![[Jenkins]](/ecp/static/e8bbdb94/images/svgs/logo.svg){kind=logo}
Package: EMFFormsContextTracker
EMFFormsContextTracker
| name | instruction | branch | complexity | line | method | ||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| EMFFormsContextTracker(EMFFormsViewContext) |
|
|
|
|
|
||||||||||||||||||||
| close() |
|
|
|
|
|
||||||||||||||||||||
| getListener(EMFFormsViewContext) |
|
|
|
|
|
||||||||||||||||||||
| handleChildContextAdded(EMFFormsViewContext, VElement, EMFFormsViewContext) |
|
|
|
|
|
||||||||||||||||||||
| handleChildContextRemoved(EMFFormsViewContext, VElement, EMFFormsViewContext) |
|
|
|
|
|
||||||||||||||||||||
| handleException(Throwable) |
|
|
|
|
|
||||||||||||||||||||
| isRoot(EMFFormsViewContext) |
|
|
|
|
|
||||||||||||||||||||
| notifyContextAdded(EMFFormsViewContext, VElement, EMFFormsViewContext) |
|
|
|
|
|
||||||||||||||||||||
| notifyContextDisposed(EMFFormsViewContext) |
|
|
|
|
|
||||||||||||||||||||
| notifyContextInitialized(EMFFormsViewContext) |
|
|
|
|
|
||||||||||||||||||||
| notifyContextRemoved(EMFFormsViewContext, VElement, EMFFormsViewContext) |
|
|
|
|
|
||||||||||||||||||||
| notifyDomainModelChanged(EMFFormsViewContext) |
|
|
|
|
|
||||||||||||||||||||
| onChildContextAdded(TriConsumer) |
|
|
|
|
|
||||||||||||||||||||
| onChildContextRemoved(TriConsumer) |
|
|
|
|
|
||||||||||||||||||||
| onContextDisposed(Consumer) |
|
|
|
|
|
||||||||||||||||||||
| onContextInitialized(Consumer) |
|
|
|
|
|
||||||||||||||||||||
| onDomainModelChanged(Consumer) |
|
|
|
|
|
||||||||||||||||||||
| open() |
|
|
|
|
|
||||||||||||||||||||
| safeAccept(Consumer, Object) |
|
|
|
|
|
||||||||||||||||||||
| safeAccept(TriConsumer, Object, Object, Object) |
|
|
|
|
|
||||||||||||||||||||
Coverage
1: /*******************************************************************************
2: * Copyright (c) 2019 Christian W. Damus and others.
3: *
4: * All rights reserved. This program and the accompanying materials
5: * are made available under the terms of the Eclipse Public License 2.0
6: * which accompanies this distribution, and is available at
7: * https://www.eclipse.org/legal/epl-2.0/
8: *
9: * SPDX-License-Identifier: EPL-2.0
10: *
11: * Contributors:
12: * Christian W. Damus - initial API and implementation
13: ******************************************************************************/
14: package org.eclipse.emfforms.spi.core.services.view;
15:
16: import java.lang.ref.Reference;
17: import java.lang.ref.WeakReference;
18: import java.util.Map;
19: import java.util.Optional;
20: import java.util.WeakHashMap;
21: import java.util.function.Consumer;
22: import java.util.function.Function;
23:
24: import org.eclipse.emf.ecp.view.spi.model.VElement;
25: import org.eclipse.emfforms.common.TriConsumer;
26: import org.eclipse.emfforms.spi.common.report.AbstractReport;
27: import org.eclipse.emfforms.spi.common.report.ReportService;
28:
29: /**
30: * A tracker of the comings and goings of contexts in a hierarchy of {@link EMFFormsViewContext}s.
31: * This supplements the {@link EMFFormsContextListener} and {@link RootDomainModelChangeListener} APIs
32: * with specificity in the call-backs of which context in a hierarchy the call-back pertains to.
33: *
34: * @since 1.22
35: */
36: public class EMFFormsContextTracker {
37:
38: private final Map<EMFFormsViewContext, ContextListener> contextListeners = new WeakHashMap<>();
39: private final Function<EMFFormsViewContext, ContextListener> listenerFactory = ContextListener::new;
40:
41: private final EMFFormsViewContext root;
42: private final ReportService reportService;
43:
44: private boolean active;
45:
46: private Consumer<? super EMFFormsViewContext> initializedHandler;
47: private Consumer<? super EMFFormsViewContext> disposedHandler;
48: private TriConsumer<? super EMFFormsViewContext, ? super VElement, ? super EMFFormsViewContext> addedHandler;
49: private TriConsumer<? super EMFFormsViewContext, ? super VElement, ? super EMFFormsViewContext> removedHandler;
50: private Consumer<? super EMFFormsViewContext> domainModelChangedHandler;
51:
52: /**
53: * Initializes me with the root context to track.
54: *
55: * @param context the root context
56: */
57: public EMFFormsContextTracker(EMFFormsViewContext context) {
58: super();
59:
60: root = context;
61: reportService = context.getService(ReportService.class);
62: }
63:
64: /**
65: * Query whether a {@code context} is the root of this tracker.
66: *
67: * @param context a context
68: * @return whether it is the root of the context tree being tracked
69: */
70: public boolean isRoot(EMFFormsViewContext context) {
71:• return context == root;
72: }
73:
74: /**
75: * Add a call-back to handle the initialization of a new context, including the
76: * {@linkplain #isRoot(EMFFormsViewContext) root context}.
77: *
78: * @param handler the call-back. It is invoked with the context that was initialized
79: * @return myself, for convenience of call chaining
80: */
81: public EMFFormsContextTracker onContextInitialized(Consumer<? super EMFFormsViewContext> handler) {
82: initializedHandler = handler;
83: return this;
84: }
85:
86: /**
87: * Add a call-back to handle the disposal of a context, including the {@linkplain #isRoot(EMFFormsViewContext) root
88: * context}.
89: *
90: * @param handler the call-back. It is invoked with the context that was disposed
91: * @return myself, for convenience of call chaining
92: */
93: public EMFFormsContextTracker onContextDisposed(Consumer<? super EMFFormsViewContext> handler) {
94: disposedHandler = handler;
95: return this;
96: }
97:
98: /**
99: * Add a call-back to handle the replacement of a context's domain model, including the
100: * {@linkplain #isRoot(EMFFormsViewContext) root context}.
101: *
102: * @param handler the call-back. It is invoked with the context that had its domain-model
103: * replaced
104: * @return myself, for convenience of call chaining
105: */
106: public EMFFormsContextTracker onDomainModelChanged(Consumer<? super EMFFormsViewContext> handler) {
107: domainModelChangedHandler = handler;
108: return this;
109: }
110:
111: /**
112: * Add a call-back to handle the addition of a new child context to a parent context.
113: *
114: * @param handler the call-back. It is invoked with the parent context, the parent element,
115: * and the child context that was added
116: * @return myself, for convenience of call chaining
117: */
118: public EMFFormsContextTracker onChildContextAdded(
119: TriConsumer<? super EMFFormsViewContext, ? super VElement, ? super EMFFormsViewContext> handler) {
120: addedHandler = handler;
121: return this;
122: }
123:
124: /**
125: * Add a call-back to handle the removal of a child context from a parent context.
126: *
127: * @param handler the call-back. It is invoked with the parent context, the parent element with
128: * which the child context was associated, and the child context that was removed
129: * @return myself, for convenience of call chaining
130: */
131: public EMFFormsContextTracker onChildContextRemoved(
132: TriConsumer<? super EMFFormsViewContext, ? super VElement, ? super EMFFormsViewContext> handler) {
133: removedHandler = handler;
134: return this;
135: }
136:
137: /**
138: * Start tracking my {@linkplain #isRoot(EMFFormsViewContext) root context}.
139: */
140: public void open() {
141:• if (!active) {
142: active = true;
143: handleChildContextAdded(null, null, root);
144: }
145: }
146:
147: /**
148: * Stop tracking contexts.
149: */
150: public void close() {
151:• if (active) {
152: active = false;
153:
154: try {
155: contextListeners.values().forEach(ContextListener::dispose);
156: } finally {
157: contextListeners.clear();
158: }
159: }
160: }
161:
162: private void handleChildContextAdded(EMFFormsViewContext parentContext, VElement parentElement,
163: EMFFormsViewContext childContext) {
164:
165: final ContextListener listener = getListener(childContext);
166: listener.addedToParent(true);
167: listener.setParentElement(parentElement);
168: }
169:
170: private ContextListener getListener(EMFFormsViewContext context) {
171: return contextListeners.computeIfAbsent(context, listenerFactory);
172: }
173:
174: private void handleChildContextRemoved(EMFFormsViewContext parentContext, VElement parentElement,
175: EMFFormsViewContext childContext) {
176: final ContextListener listener = getListener(childContext);
177: listener.addedToParent(false);
178: listener.setParentElement(null);
179: }
180:
181: private void notifyContextInitialized(EMFFormsViewContext context) {
182:• if (initializedHandler != null) {
183: safeAccept(initializedHandler, context);
184: }
185: }
186:
187: private void notifyContextDisposed(EMFFormsViewContext context) {
188:• if (disposedHandler != null) {
189: safeAccept(disposedHandler, context);
190: }
191: }
192:
193: private void notifyDomainModelChanged(EMFFormsViewContext context) {
194:• if (domainModelChangedHandler != null) {
195: safeAccept(domainModelChangedHandler, context);
196: }
197: }
198:
199: private void notifyContextAdded(EMFFormsViewContext parent, VElement parentElement, EMFFormsViewContext child) {
200:• if (addedHandler != null) {
201: safeAccept(addedHandler, parent, parentElement, child);
202: }
203: }
204:
205: private void notifyContextRemoved(EMFFormsViewContext parent, VElement parentElement, EMFFormsViewContext child) {
206:• if (removedHandler != null) {
207: safeAccept(removedHandler, parent, parentElement, child);
208: }
209: }
210:
211: private <T> void safeAccept(Consumer<? super T> consumer, T t) {
212: try {
213: consumer.accept(t);
214: // CHECKSTYLE.OFF: IllegalCatch
215: } catch (final Exception e) {
216: handleException(e);
217: // CHECKSTYLE.ON: IllegalCatch
218: } catch (final LinkageError e) {
219: handleException(e);
220: } catch (final AssertionError e) {
221: handleException(e);
222: }
223: }
224:
225: private <T, U, V> void safeAccept(TriConsumer<? super T, ? super U, ? super V> consumer, T t, U u, V v) {
226: try {
227: consumer.accept(t, u, v);
228: // CHECKSTYLE.OFF: IllegalCatch
229: } catch (final Exception e) {
230: handleException(e);
231: // CHECKSTYLE.ON: IllegalCatch
232: } catch (final LinkageError e) {
233: handleException(e);
234: } catch (final AssertionError e) {
235: handleException(e);
236: }
237: }
238:
239: private void handleException(Throwable t) {
240: reportService.report(new AbstractReport(t, "Unhandled exception in EMFFormsContextTracker call-back")); //$NON-NLS-1$
241: }
242:
243: //
244: // Nested types
245: //
246:
247: /**
248: * Encapsulation of a context with a listener to its lifecycle events.
249: */
250: private final class ContextListener implements EMFFormsContextListener {
251: private final RootDomainModelChangeListener domainModelChangeListener = this::domainModelChanged;
252: private final Reference<EMFFormsViewContext> context;
253: private Reference<VElement> parentElement;
254: private boolean addedToParent;
255:
256: ContextListener(EMFFormsViewContext context) {
257: super();
258:
259: this.context = new WeakReference<>(context);
260: context.registerEMFFormsContextListener(this);
261: context.registerRootDomainModelChangeListener(domainModelChangeListener);
262: }
263:
264: // Note that if we're invoking this method, it's because there are events to handle
265: // involving the context, so the reference cannot have been cleared
266: private Optional<EMFFormsViewContext> getContext() {
267: return Optional.ofNullable(context.get());
268: }
269:
270: void dispose() {
271: getContext().ifPresent(ctx -> {
272: ctx.unregisterRootDomainModelChangeListener(domainModelChangeListener);
273: ctx.unregisterEMFFormsContextListener(this);
274: });
275: }
276:
277: @Override
278: public void contextInitialised() {
279: getContext().ifPresent(EMFFormsContextTracker.this::notifyContextInitialized);
280: }
281:
282: @Override
283: public void contextDispose() {
284: getContext().ifPresent(EMFFormsContextTracker.this::notifyContextDisposed);
285: }
286:
287: @Override
288: public void childContextAdded(VElement parentElement, EMFFormsViewContext childContext) {
289: // Check if we already processed the add
290: if (getListener(childContext).isAddedToParent()) {
291: return;
292: }
293:
294: getContext().ifPresent(ctx -> {
295: notifyContextAdded(ctx, parentElement, childContext);
296: handleChildContextAdded(ctx, parentElement, childContext);
297: });
298: }
299:
300: @Override
301: public void childContextDisposed(EMFFormsViewContext childContext) {
302: // Check if we already processed the disposal
303: if (!getListener(childContext).isAddedToParent()) {
304: return;
305: }
306:
307: getContext().ifPresent(ctx -> {
308: final VElement parentElement = getListener(childContext).getParentElement();
309: handleChildContextRemoved(ctx, parentElement, childContext);
310: notifyContextRemoved(ctx, parentElement, childContext);
311: });
312: }
313:
314: void domainModelChanged() {
315: getContext().ifPresent(EMFFormsContextTracker.this::notifyDomainModelChanged);
316: }
317:
318: void addedToParent(boolean added) {
319: addedToParent = added;
320: }
321:
322: /**
323: * Is my context currently added to (attached to) its parent? Note that the root
324: * context is considered as implicitly added to its null parent.
325: *
326: * @return whether my context is currently known by its parent as a child of it
327: */
328: boolean isAddedToParent() {
329: return addedToParent;
330: }
331:
332: VElement getParentElement() {
333: return parentElement != null ? parentElement.get() : null;
334: }
335:
336: void setParentElement(VElement parentElement) {
337: this.parentElement = parentElement != null ? new WeakReference<>(parentElement) : null;
338: }
339:
340: }
341:
342: }