C++ Selection::singleItem方法代码示例

void
LivePathEffectEditor::onApply()
{
    Inkscape::Selection *sel = _getSelection();
    if ( sel && !sel->isEmpty() ) {
        SPItem *item = sel->singleItem();
        if ( item && SP_IS_LPE_ITEM(item) ) {
            SPDocument *doc = current_desktop->doc();

            const Util::EnumData<LivePathEffect::EffectType>* data = combo_effecttype.get_active_data();
            if (!data) return;

            // If item is a SPRect, convert it to path first:
            if ( SP_IS_RECT(item) ) {
                sp_selected_path_to_curves(current_desktop, false);
                item = sel->singleItem(); // get new item
            }

            LivePathEffect::Effect::createAndApply(data->key.c_str(), doc, item);

            sp_document_done(doc, SP_VERB_DIALOG_LIVE_PATH_EFFECT,
                     _("Create and apply path effect"));

            lpe_list_locked = false;
            onSelectionChanged(sel);
        }
    }
}

void LpeTool::setup() {
    PenTool::setup();

    Inkscape::Selection *selection = this->desktop->getSelection();
    SPItem *item = selection->singleItem();

    this->sel_changed_connection.disconnect();
    this->sel_changed_connection =
        selection->connectChanged(sigc::bind(sigc::ptr_fun(&sp_lpetool_context_selection_changed), (gpointer)this));

    this->shape_editor = new ShapeEditor(this->desktop);

    lpetool_context_switch_mode(this, Inkscape::LivePathEffect::INVALID_LPE);
    lpetool_context_reset_limiting_bbox(this);
    lpetool_create_measuring_items(this);

// TODO temp force:
    this->enableSelectionCue();
    
    Inkscape::Preferences *prefs = Inkscape::Preferences::get();

    if (item) {
        this->shape_editor->set_item(item);
    }

    if (prefs->getBool("/tools/lpetool/selcue")) {
        this->enableSelectionCue();
    }
}

/*
 * Attempts to perform the construction of the given type (i.e., to apply the corresponding LPE) to
 * a single selected item. Returns whether we succeeded.
 */
bool
lpetool_try_construction(LpeTool *lc, Inkscape::LivePathEffect::EffectType const type)
{
    Inkscape::Selection *selection = lc->desktop->getSelection();
    SPItem *item = selection->singleItem();

    // TODO: should we check whether type represents a valid geometric construction?
    if (item && SP_IS_LPE_ITEM(item) && Inkscape::LivePathEffect::Effect::acceptsNumClicks(type) == 0) {
        Inkscape::LivePathEffect::Effect::createAndApply(type, lc->desktop->getDocument(), item);
        return true;
    }
    return false;
}

void LivePathEffectEditor::onDown()
{
    Inkscape::Selection *sel = _getSelection();
    if ( sel && !sel->isEmpty() ) {
        SPItem *item = sel->singleItem();
        if ( item && SP_IS_LPE_ITEM(item) ) {
            sp_lpe_item_down_current_path_effect(SP_LPE_ITEM(item));

            sp_document_done ( sp_desktop_document (current_desktop), SP_VERB_DIALOG_LIVE_PATH_EFFECT,
                               _("Move path effect down") );

            effect_list_reload(SP_LPE_ITEM(item));
        }
    }
}

void spdc_endpoint_snap_free(ToolBase const * const ec, Geom::Point& p, boost::optional<Geom::Point> &start_of_line, guint const /*state*/)
{
    SPDesktop *dt = ec->desktop;
    SnapManager &m = dt->namedview->snap_manager;
    Inkscape::Selection *selection = dt->getSelection();

    // selection->singleItem() is the item that is currently being drawn. This item will not be snapped to (to avoid self-snapping)
    // TODO: Allow snapping to the stationary parts of the item, and only ignore the last segment

    m.setup(dt, true, selection->singleItem());
    Inkscape::SnapCandidatePoint scp(p, Inkscape::SNAPSOURCE_NODE_HANDLE);
    if (start_of_line) {
        scp.addOrigin(*start_of_line);
    }

    Inkscape::SnappedPoint sp = m.freeSnap(scp);
    p = sp.getPoint();

    m.unSetup();
}

static void
sp_lpetool_context_setup(SPEventContext *ec)
{
    SPLPEToolContext *lc = SP_LPETOOL_CONTEXT(ec);

    if (((SPEventContextClass *) lpetool_parent_class)->setup)
        ((SPEventContextClass *) lpetool_parent_class)->setup(ec);

    Inkscape::Selection *selection = sp_desktop_selection (ec->desktop);
    SPItem *item = selection->singleItem();

    lc->sel_changed_connection.disconnect();
    lc->sel_changed_connection =
        selection->connectChanged(sigc::bind(sigc::ptr_fun(&sp_lpetool_context_selection_changed), (gpointer)lc));

    lc->shape_editor = new ShapeEditor(ec->desktop);

    lpetool_context_switch_mode(lc, Inkscape::LivePathEffect::INVALID_LPE);
    lpetool_context_reset_limiting_bbox(lc);
    lpetool_create_measuring_items(lc);

// TODO temp force:
    ec->enableSelectionCue();
    
    Inkscape::Preferences *prefs = Inkscape::Preferences::get();

    if (item) {
        lc->shape_editor->set_item(item, SH_NODEPATH);
        lc->shape_editor->set_item(item, SH_KNOTHOLDER);
    }

    if (prefs->getBool("/tools/lpetool/selcue")) {
        ec->enableSelectionCue();
    }

    lc->_lpetool_message_context = new Inkscape::MessageContext((ec->desktop)->messageStack());
}

//.........这里部分代码省略.........
                    break;
                case GDK_less:
                case GDK_comma:
                    if (MOD__ALT) {
                        gint mul = 1 + gobble_key_events(
                            get_group0_keyval(&event->key), 0); // with any mask
                        sp_selection_scale_screen(selection, -2*mul);
                    } else if (MOD__CTRL) {
                        sp_selection_scale_times(selection, 0.5);
                    } else {
                        gint mul = 1 + gobble_key_events(
                            get_group0_keyval(&event->key), 0); // with any mask
                        sp_selection_scale(selection, -offset*mul);
                    }
                    ret = TRUE;
                    break;
                case GDK_greater:
                case GDK_period:
                    if (MOD__ALT) {
                        gint mul = 1 + gobble_key_events(
                            get_group0_keyval(&event->key), 0); // with any mask
                        sp_selection_scale_screen(selection, 2*mul);
                    } else if (MOD__CTRL) {
                        sp_selection_scale_times(selection, 2);
                    } else {
                        gint mul = 1 + gobble_key_events(
                            get_group0_keyval(&event->key), 0); // with any mask
                        sp_selection_scale(selection, offset*mul);
                    }
                    ret = TRUE;
                    break;
                case GDK_Return:
                    if (MOD__CTRL_ONLY) {
                        if (selection->singleItem()) {
                            SPItem *clicked_item = selection->singleItem();
                            if ( SP_IS_GROUP(clicked_item) ||
                                 SP_IS_BOX3D(clicked_item)) { // enter group or a 3D box
                                desktop->setCurrentLayer(reinterpret_cast<SPObject *>(clicked_item));
                                sp_desktop_selection(desktop)->clear();
                            } else {
                                SP_EVENT_CONTEXT(sc)->desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Selected object is not a group. Cannot enter."));
                            }
                        }
                        ret = TRUE;
                    }
                    break;
                case GDK_BackSpace:
                    if (MOD__CTRL_ONLY) {
                        sp_select_context_up_one_layer(desktop);
                        ret = TRUE;
                    }
                    break;
                case GDK_s:
                case GDK_S:
                    if (MOD__SHIFT_ONLY) {
                        if (!selection->isEmpty()) {
                            seltrans->increaseState();
                        }
                        ret = TRUE;
                    }
                    break;
                case GDK_g:
                case GDK_G:
                    if (MOD__SHIFT_ONLY) {
                        sp_selection_to_guides(desktop);
                        ret = true;