List Picker Drop down is Transparent in Light Theme

[Adam12]

When expanding the RadListPicker and the phone theme is set to "Light" the popup picker is completely transparent.  This doesn't look right if there is content (such as an image) behind the picker.  The coloring of the expanded picker should be consistently handled regardless of what theme the phone is using - I would imagine it should use the "PhoneContrastBackgroundBrush" and "PhoneContrastForegroundBrush" by default, as opposed to a solid brush in one case and a transparent one in the other.

[Deyan]

Hi Adam,

The RadListPicker control uses the PhoneTextBoxBrush (a static OS resource that is correspondingly updated when the main theme is changed) which appears to be transparent when the theme is set to light. In other words, this is the default appearance of the control. You can, however, change this according to your requirements by setting the Background property of the control to the desired brush. Note that in this case you will loose the visual states of the control.

I hope this helps.

Regards,
Deyan
the Telerik team

[Adam12]

Hi Deyan

Thanks for responding so quickly.  I understand why the control is transparent the light theme - my point is that this is undesirable.  It's makes no difference of apps where the background is a solid color (such as your demo app or the native apps) but for apps where there is some kind of underlying image or pattern it makes the control unusable without customization.  Correct me if I'm wrong but a control should work regardless of what type of background you happen to put it on.

Also it doesn't appear to be consistent with the native controls, where the popup is always a solid color (white) regardless of the theme being used.

Anyway those are just my thoughts.  I'm a big fan of the controls so far so keep up the good work.

[Deyan]

Hello Adam12,

Thanks for writing back.

The popup of the RadListPicker control is white when using the Light theme. However, when the control expands inline the portion that holds the items is transparent - just like in the ListPicker control that comes with the Silverlight Toolkit for Windows Phone 7. Take a look at the screenshots I am attaching.

Since I am not quite sure that I correctly understand the scenario - feel free to provide me with further details and hints.

Thanks for your time.

Kind regards,
Deyan
the Telerik team

[Adam12]

Thanks Deyan but I understand why the control is working the way it is.  As a developer who has been building apps on WP7 for over a year now what I am trying to say is that I don't believe this behavior is useful.  This control doesn't work out of the box in all scenarios.  Out of the box it would cause an application to fail Marketplace ingestion if the control happened to be placed the wrong kind of background in the light theme.

You can see the problem in your own screen shot.  The items in the inline pick list blend in with the background and become difficult to read when the picker's background is transparent.  Taking your example a step further: see what happens if one of the gradients where black instead of blue (as is shown in the attached screenshot). The text becomes completely illegible.  This can't be right?  As I mentioned before this is not consistent with the native app controls - where they appear to always use a white background for the inline pickers.

The SL Toolkit may well do the same thing but unfortunately that just means that they have the same problem.  Their choice of default brush is also problematic.

For me, I've solved the problem in my own case but I wanted to bring this up because I have worked with many control suites on many technologies (Delphi through to WPF/Silverlight) over the years and I have never encountered a situation where the background obscuring content in the control was considered as anything other than a bug.

Anyway I thought you might appreciate the feedback, whether or not you agree.

PS: Sorry I just noticed I posted this in the wrong forum - it has nothing to do with the DatePicker.

[Deyan]

Hi Adam12,

Thanks for writing back and for your notes.

We tend to agree with you and will consider improving the default style of the RadListPicker control since in scenarios where the background of the page is not a solid color the content of the control might become unreadable.

In general, the controls from our suite that have an analog in the standard toolbox are designed to behave the same way since many of the developers expect this. We believe, however, that this case is a bit different and changing the style of our RadListPicker control so that it differs from the toolkit's would not cause any confusion.

Thanks for taking your time to share your thoughts and do not hesitate to get back to us in case you have further feedbak or need assistance.

All the best,
Deyan
the Telerik team