Resolve "Merge the best from 7.40 branch"

SabrehavenOTClient/modules/corelib/ui/uiscrollarea.lua

@@ -0,0 +1,190 @@
+-- @docclass
+UIScrollArea = extends(UIWidget, "UIScrollArea")
+
+-- public functions
+function UIScrollArea.create()
+  local scrollarea = UIScrollArea.internalCreate()
+  scrollarea:setClipping(true)
+  scrollarea.inverted = false
+  scrollarea.alwaysScrollMaximum = false
+  return scrollarea
+end
+
+function UIScrollArea:onStyleApply(styleName, styleNode)
+  for name,value in pairs(styleNode) do
+    if name == 'vertical-scrollbar' then
+      addEvent(function()
+        local parent = self:getParent()
+        if parent then
+          self:setVerticalScrollBar(parent:getChildById(value))
+        end
+      end)
+    elseif name == 'horizontal-scrollbar' then
+      addEvent(function()
+        local parent = self:getParent()
+        if parent then
+          self:setHorizontalScrollBar(self:getParent():getChildById(value))
+        end
+      end)
+    elseif name == 'inverted-scroll' then
+      self:setInverted(value)
+    elseif name == 'always-scroll-maximum' then
+      self:setAlwaysScrollMaximum(value)
+    end
+  end
+end
+
+function UIScrollArea:updateScrollBars()
+  local scrollWidth = math.max(self:getChildrenRect().width - self:getPaddingRect().width, 0)
+  local scrollHeight = math.max(self:getChildrenRect().height - self:getPaddingRect().height, 0)
+
+  local scrollbar = self.verticalScrollBar
+  if scrollbar then
+    if self.inverted then
+      scrollbar:setMinimum(-scrollHeight)
+      scrollbar:setMaximum(0)
+    else
+      scrollbar:setMinimum(0)
+      scrollbar:setMaximum(scrollHeight)
+    end
+  end
+
+  local scrollbar = self.horizontalScrollBar
+  if scrollbar then
+    if self.inverted then
+      scrollbar:setMinimum(-scrollWidth)
+      scrollbar:setMaximum(0)
+    else
+      scrollbar:setMinimum(0)
+      scrollbar:setMaximum(scrollWidth)
+    end
+  end
+
+  if self.lastScrollWidth ~= scrollWidth then
+    self:onScrollWidthChange()
+  end
+  if self.lastScrollHeight ~= scrollHeight then
+    self:onScrollHeightChange()
+  end
+
+  self.lastScrollWidth = scrollWidth
+  self.lastScrollHeight = scrollHeight
+end
+
+function UIScrollArea:setVerticalScrollBar(scrollbar)
+  self.verticalScrollBar = scrollbar
+  connect(self.verticalScrollBar, 'onValueChange', function(scrollbar, value)
+    local virtualOffset = self:getVirtualOffset()
+    virtualOffset.y = value
+    self:setVirtualOffset(virtualOffset)
+    signalcall(self.onScrollChange, self, virtualOffset)
+  end)
+  self:updateScrollBars()
+end
+
+function UIScrollArea:setHorizontalScrollBar(scrollbar)
+  self.horizontalScrollBar = scrollbar
+  connect(self.horizontalScrollBar, 'onValueChange', function(scrollbar, value)
+    local virtualOffset = self:getVirtualOffset()
+    virtualOffset.x = value
+    self:setVirtualOffset(virtualOffset)
+    signalcall(self.onScrollChange, self, virtualOffset)
+  end)
+  self:updateScrollBars()
+end
+
+function UIScrollArea:setInverted(inverted)
+  self.inverted = inverted
+end
+
+function UIScrollArea:setAlwaysScrollMaximum(value)
+  self.alwaysScrollMaximum = value
+end
+
+function UIScrollArea:onLayoutUpdate()
+  self:updateScrollBars()
+end
+
+function UIScrollArea:onMouseWheel(mousePos, mouseWheel)
+  if self.verticalScrollBar then
+    if not self.verticalScrollBar:isOn() then
+      return false
+    end
+    if mouseWheel == MouseWheelUp then
+      local minimum = self.verticalScrollBar:getMinimum()
+      if self.verticalScrollBar:getValue() <= minimum then
+        return false
+      end
+      self.verticalScrollBar:decrement()
+    else
+      local maximum = self.verticalScrollBar:getMaximum()
+      if self.verticalScrollBar:getValue() >= maximum then
+        return false
+      end
+      self.verticalScrollBar:increment()
+    end
+  elseif self.horizontalScrollBar then
+    if not self.horizontalScrollBar:isOn() then
+      return false
+    end
+    if mouseWheel == MouseWheelUp then
+      local maximum = self.horizontalScrollBar:getMaximum()
+      if self.horizontalScrollBar:getValue() >= maximum then
+        return false
+      end
+      self.horizontalScrollBar:increment()
+    else
+      local minimum = self.horizontalScrollBar:getMinimum()
+      if self.horizontalScrollBar:getValue() <= minimum then
+        return false
+      end
+      self.horizontalScrollBar:decrement()
+    end
+  end
+  return true
+end
+
+function UIScrollArea:ensureChildVisible(child)
+  if child then
+    local paddingRect = self:getPaddingRect()
+    if self.verticalScrollBar then
+      local deltaY = paddingRect.y - child:getY()
+      if deltaY > 0 then
+        self.verticalScrollBar:decrement(deltaY)
+      end
+
+      deltaY = (child:getY() + child:getHeight()) - (paddingRect.y + paddingRect.height)
+      if deltaY > 0 then
+        self.verticalScrollBar:increment(deltaY)
+      end
+    elseif self.horizontalScrollBar then
+      local deltaX = paddingRect.x - child:getX()
+      if deltaX > 0 then
+        self.horizontalScrollBar:decrement(deltaX)
+      end
+
+      deltaX = (child:getX() + child:getWidth()) - (paddingRect.x + paddingRect.width)
+      if deltaX > 0 then
+        self.horizontalScrollBar:increment(deltaX)
+      end
+    end
+  end
+end
+
+function UIScrollArea:onChildFocusChange(focusedChild, oldFocused, reason)
+  if focusedChild and (reason == MouseFocusReason or reason == KeyboardFocusReason) then
+    self:ensureChildVisible(focusedChild)
+  end
+end
+
+function UIScrollArea:onScrollWidthChange()
+  if self.alwaysScrollMaximum and self.horizontalScrollBar then
+    self.horizontalScrollBar:setValue(self.horizontalScrollBar:getMaximum())
+  end
+end
+
+function UIScrollArea:onScrollHeightChange()
+  if self.alwaysScrollMaximum and self.verticalScrollBar then
+    self.verticalScrollBar:setValue(self.verticalScrollBar:getMaximum())
+  end
+end