User Guide

178 Creating Advanced Visual Components in ActionScript
var buttonWidth:Number = mode_mc.getExplicitOrMeasuredWidth();
var buttonHeight:Number = mode_mc.getExplicitOrMeasuredHeight();
// The default and minimum width are the measuredWidth
// of the TextArea control plus the measuredWidth
// of the Button control.
measuredWidth = measuredMinWidth =
text_mc.measuredWidth + buttonWidth;
// The default and minimum height are the larger of the
// height of the TextArea control or the measuredHeight of the
// Button control, plus a 10 pixel border around the text.
measuredHeight = measuredMinHeight =
Math.max(mode_mc.measuredHeight,buttonHeight) + 10;
}
/*** h) Implement the updateDisplayList() method. ***/
// Size the Button control to the size of its label text
// plus a 10 pixel border area.
// Size the TextArea to the remaining area of the component.
// Place the children depending on the setting of
// the textPlacement property.
override protected function updateDisplayList(unscaledWidth:Number,
unscaledHeight:Number):void {
super.updateDisplayList(unscaledWidth, unscaledHeight);
// Subtract 1 pixel for the left and right border,
// and use a 3 pixel margin on left and right.
var usableWidth:Number = unscaledWidth - 8;
// Subtract 1 pixel for the top and bottom border,
// and use a 3 pixel margin on top and bottom.
var usableHeight:Number = unscaledHeight - 8;
// Calculate the size of the Button control based on its text.
var lineMetrics:TextLineMetrics = measureText(mode_mc.label);
// Add a 10 pixel border area around the text.
var buttonWidth:Number = lineMetrics.width + 10;
var buttonHeight:Number = lineMetrics.height + 10;
mode_mc.setActualSize(buttonWidth, buttonHeight);
// Calculate the size of the text
// Allow for a 5 pixel gap between the Button
// and the TextArea controls.
var textWidth:Number = usableWidth - buttonWidth - 5;
var textHeight:Number = usableHeight;
text_mc.setActualSize(textWidth, textHeight);
// Position the controls based on the textPlacement property.