From 38b67355324899795e56e5440ba98c61ef46c13b Mon Sep 17 00:00:00 2001
From: cilix42 <cilix42@users.sourceforge.net>
Date: Wed, 18 Jun 2008 22:30:22 +0000
Subject: [PATCH] Update LPE helper paths "live" on changes

---
 src/shape-editor.cpp |  2 +-
 src/sp-lpe-item.cpp  | 28 ++++++++++++++++++++++++++++
 src/sp-lpe-item.h    |  3 +++
 3 files changed, 32 insertions(+), 1 deletion(-)

diff --git a/src/shape-editor.cpp b/src/shape-editor.cpp
index d5712525a..4b71184e4 100644
--- a/src/shape-editor.cpp
+++ b/src/shape-editor.cpp
@@ -198,7 +198,7 @@ void ShapeEditor::set_item(SPItem *item) {
                 // or the LPE is invisible or it doesn't provide a knotholder itself
                 this->nodepath = sp_nodepath_new(desktop, item,
                                                  (prefs_get_int_attribute("tools.nodes", "show_handles", 1) != 0));
-            } else if (lpe && lpe->isVisible() && lpe->showOrigPath()) {
+            } else if (lpe && lpe->isVisible()) {
                 sp_lpe_item_add_temporary_canvasitems(lpeitem, desktop);
             }
         }
diff --git a/src/sp-lpe-item.cpp b/src/sp-lpe-item.cpp
index 4c2ca3857..2ba1c86c2 100644
--- a/src/sp-lpe-item.cpp
+++ b/src/sp-lpe-item.cpp
@@ -118,6 +118,9 @@ sp_lpe_item_init(SPLPEItem *lpeitem)
     lpeitem->current_path_effect = NULL;
 
     new (&lpeitem->lpe_modified_connection) sigc::connection();
+
+    lpeitem->adding_helperpaths = false;
+    lpeitem->removing_helperpaths = false;
 }
 
 static void
@@ -345,6 +348,13 @@ sp_lpe_item_update_patheffect (SPLPEItem *lpeitem, bool wholetree, bool write)
         top = lpeitem;
     }
 
+    // TODO: ditch inkscape_active_desktop()
+    SPDesktop *desktop = inkscape_active_desktop();
+    if (desktop) {
+        sp_lpe_item_remove_temporary_canvasitems(lpeitem, desktop);
+        sp_lpe_item_add_temporary_canvasitems(lpeitem, desktop);
+    }
+
     if (SP_LPE_ITEM_CLASS (G_OBJECT_GET_CLASS (top))->update_patheffect) {
         SP_LPE_ITEM_CLASS (G_OBJECT_GET_CLASS (top))->update_patheffect (top, write);
     }
@@ -711,20 +721,38 @@ bool sp_lpe_item_path_effects_enabled(SPLPEItem *lpeitem)
 void
 sp_lpe_item_add_temporary_canvasitems(SPLPEItem *lpeitem, SPDesktop *desktop)
 {
+    if (lpeitem->adding_helperpaths) {
+        return;
+    }
+    lpeitem->adding_helperpaths = true;
+    // FIXME: for some reason it seems that we must create the variable lpe AFTER checking
+    //        for adding_helperpaths == true; otherwise we get a crash on startup. why??
     Inkscape::LivePathEffect::Effect *lpe = sp_lpe_item_get_current_lpe(lpeitem);
     if (lpe) {
+        // TODO: can we just update the tempitem's SPCurve instead of recreating it each time?
         lpe->addHelperPaths(lpeitem, desktop);
     }
+    lpeitem->adding_helperpaths = false;
 }
 
 void
 sp_lpe_item_remove_temporary_canvasitems(SPLPEItem *lpeitem, SPDesktop *desktop)
 {
+    g_return_if_fail(lpeitem);
+    g_return_if_fail(desktop);
+
+    if (lpeitem->removing_helperpaths) {
+        return;
+    }
+    lpeitem->removing_helperpaths = true;
+
     // destroy all temporary canvasitems created by LPEs
     std::vector<Inkscape::Display::TemporaryItem*>::iterator i;
     for (i = lpeitem->lpe_helperpaths.begin(); i != lpeitem->lpe_helperpaths.end(); ++i) {
         desktop->remove_temporary_canvasitem(*i);
     }
+
+    lpeitem->removing_helperpaths = false;
 }
 
 /*
diff --git a/src/sp-lpe-item.h b/src/sp-lpe-item.h
index 7691ce980..54642f27b 100644
--- a/src/sp-lpe-item.h
+++ b/src/sp-lpe-item.h
@@ -42,6 +42,9 @@ struct SPLPEItem : public SPItem {
     Inkscape::LivePathEffect::LPEObjectReference* current_path_effect;
     std::vector<Inkscape::Display::TemporaryItem*> lpe_helperpaths;
 
+    bool adding_helperpaths;
+    bool removing_helperpaths;
+
     sigc::connection lpe_modified_connection;
 };
 
-- 
2.30.2