I am creating a canvas in actionscript like :
private var cvs_preview:Canvas = null;
private function show_preview():void
{
this.cvs_preview = new Canvas();
this.cvs_preview.id = "cvs_preview_1";
this.cvs_preview.setStyle('backgroundColor', 0x000000);
this.cvs_preview.setStyle('backgroundAlpha', 1);
this.cvs_preview.setStyle('borderColor', 0x417FDD);
this.cvs_preview.setStyle('cornerRadius', 10);
this.cvs_preview.setStyle('borderStyle', 'solid');
this.cvs_preview.setStyle('dropShadowEnabled', true);
var pt:Point = image.localToGlobal(new Point(image.x, image.y));
this.cvs_preview.x = pt.x - 50;
this.cvs_preview.y = pt.y - 50;
this.cvs_preview.height = 200;
this.cvs_preview.width = 250;
//this.cvs_preview.addEventListener(FlexEvent.CREATION_COMPLETE, get_focus_on_canvas);
//this.cvs_preview.focusManager.setFocus(
//this.cvs_preview.addEventListener(MouseEvent.CLICK, end_preview_on_focus_change);
this.cvs_preview.addEventListener(FocusEvent.MOUSE_FOCUS_CHANGE, end_preview_on_focus_change);
Application.application.addChild(this.cvs_preview); //add as top-most visible container
btn_mini_preview.enabled = false;
}
So on the focus change i want to run the "end_preview_on_focus_change()"
but this is not working.
As per my understanding, i think the canvas not getting any focus in the first place. I was trying to use focusManager.setFocus to do that after the canvas's creation complete. but even that is giving me an error.
the code i was trying on Creation.Complete is :
private function get_focus_on_canvas(e:FlexEvent)
{
focusManager.setFocus(e.target);
//Alert.show("testing img complete");
}
this is giving me an error "1118: Implicit coercion of a value with static type Object to a possibly unrelated type mx.managers:IFocusManagerComponent."
basically i just want to use the focus out event of the canvas.
Can someone help me with this...
I have been on this issue since a long time.
Regards
Zeeshan
The error is correct. You have an object of type Object which you are trying to use as an IFocusManagerComponent. This will not work. To accomplish that line of code, you need to do something like
focusManager.setFocus( IFocusManagerComponent( e.target ) );
This, of course, assumes that the target implements IFocusManagerComponent. It will give you an error otherwise (and likely will in this case because Canvas is not listed as an IFocusManagerComponent). The good news is that Canvas does have a drawFocus method which will accomplish the same thing.
As to your MOUSE_FOCUS_CHANGE event, that will only be fired if an object already HAS focus and then loses it. I think you are better off using FlexEvent.CREATION_COMPLETE. This will ensure that the component has registered itself with all of the appropriate classes in the Flex SDK so that the FocusManager can even be aware of the new object. Whatever you do, do not try to set focus on something which has not been added to the stage (ie: Event.ADDED has been called).
As another piece of advice -- Event.ADDED bubbles, make sure that event.currentTarget == event.target to make sure that you are listening to the correct object. Otherwise, you might be calling the same function multiple times erroneously.
Only a few classes implement IFocusManagerComponent as others mentioned and Canvas is not one of them. If you really must call FocusManager.setFocus() you will have to extend the canvas class to implement this interface and use that class instead. You don't have to write any methods to implement this interface, all methods have already been implemented by UIComponent itself
//FocusableCanvas.as (include appropriate package and import statements)
public class FocusableCanvas extends Canvas implements IFocusManagerComponent
{
public function FocusableCanvas()
{
super();
}
}
//Now use this class instead of Canvas
this.cvs_preview = new FocusableCanvas();
//setFocus in creation complete handler
FocusManager.setFocus(IFocusManagerComponent(e.target));
But if all you want to do is to set focus on the canvas upon it's creation, you can call canvas.setFocus() from the creationComplete handler instead.
private function get_focus_on_canvas(e:FlexEvent)
{
Canvas(e.currentTarget).setFocus();
trace("done");
}
I see two problems, and no perfect solutions. With any luck, this can help you out.
First of all, e.target returns an object typecast with type Object. This explains your implict coercion error, because Object does not implement IFocusManagerComponent.
Second, iFocusManagerComponent is only implemented by Accordion, AdvancedListBase, Button, ButtonBar, ChartBase, ComboBase, DateChooser, DateField, HTML, ListBase, MenuBar, NumericStepper, TabNavigator, TextArea, TextInput, UIMovieClip as per this entry in the Flex 3.4 AS3 Reference.
This leads me to believe that a Canvas element cannot take focus and has simply inherited access to the FocusManager through inheritance of UIComponent.
The only solutions I can see are to utilize something other than Canvas to handle your focus related concerns, or subclass Canvas and implement iFocusManagerComponent, though that looks fairly complex.
Edit
Apologies for missing drawFocus in the above solution.
Please try;
private function get_focus_on_canvas(e:FlexEvent)
{
this.cvs_preview.setFocus();
}
Related
I am using view stack...so when view change like when we move from one page to another hide event is dispatched.So i am saving the information of last page in hide event before i go to next page.but thing is that if i change nothing still change on view hide event is invoked nd call go to backend...i just want do call only if sumthing change in the view..like sum text value...So i have two options
use event listener on each component if sumthing change its make the flag true...nd hide event check, if flag is true send call to backend.
event listener at container level ..if sumthing change in child componenet through bubbling container knows if sum event is dispatched.nd makes the flag true.
I have doubt with container...
Can i use container, and how?
Reason why I can't use container?
What are the pros and cons either way?
I would recommend using a dataProvider with the ability to compare them. For instance, if you are changing things with textinputs, you could basically do something like this:
[Bindable]
private var myDataProvider:Object = new Object();
private function creationCompleteHandler():void {
myDataProvider.updated = false;
myDataProvider.defaultValue = 'default';
myDataProvider.defaultValueTwo = 'default';
}
etc.
Then, in your mxml, you can have something like this:
<mx:TextInput id="myText" text="{myDataProvider.defaultValue}" change="myDataProvider.defaultValue=myText.text; myDataProvider.updated=true;" />
Lastly, in your hide event, you can do the following:
private function hideEventHandler( event:Event ):void {
if( myDataProvider.updated ){
// Call your RemoteServices (or w/e) to update the information
}
}
This way, when anything changes, you can update your dataProvider and have access to the new information each time.
Hope this helps!
I've used an approach similar to your first option in a couple of my past projects. In the change event for each of my form's controls I make a call to a small function that just sets a changesMade flag to true in my model. When the user tries to navigate away from my form, I check the changesMade flag to see if I need to save the info.
Data models are your friend!
If you get in the habit of creating strongly typed data models out of your loaded data, questions like this become very basic.
I always have a key binding set to generate a code snipit similar to this...
private var _foo:String;
public function get foo():String
{
return _foo;
}
public function set foo(value:String):void
{
if(_foo == value)
return;
var oldVal:String = _foo;
_foo = value;
this.invalidateProperty("foo", oldVal, value);
}
If your data used getters/setters like this, it would be very easy to validate a change on the model level, cutting the view out of the process entirely.
I want my data grid to behave by default as if the user is holding the control key down. So when an item is clicked, then another item they are both part of the selection, clicking them again removes them from the selection.
I already have allowMultipleSelection = true but I can't seem to find any setting that does this. I'm working on the itemclick event in the meantime, but it seems like there might be an easy to use setting I'm missing.
Any thoughts?
You could also extend DataGrid and override the selectItem method like so:
override protected function selectItem(item:IListItemRenderer, shiftKey:Boolean, ctrlKey:Boolean, transition:Boolean = true):Boolean
{
return super.selectItem(item, shiftKey, true, transition )
}
Less code and less likely to have impact on other elements that might be listening for that MouseEvent.
You could try adding event listeners to the grid for MouseEvents (UP and/or DOWN) with the highest priority, stopping propagation, and redispatching a new MouseEvent with the same properties on the original event.target but this time with ctrlKey=true.
I'm not sure if it'll cause 10,000 other things to break.
I tried Nalandial's idea but had no luck...can't really intercept those events, but it got me going in the right direction. Worked a lot on this then found that the solution was a lot simpler than I was making it. I just needed to extend the dataGrid class and override two functions (mouseDownHandler and mouseClickHandler) adding the ctrlKey = true there then calling the rest of the function workes perfectly. In case you want to implement it, here's the code:
package com{
import flash.events.MouseEvent;
import mx.controls.DataGrid;
public class ForceCtrlDataGrid extends DataGrid{
public function ForceCtrlDataGrid(){
super();
}
override protected function mouseClickHandler(event:MouseEvent):void{
event.ctrlKey = true;
super.mouseClickHandler(event);
}
override protected function mouseDownHandler(event:MouseEvent):void{
event.ctrlKey = true;
super.mouseDownHandler(event);
}
}
}
I have a quite large Flex application with a large set of views and I ceratain views I'd like to add shortcuts.
And i'm looking for something like:
<mx:Vbox>
<foo:Shortcut keys="ctrl+s" action="{bar();}"/>
....
</mx:VBox>
Is there any framwork or component already done that does something like this? I guess it should be too difficult to build? When building this I only want the shortcuts to be active when the view is visible. How do I detect this? What base class is best to inherit from when working with non visual components?
I don't know of any framework component that does that already, but the examples above should get you started if you try to build your own.
There's no need to inherit from any component for a non-visual component like the one you've described here (your "foo" class needs no parents.) There's nothing in the Flex framework you need to inherit from for this.
However you architect it, your foo class is going to have to take in and parse keyboard codes to listen for and accept one or more methods to call. All you have to do is figure out when to add and remove the event listeners that will call the passed-in methods.
To handle turning your keyboard events on and off based on visibility, just have your foo component bind to the "visible" property of it's parent and add/remove event listeners accordingly.
You might also consider having the listeners added when the component that foo is nested in is on the display list rather than just visible. To do this, simply added and remove your event listeners in one of the component lifecycle methods - probably commitProperties is the most appropriate.
I don't think this solution answer your question directly but anyway, to help solve your problem here is an example.
For instance, I've extended the TextArea component like so. This is the best I can do so far, it can definitely be improved upon. Like, I don't know how to make the cursor go to the end after the next shortcut is pressed.
public class TextArea extends mx.controls.TextArea
{
// the keysmap is an example dictionary holding keycodes
private var keysmap:*={
112 = "some text for F1"
,113 = "the text for F2!"
//etc, etc
}
public var handleKeyDown:Boolean =false;
public function TextArea(){
if(handleKeyDown ==true){
this.addEventListener(KeyboardEvent.KEY_DOWN,this.keydownHandler);
}
}
public function keydownHandler(e:KeyboardEvent):void{
if(e.keyCode >= 112 && e.keyCode <= 123){
e.currentTarget["text"] += String(keysmap[e.keyCode]) +" ";
}//focusManager.setFocus(this);
}
}
I can't give you a solution using MXML, however my first thought would involve a singleton static class with a Dictionary that contains a list of objects as its keys and dynamically created dictionaries as the value pairing that contain keys denoting the desired key press with a function reference as the value.
So, say you had a Sprite and you wanted to capture ctrl+s for save when focus is on that object, I would get the instance of that Singleton, and call a function such as registerKeyBinding passing in the Sprite, the keyCode you want, and your pre-defined callback:
private var registeredObjects:Dictionary = new Dictionary(true);
public function registerKeyBinding(targetObject:Object, keyCode:int, callback:Function) {
if (registeredObjects[targetObject]) {
Dictionary(registeredObjects[targetObject])[keyCode] = callback;
}
else {
registeredObjects[targetObject] = new Dictionary();
Dictionary(registeredObjects[targetObject])[keyCode] = callback;
targetObject.addEventListener(KeyboardEvent.KEY_DOWN, keyDownListener);
}
}
private function keyDownListener(e:KeyboardEvent):void {
if (e.ctrlKey == true) {
//calls the function if that key exists.
Dictionary(registeredObjects[e.target])[e.keyCode];
}
}
Can't say I've tested this, but it was just the first thing that popped into my head. You could then setup functions to deregister and delete keys from the dictionaries, check states of the objects in addition to the keyCodes, remove old listeners, and delete entire dictionaries when there is no longer a need for them. Hopefully this is at least a tiny bit helpful.
I'm using a tree control that I want to customize. The data items in the tree's dataProvider have a property name that should be used for labeling the node, and a property type that should be used to select one of several embedded images for use as an icon. The simplest way to do this is by using the labelField and iconFunction properties.
However, I wanted to get started with item renderers and open the door for adding more complex customization later, so I tried making my own item renderer. I extended the TreeItemRenderer class as follows and used it in my tree control:
class DirectoryItemRenderer extends TreeItemRenderer
{
[Embed("assets/directory/DefaultIcon.png")]
private static var _DEFAULT_ICON:Class;
// ... some more icons ...
override public function set data(value:Object):void
{
super.data = value; // let the base class take care of everything I didn't think of
if (value is Node) { // only handle the data if it's our own node class
switch ((value as Node).type) {
// ... some case clauses ...
default:
this._vSetIcon(_DEFAULT_ICON);
}
this.label.text = (value as Node).name;
}
}
private function _vSetIcon(icon:Class):void
{
if (null != this.icon && this.contains(this.icon)) {
this.removeChild(this.icon);
}
this.icon = new icon();
this.addChild(this.icon);
this.invalidateDisplayList();
}
}
This code has no effect whatsoever, icon and label in the tree control remain at their defaults. Using trace(), I verified that my code is actually executed. What did I do wrong?
Looking at the base mx.controls.treeClasses.TreeItemRenderer class, I see that in the updateDisplayList function the renderer gets it's icon and disclosureIcon classes from _listData:TeeListData. Instead of overriding the updateDisplayList function, try modifying the icon and disclosureIcon classes of the renderer's private _listData instance in your _vSetIcon method using the public accessors, like so:
private function _vSetIcon(icon:Class, disclosureIcon:Class = null):void
{
var tmpListData:TreeListData;
if (disclosureIcon == null) disclosureIcon = icon;
tmpListData = this.listData;
tmpListData.icon = icon;
tmpListData.disclosureIcon = disclosureIcon;
this.listData = tmpListData;
}
EDIT
Here is some clarification on the difference between data and listData. You'll have to excuse my omission of package names but I'm editing from my phone so its tough to look them up and I don't know the package names off the top of my head. data is defined in the context of a TreeItemRenderer in the IDataRenderer interface. You create a data renderer by implementing this interface and defining a public property data, which in this case is set by the parent control and contains some data and meta-data from the dataProvider to be rendered by the data renderer class.
listData is defined in the IDropInListItemRenderer interface as a property of type BaseListData and is realized in the TreeItemRenderer class as a property TreeListData. It differs from the data property in that it contains meta-data that describes the TreeListRenderer itself (icon, indent, open) as well as (I believe, I'll have to double check this later) a reference to the data item being rendered. I gather that It's used by the the TreeItemRenderer and I would imagine the parent list control for display update and sizing purposes. Someone is free to correct or add onto that if I'm incorrect or missed something, I'm going of what I remember drom the code.
In this case, you wanted to use meta-data from the data set from the data provider to modify data that determines the display of the renderer, so you would need to modify both.
I think the real confusion here however came from the fact that you extended the TreeItemRenderer class then tried to override functionality on the component in a manner the original developer didn't intend for someone to do, hence the unexpected results. If your goal is education and not ease of implementation you would probably be better served by extending the UIComponent class and using the TreeItemRenderer code as a reference to create a class that implements the same interfaces. That would be a real dive into the pool of custom component development.
I'd probably try something simple, as in this example from the Adobe Cookbooks. I notice that they override updateDisplayList, which may have something to do with your problems.
There's another example (for Flex 2, but looks applicable to Flex 3) that shows how to manage the default icons. It looks like you'll want to manage the icon yourself, setting the default icon styles to null, instead of trying to manipulate the superclass's icon property.
Update -- Looking at the source for TreeItemRenderer, commitProperties has the following before checking the data and setting up the icon and label:
if (icon)
{
removeChild(DisplayObject(icon));
icon = null;
}
Also, it looks like the setter for data calls invalidateProperties. Hence, your icon is wiped out when the framework gets around to calling commitProperties.
I'm embedding an image like this:
[Embed(source="/tool_deleteUp.png")]
private static const c_deleteButton_styleUp:Class;
I'm using it like this:
_removeButton = new Button();
_removeButton.setStyle('upSkin', c_deleteButton_styleUp);
When I rotate the button, the image doesn't scale smoothly. I know the tricks one uses to scale an image loaded in an Image control, but I'm banging my head against a wall trying to figure out how to do it here.
Help!
a hacky way would be to traverse the children/grandchildren of the button, to find the corresponding Bitmap that is of type c_deleteButton_styleUp, and set its smoothing to true ... it is a big flaw of flex, that sometimes it requires classes for styling although some IDisplayObjectFactory would completely suffice for that purpose and would make your life a lot easier ... but life is life ...
don't know of a clean flex only way ... the only possibility i could think of, is to create an SWF, that contains your asset as a symbol, with smoothing turned on, and embed this symbol from that SWF ...
hope that helps ...
greetz
back2dos
A better, more general solution. Not only does it handle the above case, but it does it
Without subclasses
It works with any UIComponent, including IRawChildContainers (like Container), which hide skin children in rawChildren
It only smooths newly added items, instead of running every time the control updates.
public static function smoothChildBitmaps(object:UIComponent):void{
// Define a nested smooth method
function smoothChildren(val:UIComponent):void{
var childList:IChildList;
if(val is IRawChildrenContainer){
childList = (val as IRawChildrenContainer).rawChildren;
}
else{
childList = object;
}
for(var i:int = 0; i < childList.numChildren; i++){
var child:Bitmap = childList.getChildAt(i) as Bitmap;
if(child != null){
child.smoothing = true;
}
}
};
// Call the nested method on the object right away
smoothChildren(object);
// Set up an event handler to re-call the method when a child is added
object.addEventListener(
Event.ADDED,
function(args:Event):void{
smoothChildren(object);
}
);
}
Silly, but it works.
import flash.display.Bitmap;
import mx.controls.Button;
public class SmoothButton extends Button{
protected override function updateDisplayList(unscaledWidth:Number, unscaledHeight:Number):void{
for(var i:int = 0; i < this.numChildren; i++){
var child:Bitmap = this.getChildAt(i) as Bitmap;
if(child != null){
child.smoothing = true;
}
}
}
}
I do not know what you folks banged your head on no offense, just joking. I had a desk :-P
Anyway, those scripts presented are totally useless! For one thing you cannot cast a uicomponent to bitmap! The other thing is, that the seconds script with rawchildren ist more ore less the same. rawchildren gets your the children and the chrome of the container - that's it. If you have a button in a container you can try to smooth the chrome of the container - the rest stays the same since all casts to bitmap will fail.
So, did anyon rdfm?
On the other hand. One could try out stage.quality to stagequality.best. If you check the adobe forums http://forums.adobe.com/thread/427899 you will see that flex runs well - just air kind of ignores this :-(
If those two scripts ever worked - esp. the part with button as bitmap - I'll go and smash my head somewhere :-). I see NO WAY in the class hierarchy that this could work. After all, numChildren only gives you uicomponents or displayobjects but nothing more!