state & GDK_CONTROL_MASK) {
                            // guidelines normal to gridlines
                            normal_bl_to_tr = Geom::Point::polar(-axonomgrid->angle_rad[0], 1.0);
                            normal_tr_to_bl = Geom::Point::polar(axonomgrid->angle_rad[2], 1.0);
                        } else {
                            normal_bl_to_tr = rot90(Geom::Point::polar(axonomgrid->angle_rad[2], 1.0));
                            normal_tr_to_bl = rot90(Geom::Point::polar(-axonomgrid->angle_rad[0], 1.0));
                        }
                    }
                }
                if (horiz) {
                    if (wx < 50) {
                        normal = normal_bl_to_tr;
                    } else if (wx > width - 50) {
                        normal = normal_tr_to_bl;
                    } else {
                        normal = Geom::Point(0.,1.);
                    }
                } else {
                    if (wy < 50) {
                        normal = normal_bl_to_tr;
                    } else if (wy > height - 50) {
                        normal = normal_tr_to_bl;
                    } else {
                        normal = Geom::Point(1.,0.);
                    }
                }

                guide = sp_guideline_new(desktop->guides, NULL, event_dt, normal);
                sp_guideline_set_color(SP_GUIDELINE(guide), desktop->namedview->guidehicolor);

#if GTK_CHECK_VERSION(3,0,0)
                gdk_device_grab(device,
                                gtk_widget_get_window(widget), 
                                GDK_OWNERSHIP_NONE,
                                FALSE,
                                (GdkEventMask)(GDK_BUTTON_RELEASE_MASK | GDK_POINTER_MOTION_MASK ),
                                NULL,
                                event->button.time);
#else
                gdk_pointer_grab(gtk_widget_get_window (widget), FALSE,
                                 (GdkEventMask)(GDK_BUTTON_RELEASE_MASK | GDK_POINTER_MOTION_MASK ),
                                 NULL, NULL,
                                 event->button.time);
#endif
            }
            break;
    case GDK_MOTION_NOTIFY:
            if (clicked) {
                Geom::Point const event_w(sp_canvas_window_to_world(dtw->canvas, event_win));
                Geom::Point event_dt(desktop->w2d(event_w));

                Inkscape::Preferences *prefs = Inkscape::Preferences::get();
                gint tolerance = prefs->getIntLimited("/options/dragtolerance/value", 0, 0, 100);
//.........这里部分代码省略.........

gint sp_dt_guide_event(SPCanvasItem *item, GdkEvent *event, gpointer data)
{
    static bool moved = false;
    gint ret = FALSE;

    SPGuide *guide = SP_GUIDE(data);
    SPDesktop *desktop = static_cast<SPDesktop*>(g_object_get_data(G_OBJECT(item->canvas), "SPDesktop"));

    switch (event->type) {
    case GDK_2BUTTON_PRESS:
            if (event->button.button == 1) {
                drag_type = SP_DRAG_NONE;
                sp_event_context_discard_delayed_snap_event(desktop->event_context);
                sp_canvas_item_ungrab(item, event->button.time);
                Inkscape::UI::Dialogs::GuidelinePropertiesDialog::showDialog(guide, desktop);
                ret = TRUE;
            }
            break;
    case GDK_BUTTON_PRESS:
            if (event->button.button == 1) {
                Geom::Point const event_w(event->button.x, event->button.y);
                Geom::Point const event_dt(desktop->w2d(event_w));

                // Due to the tolerance allowed when grabbing a guide, event_dt will generally
                // be close to the guide but not just exactly on it. The drag origin calculated
                // here must be exactly on the guide line though, otherwise
                // small errors will occur once we snap, see
                // https://bugs.launchpad.net/inkscape/+bug/333762
                drag_origin = Geom::projection(event_dt, Geom::Line(guide->getPoint(), guide->angle()));

                if (event->button.state & GDK_SHIFT_MASK) {
                    // with shift we rotate the guide
                    drag_type = SP_DRAG_ROTATE;
                } else {
                    if (event->button.state & GDK_CONTROL_MASK) {
                        drag_type = SP_DRAG_MOVE_ORIGIN;
                    } else {
                        drag_type = SP_DRAG_TRANSLATE;
                    }
                }

                if (drag_type == SP_DRAG_ROTATE || drag_type == SP_DRAG_TRANSLATE) {
                    sp_canvas_item_grab(item,
                                        ( GDK_BUTTON_RELEASE_MASK  |
                                          GDK_BUTTON_PRESS_MASK    |
                                          GDK_POINTER_MOTION_MASK | GDK_POINTER_MOTION_HINT_MASK ),
                                        NULL,
                                        event->button.time);
                }
                ret = TRUE;
            }
            break;
        case GDK_MOTION_NOTIFY:
            if (drag_type != SP_DRAG_NONE) {
                Geom::Point const motion_w(event->motion.x,
                                           event->motion.y);
                Geom::Point motion_dt(desktop->w2d(motion_w));

                sp_event_context_snap_delay_handler(desktop->event_context, (gpointer) item, data, (GdkEventMotion *)event, Inkscape::UI::Tools::DelayedSnapEvent::GUIDE_HANDLER);

                // This is for snapping while dragging existing guidelines. New guidelines,
                // which are dragged off the ruler, are being snapped in sp_dt_ruler_event
                SnapManager &m = desktop->namedview->snap_manager;
                m.setup(desktop, true, NULL, NULL, guide);
                if (drag_type == SP_DRAG_MOVE_ORIGIN) {
                    // If we snap in guideConstrainedSnap() below, then motion_dt will
                    // be forced to be on the guide. If we don't snap however, then
                    // the origin should still be constrained to the guide. So let's do
                    // that explicitly first:
                    Geom::Line line(guide->getPoint(), guide->angle());
                    Geom::Coord t = line.nearestTime(motion_dt);
                    motion_dt = line.pointAt(t);
                    if (!(event->motion.state & GDK_SHIFT_MASK)) {
                        m.guideConstrainedSnap(motion_dt, *guide);
                    }
                } else if (!((drag_type == SP_DRAG_ROTATE) && (event->motion.state & GDK_CONTROL_MASK))) {
                    // cannot use shift here to disable snapping, because we already use it for rotating the guide
                    Geom::Point temp;
                    if (drag_type == SP_DRAG_ROTATE) {
                        temp = guide->getPoint();
                        m.guideFreeSnap(motion_dt, temp, true, false);
                        guide->moveto(temp, false);
                    } else {
                        temp = guide->getNormal();
                        m.guideFreeSnap(motion_dt, temp, false, true);
                        guide->set_normal(temp, false);
                    }
                }
                m.unSetup();

                switch (drag_type) {
                    case SP_DRAG_TRANSLATE:
                    {
                        guide->moveto(motion_dt, false);
                        break;
                    }
                    case SP_DRAG_ROTATE:
                    {
                        Geom::Point pt = motion_dt - guide->getPoint();
                        Geom::Angle angle(pt);
//.........这里部分代码省略.........

static gint sp_dropper_context_root_handler(SPEventContext *event_context, GdkEvent *event)
{
    SPDropperContext *dc = (SPDropperContext *) event_context;
    int ret = FALSE;
    SPDesktop *desktop = event_context->desktop;
    Inkscape::Preferences *prefs = Inkscape::Preferences::get();

    int pick = prefs->getInt("/tools/dropper/pick", SP_DROPPER_PICK_VISIBLE);
    bool setalpha = prefs->getBool("/tools/dropper/setalpha", true);

    switch (event->type) {
	case GDK_BUTTON_PRESS:
            if (event->button.button == 1 && !event_context->space_panning) {
                dc->centre = Geom::Point(event->button.x, event->button.y);
                dc->dragging = TRUE;
                ret = TRUE;
            }
            break;
	case GDK_MOTION_NOTIFY:
            if (event->motion.state & GDK_BUTTON2_MASK) {
                // pass on middle-drag
                ret = FALSE;
                break;
            } else if (!event_context->space_panning) {
                // otherwise, constantly calculate color no matter is any button pressed or not

                double rw = 0.0;
                double W(0), R(0), G(0), B(0), A(0);

                if (dc->dragging) {
                    // calculate average

                    // radius
                    rw = std::min(Geom::L2(Geom::Point(event->button.x, event->button.y) - dc->centre), 400.0);

                    if (rw == 0) { // happens sometimes, little idea why...
                        break;
                    }

                    Geom::Point const cd = desktop->w2d(dc->centre);
                    Geom::Matrix const w2dt = desktop->w2d();
                    const double scale = rw * w2dt.descrim();
                    Geom::Matrix const sm( Geom::Scale(scale, scale) * Geom::Translate(cd) );
                    sp_canvas_item_affine_absolute(dc->area, sm);
                    sp_canvas_item_show(dc->area);

                    /* Get buffer */
                    const int x0 = (int) floor(dc->centre[Geom::X] - rw);
                    const int y0 = (int) floor(dc->centre[Geom::Y] - rw);
                    const int x1 = (int) ceil(dc->centre[Geom::X] + rw);
                    const int y1 = (int) ceil(dc->centre[Geom::Y] + rw);

                    if ((x1 > x0) && (y1 > y0)) {
                        NRPixBlock pb;
                        nr_pixblock_setup_fast(&pb, NR_PIXBLOCK_MODE_R8G8B8A8P, x0, y0, x1, y1, TRUE);
                        /* fixme: (Lauris) */
                        sp_canvas_arena_render_pixblock(SP_CANVAS_ARENA(sp_desktop_drawing(desktop)), &pb);
                        for (int y = y0; y < y1; y++) {
                            const unsigned char *s = NR_PIXBLOCK_PX(&pb) + (y - y0) * pb.rs;
                            for (int x = x0; x < x1; x++) {
                                const double dx = x - dc->centre[Geom::X];
                                const double dy = y - dc->centre[Geom::Y];
                                const double w = exp(-((dx * dx) + (dy * dy)) / (rw * rw));
                                W += w;
                                R += w * s[0];
                                G += w * s[1];
                                B += w * s[2];
                                A += w * s[3];
                                s += 4;
                            }
                        }
                        nr_pixblock_release(&pb);

                        R = (R + 0.001) / (255.0 * W);
                        G = (G + 0.001) / (255.0 * W);
                        B = (B + 0.001) / (255.0 * W);
                        A = (A + 0.001) / (255.0 * W);

                        R = CLAMP(R, 0.0, 1.0);
                        G = CLAMP(G, 0.0, 1.0);
                        B = CLAMP(B, 0.0, 1.0);
                        A = CLAMP(A, 0.0, 1.0);
                    }

                } else {
                    // pick single pixel
                    NRPixBlock pb;
                    int x = (int) floor(event->button.x);
                    int y = (int) floor(event->button.y);
                    nr_pixblock_setup_fast(&pb, NR_PIXBLOCK_MODE_R8G8B8A8P, x, y, x+1, y+1, TRUE);
                    sp_canvas_arena_render_pixblock(SP_CANVAS_ARENA(sp_desktop_drawing(desktop)), &pb);
                    const unsigned char *s = NR_PIXBLOCK_PX(&pb);

                    R = s[0] / 255.0;
                    G = s[1] / 255.0;
                    B = s[2] / 255.0;
                    A = s[3] / 255.0;
                }

                if (pick == SP_DROPPER_PICK_VISIBLE) {
//.........这里部分代码省略.........

static gint
sp_gradient_context_root_handler(SPEventContext *event_context, GdkEvent *event)
{
    static bool dragging;

    SPDesktop *desktop = event_context->desktop;
    Inkscape::Selection *selection = sp_desktop_selection (desktop);
    Inkscape::Preferences *prefs = Inkscape::Preferences::get();

    SPGradientContext *rc = SP_GRADIENT_CONTEXT(event_context);

    event_context->tolerance = prefs->getIntLimited("/options/dragtolerance/value", 0, 0, 100);
    double const nudge = prefs->getDoubleLimited("/options/nudgedistance/value", 2, 0, 1000); // in px

    GrDrag *drag = event_context->_grdrag;
    g_assert (drag);

    gint ret = FALSE;
    switch (event->type) {
    case GDK_2BUTTON_PRESS:
        if ( event->button.button == 1 ) {
            bool over_line = false;
            SPCtrlLine *line = NULL;
            if (drag->lines) {
                for (GSList *l = drag->lines; (l != NULL) && (!over_line); l = l->next) {
                    line = (SPCtrlLine*) l->data;
                    over_line |= sp_gradient_context_is_over_line (rc, (SPItem*) line, Geom::Point(event->motion.x, event->motion.y));
                }
            }
            if (over_line) {
                // we take the first item in selection, because with doubleclick, the first click
                // always resets selection to the single object under cursor
                sp_gradient_context_add_stop_near_point(rc, SP_ITEM(selection->itemList()->data), rc->mousepoint_doc, event->button.time);
            } else {
                for (GSList const* i = selection->itemList(); i != NULL; i = i->next) {
                    SPItem *item = SP_ITEM(i->data);
                    SPGradientType new_type = (SPGradientType) prefs->getInt("/tools/gradient/newgradient", SP_GRADIENT_TYPE_LINEAR);
                    guint new_fill = prefs->getInt("/tools/gradient/newfillorstroke", 1);

                    SPGradient *vector = sp_gradient_vector_for_object(sp_desktop_document(desktop), desktop,                                                                                   SP_OBJECT (item), new_fill);

                    SPGradient *priv = sp_item_set_gradient(item, vector, new_type, new_fill);
                    sp_gradient_reset_to_userspace(priv, item);
                }

                sp_document_done (sp_desktop_document (desktop), SP_VERB_CONTEXT_GRADIENT,
                                  _("Create default gradient"));
            }
            ret = TRUE;
        }
        break;
    case GDK_BUTTON_PRESS:
        if ( event->button.button == 1 && !event_context->space_panning ) {
            Geom::Point button_w(event->button.x, event->button.y);

            // save drag origin
            event_context->xp = (gint) button_w[Geom::X];
            event_context->yp = (gint) button_w[Geom::Y];
            event_context->within_tolerance = true;

            dragging = true;

            Geom::Point button_dt = to_2geom(desktop->w2d(button_w));
            if (event->button.state & GDK_SHIFT_MASK) {
                Inkscape::Rubberband::get(desktop)->start(desktop, from_2geom(button_dt));
            } else {
                // remember clicked item, disregarding groups, honoring Alt; do nothing with Crtl to
                // enable Ctrl+doubleclick of exactly the selected item(s)
                if (!(event->button.state & GDK_CONTROL_MASK))
                    event_context->item_to_select = sp_event_context_find_item (desktop, button_w, event->button.state & GDK_MOD1_MASK, TRUE);

                /* Snap center to nearest magnetic point */
                SnapManager &m = desktop->namedview->snap_manager;
                m.setup(desktop);
                m.freeSnapReturnByRef(Inkscape::SnapPreferences::SNAPPOINT_NODE, button_dt);
                rc->origin = from_2geom(button_dt);
            }

            ret = TRUE;
        }
        break;
    case GDK_MOTION_NOTIFY:
        if ( dragging
             && ( event->motion.state & GDK_BUTTON1_MASK ) && !event_context->space_panning )
        {
            if ( event_context->within_tolerance
                 && ( abs( (gint) event->motion.x - event_context->xp ) < event_context->tolerance )
                 && ( abs( (gint) event->motion.y - event_context->yp ) < event_context->tolerance ) ) {
                break; // do not drag if we're within tolerance from origin
            }
            // Once the user has moved farther than tolerance from the original location
            // (indicating they intend to draw, not click), then always process the
            // motion notify coordinates as given (no snapping back to origin)
            event_context->within_tolerance = false;

            Geom::Point const motion_w(event->motion.x,
                                     event->motion.y);
            Geom::Point const motion_dt = event_context->desktop->w2d(motion_w);

            if (Inkscape::Rubberband::get(desktop)->is_started()) {
//.........这里部分代码省略.........

static gint sp_zoom_context_root_handler(SPEventContext *event_context, GdkEvent *event)
{
    SPDesktop *desktop = event_context->desktop;
    Inkscape::Preferences *prefs = Inkscape::Preferences::get();
	
	SPZoomContext *zc = SP_ZOOM_CONTEXT(event_context);
    tolerance = prefs->getIntLimited("/options/dragtolerance/value", 0, 0, 100);
    double const zoom_inc = prefs->getDoubleLimited("/options/zoomincrement/value", M_SQRT2, 1.01, 10);

    gint ret = FALSE;

    switch (event->type) {
        case GDK_BUTTON_PRESS:
        {
            Geom::Point const button_w(event->button.x, event->button.y);
            Geom::Point const button_dt(desktop->w2d(button_w));
            if (event->button.button == 1 && !event_context->space_panning) {
                // save drag origin
                xp = (gint) event->button.x;
                yp = (gint) event->button.y;
                within_tolerance = true;

                Inkscape::Rubberband::get(desktop)->start(desktop, button_dt);

                escaped = false;

                ret = TRUE;
            } else if (event->button.button == 3) {
                double const zoom_rel( (event->button.state & GDK_SHIFT_MASK)
                                       ? zoom_inc
                                       : 1 / zoom_inc );
                desktop->zoom_relative_keep_point(button_dt, zoom_rel);
                ret = TRUE;
            }
			
			sp_canvas_item_grab(SP_CANVAS_ITEM(desktop->acetate),
								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,
								NULL, event->button.time);
			zc->grabbed = SP_CANVAS_ITEM(desktop->acetate);
				
            break;
        }

	case GDK_MOTION_NOTIFY:
            if (event->motion.state & GDK_BUTTON1_MASK && !event_context->space_panning) {
                ret = TRUE;

                if ( within_tolerance
                     && ( abs( (gint) event->motion.x - xp ) < tolerance )
                     && ( abs( (gint) event->motion.y - yp ) < tolerance ) ) {
                    break; // do not drag if we're within tolerance from origin
                }
                // Once the user has moved farther than tolerance from the original location
                // (indicating they intend to move the object, not click), then always process the
                // motion notify coordinates as given (no snapping back to origin)
                within_tolerance = false;

                Geom::Point const motion_w(event->motion.x, event->motion.y);
                Geom::Point const motion_dt(desktop->w2d(motion_w));
                Inkscape::Rubberband::get(desktop)->move(motion_dt);
                gobble_motion_events(GDK_BUTTON1_MASK);
            }
            break;

      	case GDK_BUTTON_RELEASE:
        {
            Geom::Point const button_w(event->button.x, event->button.y);
            Geom::Point const button_dt(desktop->w2d(button_w));
            if ( event->button.button == 1  && !event_context->space_panning) {
                Geom::OptRect const b = Inkscape::Rubberband::get(desktop)->getRectangle();
                if (b && !within_tolerance) {
                    desktop->set_display_area(*b, 10);
                } else if (!escaped) {
                    double const zoom_rel( (event->button.state & GDK_SHIFT_MASK)
                                           ? 1 / zoom_inc
                                           : zoom_inc );
                    desktop->zoom_relative_keep_point(button_dt, zoom_rel);
                }
                ret = TRUE;
            } 
            Inkscape::Rubberband::get(desktop)->stop();
			
			if (zc->grabbed) {
				sp_canvas_item_ungrab(zc->grabbed, event->button.time);
				zc->grabbed = NULL;
			}
			
            xp = yp = 0;
            escaped = false;
            break;
        }
        case GDK_KEY_PRESS:
            switch (get_group0_keyval (&event->key)) {
                case GDK_Escape:
                    Inkscape::Rubberband::get(desktop)->stop();
                    xp = yp = 0;
                    escaped = true;
                    ret = TRUE;
                    break;
                case GDK_Up:
//.........这里部分代码省略.........

gint sp_spray_context_root_handler(SPEventContext *event_context, GdkEvent *event)
{
    SPSprayContext *tc = SP_SPRAY_CONTEXT(event_context);
    SPDesktop *desktop = event_context->desktop;

    gint ret = FALSE;

    switch (event->type) {
        case GDK_ENTER_NOTIFY:
            sp_canvas_item_show(tc->dilate_area);
            break;
        case GDK_LEAVE_NOTIFY:
            sp_canvas_item_hide(tc->dilate_area);
            break;
        case GDK_BUTTON_PRESS:
            if (event->button.button == 1 && !event_context->space_panning) {
                if (Inkscape::have_viable_layer(desktop, tc->_message_context) == false) {
                    return TRUE;
                }

                Geom::Point const motion_w(event->button.x, event->button.y);
                Geom::Point const motion_dt(desktop->w2d(motion_w));
                tc->last_push = desktop->dt2doc(motion_dt);

                sp_spray_extinput(tc, event);

                desktop->canvas->forceFullRedrawAfterInterruptions(3);
                tc->is_drawing = true;
                tc->is_dilating = true;
                tc->has_dilated = false;

                if(tc->is_dilating && event->button.button == 1 && !event_context->space_panning) {
                    sp_spray_dilate(tc, motion_w, desktop->dt2doc(motion_dt), Geom::Point(0,0), MOD__SHIFT);
                }

                tc->has_dilated = true;
                ret = TRUE;
            }
            break;
        case GDK_MOTION_NOTIFY: {
            Geom::Point const motion_w(event->motion.x,
                                     event->motion.y);
            Geom::Point motion_dt(desktop->w2d(motion_w));
            Geom::Point motion_doc(desktop->dt2doc(motion_dt));
            sp_spray_extinput(tc, event);

            // draw the dilating cursor
            double radius = get_dilate_radius(tc);
            Geom::Affine const sm (Geom::Scale(radius/(1-tc->ratio), radius/(1+tc->ratio)) );
            sp_canvas_item_affine_absolute(tc->dilate_area, (sm*Geom::Rotate(tc->tilt))*Geom::Translate(desktop->w2d(motion_w)));
            sp_canvas_item_show(tc->dilate_area);

            guint num = 0;
            if (!desktop->selection->isEmpty()) {
                num = g_slist_length((GSList *) desktop->selection->itemList());
            }
            if (num == 0) {
                tc->_message_context->flash(Inkscape::ERROR_MESSAGE, _("<b>Nothing selected!</b> Select objects to spray."));
            }

            // dilating:
            if (tc->is_drawing && ( event->motion.state & GDK_BUTTON1_MASK )) {
                sp_spray_dilate(tc, motion_w, motion_doc, motion_doc - tc->last_push, event->button.state & GDK_SHIFT_MASK? true : false);
                //tc->last_push = motion_doc;
                tc->has_dilated = true;

                // it's slow, so prevent clogging up with events
                gobble_motion_events(GDK_BUTTON1_MASK);
                return TRUE;
            }
        }
        break;
        /*Spray with the scroll*/
        case GDK_SCROLL: {
            if (event->scroll.state & GDK_BUTTON1_MASK) {
                double temp ;
                temp = tc->population;
                tc->population = 1.0;
                desktop->setToolboxAdjustmentValue("population", tc->population * 100);
                Geom::Point const scroll_w(event->button.x, event->button.y);
                Geom::Point const scroll_dt = desktop->point();;
                Geom::Point motion_doc(desktop->dt2doc(scroll_dt));
                switch (event->scroll.direction) {
                    case GDK_SCROLL_DOWN:
                    case GDK_SCROLL_UP: {
                        if (Inkscape::have_viable_layer(desktop, tc->_message_context) == false) {
                            return TRUE;
                        }
                        tc->last_push = desktop->dt2doc(scroll_dt);
                        sp_spray_extinput(tc, event);
                        desktop->canvas->forceFullRedrawAfterInterruptions(3);
                        tc->is_drawing = true;
                        tc->is_dilating = true;
                        tc->has_dilated = false;
                        if(tc->is_dilating && !event_context->space_panning) {
                            sp_spray_dilate(tc, scroll_w, desktop->dt2doc(scroll_dt), Geom::Point(0,0), false);
                        }
                        tc->has_dilated = true;
                        
                        tc->population = temp;
//.........这里部分代码省略.........

/**
Handles all keyboard and mouse input for meshs.
*/
static gint
sp_mesh_context_root_handler(SPEventContext *event_context, GdkEvent *event)
{
    // static int count = 0;
    // std::cout << "sp_mesh_context_root_handler: " << count++ << std::endl;
    static bool dragging;

    SPDesktop *desktop = event_context->desktop;
    Inkscape::Selection *selection = sp_desktop_selection (desktop);
    Inkscape::Preferences *prefs = Inkscape::Preferences::get();

    SPMeshContext *rc = SP_MESH_CONTEXT(event_context);

    event_context->tolerance = prefs->getIntLimited("/options/dragtolerance/value", 0, 0, 100);
    double const nudge = prefs->getDoubleLimited("/options/nudgedistance/value", 2, 0, 1000, "px"); // in px

    GrDrag *drag = event_context->_grdrag;
    g_assert (drag);

    gint ret = FALSE;
    switch (event->type) {

    case GDK_2BUTTON_PRESS:

#ifdef DEBUG_MESH
        std::cout << "sp_mesh_context_root_handler: GDK_2BUTTON_PRESS" << std::endl;
#endif

        // Double click:
        //  If over a mesh line, divide mesh row/column
        //  If not over a line, create new gradients for selected objects.

        if ( event->button.button == 1 ) {

            // Are we over a mesh line?
            bool over_line = false;
            SPCtrlCurve *line = NULL;
            if (drag->lines) {
                for (GSList *l = drag->lines; (l != NULL) && (!over_line); l = l->next) {
                    line = (SPCtrlCurve*) l->data;
                    over_line |= sp_mesh_context_is_over_line (rc, (SPItem*) line, Geom::Point(event->motion.x, event->motion.y));
                }
            }

            if (over_line) {
                // We take the first item in selection, because with doubleclick, the first click
                // always resets selection to the single object under cursor
                sp_mesh_context_split_near_point(rc, SP_ITEM(selection->itemList()->data), rc->mousepoint_doc, event->button.time);

            } else {
                // Create a new gradient with default coordinates.

                for (GSList const* i = selection->itemList(); i != NULL; i = i->next) {

                    SPItem *item = SP_ITEM(i->data);
                    SPGradientType new_type = SP_GRADIENT_TYPE_MESH;
                    Inkscape::PaintTarget fsmode = (prefs->getInt("/tools/gradient/newfillorstroke", 1) != 0) ? Inkscape::FOR_FILL : Inkscape::FOR_STROKE;

#ifdef DEBUG_MESH
                    std::cout << "sp_mesh_context_root_handler: creating new mesh on: " << (fsmode == Inkscape::FOR_FILL ? "Fill" : "Stroke") << std::endl;
#endif
                    SPGradient *vector = sp_gradient_vector_for_object(sp_desktop_document(desktop), desktop, item, fsmode);

                    SPGradient *priv = sp_item_set_gradient(item, vector, new_type, fsmode);
                    sp_gradient_reset_to_userspace(priv, item);
                }

                DocumentUndo::done(sp_desktop_document (desktop), SP_VERB_CONTEXT_MESH,
                                   _("Create default mesh"));
            }
            ret = TRUE;
        }
        break;

    case GDK_BUTTON_PRESS:

#ifdef DEBUG_MESH
        std::cout << "sp_mesh_context_root_handler: GDK_BUTTON_PRESS" << std::endl;
#endif
        // Button down
        //  If Shift key down: do rubber band selection
        //  Else set origin for drag. A drag creates a new gradient if one does not exist
 
        if ( event->button.button == 1 && !event_context->space_panning ) {
            Geom::Point button_w(event->button.x, event->button.y);

            // save drag origin
            event_context->xp = (gint) button_w[Geom::X];
            event_context->yp = (gint) button_w[Geom::Y];
            event_context->within_tolerance = true;

            dragging = true;

            Geom::Point button_dt = desktop->w2d(button_w);
            if (event->button.state & GDK_SHIFT_MASK) {
                Inkscape::Rubberband::get(desktop)->start(desktop, button_dt);
            } else {
//.........这里部分代码省略.........