How can I change the z axis of components and put one in front of the other? The new layout property in Flex 4 has changed significantly & now not sure how to do it.
It works the same way that it did in Flex 3. A components Z order is defined by the order in which they are placed as child of their parent. The second child will be in front of the first child, and the third child will be in front of the first and second child and so on.
You can still use swapChildren and swapChildrenAt to change the Z-order of children.
The layout property's value will be an instance of a Layout class; which--in a simple form your measure() and updateDisplayList() methods. IT does not, specifically, relate to moving one component in front of, or behind, another.
On a Flex 4 group, you can use swapElement and swapElementsAt, although I would bet if you were to examine the code you'd find that these are just layers of abstraction over swapChildren and swapChildrenAt.
checkout the new depth property introduced in Flex 4 e.g. see http://www.tink.ws/blog/flex-4-uicomponent-depth/
Maybe this help:
container's depth
you can use depth property of flex containers to define which element can overlap other elements.
Related
I am developing an isometric game.
I have a parent UIComponent (WorldMap). The player can choose MapElement s (game items) and drop them in the playable area WorldMap. This MapElement also is a UIComponent which contains child controls such as Sprite, Image, Label and custom Flex components to hold various information.
Now, I have written a logic to determine which one should appear in back and which one should appear in front in the Isometric area which I am calling idx (index) and I am seeting this value to the depth property of the MapElement.
I have added three components in the order shown in below pic and I have set the depth property each of them as 11077,11168 and 10630. If the depth property worked properly the 3rd item should have gone behind the 1st item but it seems like they are appearing in the order of they have added (default behavior)
If I am not wrong the depth value can be anything
Can some one help me?
I am aware of another solution using swapChildren, swapChildrenAt and and also addChildAt methods (which I don't want to use for my project specific reason) but I need to find out whats wrong with the depth
The problem, as I think, in your WorldMap component which, as you said, is UIComponent. Diving deeper to depth property shows that depth setter launches invalidateLayering method, which is empty in UIComponent and overrides with logic only in Group which is main container for every Flex 4 component. And here's example:
http://www.tink.ws/blog/flex-4-uicomponent-depth/
So, it looks like, you need to use at least Group or SkinnableContainer as your WorldMap in order to achieve depth property to work correctly.
Use UIComponent.addChildAt(child:DisplayObject, index:int). addChildAt adds a child DisplayObject instance to this DisplayObjectContainer instance. The child is added at the index position specified. An index of 0 represents the back (bottom) of the display list for this DisplayObjectContainer object.
Can anybody please tell me what about visible and includeInLayout properties of a component and what is the state of the component when they are in combination of {false,false},{false,true},{true,false}. Thank you in advance.
Ok, visible is only about visibility of component and includeInLayout is only about taking part in process of component's laying out. Talking about laying out we're talking about such layouts as vertical layout, horizontal layout or tile layout where positions of the children determines by positions of other children.
Well, according to this explanation false,false is about target display object will not visible and will not affect on the position of other objects in layout. It is the same as target display object isn't exist at all.
The case false,true describes the situation where target display object isn't visible but takes part in layout. For end user it is an empty space between other objects in layout. This space has the same dimensions as our target display object.
The case true,false makes target display object visible but with not predictable position (depends on the particular layout implementation). Anyway it is not affect other elements position which laying out the way as target display object doesn't exist. It is very likely some of the other element overlap our target display obje
How can I display one component on the top of another one in flex without explicitly mentioning x-axis & y-axis?
Use canvas and inside canvas you can add controls that will be displayed one above another, the last one added will be the top most one and first added will stay in behind.
Something else to consider, depending on your UI:
This is still a bit 'hacky' (any solution for doing this will be), but given a container (VBox etc) with two or more components, set the includeInLayout property in the first component to false. When the container renders the second component will ignore the first and draw on top.
This also would allow you to add additional components in that same container, but obviously it depends on your UI a great deal.
I want to create an MXML container component that has some of its own chrome -- a standard query display, et al -- and that supports the addition of child components to it. Something a lot like the existing mx:Panel class, which includes a title label, but acts like a plain mx:Box with regards to adding children.
What's the easiest way to do this?
Edit:
To be clear, I want to be able to extend the container using MXML, so the "Multiple visual children" problem is relevant.
Extend a container and add a title label. Probably the <mx:Canvas/> will work here. Make the title a public var and include a var for the styleName of the label.
Then override the addChild() method so that any child that is added is added instead to the that is your container.
Leave enough space for your title when you position your Box element (i.e., give its y property enough space. If there is no title you may want to reclaim that space.
That's the basics. Customize to your heart's content.
EDITED TO ADD: I do this creating an ActionScript class first, extending the container I am targeting, and I add the "furniture" — items the class will always use, like title in your case — by overriding createChildren and calling super.addChild(item) for those items. Calling addChild from then on, even in MXML markup, adds items to the inner container.
We do this with states.
We put the chrome for the base container in a state (in mx:AddChild elements) and then use the initialize event to switch to that state when the control is created. All the chrome is then added to the container.
That gets round the multiple sets of visual children problem.
The downsides to this approach are:
You don't see the chrome when editing descendents of the base.
You can't directly access the parent chrome controls from descendent components as they are not there at compile time (instead, you need to define properties, methods or events on the base that the descendents can access)
However, it works well for us.
What is the best way to change/set a registration point on a Flex 3 display object? I know this isn't really built in to easily change, but does anyone have any suggestions on how I could extend UIComponent to achieve this?
For some reason, the Flash Player API doesn't expose the registration point of DisplayObjects (and the Flash IDE makes them a pain to modify once an object is created). The best solution, as David pointed out, is to add your component as a child of another component (UIComponent would be fine). So, for example, if I had a Button and I wanted its registration point at its center, I'd add it as a child of a UIComponent (not Canvas) and offset the child by setting its position to (-button.width/2, -button.height/2).
Put your DisplayObject inside a sprite and set the DisplayObject's x & y positions to the negitive of your target registration point. Apply all transforms to the Sprite container.
Put it inside a Canvas container, with its clipContent attribute set to false. Within the canvas, you can put your object wherever you like.