Draw line chart using shapes in adobe flex - actionscript-3

Question

I want to draw line chart for ECG reading using Shapes component. I want graph exactly like this image.
i finished 90% code. but when i call clear() means all lines cleared.
i want to give some space between two different reading.
My code:
<fx:Script>
<![CDATA[
private var arrSPO2:Array = [33, 35, 36, 33, 28, 21,35, 36, 33, 28, 21, 13, 6,33, 28, 21, 13, 6, 0, 0, 0,28, 21, 13, 6, 0, 0, 0, 0, 0, 10,28, 21, 13, 6, 0, 0, 0, 0, 0, 10, 31, 56, 78,13, 6, 0, 0, 0, 0, 0, 10, 31, 56, 78, 93, 98, 94,6, 0, 0, 0, 0, 0, 10, 31, 56, 78, 93, 98, 94, 82, 68, 55,0, 0, 0, 0, 0, 10, 31, 56, 78, 93, 98, 94, 82, 68, 55, 45, 41,0, 0, 0, 0, 10, 31, 56, 78, 93, 98, 94, 82, 68, 55, 45, 41, 41, 42, 44,0, 0, 0, 10, 31, 56, 78, 93, 98, 94, 82, 68, 55, 45, 41, 41, 42, 44, 43, 39, 32,0, 0, 10, 31, 56, 78, 93, 98, 94, 82, 68, 55, 45, 41, 41, 42, 44, 43, 39, 32, 24, 15, 7,0, 10, 31, 56, 78, 93, 98, 94, 82, 68, 55, 45, 41, 41, 42, 44, 43, 39, 32, 24, 15, 7, 1, 0, 0,10, 31, 56, 78, 93, 98, 94, 82, 68, 55, 45, 41, 41, 42, 44, 43, 39, 32, 24, 15, 7, 1, 0, 0, 0, 2, 19,31, 56, 78, 93, 98, 94, 82, 68, 55, 45, 41, 41, 42, 44, 43, 39, 32, 24, 15, 7, 1, 0, 0, 0, 2, 19, 43, 68, 90,56, 78, 93, 98, 94, 82, 68, 55, 45, 41, 41, 42, 44, 43, 39, 32, 24, 15, 7, 1, 0];
private var oldX:int = 0;
private var oldY:int = 0;
private var newX:int = 0;
private var newY:int = 0;
private static const TIMER_INTERVAL:int = 50;
private var timer:Timer = new Timer(TIMER_INTERVAL);
private var shapesSPO2:Shape = new Shape();
[Bindable] private var index:int = -1;
protected function init():void {
}
private function timerHandler(event:TimerEvent):void {
trace(timer.currentCount);
index = timer.currentCount - 1;
//draw SPO2
newX += 2;
newY = ((arrSPO2[index] * -1) / 2 + 120);
if (oldY == 0) {
oldY = newY;
}
shapesSPO2.graphics.moveTo(oldX, oldY);
shapesSPO2.graphics.lineTo(newX, newY);
ui1.addChild(shapesSPO2);
oldX = newX;
oldY = newY;
if (index > arrSPO2.length) {
shapesSPO2.graphics.clear();
shapesSPO2.graphics.lineStyle(2, 0x990000, .75);
oldX = newX = 0;
timer.reset();
timer.start();
}
}
protected function btnSPO2_clickHandler(event:MouseEvent):void {
oldX = newX = 0;
shapesSPO2.graphics.lineStyle(2, 0x990000, .75);
timer.addEventListener(TimerEvent.TIMER, timerHandler);
timer.reset();
timer.start();
}
]]>
</fx:Script>
<s:VGroup width="100%" height="100%"
horizontalAlign="center" verticalAlign="middle">
<mx:HBox width="550" height="500"
borderColor="#000000" borderVisible="true" borderStyle="solid" borderAlpha="0.2"
visible="true" includeInLayout="true">
<s:VGroup id="vgGraph" width="100%" height="100%"
horizontalAlign="center"
gap="10"
padding="10">
<s:HGroup width="100%">
<s:Label text="Current Index : {index}" fontSize="16"
fontWeight="bold" />
</s:HGroup>
<mx:UIComponent id="ui1" width="100%" height="100%" />
<!--<s:SpriteVisualElement id="spriteVis" width="100%" height="100%" />-->
<s:Button id="btnSPO2" label="Draw SPO2 Graph" click="btnSPO2_clickHandler(event)" />
</s:VGroup>
</mx:HBox>
</s:VGroup>

Answer 1

To do that you can change your code like this :
private const margin:int = 10;
private function timerHandler(event:TimerEvent):void {
if (index == arrSPO2.length - 1) {
// set the margin between the last chart and the new one
newX = newX + margin;
oldX = newX;
// reset index
index = 0;
timer.reset();
timer.start();
// exit if we have reached the last element of our array
return;
}
index = timer.currentCount - 1;
newX += 2;
newY = ((arrSPO2[index] * -1) / 2 + 120);
if (oldY == 0) {
oldY = newY;
}
shapesSPO2.graphics.moveTo(oldX, oldY);
shapesSPO2.graphics.lineTo(newX, newY);
ui1.addChild(shapesSPO2);
oldX = newX;
oldY = newY;
}
Which will give you something like this :
Hope that can help.

Answer 2

I've modified your timerHandler as below:
private function timerHandler(event:TimerEvent):void {
trace(timer.currentCount);
index = timer.currentCount - 1;
if (index > arrSPO2.length) {
//shapesSPO2.graphics.clear();
//shapesSPO2.graphics.lineStyle(2, 0x990000, .75);
newX += 10;
oldX = newX;
timer.reset();
timer.start();
return;
}
//draw SPO2
newX += 2;
if(newX > ui1.width)
{
oldX = newX = 0;
}
newY = ((arrSPO2[index] * -1) / 2 + 120);
if (oldY == 0) {
oldY = newY;
}
if(index ==0)
{
oldY = newY;
}
shapesSPO2.graphics.moveTo(oldX, oldY);
shapesSPO2.graphics.lineTo(newX, newY);
ui1.addChild(shapesSPO2);
oldX = newX;
oldY = newY;
}