Canvas containing UIComponent has no scrollbar

[Ibarim]

I'm trying to crop part of display object (dispObj). Just cropping width; height is not important.

var ui:UIComponent = cut(dispObj,2000);

var can:Canvas = new Canvas;

can.horizontalScrollPolicy = 'on';

can.addChild(ui);

private function cut(can:DisplayObject,w:int):UIComponent {

     var shapeBitmapData : BitmapData = new BitmapData( w, can.height, true, 0x00000000 );

     shapeBitmapData.draw( can, can.transform.matrix);

     var bm:Bitmap = new Bitmap(shapeBitmapData);

     var ui:UIComponent = new UIComponent;

     ui.addChild(bm);

     return ui;

}

But the final canvas has no horizontal scroll, the ui element is longer than the screen, but canvas don't detect it's content. How else can I crop display objects? Is any simpler way than changing display objects to bitmapData and Bitmap and then uiComponent?

[Ned Murphy]

It is possible the canvas does not automatically adjust when you added content to it dynamically.  Go thru the various methods, both native and inherited to see if there is one that updates/sizes the canvas object after you have added content to it.

[Ibarim]

Do you mean invalidating stuff? Nothing helps. I've tried:

can.addChild(ui);

can.invalidateSize();

can.invalidateProperties()

can.invalidateDisplayList()

But still no way to scroll. Besides I can see the displayObject on screen.

Strange thing - I made a background for this canvas and it seems the image is not inside? I don't know what to make of it. In this example: https://ibb.co/4sp6j28

blue is canvas and building shapes are the image I put inside canvas. But the canvas is only a scroll bar with no content. How is this even possible...

[Ned Murphy]

Have you tried using double quotes rather than single quotes for the parameter ...  can.horizontalScrollPolicy = "on";

[Ibarim]

I've just tried that. No effect. I didn't know single/double quotes make a difference:)

I'll have to cut this displayObject with another canvas. Then I will get scrollBar in outer canvas as it should be.

var canInside:Canvas = new Canvas;

canInside.width = 2000;

canInside.horizontalScrollPolicy = 'off';

canInside.addChild(dispObj);

var canOutside:Canvas = new Canvas;

canOutside.addChild(canInside);

canOutside.width = 1024;

canOutside.horizontalScrollPolicy = "on";