Avoiding collection view "stretched" cells - ios

I'm setting up a collection view and customizing its cell's width, inset, and inter-item spacing. With the current size that means there would be two columns in portrait and three in landscape. I let flow layout do the rotation adjustments & calculations, but the result is a stretched middle column. I think what is happening is flow layout is doing the math for the cell padding/spacing and not getting clean whole numbers. Then it adjusts the size of the actual cell by half a point. The result is an aliased & blurry looking cell.
I'm had this issue multiple times and each time - I manually calculate the values for each orientation to come out as a clean whole number. While this works, it doesn't seem very efficient. I'm wondering if there is a better way to do this, and if FlowLayout has the ability to say, give that half point to a margin or the empty space between the cells?

Related

Resize UICollectionViewCell to fit image

I'd like to resize UICollectionViewCell to fit image that is sensibly resized and maintains dimensions/aspect ratio. If I simply set the size of cell to size of image it may be way too big. Also, If I run on different sized devices, the spacing isn't consistent. Must I implement collectionView programmatically to overcome this?
I see many apps that do this so its a very common problem that may already be solved as a framework.
Example:
UICollectionView is actually of arbitrary layout. It so happens that the default is UICollectionViewFlowLayout which is a grid, but you can change it to anything by implmenting your own instance of the UICollectionViewLayout protocol. Int the case you cited its pretty easy. The width of the cells is the collectionview (width minus the padding) divided by two. The height is the aspect ratio times the width + the spacing + the label height. all the cells with indices divisible by 2 go in the right column and the rest go in the left column. It should be easy to calculate these values for layoutAttributesForItem(at:). Unfortunately its a bit harder to calculate for collectionViewContentSize. Assuming your collectionview is sufficiently small I think its best to just precalculate all of the hieghts and use the cached values for these functions.
There're a lot of open sources on github You can refer to.
https://github.com/zhangsuya/SYStickHeaderWaterFall

How can I get pixel precision when placing text with Auto Layout?

When using Auto Layout to position a label, I always get very imprecise results. In the example below, I have aligned the top and left edges of a UILabel to a parent UIView:
There is empty space on all four sides of the text, but the amount of empty space at the top and bottom is especially horrible. It is very tedious to take screenshots and figure out how many points I would need to offset the constraint's constant value to make the text line up properly. Is there any way to for the UILabel to properly reflect the rendered text in its frame?

iOS when one views height increase with code , alignment is deteriorating

I am trying raise the height of the ranked successive views. There is a certain distance between each of these views.(Vertical spaces)When I increase the height of one of them, distorted distance between the bottom. I can not align all elements under one single at a time. This event is automatically done on Android. How do I make this operation on iOS.
That is the problem

Layout UILabels with baseline offset

I have a view with labels stacked vertically. The design specification for the view give a vertical offset from the baseline of the text in the top label to the text in the bottom label.
However when I code for this, the size of the top UILabel will always be big enough to accomodate the descender of the top label. So I can only program the offset from the descender, not from the baseline. In the attached picture, red offset is what I want to code for, but I can only code for the green offset. Is there any way that I can get the baseline offset correct either in the xib or through code? I do not want to do this by trial and error, as that would result in the programmed offset not matching the specs.
You can do it, but easier to show you in a screen shot than to explain it:
Change "30" to whatever your specified distance is.

Scrolling the TStringGrid pixel by pixel

Scrolling a TStringGrid using its horizontal scroll bar will scroll a column at a time. In some situations, this creates a really nasty behavior that makes the grid unusable: if the width of last column is large (example, 1000 pixels) the user won't be able to scroll the grid to see the entire content of the column.
There is a way to scroll by pixel? Or to set the correct scroll range for grid's scroll bar?
As far as I know, no you can't horizontally scroll the string or draw grids by pixels, only by whole columns. I agree it can be a problem by the way. I tend to autosize the columns but make the max initial size of any column be slightly less than the clientwidth of the control.
I have looked into the source code. With Borland's code it can't be done.
However, Lazarus has this capability.

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