helloword.go,not tested yet

sysgo/UI/scroller.go

@@ -1 +1,87 @@
 package UI
+
+import (
+	"github.com/veandco/go-sdl2/sdl"
+	"github.com/veandco/go-sdl2/ttf"
+	
+	"github.com/cuu/gogame/surface"
+	"github.com/cuu/gogame/rect"
+	"github.com/cuu/gogame/color"
+	"github.com/cuu/gogame/font"
+	"github.com/cuu/gogame/draw"
+)
+
+type ListScroller struct{
+	PosX int
+	PosY int
+	Width int
+	Height int
+	MinHeight int
+	Parent PageInterface
+	Color  *color.Color
+	
+	StartX int
+	StartY int
+	EndX   int
+	EndY   int
+	Value  int
+	CanvasHWND *sdl.Surface
+}
+
+
+func NewListScroller() *ListScroller {
+	l := &ListScroller{}
+	l.Color = &color.Color{131,199,219,255} // SkinManager().GiveColor('Front')
+	return l
+}
+
+func (self *ListScroller) Init() {
+	//just set the CanvasHWND
+}
+
+func (self *ListScroller) SetCanvasHWND( canvas *sdl.Surface) {
+	self.CanvasHWND = canvas
+}
+
+func (self *ListScroller) AnimateDraw(x2,y2 int) {
+	
+}
+
+func (self *ListScroller) UpdateSize(bigheight, dirtyheight int) {
+	_,h_ := self.Parent.Size()
+	
+	bodyheight := float64(h_)/float64(bigheight)
+	if bodyheight > 1.0 {
+		bodyheight = 1.0
+	}
+
+	margin := 4
+
+	self.Height = int( bodyheight * float64(h_) - float64(margin) )
+
+	if self.Height < self.MinHeight {
+		self.Height = self.MinHeight
+	}
+
+	self.StartX = self.Width/2
+	self.StartY = margin/2 + self.Height/2
+
+	self.EndX = self.Width/2
+	self.EndY = h_ - margin/2 - self.Height/2
+
+	process  := float64(dirtyheight) / float64(bigheight)
+
+	value := process * float64(self.EndY - self.StartY)
+
+	self.Value = int(value)
+	
+}
+
+func (self *ListScroller) Draw() {
+	w_,h_ := self.Parent.Size()
+
+	start_rect := draw.MidRect(self.PosX+self.StartX,self.StartY+self.Value,self.Width,self.Height,w_,h_)
+	
+	draw.AARoundRect(self.CanvasHWND,start_rect,self.Color,3,0,self.Color)
+
+}