I have this problem that I have a little menu with a croll bar.. inside there's a couple of items with checkboxes.. On iterating through these checkboxes I get a null error.It seems like this is caused whenever a checkbox is not part of the visible space of the menu thingy.. Like Silverlight only initiate the checkbox when you scroll down so it is visible..
Anyone have any idee how to get around this?
When iterating thru the checkboxes, try adding a check to see if you're actualy dealing with a checkbox and not something else that's in the elementtree.
Loop thru children
if(child is CheckBox){
// Do what you want with the checkbox
}
Related
I want to create a custom Picker component, with the same functionality as the iOS Picker. The problem is that I want a completely different UI, basically a horizontal scrollview with two methods of input:
First one is easy, clicking one item results in that item being selected. The second way of inputting should be by scrolling, where the center one gets selected (like the iOS Picker). That's where I'm stuck.
While planing, I thought about using react-native-snap-carousel, my problem with that is that it needs a fixed itemWidth, which isn't suitable for text as the elements.
I also thought about somehow enabling snapping for my List, but that seems only to be possible with pagingEnabled = true, which isn't suitable for my use case.
What else could I try?
Thank's to anyone who is willing to help!
I've got a dropdown in this spreadsheet-like UI which provides a list of names as possible valid entries for the cell. When I tab or return out of the cell, it disappears as it should, but when I click away, to a different cell, the dropdown list isn't dismissed. Any thoughts on how to get that to work? (Theres a lot going on in the code, including ng-keydown and ng-blur directives, too involved to show here, but any pointers what to look for would be appreciated.)
Here are some pictures:
Works properly as I start typing -- but when I click to another cell:
Drop down still remains...
Found the problem, there was an 'event.preventDefault' in the blur event in certain circumstances which is responsible for the box not dismissing.
I have a Source ComboBox to populate source fields (25-30 items) shown below in first page
"A"
"B"
...
"Z"
I have selected last item from ComboBox as shown below
"Z"
and when traversing to the next page after saving, i need to make the source combo selection blank, so i have return the below code to reset the Source combobox to point to first item (to reset the display to start from top of dropdown list for user selection)
// my first value in source List is empty space - “”
sourceComboBox.setValue("");
even if you use below code snippets like
sourceComboBox.getSelectionModel().selectFirst();
sourceComboBox.getItems().clear();
sourceComboBox.getSelectionModel().clearAndSelect(0);
but when i click open the combobox dropdown it still shows dropdown display from bottom as shown below
...
"X"
"Y"
"Z"
I am unable to post images for representing combobox values, so has put in above examples.
This looks like a graphics bug to me or am I doing something wrong?
I have seen similar issue reported in below question but no work around suggested so far
Combobox clearing value issue
If you want to simply "reset" the combo box, I think all you have to do is set the value to null, like so:
sourceComboBox.setValue(null);
I ran into nearly the exact same situation and came across your question while looking for a solution. Fortunately, I came up with a workaround that forces the ComboBoxes to reset. When you reset the data on your pane, instead of doing something like:
sourceComboBox.getSelectionModel().clearSelection();
sourceComboBox.getItems.clear();
do something like this...
parentNode.getChildren().remove(sourceComboBox);
sourceComboBox= new ComboBox(); // do whatever else you need to format your ComboBox
parentNode.add(sourceComboBox);
You'll also need to do a setItems() again on your ComboBox so the new one will be populated. This is not an ideal solution but it seems to be working as I expect the provided clearSelection() method would.
Below is the code you're looking for. It will reset it to whatever index you give in within the parenthesis.
sourceComboBox.setSelectedIndex(0);
Goodluck
Most of the things were giving me an error when I tried them. What worked best for me was to use this
comboBox.getSelectionModel.clearSelection();
This will essentially set the value of your ComboBox to null. Because of this, if you are referring to the value of the ComboBox in another place, it becomes important to check for whether the value of the ComboBox is null using this
if(comboBox.getValue() != null)
//Code segment here
The ComboBox control has not a method like scrollTo(index) of the ListView. So it seems hard to workaround that behavior. You can issue a feature request at JavaFX Jira.
I'm wondering if I can make fake sections in the popup menu:
The rule would be, if the 5th character of the displayed item is different from the 5th char of the previous item in the menu, it has to be highlighted
What do you think?
Thanks!
To achieve this would be a hack.
Normally the items that appear in the popup part of a combo box will be an instantiated data template, and each gets its own data item and has no clue or knowledge of the other items in the list, so you couldn't use a converter or anything else to achieve this behavior.
What you could do though is inject (attach) your own control into the popup part of the combo box, and take over the rendering of the data items. How you do this will depend upon which combo box you are using (i.e. MS or some other vendor's) and would be a whole new question.
Would that be easier if I were to create my own combobox as follow:
a TextBox associated with a Button that when pushed would popup a datagrid in which I could implement this conditional formatting?
This is a bit of a strange one, but I've been struggling for a few hours now and I can't understand what is happening.
I was wondering if anyone else has experienced this problem, and can perhaps explain it. I'm building a simple Winforms app and trying to use many of the built in controls.
Basically, I've got a form with a user control and some data capture fields. 3 of the fields are dropdown lists and on the user control I have a bindingSource control that binds directly to a Product class.
At run time I provide an instance of the Product class to the BindingSource and the class contains a property of ProductType. For simplicity I also added a List<ProductType> ProductTypes to the Product Class which loads itself when queried, which means I can just use the same bindingSource and choose the ProductTypes Data Member as the Datasource for the dropdownlist.
Upon running the form, the list binds perfectly and I can see all the product types listed, and I can select one and tab or click to the next field. But obviously the selected value won't bind because I've not chosen any bindings-SelectedValue for the dropdown, only a datasource. As soon as I make sure that the drop down modifies the instance of the Product by binding to the Bindings-SelectedValue, and then run the form, the list still gets populated perfectly and I can tab through the controls as long as I don't make a selection from the dropdown. If I make a selection from the dropdown then the dropdown holds focus. I cannot tab out for love or money and can't even click cancel button on the form, the close button top right is the only button I can click which works and I can't click any other field or dropdown. This affects all three dropdowns as soon as a selection is made.
Anyone have any ideas what I'm missing?
I have tried changing a few things and had some success by feeding the dropdown values a string[] instead of a member of an object. That seems to work, but defeats the object of using databinding doesn't it?
Any help appreciated!
Just guessing here, because I don't have time to set up a test and confirm right now, but are you doing any validating? I seem to remember that data-bound controls won't let you leave if the contents don't validate. Even if you aren't explicitly, try setting CausesValidation to False to see if there's any sort of validation going on behind the scenes, that might at least give you a hint.
Thanks for the input on this, helped me wrap my head around this.
In my case, it turns out that an exception was being thrown in one of the EventHadlers for my ComboBox.Validating event. It was hard to track down, because the IDE didn't show me that exception. I was able to modify the Exception behavior (in the debug menu) and have it show me any InvalidOperationException that was being thrown, and then I was able to track it down.
As Tom suggested, turning off CuasesValidation was the ticket to figuring it out.
For Infragisticst Dropdowns (may not be true for other winform dropdowns): If you have "LimitToList" set to true you can be stuck in a dropdown that you can't get out of without realizing it. Use the ItemNotInList even to trigger a warning message.