Tooltips, Drag and Drop: Stabilized name of drag and drop tooltip window. (#8036)

docs/CHANGELOG.txt

@@ -73,6 +73,9 @@ Other changes:
   Set io.ConfigScrollbarScrollByPage=false to enforce always scrolling to clicked location.
 - Tooltips, Drag and Drop: Fixed an issue where the fallback drag and drop payload tooltip
   appeared during drag and drop release.
+- Tooltips, Drag and Drop: Stabilized name of drag and drop tooltip window so that
+  transitioning from an item tooltip to a drag tooltip doesn't leak window auto-sizing
+  info from one to the other. (#8036)
 - Backends: SDL3: Update for API changes: SDL_bool removal. SDL_INIT_TIMER removal.
 - Backends: WebGPU: Fixed DAWN api change using WGPUStringView in WGPUShaderSourceWGSL.
   (#8009, #8010) [@blitz-research]

imgui.cpp

@@ -3964,6 +3964,7 @@ ImGuiContext::ImGuiContext(ImFontAtlas* shared_font_atlas)
     DisabledStackSize = 0;
     LockMarkEdited = 0;
     TooltipOverrideCount = 0;
+    TooltipPreviousWindow = NULL;
 
     PlatformImeData.InputPos = ImVec2(0.0f, 0.0f);
     PlatformImeDataPrev.InputPos = ImVec2(-1.0f, -1.0f); // Different to ensure initial submission
@@ -5152,6 +5153,7 @@ void ImGui::NewFrame()
     g.DragDropWithinSource = false;
     g.DragDropWithinTarget = false;
     g.DragDropHoldJustPressedId = 0;
+    g.TooltipPreviousWindow = NULL;
 
     // Close popups on focus lost (currently wip/opt-in)
     //if (g.IO.AppFocusLost)
@@ -7549,6 +7551,9 @@ bool ImGui::Begin(const char* name, bool* p_open, ImGuiWindowFlags flags)
         // Clear hit test shape every frame
         window->HitTestHoleSize.x = window->HitTestHoleSize.y = 0;
 
+        if (flags & ImGuiWindowFlags_Tooltip)
+            g.TooltipPreviousWindow = window;
+
         // Pressing CTRL+C while holding on a window copy its content to the clipboard
         // This works but 1. doesn't handle multiple Begin/End pairs, 2. recursing into another Begin/End pair - so we need to work that out and add better logging scope.
         // Maybe we can support CTRL+C on every element?
@@ -11504,7 +11509,8 @@ bool ImGui::BeginTooltipEx(ImGuiTooltipFlags tooltip_flags, ImGuiWindowFlags ext
 {
     ImGuiContext& g = *GImGui;
 
-    if (g.DragDropWithinSource || g.DragDropWithinTarget)
+    const bool is_dragdrop_tooltip = g.DragDropWithinSource || g.DragDropWithinTarget;
+    if (is_dragdrop_tooltip)
     {
         // Drag and Drop tooltips are positioning differently than other tooltips:
         // - offset visibility to increase visibility around mouse.
@@ -11520,16 +11526,16 @@ bool ImGui::BeginTooltipEx(ImGuiTooltipFlags tooltip_flags, ImGuiWindowFlags ext
         tooltip_flags |= ImGuiTooltipFlags_OverridePrevious;
     }
 
-    char window_name[16];
-    ImFormatString(window_name, IM_ARRAYSIZE(window_name), "##Tooltip_%02d", g.TooltipOverrideCount);
-    if (tooltip_flags & ImGuiTooltipFlags_OverridePrevious)
-        if (ImGuiWindow* window = FindWindowByName(window_name))
-            if (window->Active)
-            {
-                // Hide previous tooltip from being displayed. We can't easily "reset" the content of a window so we create a new one.
-                SetWindowHiddenAndSkipItemsForCurrentFrame(window);
-                ImFormatString(window_name, IM_ARRAYSIZE(window_name), "##Tooltip_%02d", ++g.TooltipOverrideCount);
-            }
+    const char* window_name_template = is_dragdrop_tooltip ? "##Tooltip_DragDrop_%02d" : "##Tooltip_%02d";
+    char window_name[32];
+    ImFormatString(window_name, IM_ARRAYSIZE(window_name), window_name_template, g.TooltipOverrideCount);
+    if ((tooltip_flags & ImGuiTooltipFlags_OverridePrevious) && g.TooltipPreviousWindow != NULL && g.TooltipPreviousWindow->Active)
+    {
+        // Hide previous tooltip from being displayed. We can't easily "reset" the content of a window so we create a new one.
+        //IMGUI_DEBUG_LOG("[tooltip] '%s' already active, using +1 for this frame\n", window_name);
+        SetWindowHiddenAndSkipItemsForCurrentFrame(g.TooltipPreviousWindow);
+        ImFormatString(window_name, IM_ARRAYSIZE(window_name), window_name_template, ++g.TooltipOverrideCount);
+    }
     ImGuiWindowFlags flags = ImGuiWindowFlags_Tooltip | ImGuiWindowFlags_NoInputs | ImGuiWindowFlags_NoTitleBar | ImGuiWindowFlags_NoMove | ImGuiWindowFlags_NoResize | ImGuiWindowFlags_NoSavedSettings | ImGuiWindowFlags_AlwaysAutoResize;
     Begin(window_name, NULL, flags | extra_window_flags);
     // 2023-03-09: Added bool return value to the API, but currently always returning true.

imgui.h

@@ -29,7 +29,7 @@
 // Library Version
 // (Integer encoded as XYYZZ for use in #if preprocessor conditionals, e.g. '#if IMGUI_VERSION_NUM >= 12345')
 #define IMGUI_VERSION       "1.91.3 WIP"
-#define IMGUI_VERSION_NUM   19123
+#define IMGUI_VERSION_NUM   19124
 #define IMGUI_HAS_TABLE
 
 /*

imgui_internal.h

@@ -2283,6 +2283,7 @@ struct ImGuiContext
     short                   DisabledStackSize;
     short                   LockMarkEdited;
     short                   TooltipOverrideCount;
+    ImGuiWindow*            TooltipPreviousWindow;              // Window of last tooltip submitted during the frame
     ImVector<char>          ClipboardHandlerData;               // If no custom clipboard handler is defined
     ImVector<ImGuiID>       MenusIdSubmittedThisFrame;          // A list of menu IDs that were rendered at least once
     ImGuiTypingSelectState  TypingSelectState;                  // State for GetTypingSelectRequest()