CategoryAttribute in c++/CLI - c++-cli

I read code and fuond the word CategoryAttribute.
What is a CategoryAttribute in c++/cli?

While I think it's clear, I have a few seconds to answer.
It's a CLR attribute class (a modifier available through reflection) that specifies which category/grouping the property should be listed under in a property grid view. Like when you're editing a form, the thing that you change values in like Text, Size, Docking, etc.

Related

Colorize using tokenizer on Monaco editor

I am trying to add different foreground colors using regular expressions for a method, property, and variable reference on Monaco editor using tokenizer.
Example:
Name="Hello"
var.Name()
var.Name
In these examples, Has anyone found a way to colorize "Name" differently based on how it is being used? In the first example, it is referenced as a variable. In the second example, it is referenced as a method of an object, and the third example is a property of an object.
Even though method, property, and variable are the same name, I want to colorize different foreground colors to "Name" using tokenizer on Monaco editor**.
Your suggestion would be greatly appreciated. Thanks in advance.
What you are after is called "semantic highlighting" (in opposition to syntax highlighting) and the monaco-editor component alone cannot do that.

Overriding one property for a hierarchy of classes

I have a hieraarchy of classes. Root class is abstract, and is called Contact, and it has a property DisplayName. On GUI I have a dropdown where various contacts are listed, using their DisplayName property.
I have no acess to source code of those classes.
I want to somehow override Contact.DisplayName property, to make it display something else in my particular scenario. I can not just create subclass of Contact and override property there, because there is whole hierarchy under Contact class. Is there a way to alter a property for whole hierarchy of classes ? Maybe using delegates ?
I am using exotic programming language called Gosu, but the solution based on some common object oriented language could help me a lot too.
I haven't tried but maybe with Enhancements. I'm not sure that it works because DisplayName it's a property of entities.
Update:
There is a folder in Guidewire Studio, configuration/config/Entity Names. Open Contact.en and there is you can customize the DisplayName.
Can you type cast the Contact entity to its subtype and try to display it in GUI. Something like (Contact as Person).DisplayName

Changing a oneway bound TextBlock value from code behind.

I have a TextBlock and its Text property is bound to a ViewModel property. The binding is Oneway.
When I change the Text property of the Control from the xaml.cs the binding gets broken. If the binding is TwoWay I don't have this problem but the source property is updated too. Is it possible to have OneWay binding and change the target property value without braking the binding?
I suggest a workaround, like setting the Binding to TwoWay and ignore the update in the property. Something like this:
private string textValue;
public string TextValue
{
get { return textValue; }
set
{
:
}
}
Now the Property can no longer be set by the view.
Although no code is provided, this scenario typically occurs when you have bound a control to a view model and at a later stage your logic tries to update the value in the control programmatically.
You should not try to do this, that is define multiple sources of the value for a control. If you bind the control to a property on the view model, then to update the value in the control you should update the field in the view model.
If you were to set the value of a bound control programmatically at runtime so that it no longer matched the bound object value, when some other event causes the control binding to be re-evaluated, the value that you have provided programmatically would be overwritten again, you could easily end up with a scenario where the value you provided programmatically is never visible to the user.
In this scenario you should either:
Add a new property to the view model, bind this value to the control, then your program logic can set this value equal to the original property when the data is loaded, and updated when you need to
Not use bindings at all, always write to the control programatically that way you tightly control when the value is updated.
There is a workaround to this if you absolutely must have one. if you are using compiled bindings (x:Bind), then because the bindings are compiled it is possible to call SetValue on the bound dependency property at runtime and the previously compiled bindings will still be evaluated. However I advise against exploiting this because it makes your code a lot harder to follow and debug, when bindings are used, we tend not to look for code that directly addresses and sets control values.

Yii - Cactiveform, cform, form builder - confusion

Those are three concepts on Yii that I really don't get what should we use, on what scenarios?
Can anyone be kind enough to clarify those Yii elements, and on what situation should we use them?
In documentation of CForm one can read the following:
...we can divide a form
in two parts: those that specify each individual form inputs, and
those that decorate the form inputs. A CForm object represents the former part...
...and CActiveForm represents the latter.
In other words, CForm specifies elements of the form but CActiveForm (being a widget) renders it.
Looking at the source code we state that CForm can also render() itself and its rendering relies on and is wrapped by CActiveForm widget by introducing its configuration property activeForm, though rendering input elements and buttons is implemented by its own methods renderElements() and renderButtons() relatively. By default their implementations rely on classes using CHtml's static methods what is exactly the same (or almost exactly the same) what CActiveForm's rendering methods do. Of course, default behavior can be overriden by extending the class.
That's why it's the question of a taste which technique to use: CActiveForm widget alone combining form fields' and buttons' declaration with their representation in a view file by calling convenient (required) methods of CActiveForm instance or CForm class declaring form's input specifications in a separate configuration file and customizing its rendering by pointing at appropriate active form widget and/or by overriding default rendering methods. The latter technique allows to reuse a form in several actions easily and is no more than using form builder.
Check here for live examples of ActiveForm, CForm, et cetera. You can also see the live Model, View & Controller files.

How to correctly inherit from a usercontrol defined in XAML in Silverlight

If I have a usercontrol (in Silverlight) that I've written, that uses XAML to define it's appearance, how can I make a customised version of it?
i.e. I have MyControl.xaml & MyControl.xaml.cs
What do I need to do if I want a "SpecialisedControl" child class? I assume I just make a new code file, then inherit from MyControl. But what if I want to change the appearance of the base class - then what do I do?
I wrote this thinking you were talking about WPF, rather than Silverlight, but there may be enough overlap for this to be helpful, so I'm posting it, anyway.
If by "change the appearance of the base class" you mean "provide a new template", then what you need is probably a CustomControl, not a UserControl.
The best way to accomplish this is to follow the example set by other Microsoft controls, such as Button or ListBox:
Create a class that derives directly from Control (or whatever is closest to your control).
If any properties will need to be exposed to the control (such as text on a button, for example), make sure that you properly define them as DependencyProperties.
As described here, create a ResourceDictionary called Themes/generic.xaml and add a style for your class that includes a template (don't give the style a key).
Use TemplateBindings for any properties of elements on your control that need to get values from your control.
If you'll need to attach any event handlers to elements in your template, give them a unique name. Microsoft uses the convention of prefixing these names with "PART_", and I think it's a good thing to do for the sake of consistency, but it's not strictly required.
Again, if you need to attach event handlers, overload OnApplyTemplate(). In this method, you should detach any old event handlers (we certainly don't want any memory leaks!), and look for elements that have the names your provided in your template--when you find them, attach event handlers, as necessary.
This is certainly much more work than simply deriving from UserControl, but if you want to be able to totally re-template controls, like you can with the built-in controls, this is the way to do it.
On the other hand, if all you want to do is to provide a certain amount of limited customization, such as changing the background, or associating a Command with some user action, then the best thing to do is to expose DependencyProperties, which can then be set in styles for your control, or on instances of your control, itself.
In the case you mentioned of wanting to customize the look in an inherited control, the process is pretty similar: just add a default style for the new control with a new template; if you need to add more event handlers, just be absolutely certain that you call base.OnApplyTemplate().
I dunno, I like doing things with just plain objects. Here's an article that describes an easy way to slip a XAML-designed control outside your inheritance hierarchy so that you can customize appearance and behavior using SimpleThingsLikeInheritance rather than MicrosoftStuffThatAlmostWorks
http://gen5.info/q/2009/02/10/subverting-xaml-how-to-inherit-from-silverlight-user-controls/
As Mihnea's link describes, the easiest solution is to simply add a namespace in your XAML:
C#
public class MyBase : UserControl
{
}
public class FirstUserControl : MyBase
{
...
}
XAML
<local:MyBase
x:Class="FirstUserControl"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:local="YourAssembly" ...>
<!-- Sticking with UserControl instead of local:MyBase makes this clearer -->
<UserControl.Resources>
<ResourceDictionary>
<ResourceDictionary.MergedDictionaries>
..
</ResourceDictionary.MergedDictionaries>
</ResourceDictionary>
</UserControl.Resources>
..Your XAML
</local:MyBase>
You can solve this by using a wrapper as described in the link above.
But you can also use the strategy pattern to solve this problem.
In this post I explain how you implement these two methods.
http://www.lab101.be/2008/07/silverlight-usercontrol-inheritance/