Java tutorial
/******************************************************************************* * Copyright (c) 2013 Tasktop Technologies and others. * All rights reserved. This program and the accompanying materials * are made available under the terms of the Eclipse Public License v1.0 * which accompanies this distribution, and is available at * http://www.eclipse.org/legal/epl-v10.html * * Contributors: * Tasktop Technologies - initial API and implementation *******************************************************************************/ package org.eclipse.mylyn.internal.tasks.ui.views; import java.util.Arrays; import java.util.HashSet; import java.util.Set; import org.eclipse.core.runtime.IStatus; import org.eclipse.core.runtime.Status; import org.eclipse.jface.viewers.ISelection; import org.eclipse.jface.viewers.TreePath; import org.eclipse.jface.viewers.TreeSelection; import org.eclipse.jface.viewers.TreeViewer; import org.eclipse.mylyn.commons.core.StatusHandler; import org.eclipse.mylyn.commons.workbench.DelayedRefreshJob; import org.eclipse.mylyn.internal.tasks.core.AbstractTask; import org.eclipse.mylyn.internal.tasks.core.AbstractTaskContainer; import org.eclipse.mylyn.internal.tasks.core.ITaskListChangeListener; import org.eclipse.mylyn.internal.tasks.core.TaskContainerDelta; import org.eclipse.mylyn.internal.tasks.core.UncategorizedTaskContainer; import org.eclipse.mylyn.internal.tasks.core.UnmatchedTaskContainer; import org.eclipse.mylyn.internal.tasks.core.UnsubmittedTaskContainer; import org.eclipse.mylyn.internal.tasks.ui.TasksUiPlugin; import org.eclipse.mylyn.internal.tasks.ui.editors.TaskListChangeAdapter; import org.eclipse.mylyn.internal.tasks.ui.util.TasksUiInternal; import org.eclipse.mylyn.internal.tasks.ui.util.TreeWalker; import org.eclipse.mylyn.internal.tasks.ui.util.TreeWalker.TreeVisitor; import org.eclipse.mylyn.tasks.core.ITaskContainer; import org.eclipse.swt.SWTException; import org.eclipse.swt.widgets.TreeItem; import org.eclipse.ui.PlatformUI; public final class TaskListRefreshJob extends DelayedRefreshJob { private final AbstractTaskListView taskListView; private final ITaskListChangeListener TASKLIST_CHANGE_LISTENER = new TaskListChangeAdapter() { @Override public void containersChanged(final Set<TaskContainerDelta> deltas) { PlatformUI.getWorkbench().getDisplay().asyncExec(new Runnable() { public void run() { for (TaskContainerDelta taskContainerDelta : deltas) { if (taskListView.isScheduledPresentation()) { // TODO: implement refresh policy for scheduled presentation refresh(); } else { switch (taskContainerDelta.getKind()) { case ROOT: refresh(); break; case ADDED: case REMOVED: if (isFilteredContainer(taskContainerDelta)) { // container may have changed visibility, refresh root refresh(); } else { if (taskContainerDelta.getElement() != null) { refreshElement(taskContainerDelta.getElement()); } if (taskContainerDelta.getParent() != null) { refreshElement(taskContainerDelta.getParent()); } else { // element was added/removed from the root refresh(); } } break; case CONTENT: refreshElement(taskContainerDelta.getElement()); } } } } private boolean isFilteredContainer(TaskContainerDelta taskContainerDelta) { ITaskContainer parent = taskContainerDelta.getParent(); return parent instanceof UnsubmittedTaskContainer || parent instanceof UnmatchedTaskContainer || parent instanceof UncategorizedTaskContainer; } }); } }; public TaskListRefreshJob(AbstractTaskListView taskListView, TreeViewer treeViewer, String name) { super(treeViewer, name); this.taskListView = taskListView; TasksUiInternal.getTaskList().addChangeListener(TASKLIST_CHANGE_LISTENER); } @Override protected void doRefresh(Object[] items) { TreePath selection = preserveSelection(); if (items == null) { viewer.refresh(true); } else if (items.length > 0) { try { if (taskListView.isFocusedMode()) { Set<Object> children = new HashSet<Object>(Arrays.asList(items)); Set<AbstractTaskContainer> parents = new HashSet<AbstractTaskContainer>(); for (Object item : items) { if (item instanceof AbstractTask) { parents.addAll(((AbstractTask) item).getParentContainers()); } } // 1. refresh parents children.removeAll(parents); for (AbstractTaskContainer parent : parents) { viewer.refresh(parent, false); // only refresh label of parent viewer.update(parent, null); } // 2. refresh children for (Object item : children) { viewer.refresh(item, true); } // 3. update states of all changed items for (Object item : items) { updateExpansionState(item); } } else { Set<AbstractTaskContainer> parents = new HashSet<AbstractTaskContainer>(); for (Object item : items) { if (item instanceof AbstractTask) { parents.addAll(((AbstractTask) item).getParentContainers()); } viewer.refresh(item, true); updateExpansionState(item); } // refresh labels of parents for task activation or incoming indicators for (AbstractTaskContainer parent : parents) { // only refresh label viewer.update(parent, null); } } } catch (SWTException e) { StatusHandler.log(new Status(IStatus.ERROR, TasksUiPlugin.ID_PLUGIN, "Failed to refresh viewer: " //$NON-NLS-1$ + viewer, e)); } } taskListView.updateToolTip(false); restoreSelection(selection); } private TreePath preserveSelection() { if (viewer instanceof TreeViewer) { TreeViewer treeViewer = (TreeViewer) viewer; // in case the refresh removes the currently selected item, // remember the next item in the tree to restore the selection // TODO: consider making this optional TreeItem[] selection = treeViewer.getTree().getSelection(); if (selection.length > 0) { TreeWalker treeWalker = new TreeWalker(treeViewer); return treeWalker.walk(new TreeVisitor() { @Override public boolean visit(Object object) { return true; } }, selection[selection.length - 1]); } } return null; } private void restoreSelection(TreePath treePath) { if (treePath != null) { ISelection newSelection = viewer.getSelection(); if (newSelection == null || newSelection.isEmpty()) { viewer.setSelection(new TreeSelection(treePath), true); } } } protected void updateExpansionState(Object item) { if (taskListView.isFocusedMode() && taskListView.isAutoExpandMode()) { taskListView.getViewer().expandToLevel(item, 3); } } public void dispose() { TasksUiInternal.getTaskList().removeChangeListener(TASKLIST_CHANGE_LISTENER); } }