Making Ctrl-C copy from whichever SourceViewer has focus in Eclipse plug-in - eclipse

Question

I successfully extended the PyDev editor in Eclipse with a side-by-side display, but I can't copy the contents of the extra SourceViewer that I added. I can select some text in the display, but when I press Ctrl+C, it always copies the main PyDev editor's selected text.
I found an article on key bindings in Eclipse editors, but the code there seems incomplete and a bit out-of-date. How can I configure the copy command to copy from whichever SourceViewer has focus?
The reason I want to do this is that I've written a tool for live coding in Python, and it would be much easier for users to submit bug reports if they could just copy the display and paste it into the bug description.

Answer 1

David Green's article was a good start, but it took a bit of digging to make it all work. I published a full example project on GitHub, and I'll post a couple of snippets here.
The TextViewerSupport class wires up a new action handler for each command you want to delegate to the extra text viewer. If you have multiple text viewers, just instantiate a TextViewerSupport object for each of them. It wires up everything in its constructor.
public TextViewerSupport(TextViewer textViewer) {
this.textViewer = textViewer;
StyledText textWidget = textViewer.getTextWidget();
textWidget.addFocusListener(this);
textWidget.addDisposeListener(this);
IWorkbenchWindow window = PlatformUI.getWorkbench()
.getActiveWorkbenchWindow();
handlerService = (IHandlerService) window
.getService(IHandlerService.class);
if (textViewer.getTextWidget().isFocusControl()) {
activateContext();
}
}
The activateContext() method has a list of all the commands you want to delegate, and registers a new handler for each one. This was one of the changes from David's article; his ITextEditorActionDefinitionIds has been deprecated and replaced with IWorkbenchCommandConstants.
protected void activateContext() {
if (handlerActivations.isEmpty()) {
activateHandler(ITextOperationTarget.COPY,
IWorkbenchCommandConstants.EDIT_COPY);
}
}
// Add a single handler.
protected void activateHandler(int operation, String actionDefinitionId) {
StyledText textWidget = textViewer.getTextWidget();
IHandler actionHandler = createActionHandler(operation,
actionDefinitionId);
IHandlerActivation handlerActivation = handlerService.activateHandler(
actionDefinitionId, actionHandler,
new ActiveFocusControlExpression(textWidget));
handlerActivations.add(handlerActivation);
}
// Create a handler that delegates to the text viewer.
private IHandler createActionHandler(final int operation,
String actionDefinitionId) {
Action action = new Action() {
#Override
public void run() {
if (textViewer.canDoOperation(operation)) {
textViewer.doOperation(operation);
}
}
};
action.setActionDefinitionId(actionDefinitionId);
return new ActionHandler(action);
}
The ActiveFocusControlExpression gives the new handler a high enough priority that it will replace the standard handler, and it's almost identical to David's version. However, to get it to compile, I had to add extra dependencies to my plug-in manifest: I imported packages org.eclipse.core.expressions and org.eclipse.ui.texteditor.