org.eclipse.jface.util.OpenStrategy Maven / Gradle / Ivy
/*******************************************************************************
* Copyright (c) 2000, 2016 IBM Corporation and others.
*
* This program and the accompanying materials
* are made available under the terms of the Eclipse Public License 2.0
* which accompanies this distribution, and is available at
* https://www.eclipse.org/legal/epl-2.0/
*
* SPDX-License-Identifier: EPL-2.0
*
* Contributors:
* IBM Corporation - initial API and implementation
*******************************************************************************/
package org.eclipse.jface.util;
import java.time.Duration;
import org.eclipse.core.runtime.ListenerList;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.events.SelectionListener;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Event;
import org.eclipse.swt.widgets.Listener;
import org.eclipse.swt.widgets.Table;
import org.eclipse.swt.widgets.TableItem;
import org.eclipse.swt.widgets.Tree;
import org.eclipse.swt.widgets.TreeItem;
import org.eclipse.swt.widgets.Widget;
/**
* Implementation of single-click and double-click strategies.
*
* Usage:
*
*
*
* OpenStrategy handler = new OpenStrategy(control);
* handler.addOpenListener(new IOpenEventListener() {
* public void handleOpen(SelectionEvent e) {
* ... // code to handle the open event.
* }
* });
*
*/
public class OpenStrategy {
/**
* Default behavior. Double click to open the item.
*/
public static final int DOUBLE_CLICK = 0;
/**
* Single click will open the item.
*/
public static final int SINGLE_CLICK = 1;
/**
* Hover will select the item.
*/
public static final int SELECT_ON_HOVER = 1 << 1;
/**
* Open item when using arrow keys
*/
public static final int ARROW_KEYS_OPEN = 1 << 2;
/** A single click will generate
* an open event but key arrows will not do anything.
*
* @deprecated
*/
@Deprecated
public static final int NO_TIMER = SINGLE_CLICK;
/** A single click will generate an open
* event and key arrows will generate an open event after a
* small time.
*
* @deprecated
*/
@Deprecated
public static final int FILE_EXPLORER = SINGLE_CLICK | ARROW_KEYS_OPEN;
/** Pointing to an item will change the selection
* and a single click will gererate an open event
*
* @deprecated
*/
@Deprecated
public static final int ACTIVE_DESKTOP = SINGLE_CLICK | SELECT_ON_HOVER;
// Time used in FILE_EXPLORER and ACTIVE_DESKTOP
// Not declared final, see bug 246209
private static int TIME = 500;
/**
* Returns the delay for post selection events.
*
* @return the delay for post selection events in milliseconds
* @since 3.7
*/
public static final int getPostSelectionDelay() {
return TIME;
}
/* SINGLE_CLICK or DOUBLE_CLICK;
* In case of SINGLE_CLICK, the bits SELECT_ON_HOVER and ARROW_KEYS_OPEN
* my be set as well. */
private static int CURRENT_METHOD = DOUBLE_CLICK;
private Listener eventHandler;
private ListenerList openEventListeners = new ListenerList<>();
private ListenerList selectionEventListeners = new ListenerList<>();
private ListenerList postSelectionEventListeners = new ListenerList<>();
final Throttler throttledPostSelection;
final PostSelectionEvent postSelectionEvent = new PostSelectionEvent();
class PostSelectionEvent implements Runnable {
volatile Event e;
void setEvent(Event e) {
this.e = e;
}
@Override
public void run() {
firePostSelectionEvent(new SelectionEvent(e));
if ((CURRENT_METHOD & ARROW_KEYS_OPEN) != 0) {
fireOpenEvent(new SelectionEvent(e));
}
}
}
/**
* @param control the control the strategy is applied to
*/
public OpenStrategy(Control control) {
initializeHandler(control.getDisplay());
addListener(control);
throttledPostSelection = new Throttler(control.getDisplay(), Duration.ofMillis(TIME), postSelectionEvent);
}
/**
* Adds an IOpenEventListener to the collection of openEventListeners
* @param listener the listener to add
*/
public void addOpenListener(IOpenEventListener listener) {
openEventListeners.add(listener);
}
/**
* Removes an IOpenEventListener to the collection of openEventListeners
* @param listener the listener to remove
*/
public void removeOpenListener(IOpenEventListener listener) {
openEventListeners.remove(listener);
}
/**
* Adds an SelectionListener to the collection of selectionEventListeners
* @param listener the listener to add
*/
public void addSelectionListener(SelectionListener listener) {
selectionEventListeners.add(listener);
}
/**
* Removes an SelectionListener to the collection of selectionEventListeners
* @param listener the listener to remove
*/
public void removeSelectionListener(SelectionListener listener) {
selectionEventListeners.remove(listener);
}
/**
* Adds an SelectionListener to the collection of selectionEventListeners
* @param listener the listener to add
*/
public void addPostSelectionListener(SelectionListener listener) {
postSelectionEventListeners.add(listener);
}
/**
* Removes an SelectionListener to the collection of selectionEventListeners
* @param listener the listener to remove
*/
public void removePostSelectionListener(SelectionListener listener) {
postSelectionEventListeners.remove(listener);
}
/**
* This method is internal to the framework; it should not be implemented outside
* the framework.
* @return the current used single/double-click method
*/
public static int getOpenMethod() {
return CURRENT_METHOD;
}
/**
* Set the current used single/double-click method.
*
* This method is internal to the framework; it should not be implemented outside
* the framework.
* @param method the method to be used
* @see OpenStrategy#DOUBLE_CLICK
* @see OpenStrategy#SINGLE_CLICK
* @see OpenStrategy#SELECT_ON_HOVER
* @see OpenStrategy#ARROW_KEYS_OPEN
*/
public static void setOpenMethod(int method) {
if (method == DOUBLE_CLICK) {
CURRENT_METHOD = method;
return;
}
if ((method & SINGLE_CLICK) == 0) {
throw new IllegalArgumentException("Invalid open mode"); //$NON-NLS-1$
}
if ((method & (SINGLE_CLICK | SELECT_ON_HOVER | ARROW_KEYS_OPEN)) == 0) {
throw new IllegalArgumentException("Invalid open mode"); //$NON-NLS-1$
}
CURRENT_METHOD = method;
}
/**
* @return true if editors should be activated when opened.
*/
public static boolean activateOnOpen() {
return getOpenMethod() == DOUBLE_CLICK;
}
/*
* Adds all needed listener to the control in order to implement
* single-click/double-click strategies.
*/
private void addListener(Control c) {
c.addListener(SWT.MouseEnter, eventHandler);
c.addListener(SWT.MouseExit, eventHandler);
c.addListener(SWT.MouseMove, eventHandler);
c.addListener(SWT.MouseDown, eventHandler);
c.addListener(SWT.MouseUp, eventHandler);
c.addListener(SWT.KeyDown, eventHandler);
c.addListener(SWT.Selection, eventHandler);
c.addListener(SWT.DefaultSelection, eventHandler);
c.addListener(SWT.Collapse, eventHandler);
c.addListener(SWT.Expand, eventHandler);
}
/*
* Fire the selection event to all selectionEventListeners
*/
private void fireSelectionEvent(SelectionEvent e) {
if (e.item != null && e.item.isDisposed()) {
return;
}
for (SelectionListener l : selectionEventListeners) {
l.widgetSelected(e);
}
}
/*
* Fire the default selection event to all selectionEventListeners
*/
private void fireDefaultSelectionEvent(SelectionEvent e) {
for (SelectionListener l : selectionEventListeners) {
l.widgetDefaultSelected(e);
}
}
/*
* Fire the post selection event to all postSelectionEventListeners
*/
private void firePostSelectionEvent(SelectionEvent e) {
if (e.item != null && e.item.isDisposed()) {
return;
}
for (SelectionListener l : postSelectionEventListeners) {
l.widgetSelected(e);
}
}
/*
* Fire the open event to all openEventListeners
*/
private void fireOpenEvent(SelectionEvent e) {
if (e.item != null && e.item.isDisposed()) {
return;
}
for (IOpenEventListener l : openEventListeners) {
l.handleOpen(e);
}
}
//Initialize event handler.
private void initializeHandler(final Display display) {
eventHandler = new Listener() {
boolean timerStarted = false;
Event mouseUpEvent = null;
Event mouseMoveEvent = null;
SelectionEvent selectionPendent = null;
boolean enterKeyDown = false;
SelectionEvent defaultSelectionPendent = null;
boolean arrowKeyDown = false;
final int[] count = new int[1];
long startTime = System.currentTimeMillis();
boolean collapseOccurred = false;
boolean expandOccurred = false;
@Override
public void handleEvent(final Event e) {
if (e.type == SWT.DefaultSelection) {
SelectionEvent event = new SelectionEvent(e);
fireDefaultSelectionEvent(event);
if (CURRENT_METHOD == DOUBLE_CLICK) {
fireOpenEvent(event);
} else if (enterKeyDown) {
fireOpenEvent(event);
enterKeyDown = false;
defaultSelectionPendent = null;
} else {
defaultSelectionPendent = event;
}
return;
}
switch (e.type) {
case SWT.MouseEnter:
case SWT.MouseExit:
mouseUpEvent = null;
mouseMoveEvent = null;
selectionPendent = null;
break;
case SWT.MouseMove:
if ((CURRENT_METHOD & SELECT_ON_HOVER) == 0) {
return;
}
if (e.stateMask != 0) {
return;
}
if (e.widget.getDisplay().getFocusControl() != e.widget) {
return;
}
mouseMoveEvent = e;
final Runnable runnable[] = new Runnable[1];
runnable[0] = () -> {
long time = System.currentTimeMillis();
int diff = (int) (time - startTime);
if (diff <= TIME) {
display.timerExec(diff * 2 / 3, runnable[0]);
} else {
timerStarted = false;
setSelection(mouseMoveEvent);
}
};
startTime = System.currentTimeMillis();
if (!timerStarted) {
timerStarted = true;
display.timerExec(TIME * 2 / 3, runnable[0]);
}
break;
case SWT.MouseDown:
mouseUpEvent = null;
arrowKeyDown = false;
break;
case SWT.Expand:
expandOccurred = true;
break;
case SWT.Collapse:
collapseOccurred = true;
break;
case SWT.MouseUp:
mouseMoveEvent = null;
if ((e.button != 1) || ((e.stateMask & ~SWT.BUTTON1) != 0)) {
return;
}
if (selectionPendent != null
&& !(collapseOccurred || expandOccurred)) {
mouseSelectItem(selectionPendent);
} else {
mouseUpEvent = e;
collapseOccurred = false;
expandOccurred = false;
selectionPendent= null;
}
break;
case SWT.KeyDown:
mouseMoveEvent = null;
mouseUpEvent = null;
arrowKeyDown = ((e.keyCode == SWT.ARROW_UP) || (e.keyCode == SWT.ARROW_DOWN))
&& e.stateMask == 0;
if (e.character == SWT.CR) {
if (defaultSelectionPendent != null) {
fireOpenEvent(new SelectionEvent(e));
enterKeyDown = false;
defaultSelectionPendent = null;
} else {
enterKeyDown = true;
}
}
collapseOccurred= false;
expandOccurred= false;
break;
case SWT.Selection:
SelectionEvent event = new SelectionEvent(e);
fireSelectionEvent(event);
mouseMoveEvent = null;
if (mouseUpEvent != null) {
mouseSelectItem(event);
} else {
selectionPendent = event;
}
count[0]++;
// In the case of arrowUp/arrowDown when in the arrowKeysOpen mode, we
// want to delay any selection until the last arrowDown/Up occurs. This
// handles the case where the user presses arrowDown/Up successively.
// We only want to open an editor for the last selected item.
display.asyncExec(() -> {
if (arrowKeyDown) {
postSelectionEvent.setEvent(e);
throttledPostSelection.throttledExec();
} else {
firePostSelectionEvent(new SelectionEvent(e));
}
});
break;
}
}
void mouseSelectItem(SelectionEvent e) {
if ((CURRENT_METHOD & SINGLE_CLICK) != 0) {
fireOpenEvent(e);
}
mouseUpEvent = null;
selectionPendent = null;
}
void setSelection(Event e) {
if (e == null) {
return;
}
Widget w = e.widget;
if (w.isDisposed()) {
return;
}
SelectionEvent selEvent = new SelectionEvent(e);
/*ISSUE: May have to create a interface with method:
setSelection(Point p) so that user's custom widgets
can use this class. If we keep this option. */
if (w instanceof Tree) {
Tree tree = (Tree) w;
TreeItem item = tree.getItem(new Point(e.x, e.y));
if (item != null) {
tree.setSelection(new TreeItem[] { item });
}
selEvent.item = item;
} else if (w instanceof Table) {
Table table = (Table) w;
TableItem item = table.getItem(new Point(e.x, e.y));
if (item != null) {
table.setSelection(new TableItem[] { item });
}
selEvent.item = item;
} else {
return;
}
if (selEvent.item == null) {
return;
}
fireSelectionEvent(selEvent);
firePostSelectionEvent(selEvent);
}
};
}
}