How create WPF scrollbar to look like iTunes cover flow scrollbar? - wpf

I would like to create a scrollbar in WPF that looks like the one seen in iTunes cover flow. See scrollbar image below, which also shows the reflection of the album art underneath the scrollbar.
Scrollbar Image http://www.barramsoft.com/pub/images/scrollbar2.jpg
Below is a basic scrollbar control in xaml.
<ScrollBar Name="scrollBar1" Height="24" Width="Auto" Orientation="Horizontal"
SmallChange="1" />
How can I get from the above to an iTunes cover flow scroll bar look? The full ready to use source code sample would be preferred.

Start with the ScrollBar ControlTemplate Example in MSDN from http://msdn.microsoft.com/en-us/library/ms742173.aspx (that is much easier to modify than the window style you can get from Blend or ShowMeTheTemplate)
Now start to edit the template, change the colors, the templates for the arrow buttons and the thumb until it looks like you want.

Have you got Expression Blend? If not I'd recommend installing it (there is a 30 day trial version if you don't have an MSDN license).
There are quite a few Expression Blend tutorials out there here's a good place to start for example.
Basically you copy the template for the standard scroll bar which will give you all the elements that go to make it up. You then change what each element looks like until you get it looking how you want it. There will be a fairly large amount of trial and error in this process.

The first task is to show the scrolled area underneath the scrollbar. You have to change the structure of the ScrollViewer control. By default it is a 2x2 Grid so the horizontal scrollbar is under the scrolled area. Edit its template to put the scrolled area and the scrollbar in the same cell, vertically aligning the scrollbar to bottom.
The second part is to style the scrollbar itself. I don't believe this can't be done with rounded rectangles.
I usually extract the template to modify it using Blend, there is also a free ShowMeTheTemplate tool.

Have a look at the WPF Themes project at codeplex. The Expression Blend Theme (light/dark) is very close to the example you've provided. It is released under Ms PL.

Related

Showing Canvas Outside UserControl boundary

I've found several threads on various sites vaguely related this, but no solid answers.
Here's a simplified example: I want to create a usercontrol that has a textbox and a small icon beside it. If you click the image, I want to have a canvas appear under the control that has information in it. The canvas would be outside the usercontrol's boundary.
I have gotten this "sorta" working. If I put the textbox, graphic, and just a canvas on the control, with the canvas outside the clip of the usercontrol - I can make the canvas visible/invisible as desired.
When I add stackpanels and such, it starts exhibiting odd behavior - sometime simply vanishing.
So, here's the question - what is the right way to do this? Or, is there a "right way"?
what you need to do is put your canvas into a <Popup> control. then, show the popup when needed. Here is a video showing how to use a <Popup> control, Here is the MSDN documentation.

Scale usercontrol in wpf ? vertical and horizontal scrollbars

I implemented a usercontrol, but i have a problem with rescaling the window. I know when i make the window smaller, everything scales, and every textbox and label becomes also smaller. But this is not what i want, i just want that when i make the screen smaller, everything stays the same size, and that scrollbars appear ( vertical and horizontal ). How do i do that?
Thanks
Assumption
The behaviour you describe, is not mandatory the default layout-behaviour of WPF. It depends on the layout-controls you use. I assume, you're using a Grid with setting it's columns and rows to the Start (*)-GridLengths. This would have more or less such an effect as you describe (without scaling). Or maybe you are using a ViewBox, this control scales the whole content based on the available layout size.
Solution
I guess that wrapping your whole content into a ScrollViewer will probably do what you desire. If not, I suggest that you post some XAML-code to show us how you have built your content.
<ScrollViewer>
<YourContent>
</YourContent>
</ScrollViewer>
Update
If you really scale your window (applying a ScaleTransformation) and you want your UserControl to be the only control within that does not scale, you have to scale your UserControl in the opposite direction as you have done it with your window. Apply a ScaleTransformation and set the scale values to 1/scale. Or try to use the ViewBox to blow up the content of your UserControl, but this will not be very exact.

WPF Tiled Background Misalignment

We have quite a complex WPF application (that I cannot show here) that somehow has the tiled background misaligned of one of its user controls. I was unable to reproduce this problem in a "clean" WPF project but will try to illustrate the problem in this picture:
(source: kintespace.com)
The gray area represents the user control and the black and red checks represents the tiled background inside the user control. The white background represents the window hosting the control. The VisualBrush is used here but the same problem comes with the DrawingBrush. I would prefer not to use the ImageBrush.
Can you open a "clean" WPF project and build something that will cause a tiled background to be misaligned like this?
You can do this if the layout root of the user control has a -10 left margin and a -10 top margin. the tiled backgoround in on the layout root of the usercontrol so, it looks like a alignment problem not a brush problem.
This problem is related to the tiled background cramming itself into the calculated height of the UserControl instance in the hosting Window. I am still unable to replicate this problem in a new project but it is "solved" (by stacking panels in the user control horizontally instead of vertically).
Here are two diagnostic techniques that can be useful in situations like yours:
Take your complex project, make a copy, and start tearing out large sections of code and XAML until the problem disappears. Then put the last section back and tear things out more gently. Repeat until you find the change that makes the difference.
Run the application, break where a local variable references your UserControl, then explore the visual tree just above and below your UserControl in the Locals or Watch window. Look at each Visual's internal properties VisualOffset, VisualTransform, and VisualContentBounds. These properties will usually clue you in to what property is being set incorrectly, and from there you can figure out why.

WPF and Silverlight controls and layouts pan and zoom capabilities

I would like to understand the general requirements for WPF/Silverlight layout for making it possible to implement pan&zoom (drag and zoom) features. I don't mean pan&zoom for an image but for a total page (window) layout (or part of it) with some controls.
What features of the layout and what features of used custom controls make layout fixed and pan&zoom impossible?
General rule
With few exceptions, everything in WPF can be panned, zoomed, rotated, stretched, etc to your heart's content. This include single controls like Button, compound controls like ListBox, and containers like StackPanel.
The exceptions
Here are the exceptions:
If you are using Adorner and your AdornerDecorator is outside the panned/zoomed area, then the Adorners attached to your panned/zoomed area will pan but not zoom. The solution is to put an additional AdornerDecorator inside the panned/zoomed area.
If you use a Popup, it will display at the panned/zoomed location of its PlacementTarget but it will not itself be scaled. It will also not move as you pan the area containing its PlacementTarget (basically it sits in its own surface above the target control). To get around this, use a zero-size Canvas with high Z order instead when you want something to pop up within the zoom/pan area.
Any ContextMenu you define will be shown inside a popup, so the menu items will display normal size even when the area you clicked on is zoomed in or out. Because of the nature of a context menu, this is probably desirable behavior. If not, you can wrap the menu items in a ViewBox and tie the zoom to your main area's zoom.
Your ToolTips will display normal size even if the UI is panned or zoomed. Same solution as for ContextMenu.
If you used WinForms integration to integrated legacy WinForms controls and UI, they will not properly pan, zoom and clip in certain situations. There is an advanced technique for working around this, where you implement the WinForms control off-screen, then using BitBlt or similar copy the image into your window as an image, and forward mouse clicks and keystrokes to the offscreen window. This is a lot of work, though.
If you bypass WPF and directly use GDI+ or DirectX, or use Win32 hWnds to display content or UI, that content or UI will not be properly panned, zoomed or clipped to the window unless you do it yourself in your interface code.
Final notes
A good WPF UI always uses panels like Grid, DockPanel, etc to lay out controls in a flexible manner so they automatically adjust to container sizes, rather than using fixed sizes and positions. This is also true for the internal contents of your pan/zoom area as well, BUT there is an exception to this rule: the outermost element in your pan/zoom area must have a specified size. Otherwise what will define the area being panned/zoomed over?
The easy way to implement pan/zoom capabilities is to adjust the RenderTransform of the outermost control in your pan/zoom area. There are many different ways to implement controls for panning and zooming, for example you could use toolbar buttons and sliders, scroll bars, mouse wheel, spacebar+drag to pan, draggable areas of panned UI itself, or any combination of these. Whichever interface you choose, just have it update the RenderTransform appropriately from the code-behind and you're good to go.
If your chosen panning mechanism is scroll bars, you might want to use a ScrollViewer and only use the RenderTransform for the zoom.
Be sure you set clipping on the pan/zoom area. Otherwise if you zoom in or pan items off the side, they will still be visible outside the pan/zoom area.
Use a MultiScaleImage or Canvas area, and place everything you need to pan and zoom in it
<Canvas x:Name="panZoomPanel" Background="Transparent">
</Canvas>
In code use make a TranslateTransform and a ScaleTransform in a TransformGroup to pan and zoom
Check out other SO post or this example or this one
In general you can treat any composite set of UI elements the same as you would treat a single UIElement so the case of an image isn't really different than doing the same for an entire application. The best way to handle zooming based on user input (as opposed to automatic scaling that Viewbox does) is applying a ScaleTransform. This can be set on a high level parent element, like a Grid at the root of a Window layout. For panning you can combine in a TranslateTransform or in some cases use a ScrollViewer to handle moving the view of the content.
One really easy way of implementing zoom in XAML is to use a Silverlight ViewBox. This zooms the XAML not the pixels. You can specify the stretch to use and the ViewBox will scale based on this (Fill, None, Uniform etc). There are some great Viewbox blog posts on the web if you search for Silverlight+Viewbox on Google.
The panning is easily accomplished with a similar mechanism to drag and drop and there are also numerous how-to blog posts on this, available via Google. Just amounts to capturing MouseDown, MouseMove and MouseUp events.

Auto-size controls in .NET CF to avoid horizontal scrolling?

I am developing a form in .NET Compact Framework, which hosts a variable number of controls. Every control should have the same width as the form. When there are only a few controls, no vertical scrollbar appears. When there are more controls than they can fit in one form, a vertical scrollbar appears. The width of the controls should then be modified, so that no horizontal scrollbar appears.
What is the best way to achieve this? I am interested in a solution that will work in all platforms/screen sizes and that can support screen orientation changes.
If I get this right, at one point, both a vertical and horizontal scrollbar appear, and you want only the vertical scrollbar? Doesn't setting the Anchor of each control to "Top|Left|Right" solve this problem automatically?
If every control is to be the same width as the form, why not just Dock every control to Top (or Bottom)? It'll take care of the resizing for you then. It might not look very attractive however, so I suggest adding in some empty Panels (docked the same way) to be used as vertical spacers.
I did some quick testing, and it seems, when you add controls, the panel raises the resize event when the added control tiggers the scollbars to go visible. The annoying part is here that the resize event is triggered a couple of times during startup :(
But knowing the compact framework, this might be your best shot at handling this.
Normally on the full framework you could if the DisplayRectangle is bigger than the size of the panel, but no such thing exists on the cf.
Hope this is of some help, I'll see if I can find anything more in the morning.

Resources