Java tutorial
/******************************************************************************* * Copyright (c) 2000, 2013 IBM Corporation 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: * IBM Corporation - initial API and implementation * Sebastian Davids - bug 128526, bug 128529 *******************************************************************************/ package org.eclipse.ui.internal.dialogs; import java.util.ArrayList; import java.util.Iterator; import org.eclipse.jface.dialogs.Dialog; import org.eclipse.jface.dialogs.IDialogConstants; import org.eclipse.jface.dialogs.IDialogLabelKeys; import org.eclipse.jface.dialogs.IDialogSettings; import org.eclipse.jface.dialogs.PopupDialog; import org.eclipse.jface.resource.JFaceResources; import org.eclipse.jface.viewers.DoubleClickEvent; import org.eclipse.jface.viewers.IDoubleClickListener; import org.eclipse.jface.viewers.ISelectionChangedListener; import org.eclipse.jface.viewers.IStructuredSelection; import org.eclipse.jface.viewers.ITreeContentProvider; import org.eclipse.jface.viewers.ITreeSelection; import org.eclipse.jface.viewers.SelectionChangedEvent; import org.eclipse.jface.viewers.StructuredSelection; import org.eclipse.jface.viewers.TreeViewer; import org.eclipse.swt.SWT; import org.eclipse.swt.events.DisposeEvent; import org.eclipse.swt.events.DisposeListener; import org.eclipse.swt.events.FocusAdapter; import org.eclipse.swt.events.FocusEvent; import org.eclipse.swt.events.KeyAdapter; import org.eclipse.swt.events.KeyEvent; import org.eclipse.swt.graphics.Color; import org.eclipse.swt.graphics.Point; import org.eclipse.swt.graphics.RGB; import org.eclipse.swt.layout.GridData; import org.eclipse.swt.widgets.Button; import org.eclipse.swt.widgets.Composite; import org.eclipse.swt.widgets.Control; import org.eclipse.swt.widgets.Display; import org.eclipse.swt.widgets.Label; import org.eclipse.swt.widgets.Shell; import org.eclipse.swt.widgets.Text; import org.eclipse.ui.IWorkbenchWindow; import org.eclipse.ui.PlatformUI; import org.eclipse.ui.dialogs.FilteredTree; import org.eclipse.ui.dialogs.PatternFilter; import org.eclipse.ui.internal.IWorkbenchHelpContextIds; import org.eclipse.ui.internal.WorkbenchMessages; import org.eclipse.ui.internal.WorkbenchPlugin; import org.eclipse.ui.internal.registry.ViewRegistry; import org.eclipse.ui.views.IViewCategory; import org.eclipse.ui.views.IViewDescriptor; import org.eclipse.ui.views.IViewRegistry; /** * The Show View dialog. */ public class ShowViewDialog extends Dialog implements ISelectionChangedListener, IDoubleClickListener { private static final String DIALOG_SETTING_SECTION_NAME = "ShowViewDialog"; //$NON-NLS-1$ private static final int LIST_HEIGHT = 300; private static final int LIST_WIDTH = 250; private static final String STORE_EXPANDED_CATEGORIES_ID = DIALOG_SETTING_SECTION_NAME + ".STORE_EXPANDED_CATEGORIES_ID"; //$NON-NLS-1$ private static final String STORE_SELECTED_VIEW_ID = DIALOG_SETTING_SECTION_NAME + ".STORE_SELECTED_VIEW_ID"; //$NON-NLS-1$ private FilteredTree filteredTree; private Button okButton; private IViewDescriptor[] viewDescs = new IViewDescriptor[0]; private IViewRegistry viewReg; private IWorkbenchWindow window; private Color dimmedForeground; private Label descriptionHint; /** * Constructs a new ShowViewDialog. * * @param window the workbench window * @param viewReg the view registry */ public ShowViewDialog(IWorkbenchWindow window, IViewRegistry viewReg) { super(window.getShell()); this.window = window; this.viewReg = viewReg; } /** * This method is called if a button has been pressed. */ protected void buttonPressed(int buttonId) { if (buttonId == IDialogConstants.OK_ID) { saveWidgetValues(); } super.buttonPressed(buttonId); } /** * Notifies that the cancel button of this dialog has been pressed. */ protected void cancelPressed() { viewDescs = new IViewDescriptor[0]; super.cancelPressed(); } /* * (non-Javadoc) * * @see org.eclipse.jface.window.Window#configureShell(org.eclipse.swt.widgets.Shell) */ protected void configureShell(Shell shell) { super.configureShell(shell); shell.setText(WorkbenchMessages.ShowView_shellTitle); PlatformUI.getWorkbench().getHelpSystem().setHelp(shell, IWorkbenchHelpContextIds.SHOW_VIEW_DIALOG); } /** * Adds buttons to this dialog's button bar. * <p> * The default implementation of this framework method adds standard ok and * cancel buttons using the <code>createButton</code> framework method. * Subclasses may override. * </p> * * @param parent the button bar composite */ protected void createButtonsForButtonBar(Composite parent) { okButton = createButton(parent, IDialogConstants.OK_ID, JFaceResources.getString(IDialogLabelKeys.OK_LABEL_KEY), true); createButton(parent, IDialogConstants.CANCEL_ID, JFaceResources.getString(IDialogLabelKeys.CANCEL_LABEL_KEY), false); updateButtons(); } /** * Creates and returns the contents of the upper part of this dialog (above * the button bar). * * @param parent the parent composite to contain the dialog area * @return the dialog area control */ protected Control createDialogArea(Composite parent) { // Run super. Composite composite = (Composite) super.createDialogArea(parent); composite.setFont(parent.getFont()); createFilteredTreeViewer(composite); layoutTopControl(filteredTree); // Use F2... label descriptionHint = new Label(composite, SWT.WRAP); descriptionHint.setText(WorkbenchMessages.ShowView_selectViewHelp); descriptionHint.setLayoutData(new GridData(SWT.FILL, SWT.CENTER, true, false)); descriptionHint.setVisible(false); // Restore the last state restoreWidgetValues(); applyDialogFont(composite); // Return results. return composite; } /** * Blends c1 and c2 based in the provided ratio. * * @param c1 * first color * @param c2 * second color * @param ratio * percentage of the first color in the blend (0-100) * @return the RGB value of the blended color * * copied from FormColors.java */ private static RGB blend(RGB c1, RGB c2, int ratio) { int r = blend(c1.red, c2.red, ratio); int g = blend(c1.green, c2.green, ratio); int b = blend(c1.blue, c2.blue, ratio); return new RGB(r, g, b); } private static int blend(int v1, int v2, int ratio) { int b = (ratio * v1 + (100 - ratio) * v2) / 100; return Math.min(255, b); } /** * Create a new filtered tree viewer in the parent. * * @param parent the parent <code>Composite</code>. */ private void createFilteredTreeViewer(Composite parent) { PatternFilter filter = new ViewPatternFilter(); int styleBits = SWT.MULTI | SWT.H_SCROLL | SWT.V_SCROLL | SWT.BORDER; filteredTree = new FilteredTree(parent, styleBits, filter, true); filteredTree.setQuickSelectionMode(true); filteredTree.setBackground(parent.getDisplay().getSystemColor(SWT.COLOR_WIDGET_BACKGROUND)); TreeViewer treeViewer = filteredTree.getViewer(); Control treeControl = treeViewer.getControl(); RGB dimmedRGB = blend(treeControl.getForeground().getRGB(), treeControl.getBackground().getRGB(), 60); dimmedForeground = new Color(treeControl.getDisplay(), dimmedRGB); treeControl.addDisposeListener(new DisposeListener() { public void widgetDisposed(DisposeEvent e) { dimmedForeground.dispose(); } }); treeViewer.setLabelProvider(new ViewLabelProvider(window, dimmedForeground)); treeViewer.setContentProvider(new ViewContentProvider()); treeViewer.setComparator(new ViewComparator((ViewRegistry) viewReg)); treeViewer.setInput(viewReg); treeViewer.addSelectionChangedListener(this); treeViewer.addDoubleClickListener(this); treeViewer.addFilter(new CapabilityFilter()); treeViewer.getControl().addKeyListener(new KeyAdapter() { public void keyPressed(KeyEvent e) { handleTreeViewerKeyPressed(e); } }); // if the tree has only one or zero views, disable the filter text control if (hasAtMostOneView(filteredTree.getViewer())) { Text filterText = filteredTree.getFilterControl(); if (filterText != null) { filterText.setEnabled(false); } } } /** * Return whether or not there are less than two views in the list. * * @param tree * @return <code>true</code> if there are less than two views in the list. */ private boolean hasAtMostOneView(TreeViewer tree) { ITreeContentProvider contentProvider = (ITreeContentProvider) tree.getContentProvider(); Object[] children = contentProvider.getElements(tree.getInput()); if (children.length <= 1) { if (children.length == 0) { return true; } return !contentProvider.hasChildren(children[0]); } return false; } /* * (non-Javadoc) * * @see org.eclipse.jface.viewers.IDoubleClickListener#doubleClick(org.eclipse.jface.viewers.DoubleClickEvent) */ public void doubleClick(DoubleClickEvent event) { IStructuredSelection s = (IStructuredSelection) event.getSelection(); Object element = s.getFirstElement(); if (filteredTree.getViewer().isExpandable(element)) { filteredTree.getViewer().setExpandedState(element, !filteredTree.getViewer().getExpandedState(element)); } else if (viewDescs.length > 0) { saveWidgetValues(); setReturnCode(OK); close(); } } /** * Return the dialog store to cache values into */ protected IDialogSettings getDialogSettings() { IDialogSettings workbenchSettings = WorkbenchPlugin.getDefault().getDialogSettings(); IDialogSettings section = workbenchSettings.getSection(DIALOG_SETTING_SECTION_NAME); if (section == null) { section = workbenchSettings.addNewSection(DIALOG_SETTING_SECTION_NAME); } return section; } /** * Returns the descriptors for the selected views. * * @return the descriptors for the selected views */ public IViewDescriptor[] getSelection() { return viewDescs; } /** * Layout the top control. * * @param control the control. */ private void layoutTopControl(Control control) { GridData spec = new GridData(GridData.FILL_BOTH); spec.widthHint = LIST_WIDTH; spec.heightHint = LIST_HEIGHT; control.setLayoutData(spec); } /** * Use the dialog store to restore widget values to the values that they * held last time this dialog was used to completion. */ protected void restoreWidgetValues() { Object selection = null; IDialogSettings settings = getDialogSettings(); String[] expandedCategoryIds = settings.getArray(STORE_EXPANDED_CATEGORIES_ID); if (expandedCategoryIds != null) { ViewRegistry reg = (ViewRegistry) viewReg; ArrayList categoriesToExpand = new ArrayList(expandedCategoryIds.length); for (int i = 0; i < expandedCategoryIds.length; i++) { IViewCategory category = reg.findCategory(expandedCategoryIds[i]); if (category != null) { categoriesToExpand.add(category); } } if (!categoriesToExpand.isEmpty()) { filteredTree.getViewer().setExpandedElements(categoriesToExpand.toArray()); } String selectedViewId = settings.get(STORE_SELECTED_VIEW_ID); if (selectedViewId != null) { selection = reg.find(selectedViewId); } } // Make sure there's a selection in the tree if (selection == null) selection = filteredTree.getViewer().getTree().getItem(0).getData(); filteredTree.getViewer().setSelection(new StructuredSelection(selection), true); } /** * Since OK was pressed, write widget values to the dialog store so that * they will persist into the next invocation of this dialog */ protected void saveWidgetValues() { IDialogSettings settings = getDialogSettings(); // Collect the ids of the all expanded categories Object[] expandedElements = filteredTree.getViewer().getExpandedElements(); String[] expandedCategoryIds = new String[expandedElements.length]; for (int i = 0; i < expandedElements.length; ++i) { expandedCategoryIds[i] = ((IViewCategory) expandedElements[i]).getId(); } // Save them for next time. settings.put(STORE_EXPANDED_CATEGORIES_ID, expandedCategoryIds); String selectedViewId = ""; //$NON-NLS-1$ if (viewDescs.length > 0) { // in the case of a multi-selection, it's probably less confusing // to store just the first rather than the whole multi-selection selectedViewId = viewDescs[0].getId(); } settings.put(STORE_SELECTED_VIEW_ID, selectedViewId); } /** * Notifies that the selection has changed. * * @param event event object describing the change */ public void selectionChanged(SelectionChangedEvent event) { updateSelection(event); updateButtons(); descriptionHint.setVisible(viewDescs.length == 1 && viewDescs[0].getDescription().length() > 0); } /** * Update the button enablement state. */ protected void updateButtons() { if (okButton != null) { okButton.setEnabled(getSelection().length > 0); } } /** * Update the selection object. */ protected void updateSelection(SelectionChangedEvent event) { ArrayList descs = new ArrayList(); IStructuredSelection sel = (IStructuredSelection) event.getSelection(); for (Iterator i = sel.iterator(); i.hasNext();) { Object o = i.next(); if (o instanceof IViewDescriptor) { descs.add(o); } } viewDescs = new IViewDescriptor[descs.size()]; descs.toArray(viewDescs); } /* (non-Javadoc) * @see org.eclipse.jface.window.Dialog#getDialogBoundsSettings() * * @since 3.4 */ protected IDialogSettings getDialogBoundsSettings() { return getDialogSettings(); } void handleTreeViewerKeyPressed(KeyEvent event) { // popup the description for the selected view if (descriptionHint.isVisible() && event.keyCode == SWT.F2 && event.stateMask == 0) { ITreeSelection selection = (ITreeSelection) filteredTree.getViewer().getSelection(); // only show description if one view is selected if (selection.size() == 1) { Object o = selection.getFirstElement(); if (o instanceof IViewDescriptor) { String description = ((IViewDescriptor) o).getDescription(); if (description.length() == 0) description = WorkbenchMessages.ShowView_noDesc; popUp(description); } } } } private void popUp(final String description) { new PopupDialog(filteredTree.getShell(), PopupDialog.HOVER_SHELLSTYLE, true, false, false, false, false, null, null) { private static final int CURSOR_SIZE = 15; protected Point getInitialLocation(Point initialSize) { //show popup relative to cursor Display display = getShell().getDisplay(); Point location = display.getCursorLocation(); location.x += CURSOR_SIZE; location.y += CURSOR_SIZE; return location; } protected Control createDialogArea(Composite parent) { Label label = new Label(parent, SWT.WRAP); label.setText(description); label.addFocusListener(new FocusAdapter() { public void focusLost(FocusEvent event) { close(); } }); // Use the compact margins employed by PopupDialog. GridData gd = new GridData(GridData.BEGINNING | GridData.FILL_BOTH); gd.horizontalIndent = PopupDialog.POPUP_HORIZONTALSPACING; gd.verticalIndent = PopupDialog.POPUP_VERTICALSPACING; label.setLayoutData(gd); return label; } }.open(); } /* * (non-Javadoc) * @see org.eclipse.jface.dialogs.Dialog#isResizable() */ protected boolean isResizable() { return true; } }