org.eclipse.jface.action.StatusLineContributionItem Maven / Gradle / Ivy
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/*******************************************************************************
* Copyright (c) 2000, 2019 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.action;
import org.eclipse.core.runtime.Assert;
import org.eclipse.jface.util.Util;
import org.eclipse.swt.SWT;
import org.eclipse.swt.custom.CLabel;
import org.eclipse.swt.graphics.FontMetrics;
import org.eclipse.swt.graphics.GC;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Label;
/**
* A contribution item to be used with status line managers.
*
* This class may be instantiated; it is not intended to be subclassed.
*
*
* @since 3.4
*/
public class StatusLineContributionItem extends ContributionItem {
private static final int DEFAULT_CHAR_WIDTH = 40;
/**
* A constant indicating that the contribution should compute its actual
* size depending on the text. It will grab all space necessary to display
* the whole text.
*
* @since 3.6
*/
public static final int CALC_TRUE_WIDTH = -1;
private int charWidth;
private CLabel label;
/**
* The composite into which this contribution item has been placed. This
* will be null
if this instance has not yet been
* initialized.
*/
private Composite statusLine = null;
private String text = Util.ZERO_LENGTH_STRING;
private int widthHint = -1;
private int heightHint = -1;
/**
* Creates a status line contribution item with the given id.
*
* @param id
* the contribution item's id, or null
if it is to
* have no id
*/
public StatusLineContributionItem(String id) {
this(id, DEFAULT_CHAR_WIDTH);
}
/**
* Creates a status line contribution item with the given id that displays
* the given number of characters.
*
* @param id
* the contribution item's id, or null
if it is to
* have no id
* @param charWidth
* the number of characters to display. If the value is
* CALC_TRUE_WIDTH then the contribution will compute the
* preferred size exactly. Otherwise the size will be based on the
* average character size * 'charWidth'
*/
public StatusLineContributionItem(String id, int charWidth) {
super(id);
this.charWidth = charWidth;
setVisible(false); // no text to start with
}
@Override
public void fill(Composite parent) {
statusLine = parent;
Label sep = new Label(parent, SWT.SEPARATOR);
label = new CLabel(statusLine, SWT.SHADOW_NONE);
label.setText(text);
if (charWidth == CALC_TRUE_WIDTH) {
// compute the size of the label to get the width hint for the contribution
Point preferredSize = label.computeSize(SWT.DEFAULT, SWT.DEFAULT);
widthHint = preferredSize.x;
heightHint = preferredSize.y;
} else if (widthHint < 0) {
// Compute the size base on 'charWidth' average char widths
GC gc = new GC(statusLine);
gc.setFont(statusLine.getFont());
FontMetrics fm = gc.getFontMetrics();
widthHint = (int) (fm.getAverageCharacterWidth() * charWidth);
heightHint = fm.getHeight();
gc.dispose();
}
StatusLineLayoutData data = new StatusLineLayoutData();
data.widthHint = widthHint;
label.setLayoutData(data);
data = new StatusLineLayoutData();
data.heightHint = heightHint;
sep.setLayoutData(data);
}
/**
* An accessor for the current location of this status line contribution
* item -- relative to the display.
*
* @return The current location of this status line; null
if
* not yet initialized.
*/
public Point getDisplayLocation() {
if ((label != null) && (statusLine != null)) {
return statusLine.toDisplay(label.getLocation());
}
return null;
}
/**
* Retrieves the text that is being displayed in the status line.
*
* @return the text that is currently being displayed
*/
public String getText() {
return text;
}
/**
* Sets the text to be displayed in the status line.
*
* @param text
* the text to be displayed, must not be null
*/
public void setText(String text) {
Assert.isNotNull(text);
this.text = LegacyActionTools.escapeMnemonics(text);
if (label != null && !label.isDisposed()) {
label.setText(this.text);
}
if (this.text.isEmpty()) {
if (isVisible()) {
setVisible(false);
IContributionManager contributionManager = getParent();
if (contributionManager != null) {
contributionManager.update(true);
}
}
} else // Always update if using 'CALC_TRUE_WIDTH'
if (!isVisible() || charWidth == CALC_TRUE_WIDTH) {
setVisible(true);
IContributionManager contributionManager = getParent();
if (contributionManager != null) {
contributionManager.update(true);
}
}
}
}