TextBox ContextMenu usage improvement

[punker76]

What changed?

@Deadpikle created this PR Added more TextBox ContextMenu configuration #2758 which was a good idea to enhance the current ContextMenu implementation. I need some days to review theses changes and come to the conclusion that we don't need this extra attached properties to add some more context menu items to the default one and the spell checker items.

So here is my solution...

• If you want to use the default context menu items cut, copy and paste you must do nothing
• If you want to use your own context menu items without the default items you must do this

<TextBox Text="Yeahh">
    <TextBox.ContextMenu>
        <ContextMenu>
            <MenuItem Header="This is only a Test-Item" />
        </ContextMenu>
    </TextBox.ContextMenu>
</TextBox>

• If you want to use your own context menu items with the spell checker items then you must do this

<TextBox Margin="{StaticResource ControlMargin}"
         Controls:TextBoxHelper.IsSpellCheckContextMenuEnabled="True"
         Text="Enabled">
    <TextBox.ContextMenu>
        <ContextMenu>
            <MenuItem Header="This is only a Test-Item" />
        </ContextMenu>
    </TextBox.ContextMenu>
</TextBox>

• If you want to use your own context menu items with the deafult items then you must do this

<TextBox Controls:TextBoxHelper.ClearTextButton="True"
         Controls:TextBoxHelper.UseFloatingWatermark="True"
         Controls:TextBoxHelper.Watermark="Watermark">
    <TextBox.ContextMenu>
        <ContextMenu>
            <MenuItem Header="Custom Item" />
            <Separator />
            <MenuItem Style="{DynamicResource MetroMenuItem}" Command="ApplicationCommands.Cut" />
            <MenuItem Style="{DynamicResource MetroMenuItem}" Command="ApplicationCommands.Copy" />
            <MenuItem Style="{DynamicResource MetroMenuItem}" Command="ApplicationCommands.Paste" />
        </ContextMenu>
    </TextBox.ContextMenu>
</TextBox>

[thoemmi]

I like that. I was unsure about the changes proposed by @Deadpikle, because it solved a very special use case. @punker76 your solution is much more general, which I prefer.

[Deadpikle]

@punker76 Yeah, that's a much better solution. Thanks!