Fixed column wider than ClientWidth of the control cannot be resized any more

[joachimmarder]

Make a column fixed using the coFixed flag and make it larger than the ClientWidth of the control. Neither scrolling nor resizing the column works any more.

[joachimmarder]

By setting TVTHeader.FixedAreaConstraints.maxWidthPercent to 95 this problem can be fixed.

Would it make sense to use a default value of 95 for this property, instead of not limiting it?

[obones]

Hello,

I'm having an issue with the change to the if statement done in the associated commit.
Right below it, it makes this code:

        if (FMinWidthPercent > 0) and (FixedWidth < MinFixedWidth) then
          ResizeColumns(MinFixedWidth - FixedWidth, 0, Count - 1, [coVisible, coFixed]);

being called with the first argument set at 42
This means that inside ResizeColumns we have BonusPixel set to True which means that the local ReduceConstraints method will always return True

My issue comes from the fact that ReduceConstraints is used as a stop condition for the smaller repeat..until loop if MaxDelta is lower than Abs(ChangeBy)
In my case, the test right above that decides to call IncDelta is always False because (Options * FColumns[I].Options = Options) is False for all columns.
This means that MaxDelta keeps its default value of 0 and there is no way to escape the repeat..until loop resulting in an unresponsive application eating up one CPU core.

I have reverted the change to the if condition locally, but I'm not sure that this is an appropriate course of action

[joachimmarder]

I have reverted the change to the if condition locally, but I'm not sure that this is an appropriate course of action

Reverting the change to the if statement brings back the problem that the MaxWidthPercent property is not taken into account. I guess that just covered the problem you encountered here, and the change is the trigger but not the root cause. But I have to admit that I never looked into this code so far. Reading your bug report above may explain why....

[obones]

Yes, you are right, the erroneous if statement is most likely hiding a deeper issue. But between breaking a property that I do not use and having an infinite loop that blocks my application, I took the shortest route for my own use case.

Obviously, it would be much nicer to have both the if statement and the MaxDelta loop function properly.

[joachimmarder]

Can you provide a sample project or the relevant property settings that allow me to reproduce the infinite loop? Even better would be a unit test.

[obones]

Here you are: VTVHeaderMinWidthPercent.zip

The only thing that was done here is to set Header.FixedAreaConstraints.MinWidthPercent to 5

[joachimmarder]

Sorry for the late response @obones. It seems that the form file "MainForm" is missing in the ZIP archive.