Java tutorial
/* ********************************************************************** ** ** Copyright notice ** ** ** ** (c) 2005-2009 RSSOwl Development Team ** ** http://www.rssowl.org/ ** ** ** ** 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.rssowl.org/legal/epl-v10.html ** ** ** ** A copy is found in the file epl-v10.html and important notices to the ** ** license from the team is found in the textfile LICENSE.txt distributed ** ** in this package. ** ** ** ** This copyright notice MUST APPEAR in all copies of the file! ** ** ** ** Contributors: ** ** RSSOwl Development Team - initial API and implementation ** ** ** ** ********************************************************************** */ package org.rssowl.ui.internal.views.explorer; import org.eclipse.core.runtime.ListenerList; import org.eclipse.jface.util.IOpenEventListener; import org.eclipse.jface.util.SafeRunnable; import org.eclipse.jface.viewers.IOpenListener; import org.eclipse.jface.viewers.ISelection; import org.eclipse.jface.viewers.IStructuredSelection; import org.eclipse.jface.viewers.OpenEvent; import org.eclipse.jface.viewers.StructuredSelection; import org.eclipse.jface.viewers.TreeViewer; import org.eclipse.swt.events.SelectionEvent; import org.eclipse.swt.widgets.Composite; import org.eclipse.swt.widgets.Control; import org.eclipse.swt.widgets.Tree; import org.eclipse.swt.widgets.TreeItem; import org.eclipse.swt.widgets.Widget; import org.rssowl.ui.internal.util.TreeItemAdapter; import org.rssowl.ui.internal.util.ViewerOpenStrategy; import java.util.List; /** * A Subclass of <code>TreeViewer</code> to display Folders and all kinds of * Marks in the "Feeds" view. * * @author bpasero */ public class BookMarkViewer extends TreeViewer { private final BookMarkExplorer fExplorer; private ListenerList fOpenListeners = new ListenerList(); private ViewerOpenStrategy fViewerOpenStrategy; /** * @param explorer * @param parent * @param style */ public BookMarkViewer(BookMarkExplorer explorer, Composite parent, int style) { super(parent, style); fExplorer = explorer; } /* * @see org.eclipse.jface.viewers.TreeViewer#createChildren(org.eclipse.swt.widgets.Widget) */ @Override public void createChildren(Widget widget) { super.createChildren(widget); } /* * @see org.eclipse.jface.viewers.StructuredViewer#refresh(boolean) */ @Override public void refresh(boolean updateLabels) { getControl().getParent().setRedraw(false); try { super.refresh(updateLabels); } finally { getControl().getParent().setRedraw(true); } } /* * @see org.eclipse.jface.viewers.ColumnViewer#refresh(java.lang.Object) */ @Override public void refresh(Object element) { super.refresh(element); /* Avoid restoring expanded elements on refresh() */ if (element == getRoot()) return; /* TODO Revisit later */ fExplorer.restoreExpandedElements(); } /* * @see org.eclipse.jface.viewers.StructuredViewer#refresh(java.lang.Object, * boolean) */ @Override public void refresh(Object element, boolean updateLabels) { super.refresh(element, updateLabels); /* TODO Revisit later */ fExplorer.restoreExpandedElements(); } /* * @see org.eclipse.jface.viewers.AbstractTreeViewer#remove(java.lang.Object[]) */ @Override public void remove(final Object[] elements) { updateSelectionAfterDelete(new Runnable() { public void run() { internalRemove(elements); } }); } /* * @see org.eclipse.jface.viewers.Viewer#setSelection(org.eclipse.jface.viewers.ISelection) */ @Override public void setSelection(ISelection selection) { super.setSelection(selection); if (fViewerOpenStrategy != null) fViewerOpenStrategy.clearExpandFlag(); // See Bug 164372 } /* * @see org.eclipse.jface.viewers.StructuredViewer#setSelection(org.eclipse.jface.viewers.ISelection, * boolean) */ @Override public void setSelection(ISelection selection, boolean reveal) { super.setSelection(selection, reveal); if (fViewerOpenStrategy != null) fViewerOpenStrategy.clearExpandFlag(); // See Bug 164372 } /* * @see org.eclipse.jface.viewers.TreeViewer#setSelection(java.util.List) */ @SuppressWarnings("unchecked") @Override protected void setSelection(List items) { super.setSelection(items); if (fViewerOpenStrategy != null) fViewerOpenStrategy.clearExpandFlag(); // See Bug 164372 } /* * @see org.eclipse.jface.viewers.AbstractTreeViewer#setSelectionToWidget(org.eclipse.jface.viewers.ISelection, boolean) */ @Override protected void setSelectionToWidget(ISelection selection, boolean reveal) { super.setSelectionToWidget(selection, reveal); if (fViewerOpenStrategy != null) fViewerOpenStrategy.clearExpandFlag(); // See Bug 164372 } /* * @see org.eclipse.jface.viewers.AbstractTreeViewer#setSelectionToWidget(java.util.List, boolean) */ @SuppressWarnings("unchecked") @Override protected void setSelectionToWidget(List v, boolean reveal) { super.setSelectionToWidget(v, reveal); if (fViewerOpenStrategy != null) fViewerOpenStrategy.clearExpandFlag(); // See Bug 164372 } /* * @see org.eclipse.jface.viewers.TreeViewer#hookControl(org.eclipse.swt.widgets.Control) */ @Override protected void hookControl(Control control) { super.hookControl(control); /* Add a ViewerOpenStrategy */ fViewerOpenStrategy = new ViewerOpenStrategy(control); fViewerOpenStrategy.addOpenListener(new IOpenEventListener() { public void handleOpen(SelectionEvent e) { internalHandleOpen(); } }); } /* * Overrides the open-listener to work with the ViewerOpenStrategy. * * @see org.eclipse.jface.viewers.StructuredViewer#addOpenListener(org.eclipse.jface.viewers.IOpenListener) */ @Override public void addOpenListener(IOpenListener listener) { fOpenListeners.add(listener); } private void internalHandleOpen() { Control control = getControl(); if (control != null && !control.isDisposed()) { ISelection selection = getSelection(); internalFireOpen(new OpenEvent(this, selection)); } } private void internalFireOpen(final OpenEvent event) { Object[] listeners = fOpenListeners.getListeners(); for (int i = 0; i < listeners.length; ++i) { final IOpenListener listener = (IOpenListener) listeners[i]; SafeRunnable.run(new SafeRunnable() { public void run() { listener.open(event); } }); } } private void updateSelectionAfterDelete(Runnable runnable) { Tree tree = (Tree) getControl(); IStructuredSelection selection = (IStructuredSelection) getSelection(); /* Nothing to do, since no selection */ if (selection.isEmpty()) { runnable.run(); return; } /* Look for the minimal Index of all selected Elements */ int minSelectedIndex = Integer.MAX_VALUE; TreeItemAdapter parentOfMinSelected = new TreeItemAdapter(tree); /* For each selected Element */ Object[] selectedElements = selection.toArray(); for (Object selectedElement : selectedElements) { Widget widget = findItem(selectedElement); if (widget instanceof TreeItem) { TreeItem item = (TreeItem) widget; TreeItemAdapter parent = new TreeItemAdapter(item).getParent(); int index = parent.indexOf(item); minSelectedIndex = Math.min(minSelectedIndex, index); if (index == minSelectedIndex) parentOfMinSelected.setItem(parent.getItem()); } } /* Perform Deletion */ runnable.run(); Object data = null; /* Parent itself has been deleted */ if (parentOfMinSelected.getItem().isDisposed()) return; /* Restore selection to next Element */ if (parentOfMinSelected.getItemCount() > minSelectedIndex) data = parentOfMinSelected.getItem(minSelectedIndex).getData(); /* Restore selection to last Element */ else if (parentOfMinSelected.getItemCount() > 0) data = parentOfMinSelected.getItem(parentOfMinSelected.getItemCount() - 1).getData(); /* Restore selection on actual Element */ else data = parentOfMinSelected.getItem().getData(); /* Apply selection */ if (data != null) { IStructuredSelection newSelection = new StructuredSelection(data); setSelection(newSelection); } } }