I'm trying to have multiple item renderers in a list, as I have several different types of objects that I want to display. I tried creating a new class that extends ListBase, and adding override public function createItemRenderer with my code within this function. I then instantiate the new class and give it my array of data as its dataProvider, but createItemRenderer is never called within my new class, can anyone help me please?
Thank you
I managed to solve this by extending List instead of ListBase, so thanks shakakai for making me think about that :)
Incase anyone else has a similar problem here is what my code looks like:
public class MultipleRenderersList extends List
{
override public function createItemRenderer(data:Object):IListItemRenderer
{
if (data is Type1)
{
return new Type1Component;
}
else if (data is Type2)
{
return new Type2Component;
}
return null;
}
I've dealt with this in the past by creating a single item renderer that can handle different types of data. There are a few ways to do this, such as changing states based on data type, or using a ViewStack that switches based on data type, or using actionscript to create/add a sub-component to display the data appropriately. Just override the set data method on your item renderer and switch up the components as necessary. Hope that helps.
Related
I am implementing a category mapper. There are 2 TreeViews. Both contain categories from different sources. (Even they look like from the same source)
The user should be able to map ONE category from the left to multiple of the right treeview. This gets stored in a config file.
However, when the view is initially loaded and the user clicks on a category on the left, I want to preselect the mapped categories on the right, loaded from the config file.
I saw that I can do this with ONE selection, but I don't see an option to do this for multiple ones.
How can I achive this?
Here a ootb running demo implementation
I went through your gist and it seemed that the problem was binding selections right? I did some light digging and found that binding observable lists isn't easy. I don't think I even saw a solution that wasn't just adding listeners to mock a binding. However, wrapping that list in a SimpleListProperty seemed to do the trick. Here's a demo:
class TestView : View() {
// This mocks your target list in the ViewModel
val targetList = SimpleListProperty(listOf<String>().asObservable())
override val root = vbox(10) {
// Both table views and tree views use an Observable Selection list
listview(listOf("asefas", "asefasef", "asefasefasefase").asObservable()) {
// Wrap in SimpleListProperty, then bind
targetList.bind(SimpleListProperty(selectionModel.selectedItems))
selectionModel.selectionMode = SelectionMode.MULTIPLE
}
setPrefSize(300.0, 300.0)
}
init {
// Target list now reflects changes made to selection model
targetList.addListener { _, _, change ->
println("Selections changed to: $change")
}
}
}
I have a Flex LineChart which contains three series:
two LineSeries
one ColumnSet
Has anyone seen or heard of a way to set the dataTipRenderer on a per-series basis? You can only override it for the entire chart and I would prefer to not have to overlay multiple charts just to achieve this effect.
do you found a answer for your problem? i want to pick up the question of david goshadze and suggest you to look what i did:
there is a way to get the series by the data object. you have to choose for the dataTipRenderer a component (e.g. canvas but its mx) which implements the IFlexDisplayObject and IDataRenderer and then override the data getter and setter or you implement in your own DataTipRenderer class the interfaces (optional: extends e.g. VGroup) and implement the data getter and setter. now you could cast the value parameter in the data setter to HitData and then check which class the element object is:
public override function set data(value:Object):void
{
var hitData:HitData = value as HitData;
if(hitData.element is LineSeries)
// do lineseries stuff
else if(hitData.element is ColumnSeries)
// do columnseries stuff
}
now you know which series take the renderer and you can render individual datatips.
hope this helps!
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 am trying to come up with the best way to render some hierarchical data in to a nested unordered list using ASP.NET MVC. Does anyone have any tips on how to do this?
I suggest jquery tree view plugins for making it function like a tree, but as for render, just put it in a recursive lambda helper to do the nesting.
You mean... you want some sort of tree view?
You can actually get the treeview control to work... but you have to wrap it in server side form tag to function. You'll get the usual nastiness that that brings (like generated ids and viewstate) but it will work from a rendering perspective.
If you want to just create tags and nest them, it would be pretty easy to do with foreach() loops.
I believe currently there is no such control.... TreeViews are complex by nature. You can of course "draw" a hierarchy as much as you like using all sorts of repeaters and loops, but to achieve functionality of a tree view like the one in the Web forms toolbox... you have to wait !
Why don't you pass your model in the form of a tree to the view?
/// This is the model class
public class MyTreeNode<T>
{
public ICollection<MyTreeNode> ChildNodes {get;}
public T MyValue { get; set; }
bool HasChildren { get { return ChildNodes.Any(); } }
}
///This is the html helper:
public static string RenderTree<T>(this HtmlHelper html, MyTreeNode<T> root, Func<T, string> renderNode)
{
var sb = new StringBuilder();
sb.Append(renderNode(root.MyValue));
if (root.HasChildren)
{
foreach(var child in root.ChildNodes)
{
sb.Append(RenderTree<T>(html, child, renderNode));
}
}
return sb.ToString();
}
I didn't actually test this code, but it's about the idea. You can imagine creating your own recursive html helper to render a tree.
For that (rendering hierarchical menu, treeview, etc) i use recursive calls of custom component (ascx, or aspx in new preview5).
I give component first level of items (List of items), and component then check for each item in list if there's any child items and call itself with list of that child items.
You can build hierarchical graph of objects in controller, or just 1 dimensional list with ParentID property.