WPF Adorner Transforms - wpf

I am building a control, where the user can "draw" resizable rectangles that are laid over the content. To resize those rectangles, I use an Adorner on top of them which contains 4 Thumbs to change the size of the rectangle.
The problem is, that this control is is "zoomable", meaning a ScaleTransform is applied to the whole control depending on a zoom factor. The Thumbs in the Adorner are affected by this ScaleTransform as well.
But I need them to keep their size, independent of the zoom factor.
I tried putting the Adorners in a Layer of another non-transformed control instead of the rectangle-layer, but this didn't work.
How can I achieve this?
Thanks,
Andrej

Have you checked this post: Transformations on AdornedElement are also applied to Adorner?! ? Does it work?

I also find this question on MSDN: How to exclude scaleTransform from GeneralTransform in Adorner GetDesiredTransform method., this is good because also there is some example code.

Related

Crop WPF control

I have to crop some control to show only a half of it but the rest should be transparent and clickable so it is not enough to cover the control with something. The result should give a control with only half of the content (for example 50% of top) and the rest should be cropped (not hidden) so some other control below should be visible and not overlapped by cropped part. New control should also scale when window is scaled. How to do this in WPF?
I have finally did the trick using Border around the control and Clip property of this border was set to Multibinging that was generating Rectangle basing on ActualWidth and ActualHeight of my control
Maybe GridSplitter:
http://www.wpf-tutorial.com/panels/gridsplitter/
Can be used to split views horizontally/vertically, and can be responsive.

How to Resize Controls in silverlight

I am working on a Silverlight application and my problem is like this: I have a StackPanel
and inside the stackpanel I have a ViewBox. Inside the viewbox I am adding images and rotating them 90 and/or -90 degrees.
When rotated, my images go out of the viewbox. How can I fix this?
Use something other than StackPanel, it doesn't resize.
There's a control in the Silverlight Toolkit that addresses this problem called the LayoutTransformer. It ensures that when you change the transform, the bounds of the control are within the LayoutTransformer bounds.
You can see this at work in the Silverlight Toolkit demo. Just scroll down the tree on the left to the Layout section.

Panel with percentage coordinates

I would like use a panel whose children have coordinates specified as percentage of total panel's width/height. Moreover, I should be able to animate the coordinate property, for example to make a button move from 10% to 50% panel's width.
I've made 2 attempts:
Use a Grid and specify size as stars - this was not enough, because AFAIK by default WPF cannot animate distance properties specified by stars. I've found somewhere a custom class that enabled me to do so, it even worked, hovewer I consider that solution overly complicated an I am looking for something simpler.
Use a Canvas with fixed width and height and put it inside a Viewbox - this is a simple solution, but when resizing the Viewbox the whole content of Canvas is resized too. I want the content to have fixed size.
Is there a simple solution or should I implement my own panel (or maybe extend one of the existing ones, i.e. Canvas)?
Cheers!
I would:
subclass Canvas, perhaps calling it RelativeCanvas or RatioCanvas
add two attached properties: XRatio and YRatio
override ArrangeOverride and loop over all children. For each child, use their XRatio and YRatio along with the ActualWidth and ActualHeight of the RelativeCanvas to calculate and apply values for their Canvas.Left and Canvas.Top attached properties
You would use it as follows:
<local:RelativeCanvas>
<!-- the top-left of this button will be center of panel -->
<Button local:RelativeCanvas.XRatio="50" local:RelativeCanvas.YRatio="50"/>
</local:RelativeCanvas>
One thing you might like to add after you get that working is control over alignment. For example, I might to align the center of a control to the specified ratio, not its top-left corner.
There's one here: WPF Proportional Panel

Resize Clipping Path on window resize in WPF

I was wondering how to resize a Clipping path dynamically when resizing the window. Right now I'm taking a rectangle in Expression Blend that resizes with the window. Applying this rectangle to a circle as a clipping path makes the rectangle fixed, and it won't resize anymore.
I've seen different ways of making clipping paths in XAML, in the Clip="" property as well as style markup. But I haven't succeeded yet in finding a proper XAML solution.
Can anyone point me in the right direction?
Thanks!
I was searching for an answer to the the same question (that's how I found your post) and I came across this:
http://chriscavanagh.wordpress.com/2008/10/03/wpf-easy-rounded-corners-for-anything/
Not sure it will work for you if you have a more complex shape that you would like to use as the clipping path, but if you are just looking to round some corners that will scale automatically, I suggest you check it out. It uses a VisualBrush bound to a border element instead of a clipping path. So far I have found it to be a pretty elegant solution for my needs.

Is there a way to automagically make a canvas scroll on overflow in WPF?

Been checking the web and this site, but couldn't come up with any descent results.
Is there a way to make a canvas in WPF show scrollbars on overflow ? Been trying the scrollviewer, but can't get it to work :(
Thanks in advance..
The problem you're running into is that Canvas, unlike many WPF panels and containers, does not size to contents. That means if you add an element which goes outside the canvas boundaries it will not update it's size. Hence embedding a Canvas in a ScrollViewer will do no good unless you manually update the size of the Canvas.
It sounds like what you want is a Canvas which supports size to contents. This blog entry has exactly that control.
http://themechanicalbride.blogspot.com/2008/11/auto-sizing-canvas-for-silverlight-and.html
I took a different approach and abandoned the Canvas for Grid. The Canvas is more performant but for my purposes at least I haven't noticed a difference. The grid can mimic the behavior of canvas by doing the following.
Create a single row,single column grid.
Set the HorizontalAlignment to Left
Set the VerticalAlignment to Top
Use Margin "x,y,0,0" to set the position.
Bam..works just like canvas and it works great in a Scrollviewer.

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