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DropDown: DetectBoundaries(..) not working when pull down menu has no max height

Open Jemt opened this issue 2 years ago • 1 comments

Consider the following example:

https://jsfiddle.net/o3t8pnhk/4/

HTML

<div id="Page"></div>

StyleSheet

#Page
{
	width: 600px;
	height: 300px;
	border: 1px solid red;
	padding: 1em;
	overflow: auto;
}

JavaScript

Fit.Events.OnReady(function()
{
	dd = new Fit.Controls.WSDropDown("WSDropDown1");
	dd.Url("https://fitui.org/demo/GetUsers.php");
	dd.JsonpCallback("JsonpCallback"); // Loading data from foreign domain
	dd.MultiSelectionMode(true);
	dd.Width(100, "%");
	dd.DropDownMaxHeight(-1); // DetectBoundaries(..) doesn't work with a value of -1! Work around: use a value of 9999
	dd.DetectBoundaries(true); // Doesn't work when DropDownMaxHeight is set to -1
	dd.InputEnabled(true);
	dd.OnRequest(function(sender, eventArgs)
	{
		eventArgs.Request.SetParameter("NoCache", Fit.Data.CreateGuid());
		eventArgs.Request.SetParameter("Search", dd.GetInputValue());
	});
	dd.GetTreeView().OnPopulated(function(sender, eventArgs)
	{
		if (eventArgs.Node === null) // Root nodes received
		{
			var tv = dd.GetTreeView();
			Fit.Array.ForEach(tv.GetAllNodes(), function(n)
			{
				n.Expanded(true);
			});
		}
	});
	dd.Render(document.querySelector("#Page"));
    
    if (Fit.Browser.IsMobile())
    	dd.Width(100, "%");
});

DropDown will exceed its boundaries when DropDownMaxHeight(-1) is set. If we instead assign it a very high value such as 9999, then everything works fine.

Cause of error can be found here: https://github.com/Jemt/Fit.UI/blob/ade73e731e9e4dbfba5abbbfd7296588c3ca82ba/Controls/DropDown/DropDown.js#L2477

When we replace the variables, it becomes obvious why it fails. -1 will never be greater than spaceAvailable, e.g. 123: if (picker !== null && (maxHeight.Unit !== "px" || maxHeight.Value > spaceAvailable)) if (picker !== null && ("px" !== "px" || -1 > 123))

Jemt avatar May 20 '23 13:05 Jemt

One could argue that it works as expected. DropDownMaxHeight(-1) means assume the height necessary to show all items. But on the other hand DetectBoundaries(..) means "do not exceed boundaries". It comes down to which of the two properties should win. But it is odd that DetectBoundaries(..) takes precedence when DropDownMaxHeight is 9999, but not when its value is -1. In any case, this is a minor problem.

FlowIT-JIT avatar May 22 '23 08:05 FlowIT-JIT