| /******************************************************************************* |
| * Copyright (c) 2005, 2018 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.ui.internal.util; |
| |
| import java.lang.reflect.InvocationTargetException; |
| import java.lang.reflect.Method; |
| import java.util.ArrayList; |
| import java.util.Iterator; |
| import java.util.List; |
| import org.eclipse.jface.resource.ColorDescriptor; |
| import org.eclipse.jface.resource.DeviceResourceDescriptor; |
| import org.eclipse.jface.resource.DeviceResourceException; |
| import org.eclipse.jface.resource.FontDescriptor; |
| import org.eclipse.jface.resource.ImageDescriptor; |
| import org.eclipse.jface.resource.JFaceResources; |
| import org.eclipse.jface.resource.ResourceManager; |
| import org.eclipse.swt.events.DisposeListener; |
| import org.eclipse.swt.graphics.Color; |
| import org.eclipse.swt.graphics.Font; |
| import org.eclipse.swt.graphics.Image; |
| import org.eclipse.swt.widgets.Button; |
| import org.eclipse.swt.widgets.Control; |
| import org.eclipse.swt.widgets.Item; |
| import org.eclipse.swt.widgets.Label; |
| import org.eclipse.swt.widgets.TableItem; |
| import org.eclipse.swt.widgets.ToolItem; |
| import org.eclipse.swt.widgets.Widget; |
| import org.eclipse.ui.internal.WorkbenchPlugin; |
| |
| /** |
| * Contains a bunch of helper methods that allow JFace resource descriptors to |
| * be passed directly to SWT widgets without worrying about resource allocation. |
| * This class is internal, but it should be moved into JFace if the pattern is |
| * found generally useful. The current implementation uses a lot of reflection |
| * to save repeated code, but this could all be inlined (without reflection) if |
| * performance turns out to be a problem. |
| * |
| * <p> |
| * For example, an Image might be passed to a TableItem as follows: |
| * <p> |
| * |
| * <code> |
| * ImageDescriptor someDescriptor = ...; |
| * TableItem someTableItem = ...; |
| * ResourceManager manager = JFaceResources.getResources(); |
| * |
| * Image actualImage = manager.createImage(someDescriptor); |
| * someTableItem.setImage(actualImage); |
| * |
| * // do something with the table item |
| * |
| * someTableItem.dispose(); |
| * manager.destroyImage(someDescriptor); |
| * </code> |
| * |
| * <p> |
| * It is much more convenient to do the following: |
| * </p> |
| * |
| * <code> |
| * ImageDescriptor someDescriptor = ...; |
| * TableItem someTableItem = ...; |
| * |
| * Descriptors.setImage(someTableItem, someDescriptor); |
| * |
| * // do something with the table item |
| * |
| * someTableItem.dispose(); |
| * </code> |
| * |
| * <p> |
| * This class tries to behave as if the table item itself had a set method that |
| * took a descriptor. Resource allocation and deallocation happens for free. All |
| * the methods are leakproof. That is, if any images, colors, etc. need to be |
| * allocated and passed to the SWT widget, they will be deallocated |
| * automatically when the widget goes away (the implementation hooks a dispose |
| * listener on the widget which cleans up as soon as the widget is disposed). |
| * </p> |
| * |
| * @since 3.1 |
| */ |
| public final class Descriptors { |
| private static final String DISPOSE_LIST = "Descriptors.disposeList"; //$NON-NLS-1$ |
| |
| private Descriptors() { |
| } |
| |
| private static final class ResourceMethod { |
| ResourceMethod(Method m, String id) { |
| method = m; |
| this.id = id; |
| } |
| |
| Method method; |
| DeviceResourceDescriptor oldDescriptor; |
| String id; |
| |
| public void invoke(Widget toCall, DeviceResourceDescriptor newDescriptor) { |
| if (newDescriptor == oldDescriptor) { |
| return; |
| } |
| |
| ResourceManager mgr = JFaceResources.getResources(toCall.getDisplay()); |
| |
| Object newResource; |
| try { |
| newResource = newDescriptor == null ? null : mgr.create(newDescriptor); |
| } catch (DeviceResourceException e1) { |
| WorkbenchPlugin.log(e1); |
| return; |
| } |
| |
| try { |
| method.invoke(toCall, newResource); |
| } catch (IllegalArgumentException e) { |
| throw e; |
| } catch (IllegalAccessException e) { |
| WorkbenchPlugin.log(e); |
| return; |
| } catch (InvocationTargetException e) { |
| if (e.getTargetException() instanceof RuntimeException) { |
| throw (RuntimeException) e.getTargetException(); |
| } |
| WorkbenchPlugin.log(e); |
| return; |
| } |
| |
| // Deallocate the old image |
| if (oldDescriptor != null) { |
| // Dispose the image |
| mgr.destroy(oldDescriptor); |
| } |
| |
| // Remember the new image for next time |
| |
| oldDescriptor = newDescriptor; |
| } |
| |
| public void dispose() { |
| // Deallocate the old image |
| if (oldDescriptor != null) { |
| ResourceManager mgr = JFaceResources.getResources(); |
| // Dispose the image |
| mgr.destroy(oldDescriptor); |
| oldDescriptor = null; |
| } |
| |
| } |
| } |
| |
| private static DisposeListener disposeListener = e -> doDispose(e.widget); |
| |
| // Item |
| // ////////////////////////////////////////////////////////////////////////////////// |
| |
| /** |
| * Sets the image on the given ToolItem. The image will be automatically |
| * allocated and disposed as needed. |
| * |
| * @since 3.1 |
| * |
| * @param item |
| * @param descriptor |
| */ |
| public static void setImage(Item item, ImageDescriptor descriptor) { |
| callMethod(item, "setImage", descriptor, Image.class); //$NON-NLS-1$ |
| } |
| |
| // ToolItem |
| // ////////////////////////////////////////////////////////////////////////////// |
| |
| public static void setHotImage(ToolItem item, ImageDescriptor descriptor) { |
| callMethod(item, "setHotImage", descriptor, Image.class); //$NON-NLS-1$ |
| } |
| |
| public static void setDisabledImage(ToolItem item, ImageDescriptor descriptor) { |
| callMethod(item, "setDisabledImage", descriptor, Image.class); //$NON-NLS-1$ |
| } |
| |
| // TableItem |
| // ////////////////////////////////////////////////////////////////////////////// |
| |
| public static void setFont(TableItem item, FontDescriptor descriptor) { |
| callMethod(item, "setFont", descriptor, Font.class); //$NON-NLS-1$ |
| } |
| |
| public static void setBackground(TableItem item, ColorDescriptor descriptor) { |
| callMethod(item, "setBackground", descriptor, Color.class); //$NON-NLS-1$ |
| } |
| |
| public static void setForeground(TableItem item, ColorDescriptor descriptor) { |
| callMethod(item, "setForeground", descriptor, Color.class); //$NON-NLS-1$ |
| } |
| |
| // Control |
| // /////////////////////////////////////////////////////////////////////////////// |
| |
| public static void setBackground(Control control, ColorDescriptor descriptor) { |
| callMethod(control, "setBackground", descriptor, Color.class); //$NON-NLS-1$ |
| } |
| |
| public static void setForeground(Control control, ColorDescriptor descriptor) { |
| callMethod(control, "setForeground", descriptor, Color.class); //$NON-NLS-1$ |
| } |
| |
| // Button |
| // /////////////////////////////////////////////////////////////////////////////// |
| |
| public static void setImage(Button button, ImageDescriptor descriptor) { |
| callMethod(button, "setImage", descriptor, Image.class); //$NON-NLS-1$ |
| } |
| |
| public static void setImage(Label label, ImageDescriptor descriptor) { |
| callMethod(label, "setImage", descriptor, Image.class); //$NON-NLS-1$ |
| } |
| |
| private static ResourceMethod getResourceMethod(Widget toCall, String methodName, Class resourceType) |
| throws NoSuchMethodException { |
| Object oldData = toCall.getData(DISPOSE_LIST); |
| |
| if (oldData instanceof List) { |
| // Check for existing data |
| for (Iterator iter = ((List) oldData).iterator(); iter.hasNext();) { |
| ResourceMethod method = (ResourceMethod) iter.next(); |
| |
| if (method.id == methodName) { |
| return method; |
| } |
| } |
| } |
| if (oldData instanceof ResourceMethod) { |
| if (((ResourceMethod) oldData).id == methodName) { |
| return ((ResourceMethod) oldData); |
| } |
| |
| List newList = new ArrayList(); |
| newList.add(oldData); |
| oldData = newList; |
| toCall.setData(DISPOSE_LIST, oldData); |
| } |
| |
| // At this point, the DISPOSE_LIST data is either null or points to an ArrayList |
| |
| Class clazz = toCall.getClass(); |
| |
| Method method; |
| try { |
| method = clazz.getMethod(methodName, resourceType); |
| } catch (SecurityException e) { |
| throw e; |
| } |
| |
| ResourceMethod result = new ResourceMethod(method, methodName); |
| |
| if (oldData == null) { |
| toCall.setData(DISPOSE_LIST, result); |
| toCall.addDisposeListener(disposeListener); |
| } else { |
| ((List) oldData).add(result); |
| } |
| |
| return result; |
| } |
| |
| private static void callMethod(Widget toCall, String methodName, DeviceResourceDescriptor descriptor, |
| Class resourceType) { |
| ResourceMethod method; |
| try { |
| method = getResourceMethod(toCall, methodName, resourceType); |
| } catch (NoSuchMethodException e) { |
| WorkbenchPlugin.log(e); |
| return; |
| } |
| |
| method.invoke(toCall, descriptor); |
| } |
| |
| private static void doDispose(Widget widget) { |
| Object oldData = widget.getData(DISPOSE_LIST); |
| |
| if (oldData instanceof ArrayList) { |
| ArrayList list = ((ArrayList) oldData); |
| ResourceMethod[] data = (ResourceMethod[]) list.toArray(new ResourceMethod[list.size()]); |
| |
| // Clear out the images |
| for (ResourceMethod method : data) { |
| method.dispose(); |
| } |
| } |
| |
| if (oldData instanceof ResourceMethod) { |
| ((ResourceMethod) oldData).dispose(); |
| } |
| } |
| |
| } |