Scroll the config panels with ClassicAPI's scroll bar

pfUIScrollFrameTemplate (api/ui-widgets.xml) is a ScrollFrame with
pfUIScrollBarTemplate inside its right edge and a Content scroll child,
driven by ScrollUtil.InitScrollFrameWithScrollBar. The panels keep a
ScrollFrame because the engine measures its range from the shown frames
inside the content, which the hand-placed config rows rely on. The bar
follows OnScrollRangeChanged instead of an OnUpdate poll per panel.

A panel measures its range once its rows are built, and the search
results measure theirs with UpdateScrollChildRect instead of hiding,
re-attaching and scrolling a frame later. Clearing the search measures
again too.

CreateScrollFrame and CreateScrollChild have no users left, and nothing
called CreateTabFrame or CreateTabChild; all four are gone. pfQuest's
compat layer brings its own copies of the scroll helpers.

api/ui-widgets.lua

@@ -316,117 +316,6 @@ do -- dropdown
   end
 end
 
-function pfUI.api.CreateTabChild(self, title, bwidth, bheight, bottom, static)
-  -- create tab button
-  local b = CreateFrame("Button", "pfConfig" .. title .. "Button", self, "UIPanelButtonTemplate")
-  b:SetText(title)
-
-  -- setup env
-  local childcount = table.getn(self.childs) + 1
-  local button_width = bwidth
-  local button_height = bheight or 20
-  local border = 4
-
-  if not button_width then
-    button_width = 150
-  elseif button_width == true then
-    button_width = _G["pfConfig" .. title .. "ButtonText"]:GetStringWidth() + 4 * border
-  end
-
-  -- set dimensions
-  b:SetSize(button_width, button_height)
-  b:SetID(childcount)
-
-  if not self.align or self.align == "LEFT" then
-    local outside = self.outside and -2 * border - button_width or 0
-    if bottom then
-      b:SetPoint("BOTTOMLEFT", self, "BOTTOMLEFT", border + outside, (self.bottomcount-1) * (button_height) + (self.bottomcount * border) )
-    else
-      b:SetPoint("TOPLEFT", self, "TOPLEFT", border + outside, -(childcount-1) * (button_height) - (childcount * border) )
-    end
-  elseif self.align == "TOP" then
-    local outside = self.outside and 2 * border + button_height or 0
-    local prev_button = self.buttons[getn(self.buttons)]
-    if prev_button then
-      b:SetPoint("TOPLEFT", prev_button, "TOPRIGHT", border, 0)
-    else
-      b:SetPoint("TOPLEFT", self, "TOPLEFT", border + (self.outside and -border), -border + outside )
-    end
-  end
-
-  SkinButton(b,.2,1,.8)
-
-  if childcount ~= 1 then
-    b:SetTextColor(.5,.5,.5)
-  else
-    b:SetTextColor(.2,1,.8)
-  end
-
-  b:SetScript("OnClick", function()
-    for k,v in pairs(self.childs) do
-      v:Hide()
-    end
-    self.childs[this:GetID()]:Show()
-
-    for k,v in pairs(self.buttons) do
-      v.active = false
-      v:SetTextColor(.5,.5,.5)
-    end
-    self.buttons[this:GetID()]:SetTextColor(.2,1,.8)
-  end)
-
-  self.buttons[childcount] = b
-  self.bottomcount = bottom and self.bottomcount + 1 or self.bottomcount
-
-  -- create child frame
-  local child, scrollchild = nil, nil
-  if not static then
-    child = CreateScrollFrame("pfConfig" .. title .. "Frame", self)
-    scrollchild = CreateScrollChild("pfConfig" .. title .. "ScrollChild", child)
-  else
-    child = CreateFrame("Frame", "pfConfig" .. title .. "Frame", self)
-  end
-
-  if childcount ~= 1 then child:Hide() end
-
-  if not self.align or self.align == "LEFT" then
-    child:SetPoint("TOPLEFT", self, "TOPLEFT", button_width + 2*border + 5, -border -5)
-    child:SetPoint("BOTTOMRIGHT", self, "BOTTOMRIGHT", -border -5 , border + 5)
-  elseif self.align == "TOP" then
-    if self.outside then
-      child:SetPoint("TOPLEFT", self, "TOPLEFT", 5, -5)
-      child:SetPoint("BOTTOMRIGHT", self, "BOTTOMRIGHT", -5, 5)
-    end
-  end
-
-  CreateBackdrop(child)
-  SetAllPointsOffset(child.backdrop, child, -5,5)
-
-  local ret = scrollchild or child
-  ret.button = b
-  table.insert(self.childs, child)
-  return ret
-end
-
-function pfUI.api.CreateTabFrame(parent, align, outside)
-  local f = CreateFrame("Frame", nil, parent)
-
-  f:SetPoint("TOPLEFT", parent, "TOPLEFT", -5, 5)
-  f:SetPoint("BOTTOMRIGHT", parent, "BOTTOMRIGHT", 5, -5)
-
-  -- setup env
-  f.childs = { }
-  f.buttons = { }
-  f.align = align
-  f.outside = outside
-  f.bottomcount = 1
-
-  -- Create Child Frame
-  f.CreateTabChild = pfUI.api.CreateTabChild
-
-  return f
-end
-
 -- [ pfUIScrollingEditBoxTemplate ]
 -- Mixin of the template in ui-widgets.xml: ClassicAPI's scrolling edit box
 -- with pfUI's scroll bar beside it.
@@ -451,77 +340,6 @@ function pfUIScrollingEditBoxMixin:SetFont(font, size, flags)
   self:SetFontObject(self.font)
 end
 
-function pfUI.api.CreateScrollFrame(name, parent)
-  local f = CreateFrame("ScrollFrame", name, parent)
-
-  -- create slider
-  f.slider = CreateFrame("Slider", nil, f)
-  f.slider:SetOrientation('VERTICAL')
-  f.slider:SetPoint("TOPLEFT", f, "TOPRIGHT", -7, 0)
-  f.slider:SetPoint("BOTTOMRIGHT", 0, 0)
-  f.slider:SetThumbTexture(pfUI.media["img:col"])
-  f.slider.thumb = f.slider:GetThumbTexture()
-  f.slider.thumb:SetHeight(50)
-  f.slider.thumb:SetTexture(.3,1,.8,.5)
-
-  f.slider:SetScript("OnValueChanged", function()
-    f:SetVerticalScroll(this:GetValue())
-    f.UpdateScrollState()
-  end)
-
-  f.UpdateScrollState = function()
-    f.slider:SetMinMaxValues(0, f:GetVerticalScrollRange())
-    f.slider:SetValue(f:GetVerticalScroll())
-
-    local m = f:GetHeight()+f:GetVerticalScrollRange()
-    local v = f:GetHeight()
-    local ratio = v / m
-
-    if ratio < 1 then
-      local size = math.floor(v * ratio)
-      f.slider.thumb:SetHeight(size)
-      f.slider:Show()
-    else
-      f.slider:Hide()
-    end
-  end
-
-  f.Scroll = function(self, step)
-    local step = step or 0
-
-    local current = f:GetVerticalScroll()
-    local max = f:GetVerticalScrollRange()
-    local new = current - step
-
-    f:SetVerticalScroll(Clamp(new, 0, max))
-
-    f:UpdateScrollState()
-  end
-
-  f:EnableMouseWheel(1)
-  f:SetScript("OnMouseWheel", function()
-    this:Scroll(arg1*10)
-  end)
-
-  return f
-end
-
-function pfUI.api.CreateScrollChild(name, parent)
-  local f = CreateFrame("Frame", name, parent)
-
-  -- dummy values required
-  f:SetSize(1, 1)
-  f:SetAllPoints(parent)
-
-  parent:SetScrollChild(f)
-
-  f:SetScript("OnUpdate", function()
-    this:GetParent():UpdateScrollState()
-  end)
-
-  return f
-end
-
 -- [ CreateTextBox ]
 -- Creates and returns a default pfUI skinned EditBox
 function pfUI.api.CreateTextBox(name, parent)

api/ui-widgets.xml

@@ -29,6 +29,36 @@
     </Frames>
   </EventFrame>
 
+  <!--
+  A ScrollFrame for free-form content, with pfUIScrollBarTemplate inside its
+  right edge. Put the content in frame.Content, which spans the frame: the
+  engine measures the scroll range from the shown frames inside it, so the
+  content needs no height. Changes inside it are not measured until
+  frame:UpdateScrollChildRect().
+  -->
+  <ScrollFrame name="pfUIScrollFrameTemplate" virtual="true">
+    <Frames>
+      <EventFrame parentKey="ScrollBar" inherits="pfUIScrollBarTemplate">
+        <Anchors>
+          <Anchor point="TOPRIGHT"/>
+          <Anchor point="BOTTOMRIGHT"/>
+        </Anchors>
+      </EventFrame>
+    </Frames>
+    <ScrollChild>
+      <Frame parentKey="Content">
+        <Size x="1" y="1"/>
+      </Frame>
+    </ScrollChild>
+    <Scripts>
+      <OnLoad>
+        self.Content:SetAllPoints()
+        self:EnableMouseWheel(true)
+        ScrollUtil.InitScrollFrameWithScrollBar(self, self.ScrollBar)
+      </OnLoad>
+    </Scripts>
+  </ScrollFrame>
+
   <!--
   A WowScrollBoxList with pfUIScrollBarTemplate beside it, both 5px inside the
   frame so CreateBackdrop(frame, nil, true) can frame them. Fill it with

modules/gui.lua

@@ -515,14 +515,15 @@ pfUI:RegisterModule("gui", function ()
 
       -- are we a frame with contents?
       if func then
-        f.scroll = CreateScrollFrame(nil, f)
+        f.scroll = CreateFrame("ScrollFrame", nil, f, "pfUIScrollFrameTemplate")
         SetAllPointsOffset(f.scroll, f, 2)
-        f.scroll.content = CreateScrollChild(nil, f.scroll)
+        f.scroll.content = f.scroll.Content
         f.scroll.content.parent = f.scroll
         f.scroll.content:SetScript("OnShow", function()
           if not this.setup then
             func()
             this.setup = true
+            this.parent:UpdateScrollChildRect()
           end
         end)
       end
@@ -774,7 +775,10 @@ pfUI:RegisterModule("gui", function ()
         end
       end
 
-      if strlen(this:GetText()) < 1 then return end
+      if strlen(this:GetText()) < 1 then
+        parent:UpdateScrollChildRect()
+        return
+      end
 
       local i = 1
       local search = strlower(this:GetText())
@@ -798,16 +802,9 @@ pfUI:RegisterModule("gui", function ()
         end
       end
 
-      -- reload scroll frames
+      -- measure the new results and start at the top
-      scroll:Hide()
+      parent:UpdateScrollChildRect()
-      scroll:SetHeight(i * 25 )
+      parent:SetVerticalScroll(0)
-      scroll:Show()
-      parent:SetScrollChild(scroll)
-      QueueFunction(function()
-        parent:SetVerticalScroll(0)
-        parent:UpdateScrollState()
-        parent:Scroll()
-      end)
     end)
 
     pfUI.gui.search:SetScript("OnEditFocusGained", function(self)