Develop Reference

How to implement printing in chrome pacakaged app created from GWT Application.?

I have integrated the GWT application with Chrome packaged app with help of DirectLinkerinstaller like the code below:
public class CSPCompatibleLinker extends DirectInstallLinker {
#Override
protected String getJsInstallLocation(LinkerContext context) {
return "com/google/gwt/core/ext/linker/impl/installLocationMainWindow.js";
}
}
But now I want to call print function from Chrome packaged app. When I call window.print() it allows me to print current window, but I need to open a new separate window and print that.
Could you anyone please help me in this?

I can't answer anything about GWT or DirectLinkerinstaller, but here's an answer about Chrome Apps, assuming that's what you're asking about:
You use the chrome.app.window.create API to create a window. Then, you can call the print method for that window.
In my apps, I seldom want to print what's in a window, but rather something I've generated specifically for printing. For that, I create a PDF with jsPDF (Google it), which works well. Then I display the PDF in a window, and let the user print the PDF (or save it).

Making program extensions

I am making a program for computer surveillance at the moment.
It's for a competition in my country Croatia(InfoKup).
I have several options for sending command to another PC, but I
want to make the possibility for the command extension for people
who know Java. So I want to make the user be able to add some of his
custom commands for the program. For example something like
Minecraft mods. I know it is possible, but how would I go about
doing that.
Any help would be greatly appreciated. My code on GitHub:GitHub
Don't mind the stream thing.
It's something my friend is experimenting with.
EDIT: e.g.
Currently I have the possibility to send popups to another PC. What if the extension maker knew the code to send cmd commands and wants to add that function. He makes an extension and puts it in the extension folder. Voila we have a new possibility.
EDIT 2:
Don't be so harsh on me pls :). Thx for the dynamic class loading tip. I have been looking into that, and it looks promising.
Basically what I want to have possible is the user to drop the "mod/extension/whatever" in the "mod/extension/whatever" folder, and the program would load it and put all of the buttons declared in the class in to the GUI, and with them the function. I think I'm getting the hang of this, but any tips would be helpful.
e.g.
package sth.sth;
import blah.blah.*;
public class ClassSTH extends SchoolarButton{
public ClassSTH(String params){
super(params);
}
#Override
public void OnClick(){
doStuff();
}
}
EDIT:
The problem is easily solvable using Java Reflection! I wish someone posted that as an answer befpre blatanty downvoting a question because pf a GitHub link that was there to prpve that I've actually done something.

This kind of thing can be accomplished by using Java Reflection!
How to load and invoke a method on an external jar:
File f = new File("plugin.jar");
URLClassLoader cl = new URLClassLoader(new URL[]{f.toURI().toURL(), null});
Class<?> clazz = cl.loadClass("epicurus.Client");
Method main = clazz.getMethod("main", String[].class);
main.invoke(null, new Object[]{new String[]{}});

Eclipse RCP view will not update when editor data is modified

I'm attempting to do something that seems like it should be quite common, so I'm surprised I'm having a hard time finding a solution.
I have a simple Eclipse RCP application. It consists of a view, containing a treeViewer that displays elements of an xml file hierarchically. The other side is an editor, which contains various fields such as textboxes, etc, for displaying and also modifying the xml values. The treeviewer displays icons alongside the element name, and what I'm trying to do is change the icon to a "modified" version of the icon whenever a change is made in the editor - signifying that a value of that element has been changed. This is very similar to how Eclipse, when integrated with subversion, shows that a file has been modified from the base revision in the Package Explorer.
I'll try to just show the parts of the code relevant to this specific issue and hope I don't leave anything out. This is the editor class:
public class XmlEditor extends EditorPart
{
protected boolean dirty = false;
public void setDirty(boolean value)
{
dirty = value;
firePropertyChange(PROP_DIRTY);
}
}
and this is the view with the tree:
public class TreeView extends ViewPart implements IPropertyChangeListener {
public void createPartControl(Composite parent) {
treeViewer = new TreeViewer(parent, SWT.BORDER | SWT.MULTI | SWT.V_SCROLL);
getSite().setSelectionProvider(treeViewer);
treeViewer.setLabelProvider(new TreeObjLabelProvider());
treeViewer.setContentProvider(new TreeObjContentProvider());
PlatformUI.getWorkbench().getWorkingSetManager().addPropertyChangeListener(this);
}
public void propertyChange(PropertyChangeEvent event) {
if (event.getProperty().equals(IWorkbenchPartConstants.PROP_DIRTY)) {
treeViewer.refresh();
}
}
}
In this scenario, TreeView::propertyChange() is not getting called, even though firePropertyChange() is getting fired. Any ideas why? I'm also open to any other ideas that don't involve PropertyChangeListener, it just seemed like this would be the easiest way at the time. Thank you.

Here's how I ended up solving the problem:
Changed TreeView to implement IPropertyListener instead of IPropertyChangeListener
Implemented the propertyChanged() method to perform a treeViewer.refresh()
In the XmlEditor::createPartControl() method I got a reference to the Treeview part and then added it to the property listeners like so:
TreeView treeView = (TreeView) getSite().getPage().findView(TreeView.ID);
addPropertyListener(treeView);
Now, TreeView::propertyChanged() gets called after firePropertyChanged(), just like I needed. It took quite a bit of experimentation to learn the difference between IPropertyListener and IPropertyChangeListener, addPropertyListener() and addPartPropertyListener().
Thanks to nitind for giving me a new perspective, and for showing me about Decorators, which is definitely the right way to go as opposed to changing the tree icon to a modified version.

You fired a property change in the editor part, which is unrelated to the working set manager. Nothing you've done connects the view to the editor. If you want the two to talk to each other, write them to talk to each other, or at least create and react to events from making the modifications you describe.
I'm also pretty certain that's not how SVN shows that a file has been modified.
SVN is probably supplying a Decorator: http://eclipse.org/articles/Article-Decorators/decorators.html

Add this bunch of code in your create part control this will may be help you
ResourcesPlugin.getWorkspace().addResourceChangeListener(new IResourceChangeListener() {
#Override
public void resourceChanged(IResourceChangeEvent event) {
treeViewer.refresh();
}
});

Adding figures using contextual menu - Eclipse GEF

All,
I am creating a palette less eclipse plugin where am adding figures to the custom editor through the contextual menu, but am not finding a way to do it. Can anyone please guide me as to how to go about adding figures to editor dynamically through context menu i.e. adding actions/commands.
Since Eclipse GEF plugin development finds so less examples to look at, I am adding my solution so others find it useful. This code helps to render a node to the editor.
Source code for Action class to render figures to the editor:
public class AddNodeAction extends EditorPartAction
{
public static final String ADD_NODE = "ADDNODE";
public AddNodeAction(IEditorPart editor) {
super(editor);
setText("Add a Node");
setId(ADD_NODE); // Important to set ID
}
public void run()
{
<ParentModelClass> parent= (<ParentModelClass>)getEditorPart().getAdapter(<ParentModelClass>.class);
if (parent== null)
return;
CommandStack command = (CommandStack)getEditorPart().getAdapter(CommandStack.class);
if (command != null)
{
CompoundCommand totalCmd = new CompoundCommand();
<ChildModelToRenderFigureCommand>cmd = new <ChildModelToRenderFigureCommand>(parent);
cmd.setParent(parent);
<ChildModelClass> newNode = new <ChildModelClass>();
cmd.setNode(newNode);
cmd.setLocation(getLocation()); // Any location you wish to set to
totalCmd.add(cmd);
command.execute(totalCmd);
}
}
#Override
protected boolean calculateEnabled()
{
return true;
}
}

I think you need multiple different things here. Please remember that GEF would like you to have proper MVC pattern, where you have your own model, Figures as View and EditParts as controllers.
From the top of my head I would say that you need at least these things:
CreateCommand
contains all model level modifications that you need to
perform to add your new data to your
data model (undoable and transactional)
CreateAction
makes that CreateCommand instance, initializes it with current selection and executes that command in editdomain
ContextMenuProvider
Provides that CreateAction to context menu
If you happen to be using GMF the canonical mechanism will generate the editparts for you automatically when you make the model modifications inside a command, but if you are not using GMF, you must make sure that your own models and editparts are handling and refreshing the new item adding properly.
EDIT:
Ok, here is some code suggestion with playing around with requests.
public void run() {
// Fetch viewer from editor part (might not work, if not, try some other way)
EditPartViewer viewer = (EditPartViewer) part.getAdapter(EditPartViewer.class);
// get Target EditPart that is under the mouse
EditPart targetEditPart = viewer.findObjectAt(getLocation());
// If nothing under mouse, set root item as target (just playing safe)
if(targetEditPart == null)
targetEditPart = viewer.getContents();
// Make and initialize create request with proper information
CreateRequest createReq = new CreateRequest();
createReq.setLocation(getLocation());
createReq.setFactory(new OwnFactoryImplementation());
// Ask from target editpart command for this request
Command command = targetEditPart.getCommand(createReq);
// If command is ok, and it can be executed, go and execute it on commandstack
if(command != null && command.canExecute()) {
viewer.getEditDomain().getCommandStack().execute(command);
}
}
Now what happens is that editpart will be requested for creation, so the action itself doesn't know how the command works, what makes it objective agaist the command.
So to make things work, you need to install new EditPolicy to your EditPart. EditPolicies can be installed on EditParts createDefaultEditPolicies() function. This EditPolicy must react and return command when there is CreateRequest. This way any child can provide own kind of command for creating children for itself.
Here is a good image how it works (controller is EditPart):
Please ask if I can help you some more. I know that this looks bit more complex, but this makes your own life much more easier, and after you have done that, you actually understand Command-Request Pattern quite well, and it can be reused in many different places.

Qt: delegate to a single editor

What im trying to do is have a table which does not appear editable directly but can be edited in some widget outside the table. That is, the selected node can be edited here, and all nodes use the same editor because i want it to always be shown.
What I've tried is to subclass QItemDelegate and just return the instance of QTextEdit i already have, like this:
class Delegate extends QItemDelegate {
#Override
public QWidget createEditor(QWidget parent, QStyleOptionViewItem option, QModelIndex index) {
return qtextEdit;
}
}
which works, except that when you leave the editor it gets destroyed. Maybe delegate isn't supposed to be used this way. So how can i achieve this?
(ps. im using jambi but c++ code is fine)

The QDataWidgetMapper class is exactly what you want, to edit the values of whatever record outside of the view in external controls.
Taken straight from the documentation, this is how you'd use it:
QDataWidgetMapper *mapper = new QDataWidgetMapper;
mapper->setModel(model);
mapper->addMapping(mySpinBox, 0);
mapper->addMapping(myLineEdit, 1);
mapper->addMapping(myCountryChooser, 2);
mapper->toFirst();
And, if you have a view (QTreeView / QListView / QTableView / etc) and you want to edit the currently selected item, connect the appropriate signal & slot:
connect(&view, SIGNAL(activated(QModelIndex)), mapper, SLOT(setCurrentModelIndex(QModelIndex)));