How can I do simple text input math calculations in flash-builder? - apache-flex

Question

Can someone show me how should I correctly implement mathematical calculations like (+,-,/,*) using text inputs in 2 cases:
1 - more states
2 - input in a view an the result in other
Here is a part of my code:
<?xml version="1.0" encoding="utf-8"?>
<s:View xmlns:fx="http://ns.adobe.com/mxml/2009"
xmlns:s="library://ns.adobe.com/flex/spark"
creationComplete="init()" currentState="State1" overlayControls="false" title="Calculator">
<s:states>
<s:State name="State1"/>
<s:State name="RezultatCalculator"/>
</s:states>
<fx:Declarations>
<!-- Place non-visual elements (e.g., services, value objects) here -->
</fx:Declarations>
<fx:Script>
<![CDATA[
import spark.events.DropDownEvent;
protected function init():void
{
addEventListener(TransformGestureEvent.GESTURE_SWIPE, swipeHandler);
}
protected function swipeHandler(event:TransformGestureEvent):void
{
if (event.offsetX == 1)
{
navigator.pushView(CalculatorView);
}
}
protected function primulcalcul_openHandler(event:DropDownEvent):void
{
// TODO Auto-generated method stub
}
]]>
</fx:Script>
<s:Scroller includeIn="State1" left="3" right="3" top="0" height="547">
<s:VGroup width="100%" height="100%" gap="24" horizontalAlign="justify" paddingTop="8"
verticalAlign="top">
<s:Label id="actot" width="237" height="60" text="Active Totale" textAlign="center"
verticalAlign="middle"/>
<s:TextInput id="actot_val" width="183" height="60" fontFamily="_sans" fontSize="28"
textAlign="center" softKeyboardType="number" />
<s:Label id="disp" width="159" height="60" text="Disponibilitati" textAlign="center"
verticalAlign="middle"/>
<s:TextInput id="disp_val" width="164" height="60" fontFamily="_sans" fontSize="28"
textAlign="center" softKeyboardType="number"/>
<s:Label id="datot" width="159" height="60" text="Datorii Totale" textAlign="center"
verticalAlign="middle"/>
<s:TextInput id="datot_val" width="164" height="60" fontFamily="_sans"
fontSize="28" textAlign="center" softKeyboardType="number"/>
<s:Label id="caprop" width="159" height="60" fontSize="24" text="Capitaluri Proprii"
textAlign="center" verticalAlign="middle"/>
<s:TextInput id="caprop_val" width="164" height="60" fontFamily="_sans" fontSize="28"
textAlign="center" softKeyboardType="number"/>
<s:Button id="butstart0" width="401" height="70" label="START"
click="currentState='RezultatCalculator'" enabled="true"/>
</s:VGroup>
</s:Scroller>
<s:CalloutButton id="primulcalcul" includeIn="RezultatCalculator" x="22" y="28" width="145"
height="63" label="primulcalcul" enabled="true"
open="primulcalcul_openHandler(event)"/>
<s:TextArea id="Primul_val" includeIn="RezultatCalculator" x="203" y="27" width="267"
editable="false" prompt="result"/>
<fx:Script>
<![CDATA[
import flash.globalization.NumberFormatter;
import flashx.textLayout.formats.Float;
import flashx.textLayout.formats.Float;
import learnmath.mathml.components.MathMLFormula;
import learnmath.mathml.formula.layout.MathBox;
public function MathMLFormula():void
{
var Primul_val:Number=new Number
var datot:Number=new Number
var disp:Number=new Number
Primul_val=0
NumberFormatter(TextArea(Primul_val))==NumberFormatter(TextInput(datot))+NumberFormatter(TextInput(disp)); /* this is one of the examples, i tied some different values like valueOf */
}
]]>
</fx:Script>
</s:View>

Answer 1

I have a few suggestions, but I'm not sure exactly what your problem is.
First, use the restrict attribute on your TextArea. The restrict attribute will prevent people from entering non-numeric keys. Sort of like this:
<s:TextInput id="datot_val" width="164" height="60" fontFamily="_sans"
fontSize="28" textAlign="center" softKeyboardType="number" restrict="0-9"/>
It's entirely possible that the use of the softKeyboardType makes this a non-issue if you're using a mobile application on a device that supports it.
The line of code you mentioned in the comments looks to be error prone:
NumberFormatter(TextArea(Primul_val))==NumberFormatter(TextInput(datot))+NumberFormatter(TextInput(disp));
First, datot and disp are Labels; not TextInputs. They have hard coded non-numeric values. I think you want to use datot_val and disp_val. which are TextInputs. Since they are already inputs you do not need to cast them as such.
Second you do not need to cast the TextInput as a NumberFormatter. You would not usually use a NumberFormatter as a static class, but rather create an instance of it. More info on NumberFormatter here.
So, I believe your line would be rewritten like this:
Primul_val.text== String(
int(datot.text) + int(disp.text)
);
I added some extra lines so the parenthesis wouldn't get confused.
I take the input of datot (AKA datot.text) and cast it as an int. I take the input of disp (disp.text) and cast that as an int. I add the two together and convert them both to a String. The string is stored in the text value of Primul_val.
Does that help clear anything up?