Windows 8 xaml splitter

Active Oldest Votes. DChamberland DChamberland 31 2 2 bronze badges. Any chance you are affiliated with this project? Rob Allen Rob Allen Sign up or log in Sign up using Google. Sign up using Facebook. Sign up using Email and Password. Post as a guest Name. Email Required, but never shown. The Overflow Blog. Podcast Making Agile work for data science. Stack Gives Back Featured on Meta. Run the application again, and you should see that the Name and Phone properties have been applied to the TextBlock Text attributes.

The Name property also needs to be changed from a trivial property to a fully defined property including a user-provided backing store to support firing this event when the property is modified. This is a commonplace refactoring, because multiple properties often require notification.

The implementation is shown in Figure 6. This example only provides for the Name property to be notifiable. A similar change would need to be made for the Phone property. Running the application again with the INotifyPropertyChanged modifications made should result in the name change when the button is clicked. These are collectively referred to as ItemsControls. Open MainPage. Name that class myListView, as shown here:. In MainPage. Then assign it to the ItemsSource property of myListView:.

The ListView will then iterate over its ItemsSource and, for each element in the collection, generate the appropriate UI and bind its DataContext to that element. Note that the Text properties inside the template have the data bindings appropriate for a Person object. Figure 8 The Finished ListView. To learn more about XAML, I recommend looking for references that talk about XAML in Silverlight, as many of the same concepts apply and many controls are named similarly or the same and have the same functionality.

The codebehind for these references will be C , so some translation or interpretation is necessary. These templates demonstrate many advanced features of a well-made application, and deciphering their secrets can lead to greater understanding of the underlying frameworks. The code and documentation for this application can be found at hilo. As with any new technology, you can expect to spend many late nights browsing documentation and forums and with your nose buried in technical books.

They will enable you to write rich, fast applications in far less time. Although all seems bleak, there is one way that I found in the article to run custom code when operations are performed on the collection using the internal functions.

The one way to run custom code lies in the Visual class. This class provides a callback called OnVisualChildrenChanged. This triggers the OnVisualChildrenChangedCallback wherein now you can run custom code such as what we need to do with the custom Split Panel.

So from the above discussion, there is in fact a way to derive the SplitPanel from Panel and provide a custom collection through the Panel's CreateUIElementCollection callback and make the interface work like I want; however, I still opted to derive from FrameworkElement.

The reason is because I did not build the SplitPanel to be part of an ItemsControl, and from a logical standpoint, having a SplitPanel be an ItemsHost, just doesn't seem right. The children of a SplitPanel can be resized using the splitters, and because of that the Panel inherits an overall different class of functionality in my mind.

The Panel class provides the Children and InternalChildren collections that work closely with the ItemsControl handling. The Panel will handle properly hooking up each child to the parent when the collection is modified. In order to override this functionality and provide a custom collection, you can use the Panel's CreateUIElementCollection callback when it goes and creates the Children collection for the panel.

The custom collection must derive from UIElementCollection. So in the end, the SplitPanel derives from FrameworkElement. The Panel class provides a background DP that is manually rendered by overiding the OnRender function. The SplitPanel does the same since it does not derive from Panel and needs to manually implement the background DP.

In order to tell WPF that our panel will hold multiple children that will also be rendered, we need to override a few FrameworkElement functions to make this happen.

The custom ElementCollection that is implemented for the control holds all the Visuals that need to be rendered in the VisualTree of the control. For the GetVisualChild override, we simply return the Visual at the given index, and for the VisualChildrenCount we return the number of Visuals stored in the collection. FrameworkElements that override the two above functions, seem to not be able to be styled and as a result, anything that needs to be shown on the panel such as a Background must be manually rendered in the OnRender function.

The meat of the code of the panel is contained in the measure and arrange overrides. The overridden functions call either MeasureHorizontal, MeasureVertical, ArrangeHorizontal, and ArrangeVertical depending on the orientation of the panel.

The 2 pairs of functions do the same things except the horizontal functions operate using width and the vertical functions operate using height. During the measure phase we calculate the star sizing for the children and also the size for each of the splitters contained in the panel.

The desired size for the splitters always take precedence over measurement of the children. This means the splitters are measured first and whatever size is left over goes to the children.

How is star sizing calculated for a child? Star sizing can be thought of as a proportion based sizing mechanism. When you specify a star size, you are specifying a proportion of the available size width or height of the panel to be distributed to your child during layout.

Let's take a look at the picture:. The picture shows a panel with 3 children inside. The first child has a star size specified as 1, the second specifies a star size of 1, and the third specifies a star size of 2. At the end of the day, the actual widths of the children will be calculated as 25, 25, and The calculation to arrive at the actual widths is quite simple. Divide the available size by the addition of all the star sizes of the children in the panel.

This number in my implementation is called the "star unit size". Subsequently to calculate the actual width of a child at this point, you take the star unit size and multiply by the star size of each child.

The same calculations are used for either horizontal or vertical orientations. The only difference between the orientations is that you are either acting on width or height. Keep in mind that the example is simplified. The example shows an available width to the children of The available width for the children is calculated by taking the width passed into MeasureOverride and subtracting from it the addition of all of the desired sizes of each splitter in the panel.

The arrange pass is pretty simple. Previously in the measure pass, the star unit size was calculated. The arrange code simply arranges child, splitter pairs until the last child in the panel is reached. Then the last child is arranged. The reason it is done this way is because there is one less splitter control in the panel compared to the number of children in the panel.

To arrange everything in the panel, we keep an offset variable. The children or splitters are arranged left to right for a horizontal orientation or top to bottom for a vertical orientation. In each case, the offset is updated after each item is arranged by the width or height of the item. The width or height of a child can be calculated by taking the star unit size and multiplying by the star size as explained in the measure section. The split panel implements an orientation property.

Whenever a splitter is created through the ElementCollection, the splitter binds to the SplitPanel's orientation property. The splitter then uses the CoerceOrientation function to force the orientation of the splitter to be opposite to that of the Panel. The element collection is what is directly accessible to the user to add children to the panel. All operations in the collection are implemented in terms of Insert and RemoveAt because all other collection operations can be implemented just by using these two functions.

The split panel creates an element collection inside its constructor. The panel exposes the Children DP to remain consistent with other panels which internally accesses the custom element collection.

Internally, the collection keeps another collection called Visuals. All splitters and child elements are added to the visuals collection so that the SplitPanel can query them for the VisualChildrenCount and GetVisualChild overrides. When a child is inserted into the collection, a new splitter control is implictly created if there is already at least one element in the collection.

The collection will then wire up the splitter and child to the panel by calling AddLogicalChild and AddVisualChild on the elements. The collection also adds the elements to the visuals collection. When a child is removed, a splitter is removed from the collection if there is at least one element left in the collection.

The collection will call RemoveLogicalChild and RemoveVisualChild on the splitter and child elements to unhook them from the panel.