You probably think that it is a duplicated question but i don't need you to find an error, all i need is a decent explanation of why isn't that possible. A rough description of my problem is that i am trying to call a method to an instanced object. Specifically instance of the JavaFx UI component.
Exactly :
vbox.getChildren().addAll(new Label("1").setTranslateX(100), l2);
All i want is not to intialize and set values many times like this :
Label l1 = new Label("1");
Label l2 = new Label("2");
l1.setTranslateX(0);
l1.setTranslateY(108);
l2.setTranslateX(0);
l2.setTranslateY(121);
If anyone knows if it is possible i would like to see this solution. Thanks in advance.
While trying to produce a minimal example for the investigation of another issue with ReactFx's Var bindings, I stumbled into some IMHO strange implementation of JavaFX's properties. I am trying to use a SimpleIntegerProperty as an argument for a function expecting a Property<Integer>. However, this does not compile becauseSimpleIntegerProperty does not implement this interface. Instead, it implements Property<Number>. I find it strange that I cannot assign Property<Integer> p = new SimpleIntegerProperty(), as in the following code:
javafx.beans.property.Property<Integer> p;
javafx.beans.property.SimpleIntegerProperty s;
p = s;
I understand why this does not work given the current inheritance hierarchy, but it feels strange and I am looking for the motivation behind the design.
In a designer-based QT GUI application I'm using a QTreeView to show a tree of elements that is provided by an instance of QStandardItemModel.
The tree-view is multi-column and all elements in the first column are checkable. The screenshot shows an example of how this currently looks like:
Now let's say I'd like the user to be able to select different names for "point". The idea is to have a QComboBox right next to each of the checkboxes. And as alternatives to "point" he may chose from a set of strings, e.g. "point", "pt" and "coord2D". Later on I'd like all selections for all duplicates of "point" to be synchronized but let's start simple...
I'm not too familiar with the idea but to me it looks like the way to go is to create an ItemDelegate for the view as described in the QT Documentation or in this topic (both links refer to QTableWidgets instead of QTreeViews).
So what I did as a first step is I took the example delegate ComboBoxDelegate from the stack overflow question mentioned above and called it from within my application using this code also taken from a related question:
QStandardItemModel* model = new QStandardItemModel(20,2);
ui.tvStructures->setModel(model);
ui.tvStructures->setItemDelegate(new ComboBoxDelegate());
for (int row = 0 ; row < 20; ++row)
{
for (int col = 0; col < 2; ++col)
{
QModelIndex index = model->index(row, col, QModelIndex());
model->setData(index, QVariant((row+1) * (col+1)));
}
}
Note that I placed this code inside the constructor of the parent QDialog where the control element is located. What I ended up is a 2-column table as expected but without any combo boxes. In fact when debugging the code I observe that the constructor of the delegate is called (during the new operation) but none of createEditor, setEditorData, setModelData or updateEditorGeometry every get called. I thought this may be due to the fact that some connection magic is overwriting triggers required to do the drawing but even if I remove all code that refers to the tvStructures QTreeView apart from what I have posted I still can't see any combo boxes.
What's missing?
Note that I'm using the somewhat outdated QT 4.7.1
Looks like you're missing a parent for new QComboBoxDelegate. You can use the QDialog you mentioned as parent.
Also: follow this lengthy example to make sure you're not missing anything else.
I have a grid with bunch of columns in it. To start with this grid is build during run time in the code behind and not much code in XAML except the generic grid, so I can't bind the column background during design time. I have been reading various blogs, questions and found the following as the closest answer.
SolidColorBrush backgroundBrush = new SolidColorBrush();
Binding b = new Binding("BackGroundColor");
b.Converter = new ColorConverterForReadOnly(); //This converter return color based on parameter
b.ConverterParameter = data;
BindingOperations.SetBinding(backgroundBrush, SolidColorBrush.ColorProperty, b);
column.Background = backgroundBrush;
When I ran the code, the binding did not happen, I put a break point (in the first line) inside the converter to see if debug hits the converter at all and it did not hit the converter at all. If I would put
column.Background = new SolidColorBrush(Colors.Blue)
I can see the the column colors set to blue.
What am I missing in the binding that is not letting converter invoked?
Thanks,
The binding is targeting a "BackGroundColor" property. For the binding to be hit, the DataContext of the column control would need to be an object that has a "BackGroundColor" property.
I am trying to duplicate a flex component at run time.
For example if i have this
mx:Button label="btn" id="btn" click="handleClick(event)"/>
i should be able to call a function called DuplicateComponent() and it should return me a UI component thts exactly same as above button including the event listeners with it.
Can some one help me please??
Thanks in advance
Do a Byte Array Copy. This code segment should do it for you:
// ActionScript file
import flash.utils.ByteArray;
private function clone(source:Object):*
{
var myBA:ByteArray = new ByteArray();
myBA.writeObject(source);
myBA.position = 0;
return(myBA.readObject());
}
One note, I did not write this code myself, I'm pretty sure I got it from a post on the Flex Coder's list.
To solve that problem you should use actionscript and create the buttons dynamically.
Lets say you want the button(s) to go in a VBox called 'someVbox'
for (var i:uint = 0; i< 10; i++){
var but:Button = new Button();
but.label = 'some_id_'+i;
but.id = 'some_id_'+i;
but.addEventListener(MouseEvent.CLICK, 'handleClick');
someVbox.addChild(but);
}
I haven't tested it, but that should add 10 buttons to a vbox with a bit of luck.
You can't take a deep copy of UIComponents natively. You're best bet would be to create a new one and analyse the one you have to add a duplicate setup. To be honest this does sound like a bit of a code smell. I wonder if there may be a better solution to the problem with a bit of a rethink..
Same question as: http://www.flexforum.org/viewtopic.php?f=4&t=1421
Showing up in a google search for the same thing. So you've cut&pasted the same question a month later. No luck eh?
There is no easy way to do this that I know of. Many of a component's settings are dependent on the container/context/etc... and get instantiated during the creation process, so there's no reason to clone from that perspective.
You can clone key settings in actionscript and use those when creating new elements.
For instance, assuming you only care about properties, you might have an array ["styleName","width","height",...], and you can maybe use the array like this:
var newUI:UIComponent = new UIComponent();
for each(var s:String in propArray) {
newUI[s] = clonedUI[s];
}
If you want more bites on your question (rather than waiting a month), tell us what you are trying to achieve.
mx.utils.ObjectUtil often comes in handy, however for complex object types, it's typically good practice to implement an interface that requires a .clone() method, similar to how Events are cloned.
For example:
class MyClass implements ICanvasObject
{
...
public function clone():ICanvasObject
{
var obj:MyClass = new MyClass(parameters...);
return obj;
}
}
This gives your code more clarity and properly encapsulates concerns in the context of how the object is being used / cloned.
You are right but as per my understanding UI Components are not cloned by mx.utils.ObjectUtil.
from : http://livedocs.adobe.com/flex/201/langref/mx/utils/ObjectUtil.html#copy()
copy () method
public static function copy(value:Object):Object
Copies the specified Object and returns a reference to the copy. The copy is made using a native serialization technique. This means that custom serialization will be respected during the copy.
This method is designed for copying data objects, such as elements of a collection. It is not intended for copying a UIComponent object, such as a TextInput control. If you want to create copies of specific UIComponent objects, you can create a subclass of the component and implement a clone() method, or other method to perform the copy.
Parameters value:Object — Object that should be copied.
Returns Object — Copy of the specified Object