I want to create a news application for my website.
My question is how should i create drag-able panels/canvas inside another panel/canvas.
What i exactly intend to do can be seen on netvibes.com . The website has different panels of every news group, and this panel could be moved from one place to other, but in a well defined manner. And the other panel take over the place of dragged panel.
Is there any component in flex, which can help me make something like that.
If i was unable to make my question clear, plz let me know, i will try to make it more clear.
Regards
Zeeshan
A TileList with drag and drop enabled should be able to accomplish something like that. Or, use a Spark List with a custom layout that you create.
It might be a bit tricky getting the list elements to drag and drop based on clicking the title, but it should be doable.
I think you should consider a more advanced solution with drap-n-drop with a custom panel based component. The places the panels can move can be implemented with a different custom canvas based component. The advantage would be to move the components into different custom positions and panels can be resized independent of each other.
Adobe has some good tutorials for drag-drop operations.
Related
I am looking for some advice in regards to getting a very quick display of our reports. The problem I am working with is I receive an XML data structure that defines our layout. The report can be anywhere from 2 to 3 pages to perhaps 20 to 30. So to make the report display as quickly as possible I would like to just render the visible portion of the report. Here are the issues I need to overcome to accomplish this and I am looking for some advice how how to accomplish this.
To get a better visualization, Think of this like a word document. The reports have sections and I want to be able to get them to display as quickly as possible.
1) Of course I do not know the height of the child components I will be adding. Is there any techniques where I can determine if the components I am adding are not include in the view port and could I trigger off scroll bar movement.
2) I was thinking of adding estimation to the children components and then using that to set the height of the parent container. then when I receive scroll bar move event, I would check if the child components have been added to the parent and if not add them. Is there anyway to get the height of a component without rendering it?
3) Does Flex support anything built in that will accomplish this.
Any other techniques would be welcome. Basically I want to get the report displayed to the user as quickly as possible and delay the rendering of components that are off the screen.
Any suggestions would be welcomed. Thanks in advance.
Added Info.
Hard to provide code since I have not coded it yet. Let me try and expand with some details. I have a Parent Container where I take the some XML and using the XML creating children components based on the information in the XML. Right now when we do this it can take a long time to render a long report. What I want to do is to reduce the rendering time by delaying the rendering of those children objects. I have looked into things like the creation policy and createDeferredContent, but not sure if this is the right way to go. Guess the general problem I need to attack is how to do you stop rendering objects once you are outside the parents viewport. What I want is an item renderer like functionality but there is no similarity between the children. Perhaps a picture might be useful (will add as soon as I get to 10 points)?
Use spark List with useVirtualLayout turned on. This is what it does.
There is always similarity between children, but if you can't find it, you can use an itemRendererFunction.
I'm wanting to use Panels to drive a whole bunch of pages for data interaction, but I'm not sure how to get Panels to "interact" with each other. I think the best way to put it is with an example. Say I have one Panel which has a list of nodes (in a view?), and another Panel that I want to display an editor for any node I click. And I have a page that has the first Panel in a block on the left, and the second in a block on the right. So I suppose on click, there'd be some AJAX grab that puts some page in the other Panel. Now, this is a simple example, and I'm going to end up with many different sets of interactions among multiple panels doing all sorts of stuff. But this works as a starting point. The goal is to be able to reuse these Panels in multiple pages that may interact with similar data, but with different operations (maybe there's the above edit page example and also a similarly designed view page also utilizing the left block node selector?).
How much of this can be accomplished with Panels (and maybe supplementary modules?)? Where would I need to code to put it all together? I assume it would need code perhaps in the Panel page that contains things like the data selector panel, data view panel, etc. to "link them together". Are there any good examples floating around on how to do this, since it seems like a fairly bread-and-butter exercise for any sort of web-based data interaction...
The best and probably the simplest way probably would be to do it with some coding but if you prefer using modules there a module families like Context or Rules that should give you some functionality which you are after. I also suggest looking into AJAXification methods and modules.
I am having difficulty navigating to different MXML pages in my Flex application. I checked some other questions on SO about it but they seemed to be to do with tab navigation.
I am trying to navigate from one MXML page to another via Actionscript code. How is this possible?
Cheers
Edit:
I am a real beginner in Flex and I worked out that I actually needed to use States, and have now discovered how to use them. Thanks for your help.
You don't navigate between MXML pages. MXMLs are not pages to begin with. Instead they are components, that are displayed in the application. So if you want to change the current display, then you need to remove the already added components, and add others that should be displayed now.
There are different approaches to do this. The very raw way of manually removing elements is rarely used, instead there are two main methods: ViewStacks and display states. Display states should be used when there are not many different changes in a view, for example when you click a checkbox that adds new options to an existing formular. If you want to change the whole displayed content (this does not have to be the whole application content though, think in components instead), you can use ViewStacks.
ViewStacks are like a stack of paper, where each paper reflects a single view. So if you want to display something else, you move the new view to the top, hiding all others below. Many components, including TabNavigators, are just ViewStacks with an additional menu to select the view that should be displayed. But you can also just use a ViewStack and manually change to what you want to show.
Flex is not sidebased like html.
You have to instantiate or remove classes, components or all this stuff.
i would use the states.
You can register handler to buttons and swap the state.
Then you are able to instatiate or remove components via the tsates.
Which flex version dou you use? The management of the states are changing between flex3 and flex4
Assume, you have one app with two content areas, home and gallery. First you have to create these two areas with project->new->component and named there related.
After that, you instanciate both components in your app.
Define two states, home and gallery and swap these with a button or two.
set the propert excludefrom or include with the name of the states. finally, you have an app with two content areas, but you never swap pages, you instanciate or remove components in runtime.
br
Frank
BR
Frank
I'm wondering what the best tool is for developing a mobile UI is. My requirements are that I retain full control over the look and movement of every UI component. I think Flex might be the best way to do this but I can't tell if I'll have that level of control using their UI components.
Any links would be appreciated. Thanks!
Edit: For example, looking at the documentation I see there's a an 'enabled' field which dims the color of a container and it's children if false. Am I able to change that so, maybe a repeated bitmap pattern appears if false?
Or, if there's a sliding menu can I edit the speed and change in speed as it closes?
You can create any component you like and make it look like anything you want. You don't have to use standard components. You can reskin any components just by specifying a new skin. It's really pretty easy.
You can create custom skins for Flex, for both Spark and Halo components. You also can create custom components, either based on other existing components, or based on the base component. You could even create custom objects which are just based on Sprites or similar (if you like to have control over everything :P).
edit
In response to your updated question. Regarding the enabled/disabled property, yes, it is possible to skin that. Spark components have states, for example a Button has a up, over and down state – and an disabled state. That state is exactly what is active when the enabled property is set to false. So yes, you can skin that.
Regarding the sliding menu animation, I'm not totally sure if that would be easily possible as I believe that this is coded into the component itself and not part of the skin to decide. However even if that is the case, you could instead create your own component that basically features exactly the same functionality but has a changed animation there.
I'm not sure if the Spark skinning wouldn't be able to do this though, because what you definitely can do is creating transitions between states. So if the slide is made with different states, you'll probably be able to change the transition as well.
While reviewing the tutorials and example Flex projects, they seem to focus mainly on form elements and data grids, rather than delivering content in a more visual way. Which is what I will need for this upcoming project. As a result, I have a gap in my comfort level that I'm hoping that a seasoned Flex developer can help me hurtle.
The project that I have is a collaboration index tool to display customers products and services using an user interface with four separate panels.
the top-left panel will contain a list of categories in a vertical scroll.
The bottom left panel will contain a wheel effect of sub-categories, based on the category chosen.
The top right panel will contain the detail information - The selected Category Title and Description. And below that, the selected sub-category title and description.
The bottom right panel will contain a list of the service and product items that belong to the sub-category. Below each item in the list will be a link-group accordion with url links for more information in each.
There will be an XML file containing the complete data tree driving this collaboration index.
Additionally, depending on the category chosen, color variances will occur in the background of the some of layout sections.
So, It appears that I will need to create a few custom components, maybe adopt a few existing components, and re-skin everything so that it carries a synonymous look and feel to the client's branding.
Although I have a bunch of questions, tackling the first section seems logical, and the first question that comes to mind in this section is: in the top left panel, should the list of categories be standard Flex buttons that are re-skinned? or should they be object instances somehow brought in to Flex.
Then in the second section, I was had seen a component that displayed images in a way that was perfect for this section. But, the items show here would be just visual, rounded corner blocks with subcategory names in them. So, I'm not sure if that component will work or not.
AS3 is very different from AS2. I'm sure you've noticed by now, but it's worth mentioning in case you hadn't.
Flex Components are basically just a package of Flash objects. So you can, sort of, write every Flex component on your own using just Sprites and/or TextFields. This includes skins. A skin is pretty much just a Shape attached to an object with custom drawing.
A button is just a combination of image+textField+skin, with all the events and skin transitions managed for you.
The reason I mention this is that there is no right way to do what you want. If you're using the List control, you should probably write a component that implements IListItemRenderer. Button does, so you can simply override the Button, no problems. You can have buttons with a label + icon. Or just icon. Or just a label. You can also define where the label is positioned relative to the icon (labelPosition="above|below|left|right"). There is a lot of built-in flexibility.
Thanks for the mention of FlexSpaces. Note that it was finally ported to Flex 4 including a first pass conversion to spark controls earlier this year. Still to do: add dependency injection with Spring ActionScript, remove use of Cairngorm 2.x.
I have been developing Flex 4 quite heavily the past 6 months and must say it would make your job very easy.
Here's what I would do:
1) Check out FlexSpaces for the best Flex 3 project architecture. It's a fully featured CMS in Flex with categories, tags, searching, filesystem, collaboration, etc.
2) Download the Flex 4 SDK and install that. There's no need to use Flex 3 anymore, if you're just getting started, DEFINITELY go with Flex 4. If you need custom components, Spark (the new component architecture) has a very simple way of doing them (here's a cool blog post building a Rating Component in Spark that shows you how do it). Flex 4 is backward compatible with Flex 3 components, so you can use projects/components you find on the internet if you want to, no problem.
3) For the top-left category list, if the categories aren't nested, I would use the spark.components.List, (here's one using more complex item renderers). Then just extend the spark.components.supportClasses.ItemRenderer, which acts just like a Skin. If categories are nested, just use the mx.controls.Tree. Check out that FlexSpaces project for that (they show how to use XML/ArrayCollections in the tree, your "object instances brought into flex somehow" question).
4) For the wheel effect, the only thing I don't like about Spark so far is that it's difficult to animate layouts. But people are starting to make 3D layouts, check out Here's 5 3D Layouts for Flex 4 by Ryan Campbell. There's also OpenFlux if you want very easily animated layouts. Flex effects in general are quite clunky, so I end up just using Tweener or TweenMax for animations.
5) As for reskinning, trying to reskin using the Flex 3 architecture would be a monumental task, if you wanted to make it look clean and nice, and it would be insane trying to reuse that code in the next project. For Spark, it's a snap, and it's 100% mxml. Just copy the whole sparkSkins folder from the SDK and start changing things, and you're good to go.
But yeah, that FlexSpaces project is a very solid example for what you're talking about. Totally open source.
Cheers