/*******************************************************************************
* Copyright (c) 2006, 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.actions;
import java.util.ArrayList;
import java.util.List;
import org.eclipse.jface.action.IMenuManager;
import org.eclipse.jface.action.MenuManager;
import org.eclipse.swt.SWT;
import org.eclipse.swt.custom.StyledText;
import org.eclipse.swt.graphics.GC;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.graphics.Rectangle;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Menu;
import org.eclipse.swt.widgets.Table;
import org.eclipse.swt.widgets.TableItem;
import org.eclipse.swt.widgets.Tree;
import org.eclipse.swt.widgets.TreeItem;
/**
* Abstract class that is capable of creating a context menu. It will try and
* open the menu close to the current selection, or under the mouse pointer if
* that's not possible.
*
* @since 3.3
*/
public abstract class QuickMenuCreator {
private static final int CHAR_INDENT = 3;
/**
* Create and open the context menu.
*/
public void createMenu() {
final Display display = Display.getCurrent();
if (display == null) {
return;
}
Control focus = display.getFocusControl();
if (focus == null || focus.isDisposed()) {
return;
}
MenuManager menu = new MenuManager();
fillMenu(menu);
final Menu quickMenu = menu.createContextMenu(focus.getShell());
Point location = computeMenuLocation(focus);
if (location == null) {
return;
}
quickMenu.setLocation(location);
quickMenu.addListener(SWT.Hide, event -> {
if (!display.isDisposed()) {
display.asyncExec(() -> {
if (!quickMenu.isDisposed()) {
quickMenu.dispose();
}
});
}
});
quickMenu.setVisible(true);
}
/**
* Create the contents of the context menu.
*
* @param menu
* the menu to fill
*/
protected abstract void fillMenu(IMenuManager menu);
/**
* Determine the optimal point for this menu to appear.
*
* @param focus
* the focus control
* @return the optimal placement
* @since 3.5
*/
protected Point computeMenuLocation(Control focus) {
Point cursorLocation = focus.getDisplay().getCursorLocation();
Rectangle clientArea = null;
Point result = null;
if (focus instanceof StyledText) {
StyledText styledText = (StyledText) focus;
clientArea = styledText.getClientArea();
result = computeMenuLocation(styledText);
} else if (focus instanceof Tree) {
Tree tree = (Tree) focus;
clientArea = tree.getClientArea();
result = computeMenuLocation(tree);
} else if (focus instanceof Table) {
Table table = (Table) focus;
clientArea = table.getClientArea();
result = computeMenuLocation(table);
}
if (result == null) {
result = focus.toControl(cursorLocation);
}
if (clientArea != null && !clientArea.contains(result)) {
result = new Point(clientArea.x + clientArea.width / 2,
clientArea.y + clientArea.height / 2);
}
Rectangle shellArea = focus.getShell().getClientArea();
if (!shellArea.contains(focus.getShell().toControl(
focus.toDisplay(result)))) {
result = new Point(shellArea.x + shellArea.width / 2, shellArea.y
+ shellArea.height / 2);
}
return focus.toDisplay(result);
}
/**
* Hook to compute the menu location if the focus widget is a styled text
* widget.
*
* @param text
* the styled text widget that has the focus
*
* @return a widget relative position of the menu to pop up or
* <code>null</code> if now position inside the widget can be
* computed
* @since 3.5
*/
protected Point computeMenuLocation(StyledText text) {
Point result = text.getLocationAtOffset(text.getCaretOffset());
result.y += text.getLineHeight(text.getCaretOffset());
if (!text.getClientArea().contains(result)) {
return null;
}
return result;
}
/**
* Hook to compute the menu location if the focus widget is a tree widget.
*
* @param tree
* the tree widget that has the focus
*
* @return a widget relative position of the menu to pop up or
* <code>null</code> if now position inside the widget can be
* computed
* @since 3.5
*/
protected Point computeMenuLocation(Tree tree) {
TreeItem[] items = tree.getSelection();
Rectangle clientArea = tree.getClientArea();
switch (items.length) {
case 0:
return null;
case 1:
Rectangle bounds = items[0].getBounds();
Rectangle intersect = clientArea.intersection(bounds);
if (intersect != null && intersect.height == bounds.height) {
return new Point(Math.max(0, bounds.x
+ getAvarageCharWith(tree) * CHAR_INDENT), bounds.y
+ bounds.height);
}
return null;
default:
Rectangle[] rectangles = new Rectangle[items.length];
for (int i = 0; i < rectangles.length; i++) {
rectangles[i] = items[i].getBounds();
}
Point cursorLocation = tree.getDisplay().getCursorLocation();
Point result = findBestLocation(getIncludedPositions(rectangles,
clientArea), tree.toControl(cursorLocation));
if (result != null) {
result.x = result.x + getAvarageCharWith(tree) * CHAR_INDENT;
}
return result;
}
}
/**
* Hook to compute the menu location if the focus widget is a table widget.
*
* @param table
* the table widget that has the focus
*
* @return a widget relative position of the menu to pop up or
* <code>null</code> if now position inside the widget can be
* computed
* @since 3.5
*/
protected Point computeMenuLocation(Table table) {
TableItem[] items = table.getSelection();
Rectangle clientArea = table.getClientArea();
switch (items.length) {
case 0: {
return null;
}
case 1: {
Rectangle bounds = items[0].getBounds(0);
Rectangle iBounds = items[0].getImageBounds(0);
Rectangle intersect = clientArea.intersection(bounds);
if (intersect != null && intersect.height == bounds.height) {
return new Point(Math.max(0, bounds.x + iBounds.width
+ getAvarageCharWith(table) * CHAR_INDENT), bounds.y
+ bounds.height);
}
return null;
}
default: {
Rectangle[] rectangles = new Rectangle[items.length];
for (int i = 0; i < rectangles.length; i++) {
rectangles[i] = items[i].getBounds(0);
}
Rectangle iBounds = items[0].getImageBounds(0);
Point cursorLocation = table.getDisplay().getCursorLocation();
Point result = findBestLocation(getIncludedPositions(rectangles,
clientArea), table.toControl(cursorLocation));
if (result != null) {
result.x = result.x + iBounds.width + getAvarageCharWith(table)
* CHAR_INDENT;
}
return result;
}
}
}
private Point[] getIncludedPositions(Rectangle[] rectangles,
Rectangle widgetBounds) {
List result = new ArrayList();
for (Rectangle rectangle : rectangles) {
Rectangle intersect = widgetBounds.intersection(rectangle);
if (intersect != null && intersect.height == rectangle.height) {
result.add(new Point(intersect.x, intersect.y
+ intersect.height));
}
}
return (Point[]) result.toArray(new Point[result.size()]);
}
private Point findBestLocation(Point[] points, Point relativeCursor) {
Point result = null;
double bestDist = Double.MAX_VALUE;
for (Point point : points) {
int a = 0;
int b = 0;
if (point.x > relativeCursor.x) {
a = point.x - relativeCursor.x;
} else {
a = relativeCursor.x - point.x;
}
if (point.y > relativeCursor.y) {
b = point.y - relativeCursor.y;
} else {
b = relativeCursor.y - point.y;
}
double dist = Math.sqrt(a * a + b * b);
if (dist < bestDist) {
result = point;
bestDist = dist;
}
}
return result;
}
private int getAvarageCharWith(Control control) {
GC gc = null;
try {
gc = new GC(control);
return gc.getFontMetrics().getAverageCharWidth();
} finally {
if (gc != null) {
gc.dispose();
}
}
}
/**
* Dispose of this quick menu creator. Subclasses should ensure that they
* call this method.
*
* @deprecated As of 3.5 this is not necessary as the SWT Menu created in
* {@link #createMenu()} will be disposed shortly after the
* SWT.Hide event.
*/
@Deprecated
public void dispose() {
}
}