QGraphicsScene and fonts/shapes sizes

[olelukoie]

I don't agree, you can't state everything in the docs, it's simply not possible. You have to assume some level of knowledge of the reader and some level of curiosity and ability of finding information in outside sources.

I agree that it's not possible to describe everything down to the very basic things in docs but there are still things that should be described. I can give you another example: Z value of an item. There is a good description in setZValue method. It misses only one aspect: negative Z values and their meaning. Data type 'qreal' supposes that the value can be negative, zero and positive. But this description doesn't mentions negative values at all. Would top-level item with negative Z value be drawn above background layer or beneath it? Would child item with negative Z value still be drawn above its parent or it will be drawn behind it? Yes, I can guess and can experiment - but it should be described in docs. And BTW there are no mention about minimum and maximum limits of Z values acceptable by GV system. By default I assume they are equal to limits of 'qreal' data type ('double' in terms of C/C++ programming languages for all platforms except for ARM) - is it correct?

[wysota]

I agree that it's not possible to describe everything down to the very basic things in docs but there are still things that should be described.

Unfortunately you think the feature X should be described in more detail and someone else thinks feature Y deserves more attention. If we continue this trend, Qt Reference Manual wouldn't fit onto a DVD and still many people would be not satisfied with the contents. One thing is sure, the docs would become too bloated and it wouldn't be possible to find anything there.

I can give you another example: Z value of an item. There is a good description in setZValue method. It misses only one aspect: negative Z values and their meaning.

I'm not sure what you mean. Negative values of Z work exactly the same as positive ones.

Would top-level item with negative Z value be drawn above background layer or beneath it?

It's stated clearly in the docs that the item layer is above the background layer and items are positioned in ascending values of the Z-value. This makes the answer to your question obvious.

Would child item with negative Z value still be drawn above its parent or it will be drawn behind it?

It's also written in the docs that children are always drawn on top of their parents (in ascending Z order). That sentence answers your question as well.

Yes, I can guess and can experiment - but it should be described in docs.

It is

And BTW there are no mention about minimum and maximum limits of Z values acceptable by GV system.

So it clearly suggests the value is limited only by the datatype.

By default I assume they are equal to limits of 'qreal' data type ('double' in terms of C/C++ programming languages for all platforms except for ARM) - is it correct?

Yes, that's correct but this information is completely meaningless unless you want to add zillions of items to the scene but this would be stupid because of performance reasons

I think your problem is that you read some paragraph from the documentation and if you don't find the information you are looking for, you don't bother to look elsewhere. It might be wise to use Assistant's search tab more extensively.