org.eclipse.jface.resource.FileImageDescriptor Maven / Gradle / Ivy
/*******************************************************************************
* Copyright (c) 2000, 2022 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
* Christoph Läubrich - Bug 567898 - [JFace][HiDPI] ImageDescriptor support alternative naming scheme for high dpi
* Daniel Kruegler - #375, #376, #378, #396, #398, #401,
* #679: Ensure that a fresh ImageFileNameProvider instance is created to preserve Image#equals invariant.
*******************************************************************************/
package org.eclipse.jface.resource;
import java.io.BufferedInputStream;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.util.Objects;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import org.eclipse.core.runtime.FileLocator;
import org.eclipse.core.runtime.IAdaptable;
import org.eclipse.core.runtime.IPath;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Status;
import org.eclipse.jface.internal.InternalPolicy;
import org.eclipse.jface.util.Policy;
import org.eclipse.swt.SWT;
import org.eclipse.swt.SWTException;
import org.eclipse.swt.graphics.Device;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.graphics.ImageData;
import org.eclipse.swt.graphics.ImageFileNameProvider;
/**
* An image descriptor that loads its image information from a file.
*/
class FileImageDescriptor extends ImageDescriptor implements IAdaptable {
private class ImageProvider implements ImageFileNameProvider {
@Override
public String getImagePath(int zoom) {
final boolean logIOException = zoom == 100;
if (zoom == 100) {
return getFilePath(name, logIOException);
}
String xName = getxName(name, zoom);
if (xName != null) {
String xResult = getFilePath(xName, logIOException);
if (xResult != null) {
return xResult;
}
}
String xPath = getxPath(name, zoom);
if (xPath != null) {
String xResult = getFilePath(xPath, logIOException);
if (xResult != null) {
return xResult;
}
}
return null;
}
}
private static final Pattern XPATH_PATTERN = Pattern.compile("(\\d+)x(\\d+)"); //$NON-NLS-1$
/**
* The class whose resource directory contain the file, or null
* if none.
*/
private final Class location;
/**
* The name of the file.
*/
private final String name;
/**
* Creates a new file image descriptor. The file has the given file name and
* is located in the given class's resource directory. If the given class is
* null, the file name must be absolute.
*
* Note that the file is not accessed until its getImageDate
* method is called.
*
*
* @param clazz
* class for resource directory, or null
* @param filename
* the name of the file
*/
FileImageDescriptor(Class clazz, String filename) {
super(true);
this.location = clazz;
this.name = filename;
}
@Override
public boolean equals(Object o) {
if (!(o instanceof FileImageDescriptor)) {
return false;
}
FileImageDescriptor other = (FileImageDescriptor) o;
return Objects.equals(location, other.location) && Objects.equals(name, other.name);
}
/**
* {@inheritDoc}
*
* The FileImageDescriptor implementation of this method is not used by
* {@link ImageDescriptor#createImage(boolean, Device)} as of version
* 3.4 so that the SWT OS optimized loading can be used.
*/
@Override
public ImageData getImageData(int zoom) {
InputStream in = getStream(zoom);
if (in != null) {
try (BufferedInputStream stream = new BufferedInputStream(in)) {
return new ImageData(stream);
} catch (SWTException e) {
if (e.code != SWT.ERROR_INVALID_IMAGE) {
throw e;
// fall through otherwise
}
} catch (IOException ioe) {
// fall through
}
}
return null;
}
/**
* Returns a stream on the image contents. Returns null if a stream could
* not be opened.
*
* @param zoom the zoom factor
* @return the buffered stream on the file or null if the
* file cannot be found
*/
private InputStream getStream(int zoom) {
if (zoom == 100) {
return getStream(name);
}
InputStream xstream = getStream(getxName(name, zoom));
if (xstream != null) {
return xstream;
}
InputStream xpath = getStream(getxPath(name, zoom));
if (xpath != null) {
return xpath;
}
return null;
}
/**
* try to obtain a stream for a given name, if the name does not match a valid
* resource null is returned
*
* @param fileName the filename to check
* @return an {@link InputStream} to read from, or null if fileName
* does not denotes an existing resource
*/
private InputStream getStream(String fileName) {
if (fileName != null) {
if (location != null) {
return location.getResourceAsStream(fileName);
}
try {
return new FileInputStream(fileName);
} catch (FileNotFoundException e) {
return null;
}
}
return null;
}
static String getxPath(String name, int zoom) {
Matcher matcher = XPATH_PATTERN.matcher(name);
if (matcher.find()) {
try {
int currentWidth = Integer.parseInt(matcher.group(1));
int desiredWidth = Math.round((zoom / 100f) * currentWidth);
int currentHeight = Integer.parseInt(matcher.group(2));
int desiredHeight = Math.round((zoom / 100f) * currentHeight);
String lead = name.substring(0, matcher.start(1));
String tail = name.substring(matcher.end(2));
return lead + desiredWidth + "x" + desiredHeight + tail; //$NON-NLS-1$
} catch (RuntimeException e) {
// should never happen but if then we can't use the alternative name...
}
}
return null;
}
static String getxName(String name, int zoom) {
int dot = name.lastIndexOf('.');
if (dot != -1 && (zoom == 150 || zoom == 200)) {
String lead = name.substring(0, dot);
String tail = name.substring(dot);
if (InternalPolicy.DEBUG_LOAD_URL_IMAGE_DESCRIPTOR_2x_PNG_FOR_GIF && ".gif".equalsIgnoreCase(tail)) { //$NON-NLS-1$
tail = ".png"; //$NON-NLS-1$
}
String x = zoom == 150 ? "@1.5x" : "@2x"; //$NON-NLS-1$ //$NON-NLS-2$
return lead + x + tail;
}
return null;
}
@Override
public int hashCode() {
int code = name.hashCode();
if (location != null) {
code += location.hashCode();
}
return code;
}
/**
* The FileImageDescriptor implementation of this
* Object method returns a string representation of this
* object which is suitable only for debugging.
*/
@Override
public String toString() {
return "FileImageDescriptor(location=" + location + ", name=" + name + ")";//$NON-NLS-3$//$NON-NLS-2$//$NON-NLS-1$
}
@Override
public Image createImage(boolean returnMissingImageOnError, Device device) {
if (InternalPolicy.DEBUG_LOAD_URL_IMAGE_DESCRIPTOR_2x) {
try {
// We really want a fresh ImageFileNameProvider instance to make
// sure the code that uses created images can use equals(),
// see Image#equals
return new Image(device, new ImageProvider());
} catch (SWTException | IllegalArgumentException exception) {
// If we fail, fall back to the old 1x implementation.
}
}
String path = getFilePath(name, true);
if (path == null)
return createDefaultImage(returnMissingImageOnError, device);
try {
return new Image(device, path);
} catch (SWTException exception) {
//if we fail try the default way using a stream
}
return super.createImage(returnMissingImageOnError, device);
}
/**
* Return default image if returnMissingImageOnError is true.
*
* @return Image or null
*/
private Image createDefaultImage(boolean returnMissingImageOnError,
Device device) {
try {
if (returnMissingImageOnError)
return new Image(device, DEFAULT_IMAGE_DATA);
} catch (SWTException nextException) {
return null;
}
return null;
}
/**
* Returns the filename for the ImageData.
*
* @param name the file name
* @return {@link String} or null if the file cannot be found
*/
String getFilePath(String name, boolean logIOException) {
if (location == null)
return IPath.fromOSString(name).toOSString();
URL resource = location.getResource(name);
if (resource == null)
return null;
try {
if (!InternalPolicy.OSGI_AVAILABLE) {// Stand-alone case
return IPath.fromOSString(resource.getFile()).toOSString();
}
return IPath.fromOSString(FileLocator.toFileURL(resource).getPath()).toOSString();
} catch (IOException e) {
if (logIOException) {
Policy.logException(e);
} else if (InternalPolicy.DEBUG_LOG_URL_IMAGE_DESCRIPTOR_MISSING_2x) {
if (name.endsWith("@2x.png") || name.endsWith("@1.5x.png")) { //$NON-NLS-1$ //$NON-NLS-2$
String message = "High-resolution image missing: " + location + ' ' + name; //$NON-NLS-1$
Policy.getLog().log(new Status(IStatus.WARNING, Policy.JFACE, message, e));
}
}
return null;
}
}
@Override
public T getAdapter(Class adapter) {
if (adapter == URL.class) {
if (location != null && name != null) {
return adapter.cast(location.getResource(name));
}
}
if (adapter == ImageFileNameProvider.class) {
return adapter.cast(new ImageProvider());
}
return null;
}
}