Mysterious White Rectangle!

A very simple app relying on Canvas a lot to hold graphics. When I place a container control (Canvas + label with MouseEnter, Down, Exit events) in the Top Left Corner of the window. A ’ Window Background Color’ rectangle appears behind the Container Control. If I move the container control away from the top left corner the rectangle diminishes then disappears.

Any Ideas?

Many Thanks

can you post a simple example the replicates the problem?

Here is a sample project xojo 2016 release 2.1

Thanks

Toggle erase background on your container control on then off and things seem to be fine

are you running under Windows?
I ran you example under OSX and saw something similar but different.
What I saw was a box exactly the same size as the containers, where you example shows only partial

and the problem seems to be with your background image, well not WITH the image, but that Xojo seems to ignore the background image when drawing the transparent containers and goes right down to the window itself.
I removed your background, and put a custom color instead, and it seems to work much better (at least as far as the tranparency goes)

Norman… that did not fix it for OSX… still bleeds the window background color

I set the window back color to pink to see if it was the window or container control color that showed

image above is with original background image restored

Dave S: “What I saw was a box exactly the same size as the containers, where your example shows only partial”

Yes depending on where the placement of the CC is, with reflect how much of the mysterious Box appears.
I will try the replacement of the image with a color.

I am running on a Mac for a Mac.

Thank you Norman and Dave

Removing the Background image and the custom color. Also reveals the mysterious box in the left hand corner.

Adding a custom Color fixes the issue.

I tried moving all 3 of the containers to different parts of the window and my results all looked exactly as what I posted above

My test was different:

I deleted the left container control,
I duplicated the right container control,
I moved it near where was the deleted one,
I replaced the numbers to 2.

Run: same bad behaviour. Strange. (I even checked if the loaded file have an alpha channel !)

Sorry: no idea.

[quote=285033:@Dan cooper]Removing the Background image and the custom color. Also reveals the mysterious box in the left hand corner.

Adding a custom Color fixes the issue.[/quote]
nothing I do causes any extra box to appear…
so perhaps there is something in you actual project that didn’t make it to the example you posted… but still the fact that it doens’t honor the background image should be posted as a problem

@Dave S, the example I posted has the same box as the project. And only when the CC is placed in the Left-hand Corner of the screen.

The Custom background color of the Window and a Colored Rectangle for the Darker lower section of the screen has removed the problem. Thanks all for your help. An anomaly no doubt.

oh turn Double Buffer OFF on the canvas on the container control too