Scroll bar slider behavior - c

I am implementing a scrolled window control.
I need to draw simple scrollbar sliders for this purpose.
Usually, sliders shrink as the content grows, but I am unable to understand how.
What is the relation/ratio formula? I've made several google tries to find out, but I didn't.
Does it have a minimum size it can go or it is just really hard to shrink it that far due to exponential shrinking behavior? We are talking simple generic scrollbars. What would be the proper way to implement the proper slider dynamic sizing?

Obviously this question is so dumb that nobody would bother answering.
I used to make complex hacks but now the simplest logic just slipped away across my mind.
The horizontal scroll bar slider width is the portion of the content (child) width.
(width / content) * width
width * width / content

Related

iOS 6 AutoLayout Scale and Translate Animation

My aim is to have 3 images shrink, grow, and move along a horizontal axis depending on selection. Using Auto Layout seems to make the images jump about as they try to fulfil the Top space to superview / Bottom space to superview constraints.
So to combat this I have put all the images inside their own UIView. The UIView is set to the maximum size the images can grow to, it is centred on the horizontal axis. So now all the images must do is stay centred inside their corresponding UIView. This has fixed my problem as the UIViews perform the horizontal translation, while the images shrink/grow inside while remaining centred. My question is - is this the correct way to do this? It seems very long and like I am perhaps misusing the ability of Auto Layout. I have to perform similar tasks with more images and so any advice is welcome! Thanks.
I've just written a little essay on this topic here:
How do I adjust the anchor point of a CALayer, when Auto Layout is being used?
Basically autolayout does not play at all well with any kind of view transform. The easiest solution is to take your view out of autolayout's control altogether, but alternatively you can give it only constraints that won't fight back against the particular kind of transform you intend to apply. That second solution sounds like just the sort of thing you're doing.

Zooming into a Canvas without modifying the size of specific child controls

So I realize that I am venturing outside of the intended use of a Canvas here and will likely have to come up with a more manual solution. However, not being overly experienced in WPF I was hoping that there may be some solution which would allow me to continue using a Canvas control and the features it gives you for free.
The issue revolves around a Canvas which is used to zoom in and out of an image and some number of child controls that belong to the Canvas. These child controls are to be placed at various positions on the image and, as such, the Canvas works nicely in that it handles all of the layout/positioning for me as I zoom in or out.
However, one drawback is that the Canvas scales these child controls up as I zoom into the image, causing them to become too large to be usable in practice. What I am looking for is a solution that allows me to zoom into an image that belongs to a canvas without also zooming up the size of the child controls, preferably handling the layout for me.
I have tried modifying the width and height of these child controls as the zoom factor increases or decreases, but there is a slight lag time and it all looks a bit 'jerky'.
If it comes down to it I will simply do all of the zooming/panning/layout myself, but I thought I would ask first just to make sure that I am not missing anything that would allow me to tell the Canvas to not scale the size of certain controls. Thanks in advance.
You can bind the children's RenderTransform to the inverse of the Canvas' transform, see my answer to this similar question on rotation.
This is more of a thought than an answer, but what if you set a transform on the element that you did not want scaled that was the opposite of the canvas itself. So for example, if the canvas had a scale transform of 2.0, set the element to have a scale transform of 0.5. You could probably accomplish this by binding the transform values together using a value converter.
You'll probably want to make sure the element has a render transform origin of 0.5,0.5 so that it scales from the center.

WPF, any easy way to work with different screen resolutions?

Given a WPF Application running full screen, a fair amount of controls some of which will animate from off screen to center. I was wondering if there are any special ways to save on the amount of time required to optimize an application for different screen resolutions?
For example, using Blend I've setup some text, which is originally off screen to scroll into view. Now in design mode the start positions are static. If resolution changes the start positions will obviously not be correct.
So I guess to correct this, during app startup. I need to
Check resolution
Move the text box to the desired start location
Adjust the storyboard as required, so the frames all have correct co-ordinates depending on the res of the screen.
I don't mind doing all of this, but if there is an easier way please share!
Thanks
In WPF layout of controls should be made in such way, that when size of window or content changes, controls automaticaly resize/reposition themselves to reflect this change.
This is highly affected how your layout is made, especialy by using specific panels, that do layout of their child elements.
This is also made obvious by using device-independent units for sizes, margins and sometimes positions of controls. And also allows different kind of zooming and scaling of whole UI without any need to redesign the whole thing.
If you are trying to position your controls absolutely, either by using Canvas panel or margins, your are doing it totaly wrong.
In WPF, scene is measured in abstract units, not pixels, and controls are freely scaled. There should be no problems to center something, or what?

Silverlight 3: Techniques for adjusting to screen resolution

My developer's box has a screen resolution of 1680 x 1050. I'm developing a full-screen Silverlight 3 application that I'm considering deploying to the Internet. So, I want to make sure the application looks good on a variety of screen resolutions. I just started testing on other boxes, the first one having a screen resolution of 1024 x 768. During the test I found some of the pages on the application were partially truncated. It seems the controls on the page didn't adjust for the lower screen resolution. So, I'm looking for some tips on how to make a Silverlight application, to the extent possible, adjust for screen resolution. For example, are there things one should or should not do on XAML to make adapting to screen resolution easier? Should I just optimize for a minimum screen resolution? Your thoughts and suggestions are welcomed.
You can easily enforce a minimum acceptable resolution by setting the MinHeight and MinWidth properties of your root visual. (Of course, this should be less than the minimum screen resolution to account for browser chrome.)
Try to specify absolute Width and Height only when necessary: for example, for images or icons of fixed dimensions, or for obvious cases like TextBoxes (whose width should reflect the average length of the data entered).
Grid panels are excellent for mixing scalable and fixed layout areas. The star sizing specification takes a bit of getting used to--it's not as simple as a percentage-based proportioning--but it's much more flexible, especially in combination with row/column min/max dimensions.
You don't really need to test on multiple resolutions unless you're interested in testing a range of dots per inch--just resize the browser to approximate different screens. Since there's always a bit of give and take depending on the user's browser configuration, you'll have to account for some variance anyway.
You can make your application scale with the Silverlight Toolkit ViewBox or make it strech with layout controls like the Grid, StackPanel, and WrapPanel. Make your main UserControl have a Width and Height of Auto (or remove the width and height entirely) and the size of the app will resize to the size of the parent div (the default HTML template uses 100%x100%). Then just resize the browser accordingly. IE8 has developer tools that can help you see your app resized to specific screen resolutions.
Testing on a variety of screen resolutions is always a good idea.
I covered the resizing of elements and making it resolution independent on another thread.
You can have a look here, there are multiple ways to sizing and resizing things automatically.

WPF Scale Transform and ScrollViewer - When Zoomed can't scroll beyond original size

I have a StackPanel inside of a ScrollViewer.
I have a slider that does a scale transform on the stackpanel to allow zoom-in and zoom-out functionality. The problem is that when I zoom in, the scrollviewer doesn't treat the content as being 'bigger'.
So, if I scroll in a little and scroll as far right as I can go - it stops me before I get to the end of the content. If I zoom back out to the untransformed level, I see that it's stopping exactly at that point. If I zoom in a lot, I can only see a small fraction of my total content when I scroll all the way over.
I can change the TransformOrigin to control which side loses the most content; but I figure there should be some way for the scrollviewer (or another control?) to take care of it for me.
Are you doing render transform, or layout transform? You should be doing the latter.

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