From 2df8fa95dfe3463ece78c56b02dc815c3e71331a Mon Sep 17 00:00:00 2001 From: omar Date: Wed, 8 Nov 2017 23:17:08 +0100 Subject: [PATCH] Fixed vertical scrollbar flickering/appearing, typically when manually resizing and using a pattern of filling available height (e.g. full sized BeginChild). THIS IS A GREAT FIX, this glitch was nasty and annoying (and yet somehow nobody reported it?). Hopefully haven't broken anything else... --- imgui.cpp | 21 ++++++++++++--------- 1 file changed, 12 insertions(+), 9 deletions(-) diff --git a/imgui.cpp b/imgui.cpp index d64ac6d3..35e30968 100644 --- a/imgui.cpp +++ b/imgui.cpp @@ -4232,10 +4232,21 @@ bool ImGui::Begin(const char* name, bool* p_open, ImGuiWindowFlags flags) // SIZE - // Save contents size from last frame for auto-fitting (unless explicitly specified) + // Update contents size from last frame for auto-fitting (unless explicitly specified) window->SizeContents.x = (float)(int)((window->SizeContentsExplicit.x != 0.0f) ? window->SizeContentsExplicit.x : ((window_is_new ? 0.0f : window->DC.CursorMaxPos.x - window->Pos.x) + window->Scroll.x)); window->SizeContents.y = (float)(int)((window->SizeContentsExplicit.y != 0.0f) ? window->SizeContentsExplicit.y : ((window_is_new ? 0.0f : window->DC.CursorMaxPos.y - window->Pos.y) + window->Scroll.y)); + // Update scrollbar status based on the Size that was effective during last frame (and not the upcoming Size which we are updating below), so that user code consuming exactly the available size won't trigger scrollbars when e.g. manually resizing. + if (!window->Collapsed) + { + window->ScrollbarY = (flags & ImGuiWindowFlags_AlwaysVerticalScrollbar) || ((window->SizeContents.y > window->Size.y + style.ItemSpacing.y) && !(flags & ImGuiWindowFlags_NoScrollbar)); + window->ScrollbarX = (flags & ImGuiWindowFlags_AlwaysHorizontalScrollbar) || ((window->SizeContents.x > window->Size.x - (window->ScrollbarY ? style.ScrollbarSize : 0.0f) - window->WindowPadding.x) && !(flags & ImGuiWindowFlags_NoScrollbar) && (flags & ImGuiWindowFlags_HorizontalScrollbar)); + if (window->ScrollbarX && !window->ScrollbarY) + window->ScrollbarY = (window->SizeContents.y > window->Size.y + style.ItemSpacing.y - style.ScrollbarSize) && !(flags & ImGuiWindowFlags_NoScrollbar); + window->ScrollbarSizes = ImVec2(window->ScrollbarY ? style.ScrollbarSize : 0.0f, window->ScrollbarX ? style.ScrollbarSize : 0.0f); + window->BorderSize = (flags & ImGuiWindowFlags_ShowBorders) ? 1.0f : 0.0f; + } + // Hide popup/tooltip window when first appearing while we measure size (because we recycle them) if (window->HiddenFrames > 0) window->HiddenFrames--; @@ -4416,14 +4427,6 @@ bool ImGui::Begin(const char* name, bool* p_open, ImGuiWindowFlags flags) title_bar_rect = window->TitleBarRect(); } - // Scrollbars - window->ScrollbarY = (flags & ImGuiWindowFlags_AlwaysVerticalScrollbar) || ((window->SizeContents.y > window->Size.y + style.ItemSpacing.y) && !(flags & ImGuiWindowFlags_NoScrollbar)); - window->ScrollbarX = (flags & ImGuiWindowFlags_AlwaysHorizontalScrollbar) || ((window->SizeContents.x > window->Size.x - (window->ScrollbarY ? style.ScrollbarSize : 0.0f) - window->WindowPadding.x) && !(flags & ImGuiWindowFlags_NoScrollbar) && (flags & ImGuiWindowFlags_HorizontalScrollbar)); - if (window->ScrollbarX && !window->ScrollbarY) - window->ScrollbarY = (window->SizeContents.y > window->Size.y + style.ItemSpacing.y - style.ScrollbarSize) && !(flags & ImGuiWindowFlags_NoScrollbar); - window->ScrollbarSizes = ImVec2(window->ScrollbarY ? style.ScrollbarSize : 0.0f, window->ScrollbarX ? style.ScrollbarSize : 0.0f); - window->BorderSize = (flags & ImGuiWindowFlags_ShowBorders) ? 1.0f : 0.0f; - // Window background, Default Alpha ImU32 bg_col = GetColorU32(GetWindowBgColorIdxFromFlags(flags)); window->DrawList->AddRectFilled(window->Pos+ImVec2(0,window->TitleBarHeight()), window->Pos+window->Size, bg_col, window_rounding, (flags & ImGuiWindowFlags_NoTitleBar) ? ImGuiCorner_All : ImGuiCorner_BotLeft|ImGuiCorner_BotRight);