comboViewer.getSelection() returning null in eclipse rcp - eclipse-rcp

i have created a ComboViewer named comboViewer in a TitleAreaDialog box.
Viewer is populated by various categories which are defined in TreeViewer.
but a NullPointerException is thrown at the following line:
ISelection categorySelection = comboViewer.getSelection();
Why is it so and what will be the fix?

You can resolve this using this 'pattern', i.e. when setting up your dialog:
final ISelection selection = new ISelection[1];
Dialog diag = new Dialog(shell) {
// createDialogArea()
// remember your comboViewer as field
#Override
protected void okPressed() {
selection[0] = comboViewer.getSelection();
super.okPressed();
}
};
(Use TitleAreaDialog instead of Dialog for your case.)
I.e. override the okPressed method of the dialog. If the user has made a selection, then presses OK, selection[0] will contain the selection.

Related

Change form item editor type dynamically in smartGwt

I have a smartGwt DynamicForm with a FormItem
FormItem item = createTextItem();
form.setFields(item);
After creating the and setting fields, I need to dynamically set an editor type for the item. I have to do it dynamically based on some conditions.
I'm calling item.setEditorType(new PasswordItem());
just after I call form.editRecord(record); so that the new editor type should appear. But it is not working.
Tried calling item.redraw() and is not working.
My goal is to set the editor type dynamically based on the record that is edited.Please help.
Try with Custom Data Binding (see page 23 for more details). What you tried won't work, AFAIK, because the ListGridField has already been created with the initial custom editor, and it can't be changed dynamically with setEditorCustomizer.
Take a look at this sample (based on this showcase demo), which does what you want to do to the password field when it is being edited in the DynamicForm, and after the changes have been saved (please pay attention to the comments, as without some of these settings it won't work as expected):
public void onModuleLoad() {
final DataSource dataSource = ItemSupplyLocalDS.getInstance();
final DynamicForm form = new DynamicForm();
form.setIsGroup(true);
form.setNumCols(4);
form.setDataSource(dataSource);
// very important for not having to set all fields all over again
// when the target field is customized
form.setUseAllDataSourceFields(true);
final ListGrid listGrid = new ListGrid();
listGrid.setWidth100();
listGrid.setHeight(200);
listGrid.setDataSource(dataSource);
listGrid.setAutoFetchData(true);
IButton editButton = new IButton("Edit");
editButton.addClickHandler(new ClickHandler() {
public void onClick(ClickEvent event) {
form.editRecord(listGrid.getSelectedRecord());
// when the button is clicked, the password field is rendered with
// a plain text item editor, for easy verification of values entered
FormItem passwordField = new FormItem("passwordFieldName");
passwordField.setEditorProperties(new TextItem());
form.setFields(passwordField);
form.markForRedraw();
}
});
IButton saveButton = new IButton("Save");
saveButton.addClickHandler(new ClickHandler() {
public void onClick(ClickEvent event) {
form.saveData();
// when the button is clicked, the password field is rendered with
// a password editor, for added privacy/security
FormItem passwordField = new FormItem("passwordFieldName");
passwordField.setEditorProperties(new PasswordItem());
form.setFields(passwordField);
form.markForRedraw();
}
});
VLayout layout = new VLayout(15);
layout.setWidth100();
layout.setHeight100();
layout.addMember(listGrid);
layout.addMember(editButton);
layout.addMember(form);
layout.addMember(saveButton);
layout.draw();
}

Custom Perspective Switcher Toolbar: How can I dynamically update it?

I'm trying to implement a custom perspective switcher toolbar to replace eclipse's built-in one. I couldn't get the toolbar to display, and it was shown to me that due to a bug with the dynamic element in a menu contribution, I have to use a control element instead, as described in the workaround to the dynamic bug.
I have a toolbar displaying following that approach, but I cannot figure out how to update it dynamically. The workaround instruction is to call ContributionItem#fill(CoolBar, int) from my WorkbenchControlContributionItem's update method instead of doing the fill in the createControl method.
I don't know who is supposed to call update, but it never gets invoked no matter what I do. I have a perspective listener which knows when to update the toolbar, so from that listener's callback I call fill(CoolBar, int). But I wasn't sure how to get the CoolBar to pass to that method, so I created one on the current shell.
The end result of all this is that the toolbar displays the correct number of items initially, but when I need to add an item, it has no effect. I call fill(CoolBar, int) and it adds the new item to the toolbar, but everything I've tried to make the CoolBar and ToolBarupdate does not work. When I re-launch the app, the toolbar has the added item.
I'm sure I'm doing this wrong, but I can't figure out the right way. Here's an elided representation of my code (omitting methods, layout code, etc not related to the update problem).
public class PerspectiveSwitcherToolbar extends WorkbenchWindowControlContribution implements IPerspectiveListener {
...
#Override
protected Control createControl(Composite parent) {
this.parent = parent;
IWorkbenchPage page = PlatformUI.getWorkbench().getActiveWorkbenchWindow().getActivePage();
page.getWorkbenchWindow().addPerspectiveListener(this);
toolBarManager = (ToolBarManager)parent.getParent().getData();
fTopControl = new Composite(parent, SWT.BORDER);
fill(new CoolBar(page.getWorkbenchWindow().getShell(), SWT.HORIZONTAL), -1);
return fTopControl;
}
#Override
public void fill(CoolBar coolbar, int index) {
IPerspectiveDescriptor[] openPerspectives = page.getOpenPerspectives();
String activePerspective = getPerspectiveId();
ToolBar toolbar = new ToolBar(fTopControl, SWT.NONE);
for(IPerspectiveDescriptor descriptor : openPerspectives) {
ToolItem item = new ToolItem(toolbar, SWT.RADIO);
//overkill here, trying to find some way to upate the toolbar
toolbar.update();
parent.update();
parent.layout(true);
parent.getParent().update();
parent.getParent().layout(true);
coolbar.layout(true);
}
//PerspectiveListener callback
#Override
public void perspectiveActivated(IWorkbenchPage page, IPerspectiveDescriptor perspective) {
fill(new CoolBar(page.getWorkbenchWindow().getShell(), SWT.HORIZONTAL), -1);
if (page.getWorkbenchWindow() instanceof WorkbenchWindow){
//this non-API call doesn't help either
((WorkbenchWindow) page.getWorkbenchWindow()).updateActionBars();
}
}
...
}

How to retain the state of a treeviewer in Java RCP application?

I have a simple RCP application having couple of wizards out of which one is having a tree viewer. I want to retain the state of the selected item in the tree viewer next time I open that particular view. As of now I have implemented using static variables and its working fine.I want to know how it can be done in a better way?
//Sample Code
private static RepositoryLocationItem lastRepoItemSelected;
Composite parent=new Composite(SWT.NONE)
treeViewer = new TreeViewer(parent);
treeViewer.setContentProvider(new MovingBoxContentProvider());
treeViewer.setLabelProvider(new MovingBoxLabelProvider());
treeViewer.setInput(getInitalInput());
treeViewer.addSelectionChangedListener(new ISelectionChangedListener() {
/* Setting the value of lastRepoItemSelected */
});
if(lastRepoItemSelected !=null)
{
treeViewer.setSelection(new StructuredSelection(lastRepoItemSelected),true);
}
Assuming this is a 3.x style RCP (your view extends ViewPart) you can use the saveState method to save your view state:
#Override
public void saveState(final IMemento memento)
{
// TODO set values in the 'memento'
}
You can then use the init method to restore values from the memento when the view is shown again:
#Override
public void init(final IViewSite site, final IMemento memento)
throws PartInitException
{
super.init(site, memento);
// TODO restore from 'memento'
}
Note: Mementos are persisted across restarts of your RCP so you need to store values in them which are valid in a new instance of the RCP.
Also look at the Eclipse wiki entry for more information.
For a WizardPage you can use the IDialogSettings. You must set this up in your Wizard using something like:
IDialogSettings pluginSettings = Activator.getDefault().getDialogSettings();
IDialogSettings wizardSettings = pluginSettings.getSection("id of your wizard");
if (wizardSettings == null) {
wizardSettings= new DialogSettings("id of your wizard");
pluginSettings.addSection(wizardSettings);
}
setDialogSettings(wizardSettings);
where Activator is your plugin activator class and "name of your wizard" is a id for your wizard (which can be anything as long as it is unique in your plugin).
In your wizard page you can then get the settings with:
IDialogSettings settings = getDialogSettings();
IDialogSettings has lots of methods for saving and restore various sorts of values, such as:
settings.put("key", "string value");
String value = settings.get("key");

How to close Dialog that uses AbstractDialogAction

I am working on Netbeans building a JavaFX application.
I started using ControlsFX (http://fxexperience.com/controlsfx/)
I have implemented a simple Dialog that uses custom AbstractDialogAction s as I want specific number of buttons to appear.
I do this like this:
Action a = new AbstractDialogAction(" button a ", Dialog.ActionTrait.CLOSING) {
#Override
public void execute(ActionEvent ae) {
}
};
ArrayList<Action> actions = new ArrayList<>();
actions.add(a);
actions.add(b); // other button
actions.add(c); // another button
dialog.actions(actions);
Action response = dialog.showConfirm();
Dialog is shown correctly with the given buttons.
My question is how to force the Dialog to close when a button is pressed ?
I thought setting a Dialog.ActionTrait.CLOSING would do the trick, but the Dialog stays open.
From eugener in ControlsFX mailing list
public void execute(ActionEvent ae) {
if (ae.getSource() instanceof Dialog ) {
((Dialog) ae.getSource()).setResult(this);
}
}
The above sets the result of the Dialog to be the current Action and closes the Dialog
But maybe that is a little redundant as I can simply call:
((Dialog) ae.getSource()).hide();
.hide() hides the Dialog and also sets the current action as the result.
I can't suggest which is a better solution (hide() was suggested by jewelsea)
In addition I would suggest to always override the toString() method of class AbstractDialogAction, in order to get readable result from:
Action response = dialog.showConfirm();
System.out.println("RESPONSE = "+ response.toString());
Hide the dialog to close it => dialog.hide()

setting a default text to a GWT ListBox

I am trying to create a ListBox using GWT. I am using UiBinder to create the field.
I would like to set a default text on the list box and when a user clicks on the box, it should show me the list items. Once again, if user has not selected any option, it should show me the default text again.
Any way to do this either using Uibinder or some ListBox methods?
If I understand correctly you want a value to show but when the user clicks on the list it disappears and shows you the list items?
As far as I know there is no option to that natively.
What you can do is add the first item to hold your default value.
You can do this grammatically by using addItem in code or using:
<g:Listbox>
<g:item value="-1">Default text</g:item>
</g:Listbox>
works with gwt 2.1+
The value can still be selected.
You can choose to ignore it or add an attribute "disabled" with value "disabled" to the option element:
listbox.getElement().getFirstChildElement().setAttribute("disabled" ,"disabled" )
hope it helps a bit :)
You can also use a renderer to control what is shown if 'Null' is selected.
(Inspired by: How do I add items to GWT ListBox in Uibinder .ui.xml template ?)
private class SimpleRenderer implements Renderer<T>{
private String emptyValue = "Select a value";
#Override
public String render(T val) {
if(val == null) {
return emptyValue;
}
return val.toString();
}
#Override
public void render(T val, Appendable appendable) throws IOException {
appendable.append(render(val));
}
public void setEmptyValue(String emptyValue) {
this.emptyValue = emptyValue;
}
}