CloseButton, CollapseButton: don't include FramePadding into size. Use ItemInnerSpacing.x between title bar buttons. (#6749)

docs/CHANGELOG.txt

@@ -50,6 +50,9 @@ Other changes:
   through proper navigation logic: honor scrolling and selection. (#1079, #1131)
 - Sliders: Fixed an integer overflow and div-by-zero in SliderInt() when
   v_max=INT_MAX (#6675, #6679) [@jbarthelmes]
+- Windows: Layout of Close/Collapse buttons uses style.ItemInnerSpacing.x between items,
+  stopped incorrectly using FramePadding in a way where hit-boxes could overlap when
+  setting large values. (#6749)
 - InputFloat, SliderFloat, DragFloat: always turn both '.' and ',' into the current decimal
   point character when using Decimal/Scientific character filter. (#6719, #2278) [@adamsepp]
 - ImDrawData: Fixed an issue where TotalVtxCount/TotalIdxCount does not match the sum

imgui.cpp

@@ -6095,18 +6095,18 @@ void ImGui::RenderWindowTitleBarContents(ImGuiWindow* window, const ImRect& titl
     ImVec2 collapse_button_pos;
     if (has_close_button)
     {
-        pad_r += button_sz;
-        close_button_pos = ImVec2(title_bar_rect.Max.x - pad_r - style.FramePadding.x, title_bar_rect.Min.y);
+        close_button_pos = ImVec2(title_bar_rect.Max.x - pad_r - button_sz, title_bar_rect.Min.y + style.FramePadding.y);
+        pad_r += button_sz + style.ItemInnerSpacing.x;
     }
     if (has_collapse_button && style.WindowMenuButtonPosition == ImGuiDir_Right)
     {
-        pad_r += button_sz;
-        collapse_button_pos = ImVec2(title_bar_rect.Max.x - pad_r - style.FramePadding.x, title_bar_rect.Min.y);
+        collapse_button_pos = ImVec2(title_bar_rect.Max.x - pad_r - button_sz, title_bar_rect.Min.y + style.FramePadding.y);
+        pad_r += button_sz + style.ItemInnerSpacing.x;
     }
     if (has_collapse_button && style.WindowMenuButtonPosition == ImGuiDir_Left)
     {
-        collapse_button_pos = ImVec2(title_bar_rect.Min.x + pad_l - style.FramePadding.x, title_bar_rect.Min.y);
-        pad_l += button_sz;
+        collapse_button_pos = ImVec2(title_bar_rect.Min.x + pad_l, title_bar_rect.Min.y + style.FramePadding.y);
+        pad_l += button_sz + style.ItemInnerSpacing.x;
     }
 
     // Collapse button (submitting first so it gets priority when choosing a navigation init fallback)

imgui_widgets.cpp

@@ -802,7 +802,7 @@ bool ImGui::CloseButton(ImGuiID id, const ImVec2& pos)
 
     // Tweak 1: Shrink hit-testing area if button covers an abnormally large proportion of the visible region. That's in order to facilitate moving the window away. (#3825)
     // This may better be applied as a general hit-rect reduction mechanism for all widgets to ensure the area to move window is always accessible?
-    const ImRect bb(pos, pos + ImVec2(g.FontSize, g.FontSize) + g.Style.FramePadding * 2.0f);
+    const ImRect bb(pos, pos + ImVec2(g.FontSize, g.FontSize));
     ImRect bb_interact = bb;
     const float area_to_visible_ratio = window->OuterRectClipped.GetArea() / bb.GetArea();
     if (area_to_visible_ratio < 1.5f)
@@ -838,7 +838,7 @@ bool ImGui::CollapseButton(ImGuiID id, const ImVec2& pos)
     ImGuiContext& g = *GImGui;
     ImGuiWindow* window = g.CurrentWindow;
 
-    ImRect bb(pos, pos + ImVec2(g.FontSize, g.FontSize) + g.Style.FramePadding * 2.0f);
+    ImRect bb(pos, pos + ImVec2(g.FontSize, g.FontSize));
     bool is_clipped = !ItemAdd(bb, id);
     bool hovered, held;
     bool pressed = ButtonBehavior(bb, id, &hovered, &held, ImGuiButtonFlags_None);
@@ -850,7 +850,7 @@ bool ImGui::CollapseButton(ImGuiID id, const ImVec2& pos)
     ImU32 text_col = GetColorU32(ImGuiCol_Text);
     if (hovered || held)
         window->DrawList->AddCircleFilled(bb.GetCenter() + ImVec2(0.0f, -0.5f), g.FontSize * 0.5f + 1.0f, bg_col);
-    RenderArrow(window->DrawList, bb.Min + g.Style.FramePadding, text_col, window->Collapsed ? ImGuiDir_Right : ImGuiDir_Down, 1.0f);
+    RenderArrow(window->DrawList, bb.Min, text_col, window->Collapsed ? ImGuiDir_Right : ImGuiDir_Down, 1.0f);
 
     // Switch to moving the window after mouse is moved beyond the initial drag threshold
     if (IsItemActive() && IsMouseDragging(0))
@@ -6421,8 +6421,8 @@ bool ImGui::CollapsingHeader(const char* label, bool* p_visible, ImGuiTreeNodeFl
         ImGuiContext& g = *GImGui;
         ImGuiLastItemData last_item_backup = g.LastItemData;
         float button_size = g.FontSize;
-        float button_x = ImMax(g.LastItemData.Rect.Min.x, g.LastItemData.Rect.Max.x - g.Style.FramePadding.x * 2.0f - button_size);
-        float button_y = g.LastItemData.Rect.Min.y;
+        float button_x = ImMax(g.LastItemData.Rect.Min.x, g.LastItemData.Rect.Max.x - g.Style.FramePadding.x - button_size);
+        float button_y = g.LastItemData.Rect.Min.y + g.Style.FramePadding.y;
         ImGuiID close_button_id = GetIDWithSeed("#CLOSE", NULL, id);
         if (CloseButton(close_button_id, ImVec2(button_x, button_y)))
             *p_visible = false;
@@ -8596,7 +8596,7 @@ void ImGui::TabItemLabelAndCloseButton(ImDrawList* draw_list, const ImRect& bb,
     }
 
     const float button_sz = g.FontSize;
-    const ImVec2 button_pos(ImMax(bb.Min.x, bb.Max.x - frame_padding.x * 2.0f - button_sz), bb.Min.y);
+    const ImVec2 button_pos(ImMax(bb.Min.x, bb.Max.x - frame_padding.x - button_sz), bb.Min.y + frame_padding.y);
 
     // Close Button & Unsaved Marker
     // We are relying on a subtle and confusing distinction between 'hovered' and 'g.HoveredId' which happens because we are using ImGuiButtonFlags_AllowOverlapMode + SetItemAllowOverlap()
@@ -8614,10 +8614,8 @@ void ImGui::TabItemLabelAndCloseButton(ImDrawList* draw_list, const ImRect& bb,
     if (close_button_visible)
     {
         ImGuiLastItemData last_item_backup = g.LastItemData;
-        PushStyleVar(ImGuiStyleVar_FramePadding, frame_padding);
         if (CloseButton(close_button_id, button_pos))
             close_button_pressed = true;
-        PopStyleVar();
         g.LastItemData = last_item_backup;
 
         // Close with middle mouse button