From 8e605dd148c19e58a75d520b03d258108ffee661 Mon Sep 17 00:00:00 2001
From: Jabiertxof <jabier.arraiza@marker.es>
Date: Thu, 14 May 2020 18:35:21 +0200
Subject: [PATCH] Get precise snapping

Snaping is not precise, user couldent be sure if on release the target is snaped or not
To fix it I improve snaping in two ways:
1. General one (creartion tools) we remove snaping from root event and use only item based events
2. For transforms we define a treshold to the snaped item become unsnaped
---
 src/seltrans.cpp           | 39 ++++++++++++++++++++++++++++++--------
 src/ui/tools/tool-base.cpp | 28 ---------------------------
 2 files changed, 31 insertions(+), 36 deletions(-)

diff --git a/src/seltrans.cpp b/src/seltrans.cpp
index 96e6b2c94a..ef2207d99e 100644
--- a/src/seltrans.cpp
+++ b/src/seltrans.cpp
@@ -1404,6 +1404,12 @@ void Inkscape::SelTrans::rotate(Geom::Point &/*pt*/, guint /*state*/)
 
 void Inkscape::SelTrans::moveTo(Geom::Point const &xy, guint state)
 {
+    static bool snaped = false;
+    static Geom::Point prevsnappoint;
+    Inkscape::Preferences *prefs = Inkscape::Preferences::get();
+    double snapdistance = prefs->getDoubleLimited("/options/snapweight/value", 0.5, 0, 1);
+    snapdistance *= 50.0; //snapped-point.cpp:186
+
     SnapManager &m = _desktop->namedview->snap_manager;
 
     /* The amount that we've moved by during this drag */
@@ -1486,12 +1492,29 @@ void Inkscape::SelTrans::moveTo(Geom::Point const &xy, guint state)
             best_snapped_point = bb->best_snapped_point;
             dxy = bb->getTranslationSnapped();
         }
-
+        Geom::Point origin = best_snapped_point.getPoint();
+        Geom::Point snap = origin;
+        best_snapped_point.getPointIfSnapped(snap);
         if (best_snapped_point.getSnapped()) {
+            Geom::Point p = best_snapped_point.getPoint();
+            if (!Geom::are_near(origin, snap) || !Geom::are_near(prevsnappoint,snap)) {
+                snaped = false;
+            }
+            prevsnappoint = snap;
+            if (!snaped) {
+                snaped = true; 
+                Geom::Affine const move((Geom::Translate(dxy)));
+                Geom::Point const norm(0, 0);
+                transform(move, norm);
+            }
             _desktop->snapindicator->set_new_snaptarget(best_snapped_point);
         } else {
-            // We didn't snap, so remove any previous snap indicator
-            _desktop->snapindicator->remove_snaptarget();
+            if (snapdistance < std::abs(Geom::distance(dxy, snap))) {
+                snaped = false;
+                // We didn't snap, so remove any previous snap indicator
+                _desktop->snapindicator->remove_snaptarget();
+            } 
+            
             if (control) {
                 // If we didn't snap, then we should still constrain horizontally or vertically
                 // (When we did snap, then this constraint has already been enforced by
@@ -1506,11 +1529,11 @@ void Inkscape::SelTrans::moveTo(Geom::Point const &xy, guint state)
         delete bb;
         delete sn;
     }
-
-    Geom::Affine const move((Geom::Translate(dxy)));
-    Geom::Point const norm(0, 0);
-    transform(move, norm);
-
+    if (!snaped) {
+        Geom::Affine const move((Geom::Translate(dxy)));
+        Geom::Point const norm(0, 0);
+        transform(move, norm);
+    }
     // status text
     Inkscape::Util::Quantity x_q = Inkscape::Util::Quantity(dxy[Geom::X], "px");
     Inkscape::Util::Quantity y_q = Inkscape::Util::Quantity(dxy[Geom::Y], "px");
diff --git a/src/ui/tools/tool-base.cpp b/src/ui/tools/tool-base.cpp
index 4a12a7b829..90f4b8eef2 100644
--- a/src/ui/tools/tool-base.cpp
+++ b/src/ui/tools/tool-base.cpp
@@ -1108,34 +1108,6 @@ gint sp_event_context_root_handler(ToolBase * event_context,
         GdkEvent * event)
 {
 
-    if (!event_context->_uses_snap) {
-        return sp_event_context_virtual_root_handler(event_context, event);
-    }
-
-    switch (event->type) {
-    case GDK_MOTION_NOTIFY:
-        sp_event_context_snap_delay_handler(event_context, nullptr, nullptr,
-                (GdkEventMotion *) event,
-                DelayedSnapEvent::EVENTCONTEXT_ROOT_HANDLER);
-        break;
-    case GDK_BUTTON_RELEASE:
-        if (event_context && event_context->_delayed_snap_event) {
-            // If we have any pending snapping action, then invoke it now
-            sp_event_context_snap_watchdog_callback(
-                    event_context->_delayed_snap_event);
-        }
-        break;
-    case GDK_BUTTON_PRESS:
-    case GDK_2BUTTON_PRESS:
-    case GDK_3BUTTON_PRESS:
-        // Snapping will be on hold if we're moving the mouse at high speeds. When starting
-        // drawing a new shape we really should snap though.
-        event_context->desktop->namedview->snap_manager.snapprefs.setSnapPostponedGlobally(false);
-        break;
-    default:
-        break;
-    }
-
     return sp_event_context_virtual_root_handler(event_context, event);
 }
 
-- 
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