I'm populating a dropDownList with arrayCollection of strings. I want the width of the drop down list control to match with the size (in pixels) of the longest string in the array collection. The problem I'm facing is: the font width of the strings in the collection are different e.g. 'W' looks wider than 'l'. So I estimated the width of a character to be 8 pixels but that's not pretty neat. If a string that has many 'W' and 'M' is encountered the estimation is wrong. So I want precise pixel width of strings. How can i get the exact length of a string in pixels??
My solution that estimates all character to be 8 pixels wide is given below:
public function populateDropDownList():void{
var array:Array = new Array("o","two","three four five six seven eight wwww");
var sampleArrayCollection:ArrayCollection = new ArrayCollection(array);
var customDropDownList:DropDownList = new DropDownList();
customDropDownList.dataProvider=sampleArrayCollection;
customDropDownList.prompt="Select ...";
customDropDownList.labelField="Answer Options:";
//calculating the max width
var componentWidth=10; //default
for each(var answerText in array){
Alert.show("Txt size: "+ answerText.length + " pixels: " + answerText.length*9);
if(answerText.length * 8 > componentWidth){
componentWidth=answerText.length * 8;
}
}
customDropDownList.width=componentWidth;
answers.addChild(customDropDownList);
}
Any idea or solution is highly valued.
Thanks
To get a more accurate measurement, you can populate a TextField with the string, then measure the width of that TextField's text.
Code:
function measureString(str:String, format:TextFormat):Rectangle {
var textField:TextField = new TextField();
textField.defaultTextFormat = format;
textField.text = str;
return new Rectangle(0, 0, textField.textWidth, textField.textHeight);
}
Usage:
var format:TextFormat = new TextFormat();
format.font = "Times New Roman";
format.size = 16;
var strings:Array = [ "a", "giraffe", "foo", "!" ];
var calculatedWidth:Number = 50; // Set this to minimum width to start with
for each (var str:String in strings) {
var stringWidth:Number = measureString(str, format).width;
if (stringWidth > calculatedWidth) {
calculatedWidth = stringWidth;
}
}
trace(calculatedWidth);