imgui column header and sorting

imguiheader

static void GetColumnOffsetsFromImGui(PackFileGui *gui)
{
    for (int i = 1; i < ARRAY_ELEMENTS(gui->displayColumnOffsets); ++i)
    {
        gui->displayColumnOffsets[i] = ImGui::GetColumnOffset(i);
    }
}

static void SendColumnOffsetsToImGui(PackFileGui *gui)
{
    // Pixels to offset the column headers by to make sure we line up with the contents.                                                                                                                                                                                        
    const float COLUMN_HEADER_OFFSET = 8.0f;

    for (int i = 1; i < ARRAY_ELEMENTS(gui->displayColumnOffsets); ++i)
    {
        ImGui::SetColumnOffset(i, gui->displayColumnOffsets[i] + COLUMN_HEADER_OFFSET);
    }
}

static const char *GetSortDirectionLabel(bool sortSelected, bool descending)
{
    if (!sortSelected)
    {
        return "";
    }

    if (descending)
    {
        return "v";
    }
    else
    {
        return "^";
    }
}

void PackFileGuiInit(PackFileGui *gui)
{
    memset(gui, 0, sizeof(*gui));

    gui->selectedTab = -1;
    gui->displayComp = indexCompare;
    gui->rowSelected = -1;

    // Initial column offsets for pleasing spacing.                                                                                                                                                                                                                             
    gui->displayColumnOffsets[1] = 60.0f;
    gui->displayColumnOffsets[2] = 254.430542f;
    gui->displayColumnOffsets[3] = 954.982666f;
    gui->displayColumnOffsets[4] = 1059.500488f;
}

ImGui::Columns(5, "header");
SendColumnOffsetsToImGui(gui);
bool sortSelected = (gui->displayComp == indexCompare);

if (ImGuiSelectable(false, false, "Index %s", GetSortDirectionLabel(sortSelected, gui->displayDescending)))
{
    gui->displayDescending ^= sortSelected ? true : gui->displayDescending;
    gui->displayComp = indexCompare;
}

ImGui::Separator();
ImGui::NextColumn();
sortSelected = (gui->displayComp == typeCompare);

if (ImGuiSelectable(false, false, "Type %s", GetSortDirectionLabel(sortSelected, gui->displayDescending)))
{
    gui->displayDescending ^= sortSelected ? true : gui->displayDescending;
    gui->displayComp = typeCompare;
}

ImGui::Separator();
ImGui::NextColumn();
sortSelected = (gui->displayComp == pathCompare);

if (ImGuiSelectable(false, false, "Path %s", GetSortDirectionLabel(sortSelected, gui->displayDescending)))
{
    gui->displayDescending ^= sortSelected ? true : gui->displayDescending;
    gui->displayComp = pathCompare;
}

ImGui::Separator();
ImGui::NextColumn();
sortSelected = (gui->displayComp == offsetCompare);

if (ImGuiSelectable(false, false, "Offset %s", GetSortDirectionLabel(sortSelected, gui->displayDescending)))
{
    gui->displayDescending ^= sortSelected ? true : gui->displayDescending;
    gui->displayComp = offsetCompare;
}

ImGui::Separator();
ImGui::NextColumn();
sortSelected = (gui->displayComp == byteCompare);

if (ImGuiSelectable(false, false, "Bytes %s", GetSortDirectionLabel(sortSelected, gui->displayDescending)))
{
    gui->displayDescending ^= sortSelected ? true : gui->displayDescending;
    gui->displayComp = byteCompare;
}

ImGui::Separator();
ImGui::NextColumn();
ImGui::Columns(1);
ImGui::BeginChild("##scrolling", ImVec2(0.0f, 500.0f));
ImGui::Columns(5, "contents");

if (!gui->displayColumnsInitialized)
{
    SendColumnOffsetsToImGui(gui);
    gui->displayColumnsInitialized = true;
}

GetColumnOffsetsFromImGui(gui);

int numItems = gui->pack.manifest->numPaths;
DisplayIndex *displayIndices = PushArrayFront(&gui->imguiMemory, DisplayIndex, numItems);

// Set up the display indices for sorting.
for (int i = 0; i < numItems; ++i)
{
    displayIndices[i].manifest = gui->pack.manifest;
    displayIndices[i].index = i;
}

qsort(displayIndices, numItems, SIZEOF_ARRAY_ELEMENT(displayIndices), gui->displayComp);

if (gui->displayDescending)
{
    int lo = 0, hi = numItems - 1;

    while (lo < hi)
    {
        DisplayIndex temp = displayIndices[lo];

        displayIndices[lo] = displayIndices[hi];
        displayIndices[hi] = temp;
        ++lo;
        --hi;
    }
}

float itemHeight = ImGui::GetTextLineHeightWithSpacing();
int displayStart = 0, displayEnd = numItems;

ImGui::CalcListClipping(numItems, itemHeight, &displayStart, &displayEnd);
ImGui::SetCursorPosY(ImGui::GetCursorPosY() + (displayStart * itemHeight));

for (int i = displayStart; i < displayEnd; ++i)
{
    int indexSelected = displayIndices[i].index;
    ImGui::PushID(i);

    if (ImGuiSelectable(false, i == gui->rowSelected, "%d", indexSelected))
    {
        gui->rowSelected = i;
        gui->selectedResource = PackFileRead(&gui->pack, gui->pack.manifest->paths[indexSelected], gui->onLoaded, gui->callbackData);
        printf("\n");
    }

    ImGui::PopID();
}

ImGui::NextColumn();
ImGui::SetCursorPosY(ImGui::GetCursorPosY() + (displayStart * itemHeight));

for (int i = displayStart; i < displayEnd; ++i)
{
    int indexSelected = displayIndices[i].index;
    ImGui::PushID(i);

    if (ImGuiSelectable(false, i == gui->rowSelected, "%s", ResourceTypeToStr[gui->pack.manifest->types[indexSelected]]))
    {
        gui->rowSelected = i;
        gui->selectedResource = PackFileRead(&gui->pack, gui->pack.manifest->paths[indexSelected], gui->onLoaded, gui->callbackData);
        printf("\n");
    }

    ImGui::PopID();
}

ImGui::NextColumn();
ImGui::SetCursorPosY(ImGui::GetCursorPosY() + (displayStart * itemHeight));

for (int i = displayStart; i < displayEnd; ++i)
{
    int indexSelected = displayIndices[i].index;
    ImGui::PushID(i);

    if (ImGuiSelectable(false, i == gui->rowSelected, gui->pack.manifest->paths[indexSelected]))
    {
        gui->rowSelected = i;
        gui->selectedResource = PackFileRead(&gui->pack, gui->pack.manifest->paths[indexSelected], gui->onLoaded, gui->callbackData);
        printf("\n");
    }

    ImGui::PopID();
}

ImGui::NextColumn();
ImGui::SetCursorPosY(ImGui::GetCursorPosY() + (displayStart * itemHeight));

for (int i = displayStart; i < displayEnd; ++i)
{
    int indexSelected = displayIndices[i].index;
    ImGui::PushID(i);

    if (ImGuiSelectable(false, i == gui->rowSelected, FMT_SIZET, gui->pack.manifest->offsets[indexSelected]))
    {
        gui->rowSelected = i;
        gui->selectedResource = PackFileRead(&gui->pack, gui->pack.manifest->paths[indexSelected], gui->onLoaded, gui->callbackData);
        printf("\n");
    }

    ImGui::PopID();
}

ImGui::NextColumn();
ImGui::SetCursorPosY(ImGui::GetCursorPosY() + (displayStart * itemHeight));

for (int i = displayStart; i < displayEnd; ++i)
{
    int indexSelected = displayIndices[i].index;
    ImGui::PushID(i);

    if (ImGuiSelectable(false, i == gui->rowSelected, FMT_SIZET " (%f MB)", gui->pack.manifest->bytes[indexSelected], (double)gui->pack.manifest->bytes[indexSelected] / ((double)MEGABYTES(1))))
    {
        gui->rowSelected = i;
        gui->selectedResource = PackFileRead(&gui->pack, gui->pack.manifest->paths[indexSelected], gui->onLoaded, gui->callbackData);
        printf("\n");
    }

    ImGui::PopID();
}

ImGui::Columns(1);
ImGui::SetCursorPosY(ImGui::GetCursorPosY() + ((gui->pack.manifest->numPaths - displayEnd) * itemHeight));
ImGui::EndChild();
PopArrayFront(&gui->imguiMemory, DisplayIndex, numItems);