From c36e586cce1279b419ab4b443ca6ce63b03ce7cc Mon Sep 17 00:00:00 2001
From: omar <omarcornut@gmail.com>
Date: Wed, 29 Nov 2017 23:39:23 +0100
Subject: [PATCH] Style, Scrolling: Fixed padding and scrolling asymetry where
 lower/right sides of a window wouldn't use WindowPadding properly + causing
 minor scrolling glitches.

---
 imgui.cpp | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/imgui.cpp b/imgui.cpp
index 84bde0c4..08f4ec25 100644
--- a/imgui.cpp
+++ b/imgui.cpp
@@ -1983,7 +1983,7 @@ void ImGui::ItemSize(const ImVec2& size, float text_offset_y)
     window->DC.CursorPosPrevLine = ImVec2(window->DC.CursorPos.x + size.x, window->DC.CursorPos.y);
     window->DC.CursorPos = ImVec2((float)(int)(window->Pos.x + window->DC.IndentX + window->DC.ColumnsOffsetX), (float)(int)(window->DC.CursorPos.y + line_height + g.Style.ItemSpacing.y));
     window->DC.CursorMaxPos.x = ImMax(window->DC.CursorMaxPos.x, window->DC.CursorPosPrevLine.x);
-    window->DC.CursorMaxPos.y = ImMax(window->DC.CursorMaxPos.y, window->DC.CursorPos.y);
+    window->DC.CursorMaxPos.y = ImMax(window->DC.CursorMaxPos.y, window->DC.CursorPos.y - g.Style.ItemSpacing.y);
     //if (g.IO.KeyAlt) window->DrawList->AddCircle(window->DC.CursorMaxPos, 3.0f, IM_COL32(255,0,0,255), 4); // [DEBUG]
 
     window->DC.PrevLineHeight = line_height;
@@ -4146,18 +4146,17 @@ static ImVec2 CalcSizeAutoFit(ImGuiWindow* window)
     if ((flags & ImGuiWindowFlags_Tooltip) != 0)
     {
         // Tooltip always resize. We keep the spacing symmetric on both axises for aesthetic purpose.
-        size_auto_fit = window->SizeContents + window->WindowPadding - ImVec2(0.0f, style.ItemSpacing.y);
+        size_auto_fit = window->SizeContents;
     }
     else
     {
         // Handling case of auto fit window not fitting on the screen (on either axis): we are growing the size on the other axis to compensate for expected scrollbar. FIXME: Might turn bigger than DisplaySize-WindowPadding.
-        size_auto_fit = ImClamp(window->SizeContents + window->WindowPadding, style.WindowMinSize, ImMax(style.WindowMinSize, g.IO.DisplaySize - g.Style.DisplaySafeAreaPadding));
+        size_auto_fit = ImClamp(window->SizeContents, style.WindowMinSize, ImMax(style.WindowMinSize, g.IO.DisplaySize - g.Style.DisplaySafeAreaPadding));
         ImVec2 size_auto_fit_after_constraint = CalcSizeFullWithConstraint(window, size_auto_fit);
         if (size_auto_fit_after_constraint.x < window->SizeContents.x && !(flags & ImGuiWindowFlags_NoScrollbar) && (flags & ImGuiWindowFlags_HorizontalScrollbar))
             size_auto_fit.y += style.ScrollbarSize;
         if (size_auto_fit_after_constraint.y < window->SizeContents.y && !(flags & ImGuiWindowFlags_NoScrollbar))
             size_auto_fit.x += style.ScrollbarSize;
-        size_auto_fit.y = ImMax(size_auto_fit.y - style.ItemSpacing.y, 0.0f);
     }
     return size_auto_fit;
 }
@@ -4364,6 +4363,7 @@ bool ImGui::Begin(const char* name, bool* p_open, ImGuiWindowFlags flags)
         // 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));
+        window->SizeContents += window->WindowPadding;
 
         // Hide popup/tooltip window when first appearing while we measure size (because we recycle them)
         if (window->HiddenFrames > 0)
@@ -4430,10 +4430,10 @@ bool ImGui::Begin(const char* name, bool* p_open, ImGuiWindowFlags flags)
         // Update scrollbar status (based on the Size that was effective during last frame or the auto-resized Size). We need to do this before manual resize (below) is effective.
         if (!window->Collapsed)
         {
-            window->ScrollbarY = (flags & ImGuiWindowFlags_AlwaysVerticalScrollbar) || ((window->SizeContents.y > window->SizeFull.y + style.ItemSpacing.y) && !(flags & ImGuiWindowFlags_NoScrollbar));
+            window->ScrollbarY = (flags & ImGuiWindowFlags_AlwaysVerticalScrollbar) || ((window->SizeContents.y > window->SizeFull.y) && !(flags & ImGuiWindowFlags_NoScrollbar));
             window->ScrollbarX = (flags & ImGuiWindowFlags_AlwaysHorizontalScrollbar) || ((window->SizeContents.x > window->SizeFull.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->SizeFull.y + style.ItemSpacing.y - style.ScrollbarSize) && !(flags & ImGuiWindowFlags_NoScrollbar);
+                window->ScrollbarY = (window->SizeContents.y > window->SizeFull.y + style.ScrollbarSize) && !(flags & ImGuiWindowFlags_NoScrollbar);
             window->ScrollbarSizes = ImVec2(window->ScrollbarY ? style.ScrollbarSize : 0.0f, window->ScrollbarX ? style.ScrollbarSize : 0.0f);
         }
 
@@ -10409,7 +10409,6 @@ void ImGui::EndGroup()
     ImGuiGroupData& group_data = window->DC.GroupStack.back();
 
     ImRect group_bb(group_data.BackupCursorPos, window->DC.CursorMaxPos);
-    group_bb.Max.y -= g.Style.ItemSpacing.y;      // Cancel out last vertical spacing because we are adding one ourselves.
     group_bb.Max = ImMax(group_bb.Min, group_bb.Max);
 
     window->DC.CursorPos = group_data.BackupCursorPos;