Add arc radius to toolbar

3 files changed, 95 insertions, 34 deletions

diff --git a/src/sp-ellipse.cpp b/src/sp-ellipse.cpp
index 166237c8e..c32e3012c 100644
--- a/src/sp-ellipse.cpp
+++ b/src/sp-ellipse.cpp
@@ -721,6 +721,65 @@ bool SPGenericEllipse::_isSlice() const
     return !(Geom::are_near(a.extent(), 0) || Geom::are_near(a.extent(), SP_2PI));
 }
 
+/**
+Returns the ratio in which the vector from p0 to p1 is stretched by transform
+ */
+gdouble SPGenericEllipse::vectorStretch(Geom::Point p0, Geom::Point p1, Geom::Affine xform) {
+    if (p0 == p1) {
+        return 0;
+    }
+
+    return (Geom::distance(p0 * xform, p1 * xform) / Geom::distance(p0, p1));
+}
+
+void SPGenericEllipse::setVisibleRx(gdouble rx) {
+    if (rx == 0) {
+        this->rx.unset();
+    } else {
+        this->rx = rx / SPGenericEllipse::vectorStretch(
+            Geom::Point(this->cx.computed + 1, this->cy.computed),
+            Geom::Point(this->cx.computed, this->cy.computed),
+            this->i2doc_affine());
+    }
+
+    this->updateRepr();
+}
+
+void SPGenericEllipse::setVisibleRy(gdouble ry) {
+    if (ry == 0) {
+        this->ry.unset();
+    } else {
+        this->ry = ry / SPGenericEllipse::vectorStretch(
+            Geom::Point(this->cx.computed, this->cy.computed + 1),
+            Geom::Point(this->cx.computed, this->cy.computed),
+            this->i2doc_affine());
+    }
+
+    this->updateRepr();
+}
+
+gdouble SPGenericEllipse::getVisibleRx() const {
+    if (!this->rx._set) {
+        return 0;
+    }
+
+    return this->rx.computed * SPGenericEllipse::vectorStretch(
+        Geom::Point(this->cx.computed + 1, this->cy.computed),
+        Geom::Point(this->cx.computed, this->cy.computed),
+        this->i2doc_affine());
+}
+
+gdouble SPGenericEllipse::getVisibleRy() const {
+    if (!this->ry._set) {
+        return 0;
+    }
+
+    return this->ry.computed * SPGenericEllipse::vectorStretch(
+        Geom::Point(this->cx.computed, this->cy.computed + 1),
+        Geom::Point(this->cx.computed, this->cy.computed),
+        this->i2doc_affine());
+}
+
 /*
   Local Variables:
   mode:c++
diff --git a/src/sp-ellipse.h b/src/sp-ellipse.h
index a879c596d..a31b571d8 100644
--- a/src/sp-ellipse.h
+++ b/src/sp-ellipse.h
@@ -20,8 +20,8 @@
 #include "sp-shape.h"
 
 /* Common parent class */
-#define SP_GENERICELLIPSE(obj) (dynamic_cast<SPGenericEllipse*>(obj))
-#define SP_IS_GENERICELLIPSE(obj) (dynamic_cast<const SPGenericEllipse*>((obj)) != NULL)
+#define SP_GENERICELLIPSE(obj) (dynamic_cast<SPGenericEllipse*>((SPObject*)obj))
+#define SP_IS_GENERICELLIPSE(obj) (dynamic_cast<const SPGenericEllipse*>((SPObject*)obj) != NULL)
 
 enum GenericEllipseType {
     SP_GENERIC_ELLIPSE_UNDEFINED, // FIXME shouldn't exist
@@ -83,11 +83,20 @@ public:
     bool set_elliptical_path_attribute(Inkscape::XML::Node *repr);
     void position_set(double x, double y, double rx, double ry);
 
+    double getVisibleRx() const;
+    void setVisibleRx(double rx);
+
+    double getVisibleRy() const;
+    void setVisibleRy(double ry);
+
 protected:
     /**
      * @brief Determines whether the shape is a part of an ellipse.
      */
     bool _isSlice() const;
+
+private:
+    static double vectorStretch(Geom::Point p0, Geom::Point p1, Geom::Affine xform);
 };
 
 #endif
diff --git a/src/widgets/arc-toolbar.cpp b/src/widgets/arc-toolbar.cpp
index 3faea1750..907285a60 100644
--- a/src/widgets/arc-toolbar.cpp
+++ b/src/widgets/arc-toolbar.cpp
@@ -122,9 +122,9 @@ static void sp_arctb_value_changed(GtkAdjustment *adj, GObject *tbl, gchar const
             SPGenericEllipse *ge = SP_GENERICELLIPSE(item);
 
             if (!strcmp(value_name, "rx")) {
-                ge->rx = Quantity::convert(gtk_adjustment_get_value(adj), unit, "px") / scale[Geom::X];
+                ge->setVisibleRx(Quantity::convert(gtk_adjustment_get_value(adj), unit, "px"));
             } else {
-                ge->ry = Quantity::convert(gtk_adjustment_get_value(adj), unit, "px") / scale[Geom::Y];
+                ge->setVisibleRy(Quantity::convert(gtk_adjustment_get_value(adj), unit, "px"));
             }
 
             ge->normalize();
@@ -308,37 +308,25 @@ static void arc_tb_event_attr_changed(Inkscape::XML::Node *repr, gchar const * /
     // in turn, prevent callbacks from responding
     g_object_set_data( tbl, "freeze", GINT_TO_POINTER(TRUE) );
 
-    UnitTracker* tracker = reinterpret_cast<UnitTracker*>( g_object_get_data( tbl, "tracker" ) );
-    Unit const *unit = tracker->getActiveUnit();
-    g_return_if_fail(unit != NULL);
-
-    gdouble radius = 0;
-    gdouble rx = 0;
-    gdouble ry = 0;
-    sp_repr_get_double(repr, "r", &radius);
-    if (radius) {
-        rx = ry = radius;
-    } else {
-        sp_repr_get_double(repr, "rx", &rx);
-        sp_repr_get_double(repr, "ry", &ry);
-    }
-    if (!rx) {
-        sp_repr_get_double(repr, "sodipodi:rx", &rx);
-        sp_repr_get_double(repr, "sodipodi:ry", &ry);
-    }
+    gpointer item = g_object_get_data( tbl, "item" );
+    if (item && SP_IS_GENERICELLIPSE(item)) {
+        SPGenericEllipse *ge = SP_GENERICELLIPSE(item);
 
-    SPDesktop *desktop = static_cast<SPDesktop *>(g_object_get_data( tbl, "desktop" ));
-    SPDocument* document = desktop->getDocument();
-    Geom::Scale scale = document->getDocumentScale();
+        UnitTracker* tracker = reinterpret_cast<UnitTracker*>( g_object_get_data( tbl, "tracker" ) );
+        Unit const *unit = tracker->getActiveUnit();
+        g_return_if_fail(unit != NULL);
 
-    GtkAdjustment *adj;
-    adj = GTK_ADJUSTMENT( g_object_get_data(tbl, "rx") );
-    gtk_adjustment_set_value(adj, Quantity::convert(rx, "px", unit) * scale[Geom::X]);
-    gtk_adjustment_value_changed(adj);
+        GtkAdjustment *adj;
+        adj = GTK_ADJUSTMENT( g_object_get_data(tbl, "rx") );
+        gdouble rx = ge->getVisibleRx();
+        gtk_adjustment_set_value(adj, Quantity::convert(rx, "px", unit));
+        gtk_adjustment_value_changed(adj);
 
-    adj = GTK_ADJUSTMENT( g_object_get_data(tbl, "ry") );
-    gtk_adjustment_set_value(adj, Quantity::convert(ry, "px", unit) * scale[Geom::Y]);
-    gtk_adjustment_value_changed(adj);
+        adj = GTK_ADJUSTMENT( g_object_get_data(tbl, "ry") );
+        gdouble ry = ge->getVisibleRy();
+        gtk_adjustment_set_value(adj, Quantity::convert(ry, "px", unit));
+        gtk_adjustment_value_changed(adj);
+    }
 
     gdouble start = 0.;
     gdouble end = 0.;
@@ -387,14 +375,18 @@ static void sp_arc_toolbox_selection_changed(Inkscape::Selection *selection, GOb
 {
     int n_selected = 0;
     Inkscape::XML::Node *repr = NULL;
+    SPItem *item = NULL;
 
+    if ( g_object_get_data( tbl, "repr" ) ) {
+        g_object_set_data( tbl, "item", NULL );
+    }
     purge_repr_listener( tbl, tbl );
 
     auto itemlist= selection->items();
     for(auto i=itemlist.begin();i!=itemlist.end();++i){
-        SPItem *item = *i;
-        if (SP_IS_GENERICELLIPSE(item)) {
+        if (SP_IS_GENERICELLIPSE(*i)) {
             n_selected++;
+            item = *i;
             repr = item->getRepr();
         }
     }
@@ -415,6 +407,7 @@ static void sp_arc_toolbox_selection_changed(Inkscape::Selection *selection, GOb
 
         if (repr) {
             g_object_set_data( tbl, "repr", repr );
+            g_object_set_data( tbl, "item", item );
             Inkscape::GC::anchor(repr);
             sp_repr_add_listener(repr, &arc_tb_repr_events, tbl);
             sp_repr_synthesize_events(repr, &arc_tb_repr_events, tbl);