lpe-skeleton: add boilerplate code to create knotholder handles for LPEs

(bzr r6122)

2 files changed, 34 insertions, 0 deletions

diff --git a/src/live_effects/lpe-skeleton.cpp b/src/live_effects/lpe-skeleton.cpp
index c1a3e2601..ff601ef70 100644
--- a/src/live_effects/lpe-skeleton.cpp
+++ b/src/live_effects/lpe-skeleton.cpp
@@ -37,6 +37,9 @@ LPESkeleton::LPESkeleton(LivePathEffectObject *lpeobject) :
 
     /* register all your parameters here, so Inkscape knows which parameters this effect has: */
     registerParameter( dynamic_cast<Parameter *>(&number) );
+
+    /* register all your knotholder handles here: */
+    //registerKnotHolderHandle(new Skeleton::KnotHolderEntityAttachMyHandle(), _("help message"));
 }
 
 LPESkeleton::~LPESkeleton()
@@ -77,6 +80,25 @@ LPESkeleton::doEffect_pwd2 (Geom::Piecewise<Geom::D2<Geom::SBasis> > const & pwd
     return output;
 }
 
+/* ########################
+ *  Define the classes for your knotholder handles here
+ */
+
+namespace Skeleton {
+
+class KnotHolderEntityMyHandle : public KnotHolderEntity
+{
+public:
+    virtual bool isLPEParam() { return true; } // this is always needed
+
+    // the set() and get() methods must be implemented, click() is optional
+    virtual void knot_set(NR::Point const &p, NR::Point const &origin, guint state);
+    virtual NR::Point knot_get();
+    //virtual void knot_click(guint state);
+};
+
+} // namespace Skeleton
+
 /* ######################## */
 
 } //namespace LivePathEffect
diff --git a/src/live_effects/lpe-skeleton.h b/src/live_effects/lpe-skeleton.h
index 532176a23..d961ad954 100644
--- a/src/live_effects/lpe-skeleton.h
+++ b/src/live_effects/lpe-skeleton.h
@@ -20,6 +20,15 @@
 namespace Inkscape {
 namespace LivePathEffect {
 
+// each knotholder handle for your LPE requires a separate class derived from KnotHolderEntity;
+// define it in lpe-skeleton.cpp and register it in the effect's constructor
+/**
+namespace Skeleton {
+  // we need a separate namespace to avoid clashes with other LPEs
+  class KnotHolderEntityMyHandle;
+}
+**/
+
 class LPESkeleton : public Effect {
 public:
     LPESkeleton(LivePathEffectObject *lpeobject);
@@ -30,6 +39,9 @@ public:
 //    virtual std::vector<Geom::Path> doEffect_path (std::vector<Geom::Path> const & path_in);
     virtual Geom::Piecewise<Geom::D2<Geom::SBasis> > doEffect_pwd2 (Geom::Piecewise<Geom::D2<Geom::SBasis> > const & pwd2_in);
 
+    /* the knotholder entity classes (if any) must be declared friends */
+    //friend class Skeleton::KnotHolderEntityMyHandle;
+
 private:
     // add the parameters for your effect here:
     ScalarParam number;