Get string under a mouse hover from wrapped Silverlight TextBox - silverlight

when hovering my mouse over a wrapped textbox, I want to get the word or text position immediately under the mouse.
I've seen some samples for a single textbox, like this one, but I have a wrapped textbox.
I think I might be able to do this if I had a MeasureString function but I don't have that either in Silverlight (would be useful for other things).
Example TextBox
<Textbox TextWrapping="Wrap" Width="50" Text=" ... " />

There isn't this ability in Silverlight today. Here's what I would do as a workaround:
Have an invisible (Opacity 0, IsHitTestVisible=False) WrapPanel with a TextBlock for each word.
Make the WrapPanel the same size as the TextBlock
Adjust margins on the TextBlocks and WrapPanels until you get similar spacing.
Do hit testing on the WrapPanel with the TextBlocks to determine the word

Related

Max Height for a dynamically sized WPF Textbox

I'd like to make a TextBox in XAML that is dynamically sized to the content, but that has a max height that keeps it from growing forever if that text is very long. If that max height is reached, the TextBox should stop growing and instead show a scroll bar. Ideally, that scrollbar does not exist when the text fits. How would I go about that?
I gain the dynamic resizing property by simply not setting an explicit Height on the TextBox (and possibly turning on text wrapping). But achieving the max height and scroll bar is a mystery to me.
Currently I have a setup that always shows a scroll bar and that grows forever. How would I change this?
<ScrollViewer>
<TextBox Text="{Binding Path=Selection.SummeryDescription, UpdateSourceTrigger=PropertyChanged}" />
</ScrollViewer>
You can do that just by setting the ScrollViewer.VerticalScrollBarVisibility to Auto and the MaxHeight. See example below:
<TextBox Text="..." TextWrapping="Wrap" ScrollViewer.VerticalScrollBarVisibility="Auto" MaxHeight="500" />
This will only show a vertical scrollbar when needed.
Please notice that in my example the ScrollViewer element is omitted as I enable the ScrollViewer via the ScrollViewer.VerticalScrollBarVisibility property instead.

AdornerDecorator - what does it matter where they are placed?

With some xaml like this:
<Grid Name="grid">
<AdornerDecorator>
<TextBox Height="23" HorizontalAlignment="Left" Name="textBox1" Width="120" />
</AdornerDecorator>
</Grid>
The WPF Snoop utility indicates textBox1 is a child of AdornerDecorator (as you would expect) but also that the AdornerLayer that AdornerDecorator creates is also a child. As a custom adorner added to the AdornerLayer can be displayed 'outside' the textbox, the AdornerLayer's drawing surface must stretch outside too (presumably all over the window).
So, what real significance does the placement of AdornerDecorator have (given we bind a UI element to the custom adorner, which we place in the AdornerLayer)? I know AdornerLayer.GetAdorner(textBox1) will get the first adorner layer in the visual tree up from textbox1, but what does it matter where that is (as the custom ardorner gets added to the layer and the custom ardoner knows which element it is bound to)?
The short answer is that it matters when you start to deal with controls that overlap other controls (in the z-index plane) and you care about whether or not a particular adorner layer shows on top of the overlapping controls. For example, when you use an ErrorTemplate, its contents get rendered in an adorner layer and if you don't supply an <AdornerDecorator> in your app (meaning that you just use the one provided by most Window templates), then you can end up with this happening.
By placing the <AdornerDecorator> where we want, we can control how this overlapping behaves.

Window size and TabControl with DataBinding (Size of Items)

The following scenario bothers me:
I have a simple WPF Window that has a TabControl as content. The ItemsSource of the TabControl is bound to a list of objects. In order to visualize the objects I defined some DataTemplates. As the list of objects may have different types, the right visualization is chosen by the default template selector. This works fine and does not cause any trouble.
The issue that came up is the size of the window. The DataTemplates have different sizes. And I want the dialog to have a size that the largest DataTemplate fits. When I use SizeToContent in the Window, the Window changes its size everytime I change the tabs.
So, my questions is, how can I achieve to make the window fit the largest TabItem (which size is determined by the DataTemplate)?
thanks,
Florian
The problem you are having, is that because the larger DataTemplate is not shown, it's size is not taken into account when sizing to content.
Your options:
1) Manually set (min)width/height on appropriate controls (tabcontrol, Window, DataTemplate, etc)
2) If you know that a certain tab is always going to be bigger than the rest, you can bind the width/height of the other tabs to the bigger tab:
<TabItem>
<StackPanel Name="stackPanelBiggest" />
</TabItem>
<TabItem>
<StackPanel Width="{Binding ElementName=stackPanelBiggest, Path=ActualWidth}" />
</TabItem>
I think that for the above to work, the biggest tab has to be first one shown. Although the tab control destroys the visual tree of the previous tab when swithching to another tab, this method is still working for me (despite the fact that the ActualWidth should be 0 or NaN, after switching tabs).

WPF resizing TextBlock

I have a textblock in a grid in WPF.
I want the text to dynamically size (font) when resized. At the moment textboxes, comboboxes do this, but the the textblock stays the same. Is it possible?
Instead of trying to manually rig a TextBlock to do this, just edit the default template of a TextBox and remove the border and background, then in the style make it set the IsReadOnly flag. This way you get the textblock sizing, as well as copy-paste for free.
You can use a ViewBox for this.
eg:
<Viewbox Stretch="Uniform">
<TextBlock Text="Test" />
</Viewbox>
use expression blend for getting the default template of TextBox, then you can edit it as you required.

ListBox with ItemTemplate (and ScrollBar!)

I have a databound and itemtemplated ListBox:
<ListBox x:Name="lbLista"
ScrollViewer.VerticalScrollBarVisibility="Visible">
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal">
<CheckBox IsChecked="{Binding Deleteable, Mode=TwoWay}" />
<Label Content="{Binding Name}" />
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
The ites show fine and they come from an ObservableCollection.
The problem is the scrollbar which appears but is not usable - it does not have a handle to grab. I've tried setting some ScrollView attached properties on ListBox, but they do not affect the situation.
I pasted your code into test project, added about 20 items and I get usable scroll bars, no problem, and they work as expected. When I only add a couple items (such that scrolling is unnecessary) I get no usable scrollbar. Could this be the case? that you are not adding enough items?
If you remove the ScrollViewer.VerticalScrollBarVisibility="Visible" then the scroll bars only appear when you have need of them.
ListBox will try to expand in height that is available.. When you set the Height property of ListBox you get a scrollviewer that actually works...
If you wish your ListBox to accodate the height available, you might want to try to regulate the Height from your parent controls.. In a Grid for example, setting the Height to Auto in your RowDefinition might do the trick...
HTH
I have never had any luck with any scrollable content placed inside a stackpanel (anything derived from ScrollableContainer. The stackpanel has an odd layout mechanism that confuses child controls when the measure operation is completed and I found the vertical size ends up infinite, therefore not constrained - so it goes beyond the boundaries of the container and ends up clipped. The scrollbar doesn't show because the control thinks it has all the space in the world when it doesn't.
You should always place scrollable content inside a container that can resolve to a known height during its layout operation at runtime so that the scrollbars size appropriately. The parent container up in the visual tree must be able to resolve to an actual height, and this happens in the grid if you set the height of the RowDefinition o to auto or fixed.
This also happens in Silverlight.
-em-
Thnaks for answer. I tried it myself too to an Empty Project and - lo behold allmighty creator of heaven and seven seas - it worked. I originally had ListBox inside which was inside of root . For some reason ListBox doesn't like being inside of StackPanel, at all! =)
-pom-

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