List Component that acts as if control was permanently pressed - apache-flex

I have a list control and i want the user to be able to select many items at a time. Thus I want it to act that if the control key is pressed while he is clicking. Eg if he clicks on a selected row it should become unselected and if he clicks on a unselected row it should become selected.
Do you have any idea how to do this?
Thanks,
Dennis

If you want to follow standard UI Precedent; then set allowMultipleSelection to true and teach your users to use the control and/or shift button to select multiple items.
If you want to select multiple items without having the using press the shift or control button you'll have to extend the List class. I did a sample a while ago using the DataGrid:
http://www.flextras.com/blog/index.cfm/2009/7/23/Flextras-Friday-Lunch--Episode-22--07032009--Auto-Select-DataGrid
http://www.flextras.com/labs/AutoSelectDataGrid/
http://www.flextras.com/labs/AutoSelectDataGrid/srcview/index.html
You can probably use the same technique with a List. But, I don't recommend this approach.

Related

Using bindings with BrazosUI buttons

I'm used to using boolean bindings with IBM buttons to track if a button is clicked. The button in Brazos UI can be bound to any variable type but doesn't make automatic updates to booleans. How do I use bindings with Brazos UI buttons to track which was last-clicked?
The binding of a button is really only useful in tables. The acceptance of ANY variable type for the binding of a button stems from the use of determining the index of a selected row or obtaining the entire row object:
If you bind and integer to the button in a table, the binding will update with the index of the row when the button is clicked.
If you bind a variable of the same (singular) type as the table's binding, then clicking the button will update the binding with that row's data.
Both of those are handy interactions with the table control but don't work for tracking which button is clicked when used elsewhere on a coach. For that, you want to utilize the 'Button Control ID' configuration option. The most direct method is to bind the same string variable to all of the buttons you need to track. When clicked, a button will update that shared variable to match its own control ID. You can then use that unique ID in various scripting checks to take button-specific actions.
See the BP3 Help Center article for greater detail about this, including some examples: https://support.bp-3.com/hc/en-us/articles/217985767-Using-Button-Binding-with-Brazos-UI

How to: Allow for a ListBox to have no selection

I am wanting to allow for a user to deselect all values in a ListBox. Normally, when the user deselects all but one item, that one item cannot be deselected. I want to make it so it can be.
Thanks
Essentially I'm aware of two ways of doing this:
Add an empty item to the list. You can even name this item "None" or something similar. Using a text has the additional advantage that it informs the user.
Use JavaScript to unselect the item that is clicked if it is the last item.
Note, either way, you change the default behavior of the listbox, which is what users are accustomed to. Changing the default behavior is generally not a good idea, which is why I would go for option (1) being the clearest towards your users.

What's the best practice for generating spark radio buttons?

I have a list of radio buttons, which I want to be able to both set the value of programmatically and for the user to set the value of manually.
I have a small list of data items which I want to display as options in a list of radio buttons. The objects are stored in a model object, as is the currently selected item. The currently selected item is bound to the radiobutton group. The radio buttons are generated using a spark list.
I am having a problem setting the list programatically - whenever I set the current value on the radiobutton group to the first value in the list, all of the radio buttons are cleared, where the first one should be selected. I when checking in the debugger, I found the likely reason - there are two radiobuttons in the group that point to the same value, one of which isn't showing. My best guess is that the list control has created an extra item renderer which it is holding on to in case it needs to scroll the list.
Is there a way to create radioButtons based on an ArrayCollection without using a list? Failing that, is it possible to prevent the list from generating the extra item?
Use a DataGroup with a dataProvider (an ArrayList of objects holding data) with a custom item renderer that creates the radiobutton that you need. Add proper bindings of the data object to the radiobutton (maybe even do 2 way binding for quick saving).
In the end, I gave spark best practices the finger and used a repeater, which created the correct number of radioButtons with no extras. It may be slow, but slow iteration over a set of less than ten items is O(I don't care).

ASP.Net Cannot tab through all radio buttons when selected

I'm trying to implement accessibility (keyboard only) ability on my site, but I'm having problems with Radio Button lists. When using radiobuttonlists, when initially, none of the radio buttons is selected, I am able to tab through every single value and select one upon hitting "enter". However, after a value is selected, I can only tab to the selected values, which presents a problem if I want to change the selected value.
From what I understand, radio buttons are grouped at the container controller level, thus when it is considered a group, only one can be selected at a time.
Any ideas on how to fix this issue?
Actually, this is not an issue at all. If a value is not selected, the browser will go through each value within the group. Once a value is selected, the browser will only jump to the chosen value within that group. Thus to change values within the group, the user is to use the keyboard arrows.
I believe you're correct about the RadioButtonList being one control (and therefore tabbing doesn't work). An alternative could be to create individual radio buttons and use the GroupName property to assign them all into one group. This should let you tab between them and still ensure they work in sync with each other.

ASP:ListBox | Multi Select | Keep selected values when selecting a new one

1) Have a listbox with 3 values out of 5 selected
2) When I click to select another value without holding CTRL button, it will unselect over values
How to make it keep other selected values if new value is selected?
This is going to sound like a snide answer, but I don't mean it that way. I just like to look for the simple solutions rather than the complicated onces.
The easiest way to get a control to have the behavior you want is to use a control that has the behavior that you want, rather than modifying the behavior of an existing control.
That said, if you want a list of items where a user can select a bunch of items off the list, and don't want to have to rely on them holding control, you're using the wrong tool for the job.
Use a CheckBoxList instead of a ListBox. If you want it to be scrollable, then set it in a div of a specific height, and set the style of the div to "overflow: scroll".
If you still want to use a ListBox you should use javascript and for each click event fired, you should check if the clicked element is selected/unselected and act accordingly. It's a little bit tricky but at least it is a solution for your problem.

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