Internals/experimental: BeginComboPreview(), EndComboPreview(). (#4168, #1658)

(amended)
This commit is contained in:
ocornut
2021-06-15 15:16:39 +02:00
parent 98a6292165
commit 0cca0d1617
6 changed files with 101 additions and 3 deletions

View File

@ -1541,6 +1541,8 @@ void ImGui::ShrinkWidths(ImGuiShrinkWidthItem* items, int count, float width_exc
// - BeginCombo()
// - BeginComboPopup() [Internal]
// - EndCombo()
// - BeginComboPreview() [Internal]
// - EndComboPreview() [Internal]
// - Combo()
//-------------------------------------------------------------------------
@ -1602,6 +1604,14 @@ bool ImGui::BeginCombo(const char* label, const char* preview_value, ImGuiComboF
}
RenderFrameBorder(bb.Min, bb.Max, style.FrameRounding);
// Custom preview
if (flags & ImGuiComboFlags_CustomPreview)
{
g.ComboPreviewData.PreviewRect = ImRect(bb.Min.x, bb.Min.y, value_x2, bb.Max.y);
IM_ASSERT(preview_value == NULL || preview_value[0] == 0);
preview_value = NULL;
}
// Render preview and label
if (preview_value != NULL && !(flags & ImGuiComboFlags_NoPreview))
{
@ -1683,6 +1693,57 @@ void ImGui::EndCombo()
EndPopup();
}
// Call directly after the BeginCombo/EndCombo block. The preview is designed to only host non-interactive elements
// (Experimental, see GitHub issues: #1658, #4168)
bool ImGui::BeginComboPreview()
{
ImGuiContext& g = *GImGui;
ImGuiWindow* window = g.CurrentWindow;
ImGuiComboPreviewData* preview_data = &g.ComboPreviewData;
if (window->SkipItems || !window->ClipRect.Overlaps(window->DC.LastItemRect)) // FIXME: Because we don't have a ImGuiItemStatusFlags_Visible flag to test last ItemAdd() result
return false;
IM_ASSERT(window->DC.LastItemRect.Min.x == preview_data->PreviewRect.Min.x && window->DC.LastItemRect.Min.y == preview_data->PreviewRect.Min.y); // Didn't call after BeginCombo/EndCombo block or forgot to pass ImGuiComboFlags_CustomPreview flag?
if (!window->ClipRect.Contains(preview_data->PreviewRect)) // Narrower test (optional)
return false;
// FIXME: This could be contained in a PushWorkRect() api
preview_data->BackupCursorPos = window->DC.CursorPos;
preview_data->BackupCursorMaxPos = window->DC.CursorMaxPos;
preview_data->BackupCursorPosPrevLine = window->DC.CursorPosPrevLine;
preview_data->BackupPrevLineTextBaseOffset = window->DC.PrevLineTextBaseOffset;
preview_data->BackupLayout = window->DC.LayoutType;
window->DC.CursorPos = preview_data->PreviewRect.Min + g.Style.FramePadding;
window->DC.CursorMaxPos = window->DC.CursorPos;
window->DC.LayoutType = ImGuiLayoutType_Horizontal;
PushClipRect(preview_data->PreviewRect.Min, preview_data->PreviewRect.Max, true);
return true;
}
void ImGui::EndComboPreview()
{
ImGuiContext& g = *GImGui;
ImGuiWindow* window = g.CurrentWindow;
ImGuiComboPreviewData* preview_data = &g.ComboPreviewData;
// FIXME: Using CursorMaxPos approximation instead of correct AABB which we will store in ImDrawCmd in the future
ImDrawList* draw_list = window->DrawList;
if (window->DC.CursorMaxPos.x < preview_data->PreviewRect.Max.x && window->DC.CursorMaxPos.y < preview_data->PreviewRect.Max.y)
if (draw_list->CmdBuffer.Size > 1) // Unlikely case that the PushClipRect() didn't create a command
{
draw_list->_CmdHeader.ClipRect = draw_list->CmdBuffer[draw_list->CmdBuffer.Size - 1].ClipRect = draw_list->CmdBuffer[draw_list->CmdBuffer.Size - 2].ClipRect;
draw_list->_TryMergeDrawCmds();
}
PopClipRect();
window->DC.CursorPos = preview_data->BackupCursorPos;
window->DC.CursorMaxPos = ImMax(window->DC.CursorMaxPos, preview_data->BackupCursorMaxPos);
window->DC.CursorPosPrevLine = preview_data->BackupCursorPosPrevLine;
window->DC.PrevLineTextBaseOffset = preview_data->BackupPrevLineTextBaseOffset;
window->DC.LayoutType = preview_data->BackupLayout;
preview_data->PreviewRect = ImRect();
}
// Getter for the old Combo() API: const char*[]
static bool Items_ArrayGetter(void* data, int idx, const char** out_text)
{