TreeNode: Fixed bug where dragging a payload over a TreeNode() with either _OpenOnDoubleClick or _OpenOnArrow would open the node. (#143)

docs/CHANGELOG.txt

@@ -41,6 +41,8 @@ Other Changes:
 - TreeNode: Fixed bug where BeginDragDropSource() failed when the _OpenOnDoubleClick flag is
   enabled (bug introduced in 1.76, but pre-1.76 it would also fail unless the _OpenOnArrow
   flag was also set, and _OpenOnArrow is frequently set along with _OpenOnDoubleClick).
+- TreeNode: Fixed bug where dragging a payload over a TreeNode() with either _OpenOnDoubleClick
+  or _OpenOnArrow would open the node. (#143)
 
 
 -----------------------------------------------------------------------

imgui.cpp

@@ -3795,6 +3795,7 @@ void ImGui::NewFrame()
     g.DragDropAcceptIdCurrRectSurface = FLT_MAX;
     g.DragDropWithinSource = false;
     g.DragDropWithinTarget = false;
+    g.DragDropHoldJustPressedId = 0;
 
     // Update keyboard input state
     // Synchronize io.KeyMods with individual modifiers io.KeyXXX bools

imgui_internal.h

@@ -1165,6 +1165,7 @@ struct ImGuiContext
     ImGuiID                 DragDropAcceptIdCurr;               // Target item id (set at the time of accepting the payload)
     ImGuiID                 DragDropAcceptIdPrev;               // Target item id from previous frame (we need to store this to allow for overlapping drag and drop targets)
     int                     DragDropAcceptFrameCount;           // Last time a target expressed a desire to accept the source
+    ImGuiID                 DragDropHoldJustPressedId;          // Set when holding a payload just made ButtonBehavior() return a press.
     ImVector<unsigned char> DragDropPayloadBufHeap;             // We don't expose the ImVector<> directly, ImGuiPayload only holds pointer+size
     unsigned char           DragDropPayloadBufLocal[16];        // Local buffer for small payloads
 
@@ -1320,6 +1321,7 @@ struct ImGuiContext
         DragDropAcceptIdCurrRectSurface = 0.0f;
         DragDropAcceptIdPrev = DragDropAcceptIdCurr = 0;
         DragDropAcceptFrameCount = -1;
+        DragDropHoldJustPressedId = 0;
         memset(DragDropPayloadBufLocal, 0, sizeof(DragDropPayloadBufLocal));
 
         CurrentTabBar = NULL;

imgui_widgets.cpp

@@ -500,11 +500,13 @@ bool ImGui::ButtonBehavior(const ImRect& bb, ImGuiID id, bool* out_hovered, bool
     if (g.DragDropActive && (flags & ImGuiButtonFlags_PressedOnDragDropHold) && !(g.DragDropSourceFlags & ImGuiDragDropFlags_SourceNoHoldToOpenOthers))
         if (IsItemHovered(ImGuiHoveredFlags_AllowWhenBlockedByActiveItem))
         {
+            const float DRAG_DROP_HOLD_TIMER = 0.70f;
             hovered = true;
             SetHoveredID(id);
-            if (CalcTypematicRepeatAmount(g.HoveredIdTimer + 0.0001f - g.IO.DeltaTime, g.HoveredIdTimer + 0.0001f, 0.70f, 0.00f))
+            if (CalcTypematicRepeatAmount(g.HoveredIdTimer + 0.0001f - g.IO.DeltaTime, g.HoveredIdTimer + 0.0001f, DRAG_DROP_HOLD_TIMER, 0.00f))
             {
                 pressed = true;
+                g.DragDropHoldJustPressedId = id;
                 FocusWindow(window);
             }
         }
@@ -5376,7 +5378,7 @@ bool ImGui::TreeNodeBehavior(ImGuiID id, ImGuiTreeNodeFlags flags, const char* l
     bool toggled = false;
     if (!is_leaf)
     {
-        if (pressed)
+        if (pressed && g.DragDropHoldJustPressedId != id)
         {
             if ((flags & (ImGuiTreeNodeFlags_OpenOnArrow | ImGuiTreeNodeFlags_OpenOnDoubleClick)) == 0 || (g.NavActivateId == id))
                 toggled = true;
@@ -5384,8 +5386,12 @@ bool ImGui::TreeNodeBehavior(ImGuiID id, ImGuiTreeNodeFlags flags, const char* l
                 toggled |= is_mouse_x_over_arrow && !g.NavDisableMouseHover; // Lightweight equivalent of IsMouseHoveringRect() since ButtonBehavior() already did the job
             if ((flags & ImGuiTreeNodeFlags_OpenOnDoubleClick) && g.IO.MouseDoubleClicked[0])
                 toggled = true;
-            if (g.DragDropActive && is_open) // When using Drag and Drop "hold to open" we keep the node highlighted after opening, but never close it again.
-                toggled = false;
+        }
+        else if (pressed && g.DragDropHoldJustPressedId == id)
+        {
+            IM_ASSERT(button_flags & ImGuiButtonFlags_PressedOnDragDropHold);
+            if (!is_open) // When using Drag and Drop "hold to open" we keep the node highlighted after opening, but never close it again.
+                toggled = true;
         }
 
         if (g.NavId == id && g.NavMoveRequest && g.NavMoveDir == ImGuiDir_Left && is_open)