Tab Bar: Do not display a tooltip if the name already fits over a given tab. (#3521)

docs/CHANGELOG.txt

@@ -56,6 +56,7 @@ Other Changes:
 
 - Tab Bar: Made it possible to append to an existing tab bar by calling BeginTabBar()/EndTabBar() again.
 - Tab Bar: Fixed using more than 128 tabs in a tab bar (scrolling policy recommended).
+- Tab Bar: Do not display a tooltip if the name already fits over a given tab. (#3521)
 - Drag and Drop: Fix drag and drop to tie same-size drop targets by choosen the later one. Fixes dragging
   into a full-window-sized dockspace inside a zero-padded window. (#3519, #2717) [@Black-Cat]
 - Backends: OpenGL: use glGetString(GL_VERSION) query instead of glGetIntegerv(GL_MAJOR_VERSION, ...) 

imgui_internal.h

@@ -1971,7 +1971,7 @@ namespace ImGui
     IMGUI_API bool          TabItemEx(ImGuiTabBar* tab_bar, const char* label, bool* p_open, ImGuiTabItemFlags flags);
     IMGUI_API ImVec2        TabItemCalcSize(const char* label, bool has_close_button);
     IMGUI_API void          TabItemBackground(ImDrawList* draw_list, const ImRect& bb, ImGuiTabItemFlags flags, ImU32 col);
-    IMGUI_API bool          TabItemLabelAndCloseButton(ImDrawList* draw_list, const ImRect& bb, ImGuiTabItemFlags flags, ImVec2 frame_padding, const char* label, ImGuiID tab_id, ImGuiID close_button_id, bool is_contents_visible);
+    IMGUI_API void          TabItemLabelAndCloseButton(ImDrawList* draw_list, const ImRect& bb, ImGuiTabItemFlags flags, ImVec2 frame_padding, const char* label, ImGuiID tab_id, ImGuiID close_button_id, bool is_contents_visible, bool* out_just_closed, bool* out_text_clipped);
 
     // Render helpers
     // AVOID USING OUTSIDE OF IMGUI.CPP! NOT FOR PUBLIC CONSUMPTION. THOSE FUNCTIONS ARE A MESS. THEIR SIGNATURE AND BEHAVIOR WILL CHANGE, THEY NEED TO BE REFACTORED INTO SOMETHING DECENT.

imgui_widgets.cpp

@@ -7677,7 +7677,9 @@ bool    ImGui::TabItemEx(ImGuiTabBar* tab_bar, const char* label, bool* p_open,
 
     // Render tab label, process close button
     const ImGuiID close_button_id = p_open ? GetIDWithSeed("#CLOSE", NULL, id) : 0;
-    bool just_closed = TabItemLabelAndCloseButton(display_draw_list, bb, flags, tab_bar->FramePadding, label, id, close_button_id, tab_contents_visible);
+    bool just_closed;
+    bool text_clipped;
+    TabItemLabelAndCloseButton(display_draw_list, bb, flags, tab_bar->FramePadding, label, id, close_button_id, tab_contents_visible, &just_closed, &text_clipped);
     if (just_closed && p_open != NULL)
     {
         *p_open = false;
@@ -7691,7 +7693,7 @@ bool    ImGui::TabItemEx(ImGuiTabBar* tab_bar, const char* label, bool* p_open,
 
     // Tooltip (FIXME: Won't work over the close button because ItemOverlap systems messes up with HoveredIdTimer)
     // We test IsItemHovered() to discard e.g. when another item is active or drag and drop over the tab bar (which g.HoveredId ignores)
-    if (g.HoveredId == id && !held && g.HoveredIdNotActiveTimer > 0.50f && IsItemHovered())
+    if (text_clipped && g.HoveredId == id && !held && g.HoveredIdNotActiveTimer > 0.50f && IsItemHovered())
         if (!(tab_bar->Flags & ImGuiTabBarFlags_NoTooltip) && !(tab->Flags & ImGuiTabItemFlags_NoTooltip))
             SetTooltip("%.*s", (int)(FindRenderedTextEnd(label) - label), label);
 
@@ -7756,12 +7758,18 @@ void ImGui::TabItemBackground(ImDrawList* draw_list, const ImRect& bb, ImGuiTabI
 
 // Render text label (with custom clipping) + Unsaved Document marker + Close Button logic
 // We tend to lock style.FramePadding for a given tab-bar, hence the 'frame_padding' parameter.
-bool ImGui::TabItemLabelAndCloseButton(ImDrawList* draw_list, const ImRect& bb, ImGuiTabItemFlags flags, ImVec2 frame_padding, const char* label, ImGuiID tab_id, ImGuiID close_button_id, bool is_contents_visible)
+void ImGui::TabItemLabelAndCloseButton(ImDrawList* draw_list, const ImRect& bb, ImGuiTabItemFlags flags, ImVec2 frame_padding, const char* label, ImGuiID tab_id, ImGuiID close_button_id, bool is_contents_visible, bool* out_just_closed, bool* out_text_clipped)
 {
     ImGuiContext& g = *GImGui;
     ImVec2 label_size = CalcTextSize(label, NULL, true);
+
+    if (out_just_closed)
+        *out_just_closed = false;
+    if (out_text_clipped)
+        *out_text_clipped = false;
+
     if (bb.GetWidth() <= 1.0f)
-        return false;
+        return;
 
     // In Style V2 we'll have full override of all colors per state (e.g. focused, selected)
     // But right now if you want to alter text color of tabs this is what you need to do.
@@ -7782,6 +7790,13 @@ bool ImGui::TabItemLabelAndCloseButton(ImDrawList* draw_list, const ImRect& bb,
     }
     ImRect text_ellipsis_clip_bb = text_pixel_clip_bb;
 
+    // Return clipped state ignoring the close button
+    if (out_text_clipped)
+    {
+        *out_text_clipped = (text_ellipsis_clip_bb.Min.x + label_size.x) > text_pixel_clip_bb.Max.x;
+        //draw_list->AddCircle(text_ellipsis_clip_bb.Min, 3.0f, *out_text_clipped ? IM_COL32(255, 0, 0, 255) : IM_COL32(0, 255, 0, 255));
+    }
+
     // Close Button
     // We are relying on a subtle and confusing distinction between 'hovered' and 'g.HoveredId' which happens because we are using ImGuiButtonFlags_AllowOverlapMode + SetItemAllowOverlap()
     //  'hovered' will be true when hovering the Tab but NOT when hovering the close button
@@ -7819,7 +7834,8 @@ bool ImGui::TabItemLabelAndCloseButton(ImDrawList* draw_list, const ImRect& bb,
         g.Style.Alpha = backup_alpha;
 #endif
 
-    return close_button_pressed;
+    if (out_just_closed)
+        *out_just_closed = close_button_pressed;
 }