Build-in apps style scrollbar - how to implement them.

Question

I was wondering how to implement build-in app like scroll bar for app that allows switching active views. 
 I saw there is a way to switch views wit slide up/down animation but how overlay that with scroll bar? 
 I went through samples and API doc but could not find anything like this. 
 1727.VID_20200127_002120.m4v

obagot · Answer

Hi, 
 There is no such scrollbar object for layouts. 
 You will need to draw directly on the canvas using the DC in the onUpdate() function. 
 function onUpdate(dc) {

 // Do anything to your layout
 // ...

 View.onUpdate(dc);

 // Draw on the canvas
 var penWidth = 12;
 var x = dc.getWidth()/2;
 var y = dc.getHeight()/2;
 var radius = (x < y) ? (x - (penWidth/2)) : (y - (penWidth/2));
 var start = 180;
 var end = 90;
 
 dc.setPenWidth(penWidth);
 dc.setColor(Graphics.COLOR_LT_GRAY, Graphics.COLOR_WHITE);
 
 dc.drawArc(x, y, radius, Graphics.ARC_CLOCKWISE, start , end);
} 
 Do this for each view, playing with start and end variables, and use a different color for the current view.