IsItemHovered will overlapping items doesn't reflect visible state of item

[ocornut]

Version/Branch of Dear ImGui:

Version 1.91.8 master

Back-ends:

n/a

Compiler, OS:

n/a

Full config/build information:

Linking to e.g. #6610 for this is a different issue.

Details:

My Issue/Question:

XXX (please provide as much context as possible)

Screenshots/Video:

Minimal, Complete and Verifiable Example code:

{

    static bool overlap = false;
    ImGui::Checkbox("Allow Overlap", &overlap);

    const ImVec2 pos = ImGui::GetCursorScreenPos();
    const float offset = 100.0f;
    const ImVec2 but_size(50, 30);

    ImGui::SetCursorScreenPos(ImVec2(pos.x + offset, pos.y));
    if (overlap)
        ImGui::SetNextItemAllowOverlap();
    ImGui::Button("AAAA", but_size);

    const bool aaa_hovered = ImGui::IsItemHovered();
    const bool aaa_active = ImGui::IsItemActive();
    const bool aaa_focused = ImGui::IsItemFocused();

    ImGui::SetCursorScreenPos(ImVec2(pos.x + offset + but_size.x * 0.5f, pos.y + but_size.y * 0.5f));
    ImGui::Button("BBBB", but_size);
    const bool bbb_hovered = ImGui::IsItemHovered();
    const bool bbb_active = ImGui::IsItemActive();
    const bool bbb_focused = ImGui::IsItemFocused();

    ImGui::SetCursorScreenPos(ImVec2(pos.x + offset, pos.y + but_size.y * 2));
    ImGui::Text("AAAA = %s - %s - %s",
        aaa_hovered ? "HOVERED" : "not hovered",
        aaa_active ? "ACTIVE" : "not active",
        aaa_focused ? "FOCUSED" : "not focused"
    );

    ImGui::SetCursorScreenPos(ImVec2(pos.x + offset, pos.y + but_size.y * 3));
    ImGui::Text("BBBB = %s - %s - %s",
        bbb_hovered ? "HOVERED" : "not hovered",
        bbb_active ? "ACTIVE" : "not active",
        bbb_focused ? "FOCUSED" : "not focused"
    );
}

[ocornut]

Note for future myself:
The "naive" change would be to change the code in IsItemHovered() to:

// Test if using AllowOverlap and overlapped
if ((flags & ImGuiHoveredFlags_AllowWhenOverlappedByItem) == 0 && id != 0)
{
    if (g.LastItemData.ItemFlags & ImGuiItemFlags_AllowOverlap)
    {
        if (g.HoveredIdPreviousFrame != g.LastItemData.ID)
            return false;
    }
++    else
++    {
++        if (g.HoveredId != g.LastItemData.ID && g.HoveredId != 0 && !g.HoveredIdAllowOverlap)
++            return false;
++    }
}

Which breaks the following tests:

• window_title_context_menu
• widgets_hover
• widgets_overlap_3_timing
• widgets_selectable_span_all_columns
• widgets_selectable_span_all_table

widgets_overlap_3_timing had a IMGUI_BROKEN_TESTS block, new behavior seems better.

Both widgets_selectable_span_all_columns and widgets_selectable_span_all_table were actually incorrect and this revealed it.

But:

widgets_hover
Fails trying to call IsItemHovered() after EndChild().

window_title_context_menu
Highlight a non trivial issue: with this change BeginPopupContextItem() doesn't work when hovering the Close Button, because the function calls IsItemHovered(). In this case the submission order is: CloseButton(), then TitleBar but via SetLastItemDataForWindow() without a call to ItemHoverable().