bundles/org.eclipse.e4.ui.css.swt/src/org/eclipse/e4/ui/css/swt/dom/WidgetElement.java - platform/eclipse.platform.ui - Git at Google

 /*******************************************************************************
  * Copyright (c) 2008, 2016 Angelo Zerr 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:
  *     Angelo Zerr <angelo.zerr@gmail.com> - initial API and implementation
  *******************************************************************************/
 package org.eclipse.e4.ui.css.swt.dom;

 import java.util.Objects;
 import java.util.function.Supplier;
 import org.eclipse.core.runtime.Assert;
 import org.eclipse.e4.ui.css.core.dom.CSSStylableElement;
 import org.eclipse.e4.ui.css.core.dom.ElementAdapter;
 import org.eclipse.e4.ui.css.core.engine.CSSEngine;
 import org.eclipse.e4.ui.css.core.utils.ClassUtils;
 import org.eclipse.e4.ui.css.swt.CSSSWTConstants;
 import org.eclipse.e4.ui.css.swt.helpers.SWTStyleHelpers;
 import org.eclipse.swt.widgets.Display;
 import org.eclipse.swt.widgets.Widget;
 import org.w3c.dom.Node;
 import org.w3c.dom.NodeList;

 /**
  * {@link CSSStylableElement} implementation which wrap SWT {@link Widget}.
  *
  */
 public class WidgetElement extends ElementAdapter implements NodeList {

 	boolean dynamicEnabled = Boolean.getBoolean("org.eclipse.e4.ui.css.dynamic");

 	/**
 	 * Convenience method for getting the CSS class of a widget.
 	 *
 	 * @param widget
 	 *            SWT widget with associated CSS class name
 	 * @return CSS class name
 	 */
 	public static String getCSSClass(Widget widget) {
 		return (String) widget.getData(CSSSWTConstants.CSS_CLASS_NAME_KEY);
 	}

 	/**
 	 * Convenience method for getting the CSS ID of a widget.
 	 *
 	 * @param widget
 	 *            SWT widget with associated CSS id
 	 * @return CSS ID
 	 */
 	public static String getID(Widget widget) {
 		return (String) widget.getData(CSSSWTConstants.CSS_ID_KEY);
 	}

 	/**
 	 * Convenience method for setting the CSS class of a widget.
 	 *
 	 * @param widget
 	 *            SWT widget with associated CSS class name
 	 * @param className
 	 *            class name to set
 	 */
 	public static void setCSSClass(Widget widget, String className) {
 		widget.setData(CSSSWTConstants.CSS_CLASS_NAME_KEY, className);
 	}

 	/**
 	 * Convenience method for setting the CSS ID of a widget.
 	 *
 	 * @param widget
 	 *            SWT widget with associated CSS id
 	 * @param id
 	 *            CSS id to set
 	 */
 	public static void setID(Widget widget, String id) {
 		widget.setData(CSSSWTConstants.CSS_ID_KEY, id);
 	}

 	/**
 	 * Convenience method for getting the CSS engine responsible for a widget.
 	 * @param widget SWT widget which is styled by an engine
 	 */
 	public static CSSEngine getEngine(Widget widget) {
 		return getEngine(widget.getDisplay());
 	}

 	/**
 	 * Convenience method for getting the CSS engine responsible for a widget.
 	 *
 	 * @param display
 	 *            SWT display which is styled by an engine
 	 */
 	public static CSSEngine getEngine(Display display) {
 		return (CSSEngine) display.getData(CSSSWTConstants.CSS_ENGINE_KEY);
 	}

 	/**
 	 * Convenience method for requesting the CSS engine to re-apply styles to a
 	 * widget.
 	 *
 	 * @param widget
 	 *            widget to be restyled
 	 * @param applyStylesToChildNodes
 	 *            if true, apply styles to the child nodes
 	 */
 	public static void applyStyles(Widget widget,
 			boolean applyStylesToChildNodes) {
 		CSSEngine engine = getEngine(widget);
 		if (engine != null) {
 			engine.applyStyles(widget, applyStylesToChildNodes);
 		}
 	}

 	/**
 	 * Convenience method for setting the CSS engine responsible for a display.
 	 *
 	 * @param widget
 	 *            SWT display which is styled by an engine
 	 * @param engine
 	 *            Engine to be associated with the display
 	 */
 	public static void setEngine(Display display, CSSEngine engine) {
 		display.setData(CSSSWTConstants.CSS_ENGINE_KEY, engine);
 	}

 	protected String localName;

 	protected String namespaceURI;

 	protected String swtStyles;

 	public WidgetElement(Widget widget, CSSEngine engine) {
 		super(widget, engine);
 		this.localName = computeLocalName();
 		this.namespaceURI = computeNamespaceURI();
 		this.computeStaticPseudoInstances();
 		this.swtStyles = this.computeAttributeSWTStyle();
 	}

 	/**
 	 * Compute local name.
 	 *
 	 * @return
 	 */
 	protected String computeLocalName() {
 		// The localName is simple class name
 		// of the SWT widget. For instance
 		// for the org.eclipse.swt.widgets.Label
 		// localName is Label
 		// CSS selector will use this localName
 		// ex : Label {background-color:red;}

 		// for inner classes, the hyphen is used, e.g., for Outer$Inner,
 		// the selector is Outer-Inner {background-color:red;}
 		Widget widget = getWidget();
 		Class<?> clazz = widget.getClass();
 		return ClassUtils.getSimpleName(clazz);
 	}

 	/**
 	 * Compute namespaceURI.
 	 *
 	 * @return
 	 */
 	protected String computeNamespaceURI() {
 		// The NamespaceURI is package name
 		// of the SWT widget. For instance
 		// for the org.eclipse.swt.widgets.Label
 		// namespaceURI is org.eclipse.swt.widgets.Label
 		// CSS selector will use this localName
 		// @namespace eclipse org.eclipse.swt.widgets.Label
 		// ex : eclipse|Label {background-color:red;}
 		Widget widget = getWidget();
 		Class<?> clazz = widget.getClass();
 		return ClassUtils.getPackageName(clazz);
 	}

 	/**
 	 * Compute static pseudo instances.
 	 *
 	 */
 	protected void computeStaticPseudoInstances() {

 	}

 	/**
 	 * Compute attribute SWT style.
 	 *
 	 * @return
 	 */
 	protected String computeAttributeSWTStyle() {
 		return SWTStyleHelpers.getSWTWidgetStyleAsString(getWidget());
 	}

 	@Override
 	public final String getAttribute(String attr) {
 		Supplier<String> attribute = internalGetAttribute(attr);
 		if (attribute != null) {
 			String attributeValue = attribute.get();
 			Assert.isNotNull(attributeValue);
 			return attributeValue;
 		}
 		return "";
 	}

 	@Override
 	public final boolean hasAttribute(String attr) {
 		return internalGetAttribute(attr) != null;
 	}

 	/**
 	 *
 	 * The goal for {@link #internalGetAttribute(String)} is to share the code
 	 * of {@link #hasAttribute(String)} and {@link #getAttribute(String)} and to
 	 * keep the performance footprint for {@link #hasAttribute(String)} small.
 	 * This shall be accomplished by:
 	 * <ul>
 	 * <li>The method shall only be a lookup for a supplier, no actual
 	 * computation shall be made.
 	 * <li>The result of the supplier must hold the requirements of the result
 	 * of {@link #getAttribute(String)}. Especially it <strong>must not</strong>
 	 * return {@code null}.
 	 * <li>If the attribute isn't set on the widget, the method must return
 	 * {@code null}.
 	 * </ul>
 	 *
 	 *
 	 * @param attr
 	 *            the name of the attribute to look for.
 	 * @return a supplier which will return the actual attribute value or
 	 *         {@code null} if the attribute isn't set for the widget.
 	 */
 	protected Supplier<String> internalGetAttribute(String attr) {
 		Widget widget = getWidget();
 		switch(attr){
 		case "style":
 			return () -> swtStyles != null ? swtStyles : "";
 		case "class":
 			return () -> Objects.toString(getCSSClass(widget), "");
 		case "swt-data-class":
 			return () -> {
 				Object data = widget.getData();
 				if (data == null) {
 					return "";
 				}
 				StringBuilder sb = new StringBuilder();
 				for (Class<?> clazz = data.getClass(); clazz != Object.class; sb.append(' ')) {
 					sb.append(clazz.getName());
 					clazz = clazz.getSuperclass();
 				}
 				return sb.toString();
 			};
 		default:
 			Object o = widget.getData(attr.toLowerCase());
 			if (o != null) {
 				return o::toString;
 			}
 		}

 		return null;
 	}

 	@Override
 	public String getLocalName() {
 		return localName;
 	}

 	@Override
 	public String getNamespaceURI() {
 		return namespaceURI;
 	}

 	@Override
 	public Node getParentNode() {
 		return null;
 	}

 	@Override
 	public NodeList getChildNodes() {
 		return this;
 	}

 	@Override
 	public int getLength() {
 		return 0;
 	}

 	@Override
 	public Node item(int index) {
 		return null;
 	}

 	protected Widget getWidget() {
 		return (Widget) getNativeWidget();
 	}

 	@Override
 	public String getCSSId() {
 		Widget widget = getWidget();
 		Object id = getID(widget);
 		if (id != null) {
 			return id.toString();
 		}
 		return null;
 	}

 	@Override
 	public String getCSSClass() {
 		Widget widget = getWidget();
 		Object id = getCSSClass(widget);
 		if (id != null) {
 			return id.toString();
 		}
 		return null;
 	}

 	@Override
 	public String getCSSStyle() {
 		Widget widget = getWidget();
 		// TODO should have key in CSSSWT
 		Object id = widget.getData("style");
 		if (id != null) {
 			return id.toString();
 		}
 		return null;
 	}

 	/**
 	 * Called by the CSS engine upon a CSS theme switch. Implementations
 	 * should restore the default value so that the new theme can be applied to
 	 * the application without restart
 	 */

 	public void reset() {
 	}

 	@Override
 	public String toString() {
 		return getClass().getSimpleName() + ": " + getWidget();
 	}
 }
	/*******************************************************************************
	* Copyright (c) 2008, 2016 Angelo Zerr 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:
	* Angelo Zerr <angelo.zerr@gmail.com> - initial API and implementation
	*******************************************************************************/
	package org.eclipse.e4.ui.css.swt.dom;

	import java.util.Objects;
	import java.util.function.Supplier;
	import org.eclipse.core.runtime.Assert;
	import org.eclipse.e4.ui.css.core.dom.CSSStylableElement;
	import org.eclipse.e4.ui.css.core.dom.ElementAdapter;
	import org.eclipse.e4.ui.css.core.engine.CSSEngine;
	import org.eclipse.e4.ui.css.core.utils.ClassUtils;
	import org.eclipse.e4.ui.css.swt.CSSSWTConstants;
	import org.eclipse.e4.ui.css.swt.helpers.SWTStyleHelpers;
	import org.eclipse.swt.widgets.Display;
	import org.eclipse.swt.widgets.Widget;
	import org.w3c.dom.Node;
	import org.w3c.dom.NodeList;

	/**
	* {@link CSSStylableElement} implementation which wrap SWT {@link Widget}.
	*
	*/
	public class WidgetElement extends ElementAdapter implements NodeList {

	boolean dynamicEnabled = Boolean.getBoolean("org.eclipse.e4.ui.css.dynamic");

	/**
	* Convenience method for getting the CSS class of a widget.
	*
	* @param widget
	* SWT widget with associated CSS class name
	* @return CSS class name
	*/
	public static String getCSSClass(Widget widget) {
	return (String) widget.getData(CSSSWTConstants.CSS_CLASS_NAME_KEY);
	}

	/**
	* Convenience method for getting the CSS ID of a widget.
	*
	* @param widget
	* SWT widget with associated CSS id
	* @return CSS ID
	*/
	public static String getID(Widget widget) {
	return (String) widget.getData(CSSSWTConstants.CSS_ID_KEY);
	}

	/**
	* Convenience method for setting the CSS class of a widget.
	*
	* @param widget
	* SWT widget with associated CSS class name
	* @param className
	* class name to set
	*/
	public static void setCSSClass(Widget widget, String className) {
	widget.setData(CSSSWTConstants.CSS_CLASS_NAME_KEY, className);
	}

	/**
	* Convenience method for setting the CSS ID of a widget.
	*
	* @param widget
	* SWT widget with associated CSS id
	* @param id
	* CSS id to set
	*/
	public static void setID(Widget widget, String id) {
	widget.setData(CSSSWTConstants.CSS_ID_KEY, id);
	}

	/**
	* Convenience method for getting the CSS engine responsible for a widget.
	* @param widget SWT widget which is styled by an engine
	*/
	public static CSSEngine getEngine(Widget widget) {
	return getEngine(widget.getDisplay());
	}

	/**
	* Convenience method for getting the CSS engine responsible for a widget.
	*
	* @param display
	* SWT display which is styled by an engine
	*/
	public static CSSEngine getEngine(Display display) {
	return (CSSEngine) display.getData(CSSSWTConstants.CSS_ENGINE_KEY);
	}

	/**
	* Convenience method for requesting the CSS engine to re-apply styles to a
	* widget.
	*
	* @param widget
	* widget to be restyled
	* @param applyStylesToChildNodes
	* if true, apply styles to the child nodes
	*/
	public static void applyStyles(Widget widget,
	boolean applyStylesToChildNodes) {
	CSSEngine engine = getEngine(widget);
	if (engine != null) {
	engine.applyStyles(widget, applyStylesToChildNodes);
	}
	}

	/**
	* Convenience method for setting the CSS engine responsible for a display.
	*
	* @param widget
	* SWT display which is styled by an engine
	* @param engine
	* Engine to be associated with the display
	*/
	public static void setEngine(Display display, CSSEngine engine) {
	display.setData(CSSSWTConstants.CSS_ENGINE_KEY, engine);
	}

	protected String localName;

	protected String namespaceURI;

	protected String swtStyles;

	public WidgetElement(Widget widget, CSSEngine engine) {
	super(widget, engine);
	this.localName = computeLocalName();
	this.namespaceURI = computeNamespaceURI();
	this.computeStaticPseudoInstances();
	this.swtStyles = this.computeAttributeSWTStyle();
	}

	/**
	* Compute local name.
	*
	* @return
	*/
	protected String computeLocalName() {
	// The localName is simple class name
	// of the SWT widget. For instance
	// for the org.eclipse.swt.widgets.Label
	// localName is Label
	// CSS selector will use this localName
	// ex : Label {background-color:red;}

	// for inner classes, the hyphen is used, e.g., for Outer$Inner,
	// the selector is Outer-Inner {background-color:red;}
	Widget widget = getWidget();
	Class<?> clazz = widget.getClass();
	return ClassUtils.getSimpleName(clazz);
	}

	/**
	* Compute namespaceURI.
	*
	* @return
	*/
	protected String computeNamespaceURI() {
	// The NamespaceURI is package name
	// of the SWT widget. For instance
	// for the org.eclipse.swt.widgets.Label
	// namespaceURI is org.eclipse.swt.widgets.Label
	// CSS selector will use this localName
	// @namespace eclipse org.eclipse.swt.widgets.Label
	// ex : eclipse\|Label {background-color:red;}
	Widget widget = getWidget();
	Class<?> clazz = widget.getClass();
	return ClassUtils.getPackageName(clazz);
	}

	/**
	* Compute static pseudo instances.
	*
	*/
	protected void computeStaticPseudoInstances() {

	}

	/**
	* Compute attribute SWT style.
	*
	* @return
	*/
	protected String computeAttributeSWTStyle() {
	return SWTStyleHelpers.getSWTWidgetStyleAsString(getWidget());
	}

	@Override
	public final String getAttribute(String attr) {
	Supplier<String> attribute = internalGetAttribute(attr);
	if (attribute != null) {
	String attributeValue = attribute.get();
	Assert.isNotNull(attributeValue);
	return attributeValue;
	}
	return "";
	}

	@Override
	public final boolean hasAttribute(String attr) {
	return internalGetAttribute(attr) != null;
	}

	/**
	*
	* The goal for {@link #internalGetAttribute(String)} is to share the code
	* of {@link #hasAttribute(String)} and {@link #getAttribute(String)} and to
	* keep the performance footprint for {@link #hasAttribute(String)} small.
	* This shall be accomplished by:
	* <ul>
	* <li>The method shall only be a lookup for a supplier, no actual
	* computation shall be made.
	* <li>The result of the supplier must hold the requirements of the result
	* of {@link #getAttribute(String)}. Especially it <strong>must not</strong>
	* return {@code null}.
	* <li>If the attribute isn't set on the widget, the method must return
	* {@code null}.
	* </ul>
	*
	*
	* @param attr
	* the name of the attribute to look for.
	* @return a supplier which will return the actual attribute value or
	* {@code null} if the attribute isn't set for the widget.
	*/
	protected Supplier<String> internalGetAttribute(String attr) {
	Widget widget = getWidget();
	switch(attr){
	case "style":
	return () -> swtStyles != null ? swtStyles : "";
	case "class":
	return () -> Objects.toString(getCSSClass(widget), "");
	case "swt-data-class":
	return () -> {
	Object data = widget.getData();
	if (data == null) {
	return "";
	}
	StringBuilder sb = new StringBuilder();
	for (Class<?> clazz = data.getClass(); clazz != Object.class; sb.append(' ')) {
	sb.append(clazz.getName());
	clazz = clazz.getSuperclass();
	}
	return sb.toString();
	};
	default:
	Object o = widget.getData(attr.toLowerCase());
	if (o != null) {
	return o::toString;
	}
	}

	return null;
	}

	@Override
	public String getLocalName() {
	return localName;
	}

	@Override
	public String getNamespaceURI() {
	return namespaceURI;
	}

	@Override
	public Node getParentNode() {
	return null;
	}

	@Override
	public NodeList getChildNodes() {
	return this;
	}

	@Override
	public int getLength() {
	return 0;
	}

	@Override
	public Node item(int index) {
	return null;
	}

	protected Widget getWidget() {
	return (Widget) getNativeWidget();
	}

	@Override
	public String getCSSId() {
	Widget widget = getWidget();
	Object id = getID(widget);
	if (id != null) {
	return id.toString();
	}
	return null;
	}

	@Override
	public String getCSSClass() {
	Widget widget = getWidget();
	Object id = getCSSClass(widget);
	if (id != null) {
	return id.toString();
	}
	return null;
	}

	@Override
	public String getCSSStyle() {
	Widget widget = getWidget();
	// TODO should have key in CSSSWT
	Object id = widget.getData("style");
	if (id != null) {
	return id.toString();
	}
	return null;
	}

	/**
	* Called by the CSS engine upon a CSS theme switch. Implementations
	* should restore the default value so that the new theme can be applied to
	* the application without restart
	*/

	public void reset() {
	}

	@Override
	public String toString() {
	return getClass().getSimpleName() + ": " + getWidget();
	}
	}