I found a task which says that:
SWING does not contain component which implements separator (vertical or horizontal) depending on toolbar orientation. By inheriting JComponent, make component which has that implementation, and take into assumption that its parent should always be JToolbar component.
Would someone mind explaining to me how separator does not depend on toolbar orientation? I thought that by specifying in JToolbar constructor how should orientation be made, I already do that. (I'm using addSeparator() method from JToolbar class, not JSeparator)
Related
I have an application that switched between different graphs in Flex. Each graph is it's own state. In the MXML I have it set so that the source of the image change when the state changes:
<s:Image id="chartImage"
source.all="{ callImages.all }"
source.classA="{ callImages.classB }"
source.classB="{ callImages.classA }"
/>
I have buttons that successfully change the images. However, I have a small bug which occurs because after the line
this.currentState = chartName;
My code expected the graph image source to be changed, however the actual change to the s:Image element doesn't appear to happen until after the function ends and the screen updates, I assume. So when it grabs chartImage.height, it uses the old one from the state I just left.
Is there a way to have it get the new image (and thus it's dimensions) so I can do calculations with those dimensions on the next line? So far, chartImage.height returns the height from before the state change, but it is different after the function executes.
I could run a timmer after a fraction of a second then execute the lines there, and it would work. However, I'd rather tell it to render the screen and then continue my code. Is this possible? It just seems more elegant.
Is there a way to have it get the new image (and thus it's dimensions)
so I can do calculations with those dimensions on the next line?
Each Flex component must go through it's own validation cycle, which is built on top of the Flash Player's rendering mechanism. There are some great posts out on this, if you perform a Google search for the Flash/Flex Elastic Racetrack.
However, you can force a component to run through it's validation methods in a linear manner by calling the validateNow() method.
It is possible--especially if you have a state transition--that the properties on your Image have not changed yet after you set the currentState variable.
You generally can't change the source of an image in Flex and then immediately check ("on the next line") it's height — the exception might be when the source is a raw bitmap, but even then Flex's layout framework will vary depending on different factors so I wouldn't rely on this.
This is the classic problem with Flex: the beauty (and misery) of the framework is that it progressively renders it's changes to maximize the responsiveness of the app. Google "flex component life cycle" for a ton of resources about the details of this process.
There are a couple of ways to deal with this. Usually you'll want to use binding expressions, since they are designed for exactly this reason: asynchronous layout changes. Don't overuse them but they are a solid tool to keep the codebase simple and flexible.
You can bind to the height of a SparkImage via mxml:
<s:Image id="chartImage" />
<s:Label id="debugLabel" text="{ 'Height of chartImage: ' + chartImage.height }" />
but if you need to run logic I'd recommend using the BindingUtils (in the script block):
import mx.binding.utils.BindingUtils;
protected function someOtherFunctionBlock():void
{
BindingUtils.bindSetter( handleHeigtChange, image, "height" );
}
protected function handleHeigtChange( value:Number ):void
{
// Deal with value change
}
I have my own custom component. This component extends from a basic container. I want to be able to access the itemRenderer instances that are being visualized. I know that the component mx:list has an internal getter that provides an array of Arrays containing the itemRenderer instances that render each data provider item. I want the same thing. Any idea how of how to do that?
To be more specific: I am setting the selected property of my dataProvider items to true or false. From the updateDisplayList funcion of my ItemRenderer I check for changes of the property and correct the border color of the selected ones. Unfortunately I have to force the updateDisplayList function. I already did this once on a ItemRenderer from a list. Only with the list it was practical because by making my own list I was able to get the list of items being rendered and therefore visualized (cannot be many). It was no overhead to go trough the rendered Items and updateDisplayList. But in this case I can have 100 items. Imagine checking and changing styles on so many items. Thanks
The Flex architects intentionally made this difficult to do, because they are properly encapsulating the component. In short, to even try to do this is a violation of good OOP principles.
That said, about 90% of the things you are probably trying to do can be done by manipulating the data item, and the remaining 10% can be done by using a ClassFactory for your itemRenderer that sets a custom property on your itemRenderer to a callback where you can look at the data available to the containing context and provide back a value based on that.
If you elaborate a bit more on your end goal, I can give you more specifics.
Edit in light of clarification:
You need to make your data object class dispatch an event when it changes (one way is to make it bindable, or just make the selected property bindable). Then, in your renderer, listen for the change event and take the appropriate action.
A second way to handle this would just be to refresh() the collection, storing the selectedItem first (if you care about that) and resetting it once the refresh has finished.
I believe you can access the itemRenderer instances through getChildAt method. Flex 3's container overrides "getChildAt", "numChildren", given that some children are logical children, while some are decorative children such as background, border and scrollbars.
Keep in mind that itemRenderer may not right away become available upon dataProvider assignment, as they may be created during the next component lifecycle. Check with the underlying container's documentation and find out which event to be listened when the renderers are surely created, so you can reliably access them.
Having read many tutorials, articles and questions, I am still have confusions about updating the GUI. Plus there are numerous related questions here on this website and still no luck - even though I think my problem is very simple.
Basically, I have a JFrame that has a JLayeredPane as its root container. And I have some layers of JPanels inside it.
The main issue is with updating a particular JPanel in this JLayeredPane. And for this particular Panel, I have implemented an update method that changes the contents inside it.
updatePanel(int para)
//doesn't remove this panel
//removes some existing labels and replaces it with new ones
Once I create the whole Frame, obviously just calling this method won't show any change displayed the frame.
private void static main (String[] args){
WindowFrame frame = new WindowFrame()//WindowFrame extends JFrame
frame.updatePanel(2);
.....
.....
}
And that's where I am stuck. I want to update the contents as the frame is displayed.
I saw these methods mentioned by people but due to nature of problems, I couldn't fully grasped the concepts. Plus the documentation on these methods isn't really helping - at least to me.
revalidate()
validate()
repaint()
How/when should these methods should be called? Or is this not the right way of what I should be doing, given these methods and the problem I am trying to solve?
Thank you for your time.
Basically you need two methods:
revalidate()
This method does the same as invalidate() but in AWT event dispatching thread (i will just call it Swing thread later on)). It updates container and all of its ancestors (parent containers in which this one is placed) layouting.
Basically if you either move something inside this container or place/remove components inside of it you should call this method (or invalidate in case you are performing it in Swing thread, for example inside any Mouse/Action listener body or just inside).
repaint()
This method forces component, all its sub-components (if it has them) and parent container (basically if this component is NOT opaque) to update what they are "painting".
Usually you don't need this method since all standard Swing components know when to repaint themselves and they do it on their own (that ofcourse depends on components UIs and some other things). This method might be useful in case you have your own specific components with some unique painting-way (for e.g. some custom selection over the components) and in some rare problematic cases with standard components.
Also the way this method acts depends on the components placement (due to some Swing painting optimizations) - if you have some massive repaints rolling you'd better optimize them to repaint only those parts (rects) that you actually need to repaint. For example if you change the component bounds inside any container the best choice is either to repaint its old bounds rect and new bounds rect OR repaint rect that contains both of those bounds, but not the whole container to avoid repainting uninvolved in the action components.
So, basically in your case after some changes with panels you should call revalidate on their container (or invalidate) followed by repaint (in case revalidate leaves some visual artefacts) again for the container.
Guess i didn't miss anything and i hope that now you know the basic meaning of those methods.
revalidate at the end of your update method like so .
updatePanel(int para){
.....
.....
this.revalidate(); //of course this refer to the panel
parent.revalidate(); // parent refer to the window
}
I have various components that are skinned through a programmatic skin. The skin class references a singleton class that holds various colors to be applied to different aspects of the component. The singleton class has default colors set to variations of black/grey etc. I'm loading in custom colors from an XML file that are then loaded into the singleton. I'm applying the custom skin through a css stylesheet that is included in the main Application mxml.
The problem is that when the swf initially loads, the components that are drawn on screen are black and don't reflect the changes in color loaded from the XML file. I have some dropdown windows that show on button clicks and those dropdowns do reflect the correct colors from the XML file. Therefore, the system is working correctly, but the initial drawing of components obviously happens before the XML is loaded and applied to the singleton.
My question is, is there a way to apply a skin to an element programmatically by calling the constructor?
I have this in my css file:
.PanControlsBackground {
borderSkin:ClassReference('skins.buttons.PanControlsBackground');
}
and I'm applying the class with this:
_app.panControls.styleName = "PanControlsBackground";
Is there a way to call:
_app.panControls.styleName = new PanControlsBackground();
or something to that effect? This way, I can remove the loading of the skins in the css file and control when they are instantiated to ensure that the correct colors are applied before displaying the various components.
You could use the styleManager to manipulate the style at run time. For example,
.PanControlsBackground {
/* leave it blank */
}
And then in some script block:
styleManager.getStyleDeclaration(".PanControlsBackground").setStyle("borderSkin", skins.buttons.PanControlsBackground);
So, that's one way of changing the skin in a programmatic way.
However, I don't know much about how the garbage collection is handled on the old skins. For instance, how would the GC differ on this method of switching the skin versus just having a bunch of different CSS classes for each of your skins and switching between them? I can't really answer that.
I think one could at least say that the above method would ensure that the default (or other minimal skin you might create) is used first, and one could control when in the initialization process the other skin get's instantiated.
I'm having an issue with Movieclips inside my Swf resizing to the wrong dimensions. I'm currently tracing the width of the offending clip every half second, and I can see the value change to an incorrect size at some interval in the logged output. I really want to see what code is changing the width. My plan was to extend Movieclip, override the set width property, and dump a stack trace when the value set is too low. This isn't so simple however. Flash is complaining about undefined reference to UI components that are on the Movieclip fla.
Is there a simple way to find out when/why this value changes? I cannot use a debugger.
edit:
The reason I cannot just extend MovieClip is because I am getting my Movieclip object from Event.currentTarget.content after using a Loader. I cannot point my Test (extends MovieClip) object at this return value because it is illegal to do so.
I'll explain the problem a little more and maybe someone will have another idea. I have an app with lots of different windows. They all open to a size of around 750x570. One of these windows contains a FusionChart. when I load this, according to my trace, the background Swf I am using changes to a dimension of about 2712x1930. This doesn't make sense to me because it looks the same size as before and at those dimensions it wouldn't even come close to fitting on my screen. If I then close the window and open another, the new window is tiny, but says it has the same dimensions as the original windows (750x570).
It is almost as if the window is scaling to the huge 2712x1930 without showing a change in size, and then showing the next window (750x570) as a size relative to what the huge window would look like. If that makes sense...
Maybe using a Proxy?
The Proxy class lets you override the default behavior of ActionScript operations (such as retrieving and modifying properties) on an object.
If you can see the trace you are doing and use a debug version of the flash player, try to override the property you want to check and trace the calling stack stack within the Error object:
public class Test extends Sprite() {
// property to watch
override public function set x(value:Number):void{
super.x=value;
// trace the calling stack work only in the flash debug player
trace((new Error()).getStackTrace());
}
}
what do you mean by "Flash is complaining about undefined reference to UI components that are on the Movieclip fla."?
your idea is absolutely the right solution in general... assuming the property doesn't change from within the runtime (which is rare, unless those properties are calculated) ...
when it comes to width and height, they are the two worst properties in the flash player API ... for reading, they are calculated by the space needed by a DisplayObject in parent coordinate space (if you rotate a DisplayObject, than these properties change). for writing, they actually forward to scaleX and scaleY ...