ComboBox cmbCategory, cmbType;
I have two ComboBoxes. The 2nd ComboBox depends on the first ComboBox.
For example.
If I chose "Food" on cmbCategory, the choices on cmbType would be "desert, appetizer..")
How will I do that without clicking a button. I mean when "Food" is chosen on cmbCategory, the choices for food on cmbType would showed up automatically without clicking a button. Because what I have come up to is that my cmbType is hidden and when a button is clicked, then that's the time it will be visible.
I believe this is about MouseListener or MouseClicked but I have no idea on how to do it.
You can add an ActionListener to the cmbCategory. On select call getSelectedItem() to get category.
Define a Map> the map should keep the list f items for each category. Fill the map (or you can define some logic to get list of types by selected category). Then just remove all the existing items in cmbType and add new list of types for the selected category.
See the ombobox related code snippets here
Related
I want to create a multi select list with Jcombobox displaying object of my custom class. Initially i thought i will write a renderer and and paint a jcheckbox inside it so that user will be able to select multiple items. I also looked on internet for such type of implementations. My problem is when user selects multiple checkbox, jcombobox shows only the last selected checkbox item value as its label. I wanted in this way
Checkbox item1, Checkbox item2
Or item1, item2 can also suffice my requirement.
Also when i ask for selected items i should get both selected items.
Please help me with this.
Thanks in advance.
I have a program that I created for work. This program takes an uploaded file, reads it, and puts the data into a JList in the GUI. The GUI actually has two lists and the user is able to move items between the left and right list by highlighting them like usual with a JList and then hitting an arrow to move the items. The lists are multiple-interval selection.
One small addition I would like to add is some type of counter that shows the user how many items they have selected before they actually move them between lists. This would need to be dynamic so if the user holds control down and begins clicking the counter will continue to update the number of highlighted items.
As the lists are often quite large and a user might need to move an odd number of transactions between the lists (Think 300 transactions in left list and the user needs to move exactly 50) it would be beneficial to have this counter.
Can anyone think of how this could be done? I'm not sure how to add an action listener to just clicking on the items. Please also let me know if I need to elaborate any more.
Generally my question is can I create an action listener just for when a user clicks a item in a JList that updates a counter for the current selected indices? Also it would need to change when they no longer have selected an indice.
Register a ListSelectionListener with your JList.
The listener could simply query how many rows are selected and update the number in the panel to that. Perhaps use getSelectedValues().size().
http://docs.oracle.com/javase/8/docs/api/javax/swing/JList.html#addListSelectionListener-javax.swing.event.ListSelectionListener-
I've two jRadioButtons in Java application. Let's say Male and Female. Initially one is selected. While selecting another, the previous should be unselected and vice-versa. How to make it work? Also how can it be used to store in database?
You can give same name to all the radio buttons, from which you want to select only one. That way, you will be able to select just one button out of all. This you can do by creating a ButtonGroup.
Now, if you want to add the selected item to the database, just get the value corresponding to the name of Button Group, you will get the value of selected button.
See documentation and tutorial
What you need to use is a ButtonGroup component. Have a look at: How to Use the ButtonGroup Component
Could anyone please tell me what i should do programmatically to be able to select an item in a listbox using the keyboard when there are multiple items starting with the same character/s. For eg,
•One
•Two
•Three
•Once
•Orange
If i want to get the focus on "Once" by typing o,n,c what should i do? Instead of jumping from one item to the other as opposed to the default behaviour.
Add a KeyPress event handler to the ListBox and track the keys that are presses. Then compare the complete value that already has been typed to the values from the items in the ListBox. If there's a match, select the item.
I have created a dialog with two JLists displayed and a button that takes the selected value from the second JList and does something (say it outputs the selected value). The list of values from the second JList is updated according to the selection of the value from the first JList.
When the dialog is displayed initially, the button is disabled. When a value is selected from the first and then from the second JList, the button is enabled an the required selection listener is added to it.
The problem is that every time the button is clicked the number of output messages is equal to the time a value of the second JList is selected. For example if I select a value from the second JList, then I change my mind and select another value, the click of the button will output the message two times.
Does anyone know a method to prevent such a thing?
Your ListSelectionListener should check for (e.getValueIsAdjusting() == false) otherwise you'll respond to all of user's selections and not just the final one.
Yes: don't cache the selections, just process the actual selection in your second list.
If possible, post the code that is executed once your button is pressed. I guess, you have some sort of collection (a list or queue) that stores all the selections you do on the dialog and when you press the button, each stored selection is processed.
This looks like an intended behaviour, because you usually don't code this by accident ;)
If it is intended and you just want to eliminate duplicates, consider using a Set instead of a list, as a Set will only contain unique values.
It does perfectly what it should do.
It fires two events,
1> Selection is removed from first item.
2> Selection is done to second item.
So as fbcocq said, you should check for getValueIsAdjusting(). Check this out, it'll help.
Are you adding an ActionListener to the button every time you enable it?