/*******************************************************************************
* Copyright (c) 2004, 2015 IBM Corporation and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* IBM Corporation - initial API and implementation
*******************************************************************************/
package org.eclipse.ui.internal.handlers;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import org.eclipse.core.commands.ExecutionEvent;
import org.eclipse.core.commands.ExecutionException;
import org.eclipse.core.runtime.IConfigurationElement;
import org.eclipse.swt.SWT;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.widgets.Combo;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Display;
import org.eclipse.ui.internal.ExceptionHandler;
/**
* This handler is an adaptation of the widget method handler allowing select
* all to work even in some cases where the "selectAll" method does not exist.
* This handler attempts to use "getTextLimit" and "setSelection" to do select
* all. If this doesn't work, then it finally fails.
*
* @since 3.0
*/
public class SelectAllHandler extends WidgetMethodHandler {
/**
* The parameters for a single point select all.
*/
private static final Class[] METHOD_PARAMETERS = { Point.class };
@Override
public final Object execute(final ExecutionEvent event)
throws ExecutionException {
final Method methodToExecute = getMethodToExecute();
if (methodToExecute != null) {
try {
final Control focusControl = Display.getCurrent()
.getFocusControl();
final int numParams = methodToExecute.getParameterTypes().length;
if ((focusControl instanceof Composite)
&& ((((Composite) focusControl).getStyle() & SWT.EMBEDDED) != 0)) {
// we only support selectAll for swing components
if (numParams != 0) {
return null;
}
/*
* Okay. Have a seat. Relax a while. This is going to be a
* bumpy ride. If it is an embedded widget, then it *might*
* be a Swing widget. At the point where this handler is
* executing, the key event is already bound to be
* swallowed. If I don't do something, then the key will be
* gone for good. So, I will try to forward the event to the
* Swing widget. Unfortunately, we can't even count on the
* Swing libraries existing, so I need to use reflection
* everywhere. And, to top it off, I need to dispatch the
* event on the Swing event queue, which means that it will
* be carried out asynchronously to the SWT event queue.
*/
try {
final Object focusComponent = getFocusComponent();
if (focusComponent != null) {
Runnable methodRunnable = () -> {
try {
methodToExecute.invoke(focusComponent);
// and back to the UI thread :-)
focusControl.getDisplay().asyncExec(
() -> {
if (!focusControl
.isDisposed()) {
focusControl
.notifyListeners(
SWT.Selection,
null);
}
});
} catch (final IllegalAccessException e1) {
// The method is protected, so do
// nothing.
} catch (final InvocationTargetException e2) {
/*
* I would like to log this exception --
* and possibly show a dialog to the
* user -- but I have to go back to the
* SWT event loop to do this. So, back
* we go....
*/
focusControl.getDisplay().asyncExec(
() -> ExceptionHandler
.getInstance()
.handleException(
new ExecutionException(
"An exception occurred while executing " //$NON-NLS-1$
+ methodToExecute
.getName(),
e2
.getTargetException())));
}
};
swingInvokeLater(methodRunnable);
}
} catch (final ClassNotFoundException e) {
// There is no Swing support, so do nothing.
} catch (final NoSuchMethodException e) {
// The API has changed, which seems amazingly unlikely.
throw new Error("Something is seriously wrong here"); //$NON-NLS-1$
}
} else if (numParams == 0) {
// This is a no-argument selectAll method.
methodToExecute.invoke(focusControl);
focusControl.notifyListeners(SWT.Selection, null);
} else if (numParams == 1) {
// This is a single-point selection method.
final Method textLimitAccessor = focusControl.getClass()
.getMethod("getTextLimit", NO_PARAMETERS); //$NON-NLS-1$
final Integer textLimit = (Integer) textLimitAccessor
.invoke(focusControl);
final Object[] parameters = { new Point(0, textLimit
.intValue()) };
methodToExecute.invoke(focusControl, parameters);
if (!(focusControl instanceof Combo)) {
focusControl.notifyListeners(SWT.Selection, null);
}
} else {
/*
* This means that getMethodToExecute() has been changed,
* while this method hasn't.
*/
throw new ExecutionException(
"Too many parameters on select all", new Exception()); //$NON-NLS-1$
}
} catch (IllegalAccessException e) {
// The method is protected, so do nothing.
} catch (InvocationTargetException e) {
throw new ExecutionException(
"An exception occurred while executing " //$NON-NLS-1$
+ getMethodToExecute(), e.getTargetException());
} catch (NoSuchMethodException e) {
// I can't get the text limit. Do nothing.
}
}
return null;
}
/**
* Looks up the select all method on the given focus control.
*
* @return The method on the focus control; <code>null</code> if none.
*/
@Override
protected Method getMethodToExecute() {
Method method = super.getMethodToExecute();
// Let's see if we have a control that supports point-based selection.
if (method == null) {
final Control focusControl = Display.getCurrent().getFocusControl();
if (focusControl != null) {
try {
method = focusControl.getClass().getMethod("setSelection", //$NON-NLS-1$
METHOD_PARAMETERS);
} catch (NoSuchMethodException e) {
// Do nothing.
}
}
}
return method;
}
/**
* @see org.eclipse.core.runtime.IExecutableExtension#setInitializationData(org.eclipse.core.runtime.IConfigurationElement,
* java.lang.String, java.lang.Object)
*/
@Override
public void setInitializationData(IConfigurationElement config,
String propertyName, Object data) {
// The name is always "selectAll".
methodName = "selectAll"; //$NON-NLS-1$
}
}