From d20cb9e6ee198beb2bfd7e72d3dec0a575e3f28c Mon Sep 17 00:00:00 2001
From: Bas Ruigrok <Rexbas@proton.me>
Date: Sun, 6 Oct 2024 22:25:38 +0200
Subject: [PATCH] Gui: Fix Touchpad navigation style panning in edit mode

---
 src/Gui/NavigationStyle.h           |  3 +++
 src/Gui/TouchpadNavigationStyle.cpp | 11 +++++++++--
 2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/src/Gui/NavigationStyle.h b/src/Gui/NavigationStyle.h
index 1ed0bafcaf..ea8582055e 100644
--- a/src/Gui/NavigationStyle.h
+++ b/src/Gui/NavigationStyle.h
@@ -415,6 +415,9 @@ public:
 
 protected:
     SbBool processSoEvent(const SoEvent * const ev) override;
+
+private:
+    SbBool blockPan {false}; // Used to block the first pan in a mouse movement to prevent big jumps
 };
 
 class GuiExport OpenCascadeNavigationStyle : public UserNavigationStyle {
diff --git a/src/Gui/TouchpadNavigationStyle.cpp b/src/Gui/TouchpadNavigationStyle.cpp
index 5400440ae5..6efa6dc9a3 100644
--- a/src/Gui/TouchpadNavigationStyle.cpp
+++ b/src/Gui/TouchpadNavigationStyle.cpp
@@ -176,8 +176,11 @@ SbBool TouchpadNavigationStyle::processSoEvent(const SoEvent * const ev)
             processed = true;
         }
         else if (this->currentmode == NavigationStyle::PANNING) {
-            float ratio = vp.getViewportAspectRatio();
-            panCamera(viewer->getSoRenderManager()->getCamera(), ratio, this->panningplane, posn, prevnormalized);
+            if (!blockPan) {
+                float ratio = vp.getViewportAspectRatio();
+                panCamera(viewer->getSoRenderManager()->getCamera(), ratio, this->panningplane, posn, prevnormalized);
+            }
+            blockPan = false;
             processed = true;
         }
         else if (this->currentmode == NavigationStyle::DRAGGING) {
@@ -233,6 +236,10 @@ SbBool TouchpadNavigationStyle::processSoEvent(const SoEvent * const ev)
             processed = true;
         }
         newmode = NavigationStyle::PANNING;
+
+        if (currentmode != NavigationStyle::PANNING) {
+            blockPan = true;
+        }
         break;
     case ALTDOWN:
         if (newmode != NavigationStyle::DRAGGING) {